From Molecular Design to Scenario Adaptation: Cutting-Edge Exploration of Silicone-Modified Polyurethane in Smart Sports Fields

Abstract

To overcome the shortcomings of traditional polyurethane, such as poor weather resistance and susceptibility to hydrolysis, this study systematically explores the preparation techniques of organic silicon-modified polyurethane and its application in intelligent sports fields. By introducing siloxane into the polyurethane matrix through copolymerization, physical blending, and grafting techniques, the microphase separation structure and interfacial properties of the material are effectively optimized. In terms of synthesis processes, the one-step method achieves efficient preparation by controlling the isocyanate/hydroxyl molar ratio (1.05–1.15), while the prepolymer chain extension method optimizes the crosslinked network through dual reactions. The modified material exhibits significant performance improvements: tensile strength reaches 60 MPa, tear resistance reaches 80 kN/m, and the elastic recovery rate ranges from 85% to 92%, demonstrating outstanding weather resistance. In sports field applications, the 48% impact absorption rate meets the requirements for athletic tracks, wear resistance of <15 mg suits gym floors, and the impact resistance for skate parks reaches 55%–65%. Its environmental benefits are notable, with volatile organic compounds (VOC) <50 g/L and a recycling rate >85%, complying with green building material standards. However, its development is still constrained by multiple factors: insufficient material interface compatibility, a comprehensive cost of 435 RMB/m², and the lack of a quality evaluation system. Future research priorities include constructing dynamic covalent crosslinked networks (e.g., self-healing systems), adopting bio-based raw materials to reduce carbon footprint by 30%–50%, and integrating flexible sensing technologies for intelligent responsiveness. Through multidimensional innovation, this material is expected to evolve toward multifunctionality and environmental friendliness, providing core material support for the intelligent upgrading of sports fields.

1. Introduction

With the increasing awareness of health and the frequent hosting of sports events, the innovation of sports field materials has focused on ecology and protection. Both competitive and fitness activities, as well as advancements in field equipment, have raised higher standards for sports surfaces, which traditional materials can no longer meet. In response, researchers are committed to developing new high-performance materials, among which organic silicon-modified polyurethane (PU) has garnered significant attention. As a polymer material, polyurethane is synthesized through the polymerization of polyisocyanates and compounds containing active hydrogen, with its molecular structure featuring numerous carbamate groups. Due to the strong polarity of carbamate bonds, urea bonds, and biuret structures, PU can effectively form van der Waals forces and hydrogen bonds with surface hydrates, metal atoms, and polar groups of substrates [1]. Moisture-curable one-component polyurethane adhesives contain active isocyanate groups (-NCO), which can chemically bond with active hydrogen on material surfaces, exhibiting excellent adhesion properties and thus being widely applied [2]. However, these adhesives are prone to hydrolysis in humid environments, leading to insufficient bonding strength, poor heat resistance, weak anti-aging capabilities, and sensitivity to moisture, which limit their application scope [3]. Organic silicon materials, with Si-O bonds as their backbone, boast superior thermal stability, water resistance, and chemical corrosion resistance. By designing molecular structures to introduce siloxane groups into the main or side chains of polyurethane, the performance of PU materials can be optimized, expanding their application potential [4]. Incorporating polysiloxane into the polyurethane matrix through chemical or physical methods enables the preparation of high-performance organic silicon-modified polyurethane materials [5]. These materials combine the mechanical properties of PU with the thermal resistance, hydrophobicity, and biocompatibility advantages of organic silicon, greatly extending the application range of traditional polyurethane. The use of organic silicon-modified polyurethane in sports facilities has gradually increased, with its excellent properties—such as weather resistance, high elasticity, hydrophobicity, and environmental friendliness—making it an ideal choice for high-end sports infrastructure.

2. Preparation and Performance Regulation of Silicone-Modified PU

2.1. Modification Mechanisms and Chemical Pathways

2.1.1. Principles of Copolymerization Modification

The copolymerization method employs a precise molecular structure regulation strategy, where organosiloxane monomers such as hydroxyl-terminated polydimethylsiloxane (PDMS) are directionally embedded into the polyurethane backbone. This is followed by a catalytic condensation reaction between diisocyanate groups (-NCO) and silanol groups, constructing an organic–inorganic hybrid block copolymer bridged by Si-O-C chemical bonds [6]. The synthetic route of polyurethane modified by organosiloxane via copolymerization is shown in Figure 1 [7]. The hard segments, typically composed of isocyanates and chain extenders, provide the material with strength and hardness; the soft segments mainly consist of organosilicon chains, where hydroxyalkyl polysiloxanes possess unique siloxane bond structures, endowing the material with excellent high/low-temperature resistance and weather resistance. The combination of both allows the copolymer to integrate the advantages of each. Moderate microphase separation ensures the material exhibits both outstanding mechanical properties and chemical resistance; excessive separation leads to reduced mechanical performance, while insufficient separation makes it difficult to showcase properties such as weather resistance [8]. Research by Xue et al. [9] shows that when the siloxane segment content reaches 15%, the material’s surface energy may decrease to 22 mN/m, significantly enhancing hydrophobicity. This method requires precise control of the isocyanate index (NCO/OH = 1.05–1.15) and adopts a stepwise polymerization process to achieve a microphase-separated structure of soft–hard segments. For optimizing the compatibility between hydroxyl/amino-terminated organosilicon and isocyanates, adjustments in reaction temperature and selection of suitable solvents can be employed [10]. Appropriate reaction conditions will improve bonding efficiency and material performance [11]. The hydroxyl groups (-OH) from hydroxyl-terminated compound A (HO-B-OH), hydroxyl-terminated compound B (HO-B-OH), and HO-Si-OH react with the isocyanate groups (-NCO) to form urethane linkages (-OCNH-).

2.1.2. Technical Implementation of Physical Blending Method

The physical blending method involves mechanically blending organosilicon (such as silicone oil, silicone resin, or PDMS) with a PU prepolymer matrix using compatibilizers (e.g., silane coupling agents) to improve interfacial compatibility, ensuring thorough mixing to form a blended emulsion. This method is simple in process but requires optimization of organosilicon particle size and dispersibility to enhance material uniformity. In physical blending, regulating the compatibility between organosilicon and polyurethane becomes critical. The selection of compatibilizers, optimization of dispersion processes, and solvent polarity are key strategies to improve compatibility [12]. Choosing suitable compatibilizers effectively reduces interfacial tension between the two phases, thereby promoting thorough mixing of organosilicon and polyurethane. For example, some amphiphilic compatibilizers interact with organosilicon at one end and polyurethane at the other, enhancing their compatibility. Techniques such as high-speed stirring and ultrasonic dispersion can improve the dispersion of organosilicon in the polyurethane matrix. Solvent polarity also affects the dispersion state and interfacial bonding strength, with appropriate polarity aiding in improving compatibility between the phases.

When blending siloxane with polyurethane, microphase separation often occurs due to differences in surface energy, which may affect interfacial bonding and overall material performance. Studies show that introducing siloxane via copolymer blending slightly improves the mechanical properties of polyurethane elastomers while also enhancing the peel strength of adhesion to ethylene propylene diene monomer and isoprene rubber [13]. DSC analysis indicates that siloxane introduction makes the material’s phase structure more distinct, influencing mechanical properties. SEM observations further confirm that when interfacial bonding is strong and dispersion is uniform, the material’s mechanical performance significantly improves. For example, in tensile tests, blended materials with well-defined phase structures exhibit higher tensile strength and elongation at break [14].

