Special Issue "Multifunctional Smart Polymers and Polymeric Composites"

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Applications".

Deadline for manuscript submissions: 20 October 2022 | Viewed by 14949

Special Issue Editors

Prof. Dr. Mohamad Fotouhi
E-Mail Website
Guest Editor
School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
Interests: generative design; lightweight/smart bio-inspired composites; 4D printed self-morphing structures and multi-functional materials
Special Issues, Collections and Topics in MDPI journals
Dr. Hamed Yazdani Nezhad
E-Mail Website
Co-Guest Editor
Department of Mechanical Engineering and Aeronautics, University of London, London EC1V 0HB, UK
Interests: multifunctional composites; smart materials; composite manufacturing; composite joints; computational damage mechanics; composite repair
Special Issues, Collections and Topics in MDPI journals
Dr. Han Zhang
E-Mail Website
Co-Guest Editor
School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK
Interests: multifunctional composites; hierarchial composites; sustainable manufacturing; nanocomposites; sensing

Special Issue Information

Dear Colleagues,

The invention of multifunctional polymers and polymeric composites (MPPC) was one of the most revolutionary steps in the field of materials. Recently, research on the underlying mechanisms of MPPC to an external stimulus (for example, heat, electricity, magnetism, light, and moisture) and structures has grown rapidly in different fields. Due to their novel properties, MPPC can address challenges in many applications such as automotive, aerospace, wind, and soft robotics. This Special Issue aims to provide a platform for communication and fast publications of high-quality original research and review papers for scientists working on different aspects of MPPC across the world. It includes but is not limited to the synthesis, processing, manufacturing, and practical applications of these materials. Different types of research (such as analytical, modeling, and experimental) on MPPC are welcomed.

Dr. Hamed Yazdani Nezhad
Dr. Mohamad Fotouhi
Dr. Han Zhang
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • multifunctionality
  • polymers, composites
  • smart materials
  • bio-inspiration
  • stimuli

Published Papers (12 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Article
Numerical Modelling and Analytical Comparison of Delamination during Cryogenic Drilling of CFRP
Polymers 2021, 13(22), 3995; https://doi.org/10.3390/polym13223995 - 19 Nov 2021
Cited by 2 | Viewed by 645
Abstract
Carbon-Fibre-Reinforced Polymers (CFRPs) have seen a steady rise in modern industrial applications due to their high strength-to-weight ratio and corrosion resistance. However, their potential is being hindered by delamination which is induced on them during machining operations. This has led to the adoption [...] Read more.
Carbon-Fibre-Reinforced Polymers (CFRPs) have seen a steady rise in modern industrial applications due to their high strength-to-weight ratio and corrosion resistance. However, their potential is being hindered by delamination which is induced on them during machining operations. This has led to the adoption of new and innovative techniques like cryogenic-assisted machining which could potentially help reduce delamination. This study is aimed at investigating the effect of cryogenic conditions on achieving better hole quality with reduced delamination. In this paper, the numerical analysis of the drilling of CFRP composites is presented. Drilling tests were performed experimentally for validation purposes. The effects of cooling conditions and their subsequent effect on the thrust force and delamination were evaluated using ABAQUS/CAE. The numerical models and experimental results both demonstrated a significant reduction in the delamination factor in CFRP under cryogenic drilling conditions. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Graphical abstract

Article
Crown Ether-Immobilized Cellulose Acetate Membranes for the Retention of Gd (III)
Polymers 2021, 13(22), 3978; https://doi.org/10.3390/polym13223978 - 17 Nov 2021
Cited by 2 | Viewed by 596
Abstract
This study presents a new, revolutionary, and easy method of separating Gd (III). For this purpose, a cellulose acetate membrane surface was modified in three steps, as follows: firstly, with aminopropyl triethoxysylene; then with glutaraldehyde; and at the end, by immobilization of crown [...] Read more.
This study presents a new, revolutionary, and easy method of separating Gd (III). For this purpose, a cellulose acetate membrane surface was modified in three steps, as follows: firstly, with aminopropyl triethoxysylene; then with glutaraldehyde; and at the end, by immobilization of crown ethers. The obtained membranes were characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), through which the synthesis of membranes with Gd (III) separation properties is demonstrated. In addition, for the Gd (III) separating process, a gadolinium nitrate solution, with applications of moderator poison in nuclear reactors, was used. The membranes retention performance has been demonstrated by inductively coupled plasma mass spectrometry (ICP-MS), showing a separation efficiency of up to 91%, compared with the initial feed solution. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Graphical abstract

