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Heavy oil production and transportation are often restricted by high viscosity, poor mobility, and unfavorable low-temperature flow behavior, especially in waxy systems. While conventional polymer-based additives improve flow, they suffer from inadequate thermal stability, poor dispersibility in complex crude oil matrices, and insufficient multifunctionality. To address these issues, a nano-SiO₂-based organic-inorganic hybrid flow improver, denoted as NSDA, was synthesized via in situ free-radical copolymerization of styrene, docosyl methacrylate, acrylic acid, and acrylamide on 3-(trimethoxysilyl)propyl methacrylate (KH-570)-modified silica surfaces. Characterization revealed that this core-shell nanohybrid structure significantly improved thermal stability and oil-phase dispersibility, maintaining nanoscale dispersion in xylene. A remarkable viscosity reduction rate of 90.2% was achieved, accompanied by a substantial pour point depression of 11 °C using only 0.5 wt% of NSDA in Liaohe heavy oil. This dual-functional performance is mainly attributed to the combined effects of the robust nano-SiO₂ core and the multifunctional polymer shell, Specifically, the performance is driven by synergistic wax crystal regulation at low temperatures, alongside weakened intermolecular associations among polar heavy components and nanoparticle-assisted dispersion that govern viscosity reduction. Full article

Low-temperature conditioning is a key procedure in the flexibility evaluation of waterproofing membranes and directly affects the reliability of subsequent performance assessments. However, the internal unsteady-state heat transfer kinetics and the thermal gradient evolution mechanisms in multi-layer composite membranes under transient cold shocks require further investigation. Focusing on commonly utilized 3 mm and 4 mm thick SBS (Styrene–Butadiene–Styrene)-modified bitumen waterproofing membranes as subjects, this study investigated the internal dynamic temperature fields and microstructural response of bituminous waterproofing membranes under standard low-temperature flexibility testing conditions. By accurately pre-embedding micro-temperature sensors in situ at the interface between the surface layer and the reinforcement matrix, the transient thermal response profiles of specimens with varying specifications in a −25 °C liquid environment were quantified. Simultaneously, a three-dimensional transient heat conduction finite element model was established to elucidate the dynamic evolution of internal spatial temperature gradients. The congruence between experimental and numerical results demonstrates that upon exposure to extreme cold, composite membranes of different thicknesses exhibit a pronounced “surface-to-core” heat transfer lag effect. The cooling rate maximized within the initial 10 min of exposure. Conversely, the internal interface layer—acting as a high-thermal-resistance zone and the most unfavorable point for heat conduction—necessitated 10~20 min of nonlinear thermal dissipation to stabilize at the target ambient temperature. This study clarifies the transient thermal response and temperature-field evolution laws of bituminous waterproofing membranes, providing a robust theoretical framework for elucidating low-temperature embrittlement mechanisms and informing the material design and application of waterproofing projects in cold regions. Full article

During flotation, the hydration behavior of collector head groups plays an important role in determining collector hydrophilicity and interfacial adsorption behavior. However, although computation-assisted flotation studies have extensively investigated collector–mineral interactions, systematic comparisons of the intrinsic hydration characteristics of different collector head groups under unified computational conditions remain limited. In this work, density functional theory (DFT) calculations using the B3LYP functional with Grimme dispersion correction were conducted to investigate the hydration interactions between water molecules and representative head groups of five sulfide mineral collectors, including xanthate (X), dithiocarbamate (DTC), dithiophosphate (DTP), dithiophosphinate (3418A), and thiocarbamate (Z-200), and five oxide mineral collectors, including oleate (OA), oxidized paraffin soap (OPS–C₁₂), dodecyl sulfonate (DS), styrene phosphonic acid (SPA), and salicylhydroxamic acid (BHA). The results show that oxide mineral collectors exhibit significantly stronger hydration interactions than sulfide mineral collectors. Sulfide collectors mainly form weak S···H–O hydrogen bonds with relatively long H-bond distances (2.27–2.61 Å), whereas oxide collectors predominantly form stronger O···H–O hydrogen bonds with shorter distances (1.66–2.24 Å). The total hydration binding energies of sulfide collectors range from −150 to −290 kJ/mol, while those of oxide collectors range from −244 to −491 kJ/mol. Among the studied collectors, SPA exhibits the strongest hydration tendency due to its highly charged phosphonate group, whereas Z-200 shows the weakest hydration interaction. The results indicate that hydration behavior is strongly influenced by head group type, charge state, and hydrogen-bond characteristics. Full article