There are certain differences between mechanical blending and solution blending processes. Mechanical blending utilizes mechanical force to mix silicone with PU, which is simple to operate but may face issues of insufficient mixing uniformity. Solution blending involves dissolving both in a solvent, resulting in more uniform mixing, but requires consideration of solvent recovery and environmental concerns [15].

2.1.3. Graft Modification Chemical Mechanism

Graft modification technology involves introducing siloxane-containing functional monomers (such as γ-aminopropyltriethoxysilane) onto the main or side chains of polyurethane through radical initiators (e.g., dicumyl peroxide) or click chemistry reactions, achieving precise grafting of siloxane side chains [16]. The core chemical mechanisms of silicone-modified polyurethane methods include three categories: (1) the silane coupling agent method, where the amino group (-NH₂) of the silane coupling agent reacts with the isocyanate group (-NCO) of the PU prepolymer to form urea or urethane bonds, followed by hydrolysis and condensation to create a Si-O-Si crosslinked network, enhancing crosslinking density; (2) the hydroxy-terminated PDMS copolymerization method, where mono-/di-hydroxy-terminated PDMS undergoes polycondensation with the PU prepolymer to form block or graft structures; (3) the click chemistry method, which utilizes the efficient addition reaction between thiol (-SH) and alkenyl groups (e.g., vinyltrimethoxysilane) to achieve grafting, reducing side reactions and improving low-temperature performance [17]. The structures and synthetic routes of block-type and graft-type silicone-modified polyurethanes are illustrated in Figure 2.

Epoxy ring-opening grafting and thiol-click reactions are two common grafting methods. Epoxy ring-opening grafting offers relatively mild reaction conditions but slower reaction rates, requiring high temperatures or catalyst assistance. Thiol-click reactions feature fast reaction rates and high selectivity, achieving 90%–98% conversion under solvent-free conditions, which is 3–5 times faster than epoxy ring opening [18]. By comparing the grafting efficiency of these methods, the appropriate grafting approach can be selected based on practical needs [19].

The grafting ratio significantly regulates material properties. Increasing the grafting ratio enhances the surface density of siloxane groups, raising the contact angle from 76.8° for unmodified PU to 102.5°. However, when the grafting ratio exceeds 20%, the improvement in hydrophobicity slows due to weakened intermolecular forces. Meanwhile, the introduction of siloxane side chains can also improve mechanical strength. A moderate grafting ratio optimizes mechanical performance, such as maintaining tensile strength at 30 MPa while increasing elongation at break to 500%; however, grafting ratios above 20% may induce phase separation, thus weakening intermolecular interactions and reducing tensile strength below 10 MPa. PDMS grafting enhances thermal stability, raising the initial decomposition temperature from 250 °C to 320 °C, attributed to the higher bond energy of Si-O compared to C-C bonds. Moderate grafting stabilizes tensile strength while increasing the loss factor to 0.45 [20]. Side-chain grafting, compared to block structures, more readily migrates to the surface, significantly reducing surface energy. When the silicone mass fraction is 10%–16%, hydrophobicity is markedly enhanced without significant deterioration in mechanical properties. Increasing crosslinking density to 20% shortens surface drying time and improves hardness but reduces elongation at break. Compatibility can be optimized by adding silicone-containing polyethers or controlling reaction temperature (35–40 °C), suppressing microphase separation and enhancing interfacial adhesion. Overall, graft modification achieves synergistic optimization of hydrophobicity, mechanical strength, and thermal stability in PU materials through precise chemical structure control, with the grafting ratio, method selection, and structural design being key factors in balancing performance.

Figure 2. Structures of block-type (a) and graft-type (b) silicone-modified polyurethane [21].

Figure 2. Structures of block-type (a) and graft-type (b) silicone-modified polyurethane [21].

2.2. Optimization of Key Preparation Processes

2.2.1. One-Step Synthesis Process

In the one-step synthesis of organosilicon-modified polyurethane in a single-batch system, the synergistic reaction kinetics among polyols, isocyanates, and siloxanes are highly complex. Polyols, as the core component of the soft segment, impart excellent flexibility to the material [22]. Isocyanates, as the key element of the hard segment, enhance the material’s strength. Additionally, the incorporation of siloxanes can significantly improve the material’s resistance to high and low temperatures as well as weathering. At the beginning of the reaction, the -NCO groups of the isocyanate rapidly react with the -OH groups of the polyol to form urethane bonds [23]. Simultaneously, the active groups on the siloxane also participate in the reaction, forming chemical bonds with the isocyanate or polyol. As the reaction progresses, the molecular chains gradually extend, leading to a steady increase in system viscosity. This method offers a fast reaction rate and high siloxane conversion, but to avoid side reactions, the NCO/OH molar ratio must be precisely adjusted between 1.05 and 1.15. However, the one-step method also has some limitations. The reaction releases a significant amount of heat, and without effective temperature control measures, localized overheating may occur, triggering side reactions and adversely affecting the product’s performance. Furthermore, the rapid reaction rate often results in uneven molecular weight distribution, which can negatively impact the material’s mechanical properties and processing performance [24].

The polarity of the solution also regulates the efficiency of the one-step reaction. In the N,N-dimethylformamide/tetrahydrofuran (DMF/THF) mixed system, DMF has stronger polarity, which can promote the reaction between isocyanate, polyol, and siloxane, accelerating the reaction rate, while THF has relatively weaker polarity and can adjust the solubility and reactivity of the system [25]. An appropriate solvent polarity ratio ensures smooth reaction progress and improves product quality.

2.2.2. Prepolymer Chain Extension Technology

The prepolymer chain extension method for synthesizing silicone-modified PU adopts a two-step process: first, synthesizing NCO-terminated prepolymer, followed by reaction with a silicon-containing chain extender (such as diamino siloxane) [26]. In the prepolymer synthesis stage, precise control of NCO content is crucial. Excessively high NCO content leads to overly reactive prepolymer, which can easily cause gelation during subsequent chain extension. Insufficient NCO content results in prepolymer with too low molecular weight, affecting the performance of the final product. The selection and precise ratio of the chain extender play a key role in crosslinking density. The 1,4-butanediol (BDO) reacts with the -NCO groups in the prepolymer, further extending the molecular chains to form polymers with specific molecular weight and properties. An appropriate ratio ensures smooth chain extension, thereby enhancing the mechanical properties of the material [27].

In the two-step method, the formation mechanism of the hard and soft segment microphase structure is relatively complex. The prepolymer stage mainly forms the hard segment microphase, where isocyanate reacts with part of the polyol to form a structure with certain rigidity. During the chain extension stage, the chain extender reacts with the prepolymer, further connecting the hard and soft segments while the soft segment microphase gradually forms [28]. The hard and soft segment microphases interweave, collectively determining the comprehensive performance of the material. In related studies, there are cases where optimizing prepolymer viscosity improves chain extension efficiency [29]. For example, adjusting reaction temperature and reactant ratios to maintain prepolymer viscosity within a suitable range facilitates uniform dispersion and reaction of the chain extender, thereby enhancing chain extension efficiency and improving material performance.

2.2.3. Synergistic Control of Process Parameters for Material Performance Optimization

Temperature regulation is a key factor affecting the reaction kinetics of silicone-modified polyurethane, which has been confirmed in relevant studies. Experimental research shows that during the prepolymer synthesis stage, the temperature should be maintained at 70–85 °C. At this temperature range, moderate reactivity between isocyanate groups and polyol hydroxyl groups can be ensured while effectively inhibiting the occurrence of thermal degradation side reactions [30]. The stepwise heating program (80 °C → 120 °C) during the curing stage significantly promotes phase separation behavior between hard segment microdomains and soft segment matrices through the free volume regulation mechanism [31]. The stoichiometric ratio of the catalyst system has a significant regulatory effect on the construction of the crosslinked network. An appropriate amount of catalyst can accelerate the reaction rate, promote crosslinking, and increase the crosslinking density of the product. However, excessive catalyst usage can make the reaction too intense, leading to excessive crosslinking density and material brittleness, while insufficient catalyst (<0.2 wt%) results in excessively high reaction activation energy, inadequate crosslinking, and the formation of a loose three-dimensional network structure, preventing the material from achieving expected performance [32].