Article
Applying Acoustic Emission Technique for Detecting Various Damages Occurred in PCL Nanomodified Composite Laminates
Polymers 2021, 13(21), 3680; https://doi.org/10.3390/polym13213680 - 26 Oct 2021
Cited by 2 | Viewed by 604
Abstract
Interleaving composite laminates by nanofibers is a well-known method of increasing interlaminar fracture toughness. Among many possibilities, polycaprolactone (PCL) nanofibers is one of the best choices for toughening composite laminates. The influence of PCL on delamination mode of failure is considered before. However, [...] Read more.
Interleaving composite laminates by nanofibers is a well-known method of increasing interlaminar fracture toughness. Among many possibilities, polycaprolactone (PCL) nanofibers is one of the best choices for toughening composite laminates. The influence of PCL on delamination mode of failure is considered before. However, the effect of PCL on other damage modes, such as fiber breakage and matrix cracking, is yet to be studied. In this study, the acoustic emission (AE) technique is applied to determine the effect of toughening composite laminates by PCL nanofibers on matrix cracking, fiber/matrix debonding, and fiber breakage failure mechanisms. For this purpose, mode I and mode II fracture tests are conducted on modified and non-modified glass/epoxy laminates. Three different methods, i.e., peak frequency, wavelet transform, and sentry function, are utilized for analyzing the recorded AE data from mode I test. The results show that applying PCL nanofibers not only increases the mode I critical strain energy release rate by about 38%, but also decreases different failure mechanisms by between 75 and 94%. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Graphical abstract

Article
4D Printing of Smart Polymer Nanocomposites: Integrating Graphene and Acrylate Based Shape Memory Polymers
Polymers 2021, 13(21), 3660; https://doi.org/10.3390/polym13213660 - 24 Oct 2021
Cited by 5 | Viewed by 1154
Abstract
The ever-increasing demand for materials to have superior properties and satisfy functions in the field of soft robotics and beyond has resulted in the advent of the new field of four-dimensional (4D) printing. The ability of these materials to respond to various stimuli [...] Read more.
The ever-increasing demand for materials to have superior properties and satisfy functions in the field of soft robotics and beyond has resulted in the advent of the new field of four-dimensional (4D) printing. The ability of these materials to respond to various stimuli inspires novel applications and opens several research possibilities. In this work, we report on the 4D printing of one such Shape Memory Polymer (SMP) tBA-co-DEGDA (tert-Butyl Acrylate with diethylene glycol diacrylate). The novelty lies in establishing the relationship between the various characteristic properties (tensile stress, surface roughness, recovery time, strain fixity, and glass transition temperature) concerning the fact that the print parameters of the laser pulse frequency and print speed are governed in the micro-stereolithography (Micro SLA) method. It is found that the sample printed with a speed of 90 mm/s and 110 pulses/s possessed the best batch of properties, with shape fixity percentages of about 86.3% and recovery times as low as 6.95 s. The samples built using the optimal parameters are further subjected to the addition of graphene nanoparticles, which further enhances all the mechanical and surface properties. It has been observed that the addition of 0.3 wt.% of graphene nanoparticles provides the best results. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Figure 1

Article
Detection of Barely Visible Impact Damage in Polymeric Laminated Composites Using a Biomimetic Tactile Whisker
Polymers 2021, 13(20), 3587; https://doi.org/10.3390/polym13203587 - 18 Oct 2021
Cited by 2 | Viewed by 777
Abstract
This is a novel investigation on the possibility of detecting barely visible impact damage (BVID) in composite materials by whisking across the surface via tactile whisker sensors that resemble rats’ whiskers. A series of drop tower low-velocity impact tests were performed on quasi-isotropic [...] Read more.
This is a novel investigation on the possibility of detecting barely visible impact damage (BVID) in composite materials by whisking across the surface via tactile whisker sensors that resemble rats’ whiskers. A series of drop tower low-velocity impact tests were performed on quasi-isotropic composite plates. The plates were made from unidirectional T800 carbon/MTM49-3 epoxy prepregs with the stacking sequence of [45/0/90/−45]4S. Investigating the specimens’ surface by the naked eye does not reveal any significant damage, rather than a small dent on the surface, with no tangible difference in the different impact energy levels. Ultrasonic C-scan observations showed the existence of BVID in all the impact energy levels, with an increasing trend in the damage size by increasing the impact energy level. The collected data from whisker sensors were analyzed using the support vector machine classifier, based on their vibrational properties, to identify the impacted region and classify the impact severity. It was observed that after training for 13 whisker contacts, the BVID severity can be classified with an accuracy of 100%. This is offering a new BVID detection technique, with a high potential for automation and high reliability that can be used as an alternative or combined with available inspection systems. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Graphical abstract