Branched poly(vinyl alcohol) (PVA) was synthesized via chemical modification of linear PVA with epichlorohydrin in an alkaline aqueous medium under conditions preventing crosslinking. Branching was confirmed by IR and Heteronuclear Single Quantum Coherence (HSQC) spectroscopy, as well as by viscometric analysis. An iterative procedure is proposed for refining the branching factor (g) and the viscosity-average molecular weight of the branched macromolecules. Coil diameters determined by viscometry and dynamic light scattering showed satisfactory agreement. While an increase in the viscosity-average molecular weight of branched PVA enhances its surface activity in the low-adsorption region, the branched geometry itself hinders subsequent adsorption due to steric shielding of the interface. This correlates with wetting behavior on Teflon: lightly branched PVA requires a higher concentration to induce wetting inversion than its linear counterpart but further increase in molecular weight shifts the inversion point to lower concentrations due to a higher density of hydroxyl groups. Concurrently, the concentration dependence of the work of adhesion degenerates with increasing molecular weight. Despite their reduced adsorption capacity, the specific geometry of branched PVA macromolecules provides effective steric stabilization of micrometer-sized particles during styrene suspension polymerization. These results demonstrate that chain branching in PVA is a powerful tool for tuning its adsorption properties, stabilizing ability, and interfacial activity. Full article

Fused filament fabrication (FFF) produces components with characteristic topographical features that influence their tribological behavior. Because conventional roughness parameters may not fully describe the localized surface degradation of reinforced FFF polymers, this study evaluates the wear-track evolution of FFF aramid fiber-reinforced Acrylonitrile Styrene Acrylate (ASA) composites using a comparative profilometric framework based on pre-wear and post-wear measurements. Specimens with different infill configurations underwent dry sliding Ball-on-Disc tribological testing, followed by profilometric wear-track analysis and optical microscopy inspection. The macroscopic wear response exhibited a non-monotonic dependence on infill configuration. Under the present experimental conditions, the 30% infill configuration showed the most favorable average wear response, with the lowest wear volume and specific wear rate, whereas the 90% infill configuration showed the highest material loss. To compare the surface modifications induced by sliding, three derived relative profilometric descriptors were evaluated: Surface Texture Alteration Index (STAI), Peak Deformation Index (PDI) and Material Ratio Preservation Index (MRPI). These descriptors were used as complementary comparative parameters rather than replacements for standardized roughness or Abbott–Firestone-based measurements. Statistical analysis showed a very strong association between maximum wear-track depth and calculated volumetric material loss, indicating that deeper wear-track profiles were consistently associated with higher material removal within the investigated dataset. Furthermore, correlation analysis suggested that the initial material ratio may be more closely associated with the subsequent wear response than the initial arithmetic mean roughness. This study indicates that combining wear volume, wear-track geometry, optical microscopy and relative profilometric descriptors provides a useful comparative approach for evaluating degradation in FFF Kevlar-reinforced ASA components under sliding conditions. Full article

Gel plugging agents are key drilling fluid additives for maintaining wellbore stability. However, the downhole ultra-high-temperature, high-salinity environments, and developed micro-fractures in deep and ultra-deep wells pose severe challenges to the performance of gel plugging agents. To address this problem, this paper presents the preparation of a nano-micron gel plugging agent with a core–shell structure, denoted as LMS, suitable for high-temperature and high-salinity water-based drilling fluids. LMS was synthesized via emulsion polymerization, using a styrene–sodium p-styrenesulfonate copolymer as the core and 2-acrylamido-2-methylpropanesulfonic acid and methacryloyloxyethyltrimethyl ammonium chloride as the shell-modifying monomers. LMS was characterized by infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and particle size analysis, confirming that LMS met the design expectations. Experimental results showed that after aging at 220 °C for 16 h under saturated-salt conditions, the filtration loss of the drilling fluid with 3 wt% LMS was 10.4 mL, a reduction of 57.4% compared to the base mud. Meanwhile, LMS exhibited good plugging performance in microporous membrane tests and sand bed tests. After aging at 220 °C for 16 h under saturated-salt conditions, the core plugging rate reached 95.4%. LMS can not only adsorb onto clay surfaces to increase the thickness of the hydration film, enhancing drilling fluid stability, but can also synergistically build a filter cake with clay particles to plug nano-micron pores, preventing drilling fluid infiltration into the formation. This paper provides a preparation method for a high-temperature- and high-salinity-resistant gel plugging agent with excellent plugging effects, which is expected to support safe and efficient drilling in deep and ultra-deep formations. Full article