There is a significant structure–property relationship between the molar fraction of siloxane components and the macroscopic performance of the material. As the silicon content increases, the thermal stability of the material gradually improves, with the thermal index (TI) rising from 160 °C to 210 °C, due to the high bond energy of silicon–oxygen bonds, which can resist high-temperature degradation [33]. However, excessive silicon content may lead to a reduction in material transparency, attributed to compatibility challenges between siloxane and polyurethane, potentially inducing microphase separation and hindering light transmission. By rationally adjusting the silicon content and process parameters, it is possible to enhance thermal stability while maintaining good transparency. The molecular structure of silicone-modified polyurethane materials is closely related to key properties (such as modulus and impact resistance), and the influence of different compositional parameters on specific material properties is shown in

Table 1. Influence of different material composition parameters on specific material properties.

Component Parameters	Molecular Structural Characteristics	Key Performance Influences	Performance Variation Patterns and Mechanisms
Siloxane chain content (silicone ratio)	Si–O–Si bond ratio, proportion of flexible chain segments	Modulus, impact resistance	With increased silicon content, material flexibility improves, enhancing elongation at break and impact resistance while improving thermal stability; due to increased flexible chain segments, modulus may appropriately decrease.
Types of silicone functional groups	Different functional groups such as methyl, vinyl, phenyl, etc.	Mechanical strength, weather resistance	Phenyl groups enhance rigidity and high-temperature resistance, increasing modulus; methyl groups improve flexibility and impact resistance; vinyl groups can participate in crosslinking, enhancing strength and wear resistance.
Polyurethane hard segment content	Proportion of rigid isocyanate segments	Modulus, tensile strength	Increasing hard segment content enhances hydrogen bonding between polymer chains, improving modulus and strength, but may lead to increased brittleness and reduced impact resistance.
Type and molecular weight of soft segments	Selection of soft segments (polyether or polyester) and molecular weight	Elasticity and fatigue resistance	As the molecular weight of soft segments increases, the flexibility of long chains improves, enhancing elasticity and fatigue resistance; polyether soft segments exhibit better hydrolysis resistance, while polyester soft segments offer superior wear resistance and strength but poorer hydrolysis stability.
Combination methods of silicone and polyurethane	Graft copolymerization vs. physical doping	Performance stability, weather resistance	Chemical covalent grafting enhances interfacial bonding strength, resulting in more uniform and stable material properties with improved aging resistance; physical doping may lead to phase separation and performance degradation.
Crosslinking degree	The extent to which active groups at silicone terminals participate in crosslinking	Modulus, heat resistance, solvent resistance	High crosslinking density improves modulus and heat resistance but reduces flexibility; low crosslinking density enhances toughness and impact resistance but decreases solvent resistance.

.

2.3. Performance Characterization System of Silicone-Modified Polyurethane

2.3.1. Comprehensive Evaluation of Mechanical Properties

Silicone modification can significantly optimize the mechanical properties of polyurethane materials, with its mechanism closely related to molecular chain restructuring and microphase regulation. Siloxane segments form physical crosslinking points with PU hard segments through Si-O-C bonds, enhancing intermolecular forces. The introduction of silicone promotes the refinement of soft/hard segment microdomains to 50~200 nm, reducing stress concentration. The synergistic effect between polyether soft segments and siloxane hard segments achieves a balance between strength and elongation. The gradient of siloxane content has a significant impact on the tensile and tear strength of silicone-modified polyurethane materials [34]. For example, studies show that as siloxane content increases, the mechanical properties of polyurethane-modified silicone improve, water absorption decreases, and tensile strength increases, though elongation at break decreases slightly. The changes in mechanical properties of polyurethane modified with different silicone ratios are shown in Figure 3. Tensile strength tests conducted according to ASTM D412 standards indicate that at lower siloxane content, tensile strength gradually increases from 43 MPa as content rises [35]. Siloxane segments form stable physical crosslinks with the polyurethane matrix, strengthening intermolecular interactions. However, once siloxane content exceeds a certain threshold, tensile strength begins to decline after peaking at 60 MPa [36]. This is due to excessive siloxane disrupting the original ordered structure of polyurethane, weakening intermolecular forces. Tear strength tests according to ASTM D624 standards show that increasing siloxane content steadily improves tear strength from 15 kN/m to 80 kN/m. The flexible siloxane segments can absorb and dissipate energy during tearing, enhancing the material’s tear resistance. However, beyond a certain siloxane content, the rate of tear strength improvement slows.

Organic silicon modification synergistically enhances the resilience of PU materials through a triple mechanism of “molecular chain flexibility—microphase refinement—dynamic crosslinking network” [38]. For example, by introducing siloxane segments (such as PDMS), the high flexibility of Si-O bonds and ultra-low glass transition temperature significantly increase the freedom of molecular chain movement, enhancing the flexibility of branched chains. The formation of a dynamic crosslinking network enables rapid rebound driven by entropy increase after external force removal, while the hydrophobicity of siloxane reduces inter-chain friction and minimizes energy loss. Additionally, the size of soft/hard segment microdomains is refined from 200~500 nm in pure PU to 50~150 nm, resulting in more uniform stress distribution. Combined with the reversible interfacial slip energy dissipation mechanism, the rebound rate increases from 70%~75% to 85%~92%. These modification effects align with laboratory research results, such as the improved surface hydrophobicity and thermal stability of Si-PU [39]. By adjusting the silicon content between 8% and 12%, the molecular weight of PDMS segments (Mn = 2000 to 5000), and using a DMF/THF mixed solvent system, a balanced performance can be achieved, making it suitable for high-resilience shoe materials and flexible sensor manufacturing. Future designs incorporating dynamic covalent bonds (e.g., Diels–Alder bonds) could further develop self-healing high-resilience materials, expanding their applications in fields like smart robotics and sports medicine.

2.3.2. Weather Resistance Evaluation

UV irradiation and damp–heat cycling significantly affect the surface properties of organic silicon-modified polyurethane materials. After 3000 h of UV irradiation, although surface powdering occurs, the yellowing resistance of organic silicon-modified polyurethane is notably improved. This is because UV radiation breaks chemical bonds in the polyurethane molecular chains, leading to chain scission and degradation. Under damp–heat cycling conditions (85 °C/85% RH), moisture may penetrate the material, accelerating hydrolysis reactions of molecular chains and further exacerbating surface powdering and yellowing [40]. However, organic silicon-modified polyurethane materials, through chemical or physical modifications, can significantly enhance their hydrolysis resistance, thereby mitigating performance degradation in such environments to some extent. The molecular structure of organic silicon contains silicon–oxygen bonds (Si-O), which have high bond energy and effectively resist UV radiation, preventing material aging, discoloration, or powdering due to photo-oxidation. This gives organic silicon-modified polyurethane materials superior UV resistance and stability [41]. Organic silicon-modified polyurethane materials exhibit surface enrichment of siloxanes, maintaining hydrophobicity during aging. Tests with gloss meters and colorimeters show that materials with siloxane surface enrichment experience smaller reductions in gloss and less color change after aging, consistent with research on the aging resistance of organic silicon-modified polyurethane films, indicating better weather resistance [42].