Article
Copper Rich Composite Materials Based on Carboxylic Cation Exchangers and Their Thermal Transformation
Polymers 2021, 13(18), 3199; https://doi.org/10.3390/polym13183199 - 21 Sep 2021
Viewed by 1563
Abstract
The effect of a cupric deposit (Cu2+, CuO) on the thermal decomposition of carboxylic cation exchangers (CCEs) is not known, and such studies may have practical significance. CCEs have a very high ion exchange capacity, so an exceptionally large amount of [...] Read more.
The effect of a cupric deposit (Cu2+, CuO) on the thermal decomposition of carboxylic cation exchangers (CCEs) is not known, and such studies may have practical significance. CCEs have a very high ion exchange capacity, so an exceptionally large amount of CuO (which is a catalyst) can be precipitated inside them. Two CCEs, macroreticular (Amberlite IRC50) and gel-like (Amberlite IRC86), served as a polymeric support to obtain copper-rich hybrid ion exchangers. Composites with CuO particles inside a polyacrylic matrix (up to 35.0 wt% Cu) were obtained. Thermal analyses under air and under N2 were performed for CCEs in the H+ and Cu2+ form with and without a CuO deposit. The results of sixteen experiments are discussed based on the TG/DTG curves and XRD patterns of the solid residues. Under air, the cupric deposit shifted the particular transformations and the ultimate polymeric matter decomposition (combustion) toward lower temperatures (even about 100–150 °C). Under N2, the reduction of the cupric deposit to metallic copper took place. Unique composite materials enriched in carbonaceous matter were obtained, as the products of polymeric matrix decomposition (free radicals and hydrogen) created an additional amount of carbon char due to the utilization of a certain amount of hydrogen to reduce Cu (II) to Cu0. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Graphical abstract

Article
Tailoring of Thermo-Mechanical Properties of Hybrid Composite-Metal Bonded Joints
Polymers 2021, 13(2), 170; https://doi.org/10.3390/polym13020170 - 06 Jan 2021
Cited by 3 | Viewed by 944
Abstract
Metallic substrates and polymer adhesive in composite-metal joints have a relatively large coefficient of thermal expansion (CTE) mismatch, which is a barrier in the growing market of electric vehicles and their battery structures. It is reported that adding carbon nanotubes (CNTs) to the [...] Read more.
Metallic substrates and polymer adhesive in composite-metal joints have a relatively large coefficient of thermal expansion (CTE) mismatch, which is a barrier in the growing market of electric vehicles and their battery structures. It is reported that adding carbon nanotubes (CNTs) to the adhesive reduces the CTE of the CNT-enhanced polymer adhesive multi-material system, and therefore when used in adhesively bonded joints it would, theoretically, result in low CTE mismatch in the joint system. The current article presents the influence of two specific mass ratios of CNTs on the CTE of the enhanced polymer. It was observed that the addition of 1.0 wt% and 2.68 wt% of multi-walled CNTs (MWCNTs) decreased the CTE of the polymer adhesive from 7.5×105 °C1 (pristine level) to 5.87×105 °C1 and 4.43×105 °C1, respectively, by 22% and 41% reductions. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Figure 1

Article
A Study of Physico-Mechanical Properties of Hollow Glass Bubble, Jute Fibre and Rubber Powder Reinforced Polypropylene Compounds with and without MuCell® Technology for Lightweight Applications
Polymers 2020, 12(11), 2664; https://doi.org/10.3390/polym12112664 - 12 Nov 2020
Cited by 8 | Viewed by 974
Abstract
Lightweighting is one of the key solutions to reduce the carbon footprint of vehicles. Nowadays, it is still challenging to achieve this target because there is a conflict between the cost and final material performance, as well as the fact that many lightweight [...] Read more.
Lightweighting is one of the key solutions to reduce the carbon footprint of vehicles. Nowadays, it is still challenging to achieve this target because there is a conflict between the cost and final material performance, as well as the fact that many lightweight solutions are restricted to laboratory or small-scale production. In this work, a commercially feasible strategy was adopted to fabricate materials for lightweight applications. Hollow glass bubbles, jute fibres, and rubber powder were used as fillers with polypropylene as the base polymer. Various samples were fabricated using conventional and MuCell® injection moulding. Their performance was then characterised by their density and morphological, mechanical, and rheological properties. A comparison among hybrid fillers/polypropylene compounds with and without MuCell® technology was investigated. The filler hybridisation resulted in not only a density reduction of up to approximately 10%, but also improved tensile/flexural modulus and strength. The use of MuCell® led to a further reduction in density of roughly 10%. Meanwhile, although some compounds fabricated by MuCell® exhibited some deterioration in their tensile yield strength, tensile modulus, and impact strength, they maintained acceptable mechanical properties for automotive applications. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Figure 1