Styrene, a constituent of polystyrene food-contact materials, can migrate into hot beverages, but data on short-term consumer exposure and associated biological responses remain limited. In this single-arm longitudinal human biomonitoring pilot study, 40 healthy adults consumed tea or coffee daily in Styrofoam cups for approximately two weeks. Biomarkers were measured at baseline, day 6, and day 11, including urinary mandelic acid (MA) and phenylglyoxylic acid (PGA), salivary malondialdehyde (MDA), comet assay parameters in peripheral blood lymphocytes, and micronucleus (MN) frequency in buccal cells. Measured styrene migration into beverages ranged from 3.3 to 7.1 μg/L, below the World Health Organization guideline value. Urinary metabolites and salivary MDA showed substantial interindividual variability and no consistent temporal pattern. In contrast, generalized estimating equation models showed progressive increases in comet assay indicators over the exposure period. Tail intensity and tail moment increased over time, with stronger changes among participants consuming two cups daily. MN frequency did not change significantly. These findings suggest that repeated short-term consumption of hot beverages in polystyrene cups was associated with modest changes in selected early biomarkers of biological effect under consumer-use conditions. The results should be interpreted cautiously in light of the modest sample size, short follow-up, and absence of more specific mechanistic endpoints, but they support further study of repeated low-level exposure to food-contact materials. Full article

This paper systematically investigates the failure characteristics and mechanisms of insulating materials in DC voltage dividers under combined high-frequency voltage and high-temperature conditions via simulations and experiments. The results showed that high-frequency harmonics severely degrade the insulation strength of polypropylene/paper/polypropylene (PPLP) at 10 kHz, in which the bulk breakdown strength of PPLP decreases by over 50%. Furthermore, the surface flashover voltage in oil is reduced by 17.7% under high-frequency voltage alone, and by as much as 51% when white flocculent substances are present in the oil. The dielectric properties of PPLP strongly depend on frequency and temperature, which aggravate the heat accumulation of the divider under high-frequency voltage. Furthermore, the multilayer structure of PPLP introduces deeper trap levels due to interfacial states, which reduce the breakdown strength and flashover voltage of PPLP. Electro-thermal coupling induces a rapid temperature rising to 98 °C at 25 kHz caused by dielectric loss, leading to oil turbidity and white precipitation, consistent with finite element simulations. Consequently, a failure mechanism is proposed as follows: prolonged electro-thermal stress causes chain scission in styrene-containing materials, releasing monomers that repolymerize into white polystyrene deposits. Their porous structure and dielectric mismatch distort the interfacial field, trigger partial discharge, and aggravate surface flashover. Full article

Noise is an environmental factor that negatively affects the health of living organisms and must therefore be mitigated. One effective approach to noise reduction is the use of passive materials for sound absorption. Moreover, with the increasing use of 3D printing technology, it is now possible to produce complex material structures for noise reduction that cannot be manufactured using conventional manufacturing techniques. This study investigates the sound absorption performance of novel 3D-printed concentric tubular structures made of acrylonitrile styrene acrylate (ASA) with intermediate lattice inserts. The sound absorption properties of these structures were experimentally evaluated in the frequency range of 200–1600 Hz using a two-microphone acoustic impedance tube. Various factors influencing sound absorption properties were investigated, including the number of concentric tubes, sample height, strut diameter, and back air cavity thickness. The experimental results show that the sound absorption performance depends significantly on the design parameters of the proposed system. The average sound absorption coefficient (α_avg) increased with the number of concentric tubes and reached a maximum value of 0.264 for the configuration with five tubes. The highest sound absorption peak (α_max = 0.623) was achieved for the structure with two concentric tubes, a strut diameter of 3 mm, a height of 30 mm, and a back air cavity of 10 mm at a frequency of approximately 1548 Hz. Furthermore, increasing the strut diameter and sample height generally improved sound absorption performance, while the presence of a back air cavity significantly shifted the absorption peak toward lower frequencies, thereby enhancing low-frequency sound absorption. Full article