Compared to laboratory accelerated aging tests, long-term field validation studies are more critical. These studies systematically collect outdoor performance data of silicone-modified polyurethane sports surfaces under real environmental conditions such as wind, sun exposure, rain erosion, and temperature and humidity variations. Relevant research indicates that this material demonstrates outstanding long-term stability in practical applications: during prolonged use in multiple sports fields, its resistance to yellowing, chalking, and mechanical property retention are significantly superior to unmodified polyurethane [43]. Courts made with silicone-modified polyurethane can effectively withstand environmental factors such as UV radiation, ozone, rain, and high–low temperature cycles, avoiding issues like fading, chalking, hardening, or softening, while maintaining excellent performance and vibrant color over time. Silicone-PU sports surfaces maintain ≤2 ΔE color change after 5 years and ≤10% elasticity loss after 10 years under UV/rain/temperature cycles [44]. The silicone-PU court surface combines high strength with toughness, featuring a tensile strength ≥0.5 MPa and elongation at break ≥40%. Even after 500 h of accelerated aging, the tensile strength remains no less than 0.5 MPa, and elongation at break no less than 40% [45]. Additionally, the aging and durability evaluation of sports surfaces strictly adheres to relevant standard testing protocols, such as UV light accelerated aging (ASTM G154), damp heat cycling (ISO 16474-3), and durability testing for resilient flooring materials (ASTM F2651) [46]. These standard protocols, combined with long-term field data, comprehensively assess the material’s performance under multiple aging factors, including UV exposure, damp heat, and mechanical wear, ensuring it meets long-term usage requirements and providing solid, reliable evidence for the material’s practical application and promotion in sports fields.

2.3.3. Degradation and Recycling Performance Analysis

Silicone-modified polyurethane (Si-PU) materials significantly enhance mechanical properties and environmental stability by introducing siloxane segments with excellent heat and weather resistance into the polyurethane molecular chain, making them widely applicable in coatings, elastomers, and sealants [47]. However, their complex structure also presents unique degradation mechanisms and recycling challenges. From a degradation perspective, Si-PU materials are primarily affected by hydrolysis, photodegradation, and stress-induced phase separation. During hydrolysis, ester and urea bonds in the polyurethane backbone are prone to hydrolytic cleavage, leading to reduced mechanical strength and toughness. The siloxane segments exhibit higher hydrolytic stability, slowing the hydrolysis rate to some extent, but may still break under extreme pH conditions [48]. Researchers have adopted polyether soft segments to replace polyester soft segments for improved hydrolysis resistance, while copolymerizing with siloxane segments enhances overall stability [49]. In terms of photodegradation, urethane bonds in the polyurethane chain are susceptible to cleavage under UV irradiation, generating free radicals that initiate chain scission and crosslinking, causing embrittlement, yellowing, and strength loss. The siloxane bonds and methyl groups effectively absorb UV light and mitigate free radical reactions, thereby alleviating photo-oxidation. Stress-induced phase separation arises from incompatibility between the hard and soft segments of polyurethane, where self-assembly forms phase-separated structures, leading to microcracks and mechanical deterioration [50]. The incorporation of flexible siloxane segments improves interfacial compliance and bonding, reducing stress concentration and enhancing fatigue resistance. Studies often employ copolymerization or grafting techniques to improve compatibility between silicone and polyurethane, optimizing phase-separated structure stability.

In the recycling of polyurethane materials, mainstream industrial technologies include three methods: hydrolysis, glycolysis, and pyrolysis. Hydrolysis utilizes acids, bases, or enzymes to catalyze the cleavage of polyurethane chains, recovering monomers such as polyols and isocyanates, with a typical recycling efficiency of 80%–90% for pure polyurethane systems [51]. However, in Si-PU systems, the strong hydrolysis resistance of siloxane segments makes it difficult to decompose the silicone components during recycling, reducing overall efficiency. Additionally, silicone residues can affect the purity of recovered monomers and increase subsequent processing challenges. Glycolysis employs microorganisms and enzyme systems to biochemically degrade polyurethane, but siloxane segments are highly resistant to biodegradation, leading to the accumulation of silicone residues in the system and inhibiting enzyme activity [52]. As a result, the glycolysis recycling efficiency of silicone-modified polyurethane is significantly lower than that of conventional polyurethane, typically below 60%. Pyrolysis involves high-temperature catalytic cracking of the polyurethane backbone to recover fuel resources such as oil and gas, with an efficiency exceeding 80% for pure polyurethane [53]. However, under high temperatures, siloxane backbones tend to form solid silicon oxide residues (e.g., SiO₂), which not only cause wear on reactor equipment but also increase the burden of solid waste disposal, reducing the economic and environmental benefits of pyrolysis. The presence of silicone components lowers recycling efficiency by approximately 5%–10% [54]. Overall, silicone-modified polyurethane systems face significant challenges in industrial recycling applications, particularly due to the high stability of silicone components limiting the effectiveness of conventional hydrolysis and biological methods. While pyrolysis offers higher recycling rates, it requires overcoming issues related to solid residues.

To address these challenges, current material development focuses on optimizing the structure and content of siloxane segments through molecular design to enhance compatibility between soft and hard segments; developing more efficient light stabilizers and hydrolysis-resistant systems to reduce degradation damage during service; and incorporating nano-reinforcements and dynamic self-healing mechanisms to improve mechanical toughness and service life. In terms of recycling technology, researchers are exploring novel catalyst systems tailored to the specificity of Si-PU to selectively cleave Si-O bonds, enabling effective separation and degradation of silicone components. Additionally, combining multiple recycling techniques, such as pyrolysis followed by chemical treatment, is considered a potential route to improve recycling rates and monomer purity. With the promotion of green synthesis and design concepts, integrating efficient degradation technologies and recycling systems to advance the sustainable development of silicone-modified polyurethane materials will become a key focus for future research.

2.3.4. Microscopic Morphology Analysis

The introduction of organic silicon significantly affects the microphase separation degree of polyurethane. As the organic silicon content increases, the glass transition temperature (Tg) of the polyurethane soft segment decreases, while the Tg of the hard segment first rises and then declines [55]. The differential scanning calorimetry (DSC) analysis curves of modified polyurethanes with different silicone contents are shown in Figure 4. DSC analysis reveals that the microphase separation degree peaks at approximately 10% organic silicon content, which aligns with the conclusion that there is a certain degree of microphase separation between the organic silicon-modified polyurethane soft and hard segments. Transmission electron microscopy (TEM) further confirms this phenomenon: unmodified PU shows blurred interfaces between soft and hard segments (microphase mixing), while modified samples exhibit distinct bright and dark micro-regions, indicating more pronounced separation between hard and soft segments [56].

The TEM images of the silicone-modified polyurethane material are shown in Figure 5. TEM directly reveals the scale and distribution of phase separation. In unmodified PU (Waterborne Polyurethane 0, WSPU0), the interface between soft and hard segments is blurred, showing a mixed state; whereas the modified sample with 10% 3-Aminopropyltrimethoxysilane (APDMS) exhibits clear bright and dark micro-regions—bright regions represent rigid phases of aggregated hard segments, and dark regions represent flexible phases of soft segments and silicone, indicating significantly enhanced microphase separation [58]. This structural change is related to the hydrophobicity and chain flexibility of silicone, which disrupts the original hydrogen bond network of PU and promotes phase interface reconstruction.