Article
Influence of Polylactide (PLA) Stereocomplexation on the Microstructure of PLA/PBS Blends and the Cell Morphology of Their Microcellular Foams
Polymers 2020, 12(10), 2362; https://doi.org/10.3390/polym12102362 - 15 Oct 2020
Cited by 6 | Viewed by 1309
Abstract
Polylactide foaming materials with promising biocompatibility balance the lightweight and mechanical properties well, and thus they can be desirable candidates for biological scaffolds used in tissue engineering. However, the cells are likely to coalesce and collapse during the foaming process of polylactide (PLA) [...] Read more.
Polylactide foaming materials with promising biocompatibility balance the lightweight and mechanical properties well, and thus they can be desirable candidates for biological scaffolds used in tissue engineering. However, the cells are likely to coalesce and collapse during the foaming process of polylactide (PLA) due to its intrinsic low melt strength. This work introduces a unique PLA stereocomplexation into the microcellular foaming of poly (l-lactide)/poly (butylene succinate) (PLLA/PBS) based on supercritical carbon dioxide. The rheological properties of PLA/PBS with 5 wt% or 10 wt% poly (d-lactide) (PDLA) present enhanced melt strength owing to the formation of PLA stereocomplex crystals (sc-PLA), which act as physical pseudo-cross-link points in the molten blends by virtue of the strong intermolecular interaction between PLLA and the added PDLA. Notably, the introduction of either PBS or PDLA into the PLLA matrix could enhance its crystallization, while introducing both in the blend triggers a decreasing trend in the PLA crystallinity, which it is believed occurs due to the constrained molecular chain mobility by formed sc-PLA. Nevertheless, the enhanced melt strength and decreased crystallinity of PLA/PBS/PDLA blends are favorable for the microcellular foaming behavior, which enhanced the cell stability and provided amorphous regions for gas adsorption and homogeneous nucleation of PLLA cells, respectively. Furthermore, although the microstructure of PLA/PBS presents immiscible sea-island morphology, the miscibility was improved while the PBS domains were also refined by the introduction of PDLA. Overall, with the addition of PDLA into PLA/10PBS blends, the microcellular average cell size decreased from 3.21 to 0.66 μm with highest cell density of 2.23 × 1010 cells cm−3 achieved, confirming a stable growth of cells was achieved and more cell nucleation sites were initiated on the heterogeneous interface. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Graphical abstract

Article
Transforming Marble Waste into High-Performance, Water-Resistant, and Thermally Insulative Hybrid Polymer Composites for Environmental Sustainability
Polymers 2020, 12(8), 1781; https://doi.org/10.3390/polym12081781 - 09 Aug 2020
Cited by 15 | Viewed by 1889
Abstract
Marble waste is generated by marble processing units in large quantities and dumped onto open land areas. This creates environmental problems by contaminating soil, water, and air with adverse health effects on all the living organisms. In this work, we report on understanding [...] Read more.
Marble waste is generated by marble processing units in large quantities and dumped onto open land areas. This creates environmental problems by contaminating soil, water, and air with adverse health effects on all the living organisms. In this work, we report on understanding the use of calcium-rich marble waste particulates (MPs) as economic reinforcement in recyclable polypropylene (PP) to prepare sustainable composites via the injection molding method. The process was optimized to make lightweight and high-strength thermally insulated sustainable composites. Physicochemical, mineralogical, and microscopic characterization of the processed marble waste particulates were carried out in detail. Composite samples were subsequently prepared via the injection molding technique with different filler concentrations (0%, 20%, 40%, 60%, and 80%) on weight fraction at temperatures of 160, 180, and 200 °C. Detailed analysis of the mechanical and thermal properties of the fabricated composites was carried out. The composites showed a density varying from 0.96 to 1.27 g/cm3, while the water absorption capacity was very low at 0.006%–0.034%. Marble waste particulates were found to considerably increase the tensile, as well as flexural, strength of the sustainable composites, which varied from 22.06 to 30.65 MPa and 43.27 to 58.11MPa, respectively, for the molding temperature of 160 °C. The impact strength of the sustainable composites was found to surge with the increment in filler concentration, and the maximum impact strength was recorded as 1.66 kJ/m2with 20% particulates reinforcement at a molding temperature of 200 °C. The thermal conductivity of the particulates-reinforced sustainable composites was as low as 0.23 Wm−1K−1 at a 200 °C molding temperature with 20% and 40% filler concentrations, and the maximum thermal conductivity was 0.48 Wm−1K−1 at a 160 °C molding temperature with 80% filler concentration. Our findings have shown a technically feasible option for manufacturing a lightweight composite with better mechanical and thermal properties using marble waste particulates as a potential civil infrastructural material. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Figure 1