To reveal the long-term anti-aging mechanisms of rubber–plastic elastomer-modified asphalt in complex service environments and overcome the inherent defects of single polymer modifiers—namely their susceptibility to degradation or phase separation—this study prepared styrene-butadiene-styrene (SBS), low Mooney rubber (LMMR), and low-density polyethylene (LDPE)-modified asphalts. Simultaneously, an LMMR-LDPE rubber–plastic thermoplastic elastomer (TPE) was fabricated utilizing twin-screw extrusion technology and subsequently used to prepare a composite-modified asphalt. Three aging protocols were simulated: short-term thermo-oxidative aging (RTFOT), long-term pressure aging (PAV), and ultraviolet light aging (UV). A multi-scale quantitative characterization was conducted using a dynamic shear rheometer, Fourier transform infrared spectroscopy, and atomic force microscopy to evaluate the rutting factor, carbonyl index, and surface microroughness of each system before and after aging. The experimental results indicate that the coupled effect of long-term stress and thermal oxidation causes the most severe damage to the colloidal structure of modified asphalt. Conventional SBS-modified asphalt, due to its abundance of unsaturated double bonds, exhibits a sharp increase in the carbonyl index and aging index of the rutting factor after aging, making it highly susceptible to oxidative chain scission. Although LDPE-modified asphalt possesses chemical inertness, it is prone to crystalline phase separation under aging conditions, resulting in a microroughness distortion rate of up to 86.36%. In contrast, the LMMR-LDPE composite system, leveraging the high chemical stability of the saturated aliphatic carbon chain and the flexibility-enhancing and crystallization-inhibiting effects of LMMR, effectively reduces active oxidation sites and improves interfacial compatibility. This composite system exhibits the lowest carbonyl increment and rheological attenuation under all aging conditions, while effectively inhibiting the free migration and agglomeration of macromolecular components. The LMMR-LDPE composite modification technology effectively overcomes the inherent drawbacks of single polymers, such as susceptibility to degradation or segregation, demonstrating excellent long-term macroscopic rheological stability and microscopic phase morphology anti-aging capability. The present findings provide laboratory-scale mechanistic support for the design of durable rubber–plastic-modified asphalt systems, while further pilot-scale, economic, and field validation is still required before practical engineering application can be fully assessed. Full article

To evaluate the susceptibility of styrene–butadiene–styrene (SBS)-modified asphalt to modifier segregation during high-temperature storage, this study examined its segregation behavior and microstructural evolution under storage conditions ranging from 70 to 163 °C over durations of 48–144 h, with varying warm-mix agent dosages (0%, 3%, 4%, and 5%). The investigation was conducted using softening point measurements, dynamic shear rheometry, infrared spectroscopy, and optical microscopy. The results indicated that the incorporation of the warm-mix agent significantly reduced the difference in softening point, diminished the discrepancies in complex modulus and phase angle between the upper and lower layers, and inhibited SBS aggregation and phase separation. When the warm-mix agent content reached 5%, the softening point difference in the modified asphalt at 163 °C and 48 h decreased from 14.4 °C to 1.6 °C, essentially eliminating segregation. Infrared spectroscopy confirmed that the warm-mix agent did not induce chemical bond changes but improved the compatibility between the SBS modifier and the base asphalt. Microscopic observation further verified that the warm-mix agent facilitated a uniform dispersion of SBS modifier particles, forming a stable microphase structure. The research findings provide valuable insights for improving the storage stability and engineering performance of SBS-modified asphalt. Full article