Silicone-modified polyurethane materials introduce silicone into the side chains of PU, leveraging the excellent lubricity of polysiloxane to not only enhance wear resistance but also make the surface smoother, thereby optimizing matting performance. When modifying PU with silicone, the effect of silicone dosage on material surface morphology is shown in Figure 6. The modified material contains uniformly dispersed silicone particles ranging from nano- to micro-scale, exhibiting relatively uniform spherical or irregular shapes with even distribution in the polyurethane matrix. The particle interfaces show good bonding without obvious voids or cracks, indicating strong compatibility and interfacial adhesion between the modifier and the matrix. At lower silicone dosages, the material maintains good stability and morphology, with a surface displaying rough spherical particles. As the dosage increases, these spherical particles become finer and more densely arranged, significantly improving the matting effect [60]. However, when the silicone dosage exceeds a certain range, the material undergoes deformation and fusion, causing the spherical particles on the surface to disappear and instead present a smooth state, directly leading to a significant decline in matting performance. Additionally, some side-chain-grafted silicones, due to their strong surface migration tendency, tend to accumulate on the material surface, forming a continuous and dense silicone layer that further enhances surface properties.

3. Application Scenarios of Silicone-Modified PU in Sports Fields

3.1. Application Scenarios of Silicone-Modified Polyurethane in Athletic Fields

In the construction of athletic tracks, organic silicone-modified polyurethane demonstrates significant advantages in the application scenarios of synthetic running tracks. Its unique chemical structure meets the core requirements of high-performance sports venues for elasticity, durability, and environmental friendliness, creating an excellent venue environment for sports development. Organic silicone-modified PU introduces siloxane segments into the PU molecular chain through chemical copolymerization or physical blending, forming an organic silicone-PU interpenetrating network. In the molecular structure, the synergistic effect between organic silicone and polyurethane segments endows the material with both excellent flexibility and mechanical properties. A comparison between silicone-modified polyurethane tracks and traditional PU tracks is shown in

Table 2. Data comparison between silicone-modified PU tracks and traditional PU tracks.

Indicator	Traditional PU Track	Silicone-Modified PU Track	International Standard Requirements
Resilience rate	45%–50%	65%–75%	≥35%
Wet friction coefficient	0.6–0.7	0.8–0.9	≥0.5
Yellowing resistance (ΔE/3000 h)	4–6	<2	≤5
VOC emissions (g/L)	60~80	<50	≤80
Maintenance cycle (years)	2–3	4–5	-

. The core advantages of silicone-modified polyurethane in athletic field applications are as follows [62]. Energy return rate: The siloxane segments reduce the material’s modulus, achieving a rebound rate of 65%–75%, an improvement of about 10%–15% compared to traditional PU tracks, while also meeting the World Athletics requirement of a rebound rate ≥35% [63]. Impact absorption: The vertical impact absorption rate increases by 45%–50%, about 10% higher than ordinary PU tracks, effectively reducing joint injuries for athletes, such as significantly lowering knee joint impact forces. UV resistance is significantly improved, as the bond energy of Si-O (443 kJ/mol) in organic silicone is much higher than that of C-O (360 kJ/mol) in PU. Temperature resistance range is expanded, with an operational range extended to −40 °C to 120 °C, avoiding brittleness in winter or softening in summer. Traditional PU tends to crack below −20 °C, while organic silicone-modified PU shows better temperature resistance. Extended service life: The design lifespan reaches 8–10 years, a notable improvement over ordinary PU tracks (5–7 years), with maintenance cycles extended to once every 4 years. Wet slip resistance: The surface contact angle >110°, wet friction coefficient > 0.8, meeting the World Athletics requirement of ≥0.5, reducing the risk of slipping during rainy conditions. Antibacterial and anti-mold properties: By grafting organic silicone quaternary ammonium salts, the antibacterial rate against E. coli exceeds 99%, making it suitable for humid environments. Low VOC emissions: The water-based organic silicone-PU system has VOC content <50 g/L. Enhanced recyclability: Siloxane dynamic bonds can depolymerize at 120 °C, with old track material recovery rates >85% [64]. As shown in Figure 7, the running tracks at the Hangzhou Asian Games venues adopt a “sandwich” composite structure—the bottom layer is an organic silicone-PU foam cushion layer (8–10 mm thick), the middle layer is a high-elasticity mixed layer containing nano-SiO₂, and the top layer is a hydrophobic wear-resistant layer. Certified by World Athletics Class 1, the impact absorption rate is 48%, with a vertical deformation of 2.3 mm.

This material exhibits outstanding weather resistance and stability, maintaining consistent performance even under athletes’ sustained high-intensity training, providing reliable support for sports performance. Research indicates that silicone-modified polyurethane effectively withstands various climatic conditions, ensuring athletic tracks maintain optimal performance in diverse environments, thereby enhancing athletes’ competitive levels [65]. Silicone-modified polyurethane materials demonstrate exceptional stability under extreme weather conditions, whether under intense UV radiation, frequent rainfall, or drastic temperature fluctuations, all while preserving their performance metrics [66]. This characteristic not only ensures the long-term durability of sports surfaces but also significantly reduces the risk of material degradation due to environmental erosion. Additionally, the material boasts excellent elasticity and cushioning properties, offering athletes a safe and reliable training and competition environment, making it an ideal choice for athletic track construction. Its superior rebound properties provide ample kinetic energy to assist with actions like jumping and sprinting. The outstanding shock absorption effectively mitigates sports impacts, reducing injury risks and playing a crucial role in protecting muscles and joints [67]. The enhancement of silicone-based polyurethane has significantly optimized the quality and functionality of athletic tracks, providing solid assurance for track and field events.

3.2. Application of Silicone-Modified Polyurethane in Gymnasium Flooring Scenarios

In the construction of sports venues, silicone-modified polyurethane materials are widely favored for their excellent properties. With the vigorous development of competitive sports, the quality of the venue directly affects athletes’ competitive performance, safety protection, and fairness of the competition. Silicone-modified polyurethane, with its unique combination of properties—high elasticity, weather resistance, hydrophobicity, wear resistance, and environmental friendliness—has become an ideal material for modern gymnasium flooring [68]. Its application in smart sports flooring for basketball arenas is illustrated in Figure 8. Typical case studies and comparative data for silicone-modified polyurethane materials in sports venues are presented in

Table 3. Comparison of Typical Cases and Data in Gymnasium Flooring.

Application Scenarios	Project Cases	Technical Solutions	Performance Improvement
Basketball court main floor	Beijing Wukesong Stadium renovation	Three-layer composite structure (cushioning layer + elastic layer + wear-resistant layer)	Impact absorption rate 52%, ball rebound rate 93%
Gym floor	Shanghai One Wellness Fitness Center	Silicon carbide reinforced silicone-PU	Wear resistance increased by 3 times, maintenance cycle extended to 5 years

. Its applications in gymnasium flooring mainly include multi-functional main sports flooring, basketball, badminton, volleyball, gym and fitness training areas, locker rooms and poolside anti-slip flooring, and intelligent sports flooring [69]. The core advantages of silicone-modified polyurethane in gymnasium flooring applications include high energy absorption rate, where the silicone segments reduce the material’s modulus, adjustable to 0.5–5 MPa, with an impact absorption rate of up to 45%–50%, approximately 10% higher than traditional PU flooring, effectively reducing joint injuries in athletes, such as knee joint impact force [70]. Its rebound rate increases, with a vertical deformation recovery rate >90%, meeting the DIN 18032-2 standard for indoor sports flooring. The wear resistance index is enhanced, with a Taber abrasion test (CS10 wheel, 1 kg load) weight loss <15 mg, compared to about 50 mg for traditional PU flooring, extending its lifespan by 2–3 times. The temperature resistance range is expanded, maintaining elasticity from −40 °C to 120 °C, avoiding brittle fractures at low temperatures or softening at high temperatures. UV aging resistance is improved, making it suitable for outdoor stadiums. The dry/wet friction coefficient is significantly better, with dry state >0.8 and wet state >0.7, exceeding the FIBA requirement of ≥0.5, significantly improving slip resistance in rainy conditions. Antimicrobial performance is enhanced, with a >99.9% inhibition rate against Staphylococcus aureus through grafting silicone quaternary ammonium salts, complying with ISO 22196 standards, making it suitable for high-humidity areas like locker rooms. Recyclability is increased, with dynamic siloxane bonds supporting thermal depolymerization recycling, improving the recycling rate of old flooring materials.