Article
Enhanced Interface Adhesion by Novel Eco-Epoxy Adhesives Based on the Modified Tannic Acid on Al and CFRP Adherends
Polymers 2020, 12(7), 1541; https://doi.org/10.3390/polym12071541 - 12 Jul 2020
Cited by 6 | Viewed by 1689
Abstract
This paper presents a new process for obtaining eco-epoxide adhesives synthesized from bio-renewable raw material (tannic acid—TA) and used for bonding lightweight materials (aluminum (Al) and carbon fiber reinforced polymer (CFRP)). Two synthesized bio-epoxy components based on TA, (A) glycidyl ether and (B) [...] Read more.
This paper presents a new process for obtaining eco-epoxide adhesives synthesized from bio-renewable raw material (tannic acid—TA) and used for bonding lightweight materials (aluminum (Al) and carbon fiber reinforced polymer (CFRP)). Two synthesized bio-epoxy components based on TA, (A) glycidyl ether and (B) glycidyl phosphate ester of TA, were used as a replacement for the toxic epoxy component based on Bisphenol A. The effect of eco-epoxy components on the interface adhesion was measured by the determination of adhesion parameter b, which was compared to the reference epoxy (REF). The increase of adhesion parameter b was 77.5% for A and 151.5% for B. The adhesion of both eco-adhesives was tested using the bell peel test (BPT) with the Al and CFRP adherends. When compared to REF, the average peel load for B was 17.6% (39.3%) and 58.3% (176.9%) higher for the Al and CFRP adherends, respectively. Complete adhesion failure of REF reflected the weak adhesion to both Al and CFRP, which was improved by the addition of eco-epoxy components A and B showing the presence of cohesive failure. The microhardness testing method of interface adhesion was proven to be a fast and reliable testing method, providing a qualitative indication in adhesive selection. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Figure 1

Article
Influence of Polymer Composites and Memory Foam on Energy Absorption in Vehicle Application
Polymers 2020, 12(6), 1222; https://doi.org/10.3390/polym12061222 - 27 May 2020
Cited by 8 | Viewed by 1658
Abstract
The automotive industry is one of the biggest consumers of polymer composites. Aside from good mechanical properties, polymer composites have low mass, which positively affects the overall vehicle weight reduction and improves energy efficiency. Although polymer composites are used in various vehicle components, [...] Read more.
The automotive industry is one of the biggest consumers of polymer composites. Aside from good mechanical properties, polymer composites have low mass, which positively affects the overall vehicle weight reduction and improves energy efficiency. Although polymer composites are used in various vehicle components, this paper focused on the application in vehicle bumper production. Two different composite plates with hybrid fiber layup were made; the first plate with a combination of glass and carbon fibers and the second with carbon and aramid. For comparison, and as a cheaper variant, a third plate was made only with glass fibers. In the first two plates, epoxy resin was used as the matrix, while in the third plate, polyester resin was used. Polyurethane memory foams of different densities (60, 80, 100 kg/m3) and thicknesses (10, 15, 20 mm) were used as impact force energy absorbers. With the factorial design of experiments, it was found that the thickness of the memory foam was the main influence factor. Without the use of memory foam, the hybrid composite, made of glass and carbon fibers, showed the highest energy absorption, while with the use of foam, the highest energy absorption was achieved with the glass fiber composite. Without the memory foam, the impact force measured on the glass/carbon hybrid composite was 9319.11 ± 93.18 N. Minimum impact force to the amount of 5143.19 ± 237.65 N was measured when the glass fiber composite plate was combined with the memory foam. When using memory foam, the impact force was reduced by 30–48%, depending on the type of composite used. Full article
(This article belongs to the Special Issue Multifunctional Smart Polymers and Polymeric Composites)
Show Figures

Graphical abstract

Back to TopTop