This study evaluates the non-catalytic thermal pyrolysis of post-consumer polystyrene (PS) in a laboratory-scale batch fixed-bed reactor to recover aromatic-rich liquid products. The PS feedstock was characterized by thermogravimetric analysis (TGA) and micro-Raman spectroscopy to assess its thermal behavior and chemical homogeneity. In addition, the main TGA degradation region was analyzed using Coats–Redfern, Horowitz–Metzger, and Broido kinetic models, yielding apparent activation energies of 269.18, 288.83, and 280.69 kJ mol⁻¹, respectively. Pyrolysis experiments were performed at final temperatures of 400, 450, and 500 °C and heating rates of 10 and 20 °C min⁻¹ under continuous N₂ flow. The maximum liquid yield reached 95.2 wt% at 500 °C and 20 °C min⁻¹, while the estimated gaseous fraction decreased to approximately 2.0 wt%. ANOVA confirmed that final temperature was the dominant factor controlling liquid recovery, contributing approximately 83% of the model variability, whereas heating rate had a secondary but significant effect. GC–MS analysis showed that the pyrolysis oil was mainly composed of aromatic hydrocarbons, including styrene, toluene, and ethylbenzene, with increasing temperature promoting the redistribution of the liquid fraction toward lighter monoaromatic compounds. These results indicate that non-catalytic fixed-bed pyrolysis is a promising route for converting post-consumer PS into aromatic-rich liquid products. However, the recovered oil should be considered a complex mixture rather than a purified monomer stream, and further gas-phase characterization, downstream purification, energy-balance evaluation, life-cycle assessment, and techno-economic analysis are required before definitive claims regarding industrial circularity or environmental performance can be established. Full article

This study develops a quantitative kinetic framework for graft copolymerization of methyl methacrylate (MMA) and styrene (ST) onto natural rubber latex (NRL), with emphasis on Redox initiation and Interfacial polymerization in a multiphase system. Experiments were conducted using a cumene hydroperoxide/tetraethylenepentamine (CHPO/TEPA) system. Core–shell particles, consisting of a soft NR core and a rigid poly(vinyl monomer) shell, were obtained at 40–60 °C with initiator concentrations of 0.0051–0.0205 mol L⁻¹ and monomer concentrations of 0.39–0.83 mol L⁻¹. Radical generation occurs predominantly at the aqueous rubber interface, where monomer partitioning takes place between phases. This leads to simultaneous homopolymerization in the aqueous phase, while grafting occurs on the rubber backbone. Overall conversion (x_p), graft conversion (x_g), and grafting efficiency were determined gravimetrically, while morphology was confirmed by FTIR and TEM. The conversion profiles show nonlinear behavior consistent with power-law kinetics, allowing formulation of rate expressions for overall polymerization rate (R_p) and grafting rate (R_g). Reaction order and Arrhenius analyses indicate fractional, heterogeneous behavior characteristic of multiphase reaction kinetics. Styrene shows lower activation energy, whereas MMA exhibits higher collision frequency. The model reproduces experimental trends well (R² up to 0.95) and provides insight into propagation–grafting competition in natural rubber latex systems. Full article

Concerns about the environmental and health impacts of plasticized poly (vinyl chloride) (PVC), from plasticizer loss to microplastic formation, have created a clear demand to find alternative packaging materials for medical and pharmaceutical use. As a possible polyolefin-based alternative, we blended polypropylene–ethylene copolymers with different ethylene content-controlled phase structures with styrene–ethylene/butylene–styrene block copolymer (SEBS), as modifier. SEBS is elastomeric and performs mechanically like a cross-linked rubber due to its unique microphase-separated morphology of hard spherical polystyrene (PS) domains dispersed in the soft elastomeric ethylene-butylene copolymer (EB) phase. Tests with injection-molded samples and cast films demonstrated promising combinations of flexibility, durability, and transparency—qualities essential for soft medical packaging like infusion pouches and blow–fill–seal bottles. For the desired level of flexibility (reflected by a flexural modulus of 150–250 MPa), blends with two random-heterophasic (RAHECO) copolymers achieved the lower limit with only 15–25 wt.-% SEBS, compared to the 37 wt.-% needed for a single-phase random copolymer (RACO). These blends also exhibited greater toughness and excellent transparency. In contrast, a standard impact copolymer (HECO), with its more crystalline matrix, required a higher modifier content of 45 wt.-% SEBS. Film morphology analysis indicated a gradual shift in disperse phase structure and orientation, leading to phase inversion at the highest SEBS content without negatively affecting transparency. Full article

This work presents an approach for designing 3D-printed heaters with tunable electrical resistance by optimizing both printing and geometrical parameters. To this end, acrylonitrile butadiene styrene reinforced with carbon nanotubes (ABS-CNTs) has been processed through fused filament fabrication (FFF) in a manner that favors electrical current flow along the printing direction and enables adjustment of electrical resistance to meet the scalability needs and limitations of the power supplier available in the application field. The as-developed 3D-printed heater has been integrated into an aeronautical fiberglass composite as proof of its possible application as a de-icing system. Full article