In various ball games, frequent jumping, landing, and rapid directional changes impose high demands on court performance, requiring excellent rebound and cushioning properties [61]. Polyurethane materials modified with organic silicon can provide ideal mechanical support, effectively mitigating sports-related impacts on athletes [71]. Taking basketball courts as an example, this material enables athletes to utilize the ground’s elasticity for quick starts, stops, and jumps, thereby enhancing competitive performance. Additionally, the material boasts outstanding weather resistance and structural stability, ensuring long-lasting durability for sports courts [72]. The court performs exceptionally well under extreme climatic conditions, maintaining stable performance whether under scorching sun or rain and snow, unaffected by environmental fluctuations, thus significantly extending its service life [73]. Moreover, organic silicon-modified polyurethane combines environmental friendliness with safety, making it a standout advantage for sports court applications. As public environmental awareness grows, the green attributes of sports courts are increasingly valued. This material meets green environmental requirements, being non-toxic and harmless, ensuring the safety of users while causing no ecological impact to the surroundings [74]. Therefore, it is highly suitable for constructing sports courts in densely populated areas such as schools and communities. Applying this material to sports courts not only enhances court efficiency but also safeguards athletes’ rights and promotes the high-quality development of ball sports.

3.3. Application of Silicone-Modified Polyurethane in Special Sports Venues

Silicone-modified polyurethane not only plays a significant role in mainstream sports venues but also contributes positively to niche and specialized sports facilities. As shown in Figure 9 and Figure 10, in extreme sports venues such as skate parks, Bicycle Motocross (BMX) tracks, parkour training grounds, and climbing walls, silicone-modified polyurethane demonstrates exceptional elasticity and cushioning properties. The core requirements for extreme sports venues include high-impact resistance to withstand intense impacts from skateboards, BMX bikes, and parkour, with vertical impact forces reaching 5–10 kN. Dynamic slip resistance and grip are crucial, requiring surfaces to maintain a stable friction coefficient ≥0.6 in both dry and wet conditions while allowing quick turns and sudden stops. Strong abrasion and scratch resistance are necessary to endure repeated friction from metal-wheeled skateboards, BMX bikes, and hard-soled shoes. Safety cushioning is vital to reduce joint injury risks during high-speed movements, with impact absorption needing to be ≥50%. Weather resistance is also a key factor, as outdoor venues must endure extreme temperatures ranging from −30 °C to 60 °C, UV exposure, and rain erosion. Due to its outstanding comprehensive performance, silicone-modified polyurethane is increasingly used in specialized sports venues. These unique sports environments demand higher material standards, and silicone-modified polyurethane precisely meets these stringent requirements, showcasing its distinctive application value and potential [75]. The advantages of silicone-modified polyurethane over traditional materials in special sports environments are compared in

Table 4. Advantages of silicone-modified polyurethane compared to traditional materials.

Performance	Silicone-Modified PU	Concrete/Asphalt	Ethylene Propylene Diene Monomer Granules
Impact absorption rate	55%–65%	<10%	30%–40%
Surface temperature (summer)	15–20 °C lower than asphalt (resistant to high-temperature softening)	Can exceed 60 °C	50–55 °C
Maintenance cost	Low (only requires regular cleaning)	High (frequent crack repairs)	Medium (particles prone to falling off)
Environmental adaptability	Frost-thaw resistance, salt spray resistance (coastal areas)	Prone to freeze cracking and corrosion	Average weather resistance

.

When engaging in skateboarding, the ground must possess excellent rebound performance to allow athletes to perform complex tricks, while also requiring sufficient anti-slip properties to ensure safety. Silane-modified polyurethane materials excel in elasticity and anti-slip performance, enhancing both the sports experience and competitive level [76]. For climbing walls, the material needs outstanding adhesion and wear resistance to withstand frequent climbing friction. Thanks to its unique molecular structure, silane-modified polyurethane demonstrates superior adhesion, firmly bonding to the surface and resisting detachment even after prolonged use, ensuring the safety and stability of the venue. For water-related sports facilities such as swimming pools and water parks, silicone-modified polyurethane is an ideal choice due to its excellent waterproof and anti-slip properties. Silicone-modified polyurethane materials remain stable in long-term water immersion environments, with their surface microstructure effectively increasing the anti-slip coefficient, significantly reducing accidents caused by slippery surfaces and providing reliable safety for water activities. Additionally, in specialized sports venues with strict environmental requirements, such as equestrian arenas, this material also exhibits excellent environmental and safety characteristics. Silicone-modified polyurethane materials are non-toxic and harmless, posing no pollution risk to horses or the surrounding ecosystem, fully meeting contemporary environmental standards for sports venues [77]. Silicone-modified polyurethane demonstrates significant advantages in professional sports venue construction. With technological advancements and growing demand for specialized venues, silicone-modified polyurethane materials will play an increasingly important role in this field, providing strong support for the development of professional sports.

4. Challenges of Applying Silicone-Modified Polyurethane in Sports Venues

4.1. Compatibility Issues Between Silicone and PU

The compatibility issue between PDMS and polyurethane is one of the core challenges in their blending or chemical modification processes [78]. Due to significant differences in their molecular structures, polarity, and thermodynamic properties, the free energy change of the mixed system becomes unfavorable, leading to high interfacial tension and phase separation. This necessitates the use of chemical modification or physical methods to enhance compatibility [79]. Specifically, the backbone of PDMS consists of flexible Si-O-Si structures with low-polarity hydrophobic methyl (-CH₃) side chains, resulting in an overall low surface energy (approximately 20–25 mN/m). In contrast, the backbone of polyurethane contains polar urethane groups (-NH-CO-O-), with its hard and soft segments forming a typical microphase-separated structure, giving it a higher overall surface energy (approximately 35–45 mN/m) [80]. The significant difference in surface energy between the two increases interfacial tension, reduces the thermodynamic compatibility of the mixed system, and makes it difficult to form a stable homogeneous or finely dispersed phase morphology.

From a phase morphology perspective, when PDM and polyurethane are blended, the thermodynamically unfavorable free energy drives macroscopic or microscopic phase separation, manifesting as stratification, particle aggregation, or interfacial discontinuity [81]. This, in turn, leads to a decline in mechanical properties such as tensile strength and tear resistance [82]. Additionally, differences in viscosity and interfacial instability complicate rheological behavior during processing, making defects like bubbles and flow marks more likely to occur [83]. Thermodynamic miscibility can be quantitatively described using the Flory–Huggins parameter (χ), where a higher χ value reflects poorer compatibility between the two components, indicating the need to reduce interfacial free energy to promote uniform mixing.

To overcome these compatibility limitations, methods such as chemical modification, surfactant addition, and nanohybridization are commonly employed. These techniques enhance the interaction forces between the two phases by forming covalent bonds or physical crosslinks, reducing interfacial tension, optimizing phase morphology, promoting interfacial bonding, and lowering the Flory–Huggins parameter to achieve thermodynamic compatibility and kinetic stability. Furthermore, carefully controlling processing temperatures and reaction conditions helps regulate interfacial dynamics, suppress phase separation, and further improve the overall material performance and process stability. Therefore, the key to addressing the compatibility issue between silicone-based PDMS and polyurethane lies in effectively reducing interfacial tension and thermodynamic mismatch through material design and process optimization, achieving uniform dispersion and stable bonding [84].

4.2. Cost Issues of Applying Silicone-Modified Polyurethane Materials to Sports Venues

The application of silicone-modified polyurethane materials in sports field construction faces significant cost pressures. Despite their excellent performance, the high cost of these materials limits their large-scale adoption [85]. For example, the track and field venue for the Hangzhou Asian Games in China used BASF’s silicone-modified PU from Germany, with a total cost of approximately RMB 4.5 million (unit price of 435 RMB/m²). Based on this, constructing an International Association of Athletics Federations (IAAF)-standard track and field venue (400-m track, 8 lanes) with silicone-modified PU as the surface material would incur a total cost ranging from RMB 3.3 to 4.8 million, influenced by factors such as material performance, construction techniques, venue scale, and regional economic conditions. Among these, the cost of raw materials is a key component, with market price fluctuations of core materials like silicone and polyurethane significantly impacting the final product cost. Cost management must consider supply chain stability and price volatility [86]. Differences in raw material quality lead to noticeable price variations, and selecting appropriate quality grades is crucial to ensuring the performance and quality of sports fields. Choosing inferior materials to cut costs may reduce durability and functionality, ultimately increasing long-term maintenance and replacement expenses [87]. Additionally, the processing stage is a critical focus for cost control, as factors such as process complexity, production efficiency, and material waste significantly affect total costs. Adopting modern techniques and optimizing manufacturing processes can effectively reduce per-unit expenses. However, investing in new equipment and technology requires substantial capital, necessitating a balance between investment and output. At the same time, ensuring product quality management is essential, as increased defects lead to higher costs. In cost management, construction expenses play a pivotal role. When using silicone-enhanced PU for sports field installation, factors such as process complexity, project duration, and worker skill levels influence costs. Complex installation techniques often require additional labor and time, driving up overall expenses [88]. Moreover, material waste and equipment wear during construction are also significant contributors to cost fluctuations. Therefore, optimizing construction workflows, improving worker expertise, and strengthening on-site management are decisive in effective cost control [89]. In sports field construction, cost management for silicone-reinforced PU involves multiple dimensions. It requires coordinated efforts in raw material procurement, manufacturing processes, and on-site construction, optimizing each factor to develop cost-effective solutions that balance affordability and field performance, thereby promoting the widespread use of this material in sports venues [90].

4.3. Inadequate Quality Testing Standards for Silicone-Modified Polyurethane in Sports Venues

When organic silicon-modified polyurethane materials are used for sports fields, their performance evaluation standards are crucial. These standards not only determine the functional performance of the field but also directly relate to the safety and comfort of users [91]. A rigorous scientific testing system ensures that the modified polyurethane meets the requirements for field use and guarantees project quality [92]. The testing content covers multiple dimensions, with physical property tests including key parameters such as material rebound, rigidity, and tensile performance. Appropriate material elasticity and hardness provide effective support and cushioning for athletes, reducing the probability of sports injuries [93]. Sufficient tensile strength ensures the material maintains integrity and shape stability under continuous use and frequent impacts. From a chemical property perspective, attention must be paid to the material’s corrosion resistance and volatile organic compound (VOC) concentration. Corrosion resistance enables the field to withstand daily chemical erosion, while low VOC content meets environmental safety standards, protecting athletes’ health and the surrounding environment [94]. The functional characteristics of sports fields are strictly constrained by quality testing standards. The surface friction coefficient must be maintained within a specific range to ensure good anti-slip effects during sports activities while avoiding excessive friction that limits movement freedom. Additionally, the field’s drainage system is equally critical, as excellent drainage performance can quickly remove accumulated water after rainfall or heavy watering, maintaining the field’s normal functionality. Multi-dimensional performance testing of organic silicon-modified polyurethane effectively evaluates its practical application in sports fields [11]. Establishing a comprehensive quality control system is the core element in ensuring material performance meets standards. Through systematic testing of physical properties, chemical stability, and practical functionality, not only can field quality and safety be improved, but an ideal training environment for athletes can also be created, promoting sustainable development in the construction of sports facilities.

4.4. Maintenance and Care Challenges of Organic Silicon-Modified Polyurethane for Sports Fields

Although organic silicon-modified polyurethane offers many advantages for sports fields, specific maintenance measures are required to ensure its functionality and durability [21]. Due to the complex environments sports fields face, this coating is susceptible to multiple factors, such as UV radiation, temperature and humidity fluctuations, and mechanical wear from regular use, all of which gradually weaken the material’s properties. The material’s elasticity can change under high temperatures, leading to reduced shock absorption, and the coating can be damaged by continuous friction, resulting in diminished anti-slip functionality [95]. Therefore, regular inspections and maintenance are indispensable. By developing a reasonable maintenance plan, potential issues can be identified and addressed early, ensuring the field remains in usable condition. Maintenance plans for various sports fields should be tailored to their characteristics and usage frequency. For example, tracks, which endure significant impact from athletes’ rapid movements and frequent jumps, require special attention to surface wear and elasticity recovery. Different sports fields must prioritize safety and maintenance—such as courts focusing on anti-slip properties to ensure athlete safety, while fitness areas emphasize the impact of equipment on the ground and hygiene maintenance. To enhance the durability of organic silicon-modified PU sports fields, appropriate maintenance strategies and materials should be adopted. Daily cleaning should avoid sharp or corrosive items, and gentle cleaners with soft tools are recommended. For minor damages, specialized repair materials can be used to restore performance. Regular maintenance tasks, such as applying protective coatings, can improve the material’s anti-aging and wear-resistant properties, thereby extending the field’s lifespan. Through scientific maintenance methods, organic silicon-modified PU sports fields can provide athletes with a safe and comfortable space, fully demonstrating their value in the sports industry.

5. Current Research Challenges and Future Directions

5.1. Innovative Design of Silicone-Modified Polyurethane Materials

Silicon-modified polyurethane multifunctional modification is a research hotspot in the field of polymer materials, aiming to break through traditional performance boundaries and endow materials with intelligence, sustainability, and multi-scenario adaptability [96]. The following aspects are discussed from three dimensions: molecular design innovation, composite system construction, and structural engineering optimization. First, dynamic covalent bond design, Diels–Alder bonds, introduce furan/maleimide groups into the PU main chain to achieve material self-repair (repair rate >90% at 60 °C for 30 min), suitable for frequently impacted runways or wearable devices [97]. Disulfide bonds (-S-S-), through thiol-ene click reactions to construct dynamic networks, endow materials with shape memory function (deformation recovery rate ≥ 95%), applicable to smart sports protective gear or adaptive cushioning pads [98]. Second, composite system construction, nanohybridization and multi-component synergy, and graphene/carbon nanotubes, adding 0.5–2 wt% to enhance thermal conductivity and electromagnetic shielding efficiency, is suitable for interference-free flooring in e-sports venues [99]. MXene nanosheets combine with PU through hydrogen bonds to achieve infrared stealth and wear resistance synergy, used for camouflaging coatings on military training grounds [100]. Additionally, by combining polyvinylidene difluoride (PVDF) material with Si-PU or integrating it on the surface, PVDF sensors can achieve real-time monitoring of environmental parameters (such as stress, deformation, temperature, etc.) and generate electricity via the piezoelectric effect for self-powering, advancing the realization of smart adaptive coatings [101]. The flexibility and chemical corrosion resistance of PVDF combined with the mechanical toughness and environmental stability of Si-PU can construct structurally stable and functionally diverse smart surface systems, showing potential applications in adaptive sports fields [102]. The energy harvesting and sensing capabilities of PVDF can further enhance the adaptive response and energy self-sufficiency of Si-PU-based smart material systems, promoting the development of smart materials toward high performance and multifunctionality. Third, structural engineering optimization, such as multi-scale micro-nano structure design, hardness gradient, high hardness on the surface for wear resistance, low hardness on the bottom for energy absorption, can be applied to multi-functional flooring in comprehensive sports venues. Pore gradient, through 3D printing to control pore size, achieves integrated sound absorption and moisture permeability, used for indoor climbing gyms. Microphase separation regulation should be incorporated. Block sequence optimization, design polydimethylsiloxane-polyurethane-polycaprolactone (PDMS-PU-PCL) triblock copolymer to form an “island structure,” simultaneously improving toughness and oil resistance, suitable for automotive and motor sports tracks. Through the deep integration of molecular tailoring, nanocomposites, and structural engineering, future silicon-modified polyurethane materials will break through traditional application boundaries and play a core role in smart sports venues, wearable medical devices, and extreme environmental protection.

5.2. Silicone-Modified Polyurethane Materials Must Meet Environmental Requirements

The environmental friendliness of silicone-modified polyurethane materials is a crucial consideration for their widespread application, requiring compliance with environmental requirements throughout the entire lifecycle, from raw material selection and production processes to usage and disposal [103]. First, regarding the substitution of bio-based raw materials for silicone-modified PU, bio-based polyols such as castor oil, soybean oil, or rosin derivatives can replace petroleum-based polyether/polyester polyols—for example, BASF’s BiOH^® series—reducing carbon emissions by 30%–50% [104]. Bio-silicones use plant-derived silanes instead of traditional petroleum-based siloxanes, achieving renewable raw materials [105]. Second, in terms of greening the production process of silicone-modified PU, low-VOC and solvent-free technologies are employed. Water-based PU systems use water as the dispersion medium, with VOC emissions below 50 g/L, making them suitable for indoor sports venues (e.g., badminton halls) [106]. The 100% solid content technology utilizes UV curing or reactive hot-melt adhesive processes, achieving zero solvent use. Third, concerning the usage phase of silicone-modified PU, durability and recyclability are considered in the design. Extended service life is achieved through silicone modification, enhancing weather resistance and increasing outdoor durability to over 15 years, reducing replacement frequency and cutting waste by 50% compared to traditional PU [37]. Modular structural designs, such as Italy’s FlexiSport system, enable material classification and recycling, with PU recovery rates exceeding 90%. Finally, for the disposal of silicone-modified PU, hydrolytic depolymerization under alkaline conditions (pH > 12) breaks it down into polyols and siloxane oligomers, which can be reused as raw materials for recycled PU—for example, Dow Chemical’s Hydrolysis technology [107]. Biodegradability is introduced by incorporating polylactic acid (PLA) copolymer segments, achieving a soil degradation rate of over 30% within 180 days. For instance, the flooring of the Beijing Winter Olympics Speed Skating Rink in China used Covestro’s water-based silicone PU, with VOC emissions below 10 g/L, earning LEED Gold certification.

5.3. International Development Trends of Silicone-Modified Polyurethane Materials

The application of silicone-modified polyurethane in sports fields is facing intense global competition. As performance standards for sports surfaces become increasingly stringent, this modified material market has garnered widespread attention. Private institutions and research institutes worldwide are ramping up investments to enhance various performance metrics of the material [108]. Leveraging technological innovation, some industrial powerhouses have achieved remarkable results in improving compound structures and aging resistance. Their continuous development of eco-friendly, high-performance new products has successfully secured a dominant position in high-value-added markets [109]. For instance, leading global enterprises have set industry benchmarks in cushioning and flexibility through technological advancements, not only optimizing athletes’ experience but also building premium brand reputations worldwide. In the sports field sector, numerous international manufacturers are fiercely competing around silicone-modified PU, not only in product quality and functionality but also in pricing strategies and after-sales services. Many industry giants leverage their massive scale and mature distribution channels to offer more attractive pricing for products and services, thereby reinforcing their market dominance. However, innovative small and medium-sized enterprises (SMEs) continue emerging by precisely targeting niche segments, focusing on personalized customer needs, and implementing differentiation strategies to gradually carve out market space. In global competition, environmental standards have become a critical factor. With growing environmental awareness, countries are imposing stricter ecological requirements on sports field materials [110]. Companies with eco-technological advantages gain stronger market competitiveness. Enterprises must sustain innovation to ensure products comply with international environmental and safety regulations, adapting to industry trends. Under this global competitive landscape, the development of silicone-modified PU in sports fields faces dual influences [111].

5.4. Future Research Priorities for Silicone-Modified Polyurethane Materials in Sports Fields

Silicone-modified polyurethane holds broad prospects in sports field applications but requires further research. Combining performance enhancement, environmental considerations, and technological innovation can promote its widespread adoption in venue construction. By refining formulations to improve UV resistance, oxidation resistance, and hydrolysis resistance, material lifespan can be extended, while developing high-wear-resistant composites suitable for intensive use. Simultaneously, adjusting surface friction coefficients reduces sports injury risks, flame-retardant treatments meet fire safety standards, and microstructural designs like porous foam optimize shock absorption and breathability, ensuring health, safety, and comfort. Accelerated aging tests simulate harsh environments (freeze–thaw cycles, high humidity, etc.), advancing global standards for performance, environmental, and safety evaluations. Integrating advanced technologies—such as flexible sensors for real-time pressure and humidity monitoring, IoT systems for field condition alerts, and nanotechnology to enhance material strength or add antibacterial/conductive properties (104–106)—will drive progress. Developing sport-specific materials (e.g., for track and field or ball games), improving colorfastness and visual performance, will better meet user demands and strengthen market competitiveness.

6. Conclusions

The study conducted an in-depth analysis of the use of silicone-modified polyurethane in sports fields, highlighting its unique chemical structure and outstanding properties such as excellent weather resistance and stability. In diverse outdoor sports venues, this material demonstrates superior durability, ensuring long-term stable operation of the fields. Its exceptional elasticity and cushioning properties not only enhance athletes’ experience but also provide robust protection against sports injuries, fully meeting the contemporary demands for athlete safety in sports facilities. The material complies with environmental and safety standards, making it suitable for constructing eco-friendly sports fields, and silicone-modified PU exhibits broad applicability in this domain. Sports fields vary in characteristics: track and field areas leverage the material’s excellent friction and rebound properties to help athletes push their limits; ball game zones rely on its stable performance to ensure the ball’s trajectory adheres to physical laws, maintaining fairness in competitions; fitness and specialized sports areas can fully utilize its advantages to adapt to diverse usage scenarios based on specific needs. However, numerous technical challenges remain in practice. The complexity of construction techniques limits the full realization of the material’s potential, high costs hinder large-scale adoption, and the lack of a robust quality evaluation system coupled with cumbersome maintenance procedures present pressing issues that require further exploration and refinement. Although silicone-modified polyurethane holds significant value and development potential in sports field applications, many challenges must be addressed. This study thoroughly examines the characteristics, applications, existing problems, and impact on athletic performance of silicone-modified PU in sports fields, providing a critical foundation for future research and practice. Moving forward, efforts must focus on technological innovation, cost optimization, and standard development to facilitate the widespread adoption of this material in sports facilities.