The 50 most-cited articles in Journal of Applied Polymer Science, 2023

Abstract In recent years, there has been a significant focus on bioactive dressings suitable for treating chronic and acute wounds. Electrospinning nanofibers are considered advanced dressing options due to their high porosity and permeability to air and water, effective barrier properties against external pathogens, and excellent resemblance to the extracellular matrix for wound healing and skin regeneration. This article reviews the recent advancements in the application of electrospinning nanofibers for bioactive wound healing. The review begins with an overview of the wound healing process and electrospinning methods. It then explores the advantages and disadvantages of different synthetic and natural polymers used in the preparation of electrospinning wound dressings. The natural polymers discussed in this review include collagen, gelatin, silk fibroin, chitosan, hyaluronic acid, and sodium alginate. Additionally, the review delves into commonly used synthetic polymers like polyvinyl alcohol, polyvinyl chloride, polyethylene lactone, polylactide, and polyurethane for wound…

Abstract Superabsorbent polymers (SAPs), sometimes known as hydrogels, have been proposed as soil amendments to enhance soil water management. But the performance of SAPs as soil amendments depends on their stability in soil. Bio‐based SAPs have been praised as environmentally sustainable due to their apparent fast biodegradation relative to synthetic SAPs. But the fast biodegradation of bio‐based SAPs may come at a cost to their long‐term performance for repeated absorption and release of water in the soil. The purpose of this review is to (i) concisely summarize the methods and mechanisms involved in the biodegradation of different bio‐based and synthetic SAPs, (ii) critically review studies conducted on the biodegradability of bio‐based and synthetic SAPs when used as soil amendments, and (iii) discuss the implications of the biodegradability of bio‐based and synthetic SAPs on their physical properties and stability in soil and (iv) identify potential research directions. Understanding the biodegradability of synthetic compared to bio‐based SAPs and their advantages and…

Abstract Owing to their competitive price, ease of processability, and rust resistance, polymers are the most extensively used materials in everyday life. However, consistent exposure to ultraviolet (UV) radiation can lead to the degradation and discoloration of polymeric materials. Various polymer composites containing inorganic and organic nanoparticles (NPs) have been developed to improve the UV‐shielding properties of neat polymers. However, the most used UV‐shielding inorganic NPs are prone to photocatalytic processes, leading to further polymer chain degradation. To overcome this challenge, organic NPs have been used; however, they easily agglomerate, decreasing the UV‐shielding performance of the polymer composites. Herein, we critically report the fundamentals of the UV‐shielding mechanism and the synthesis methods, surface modification, and characterization of the most important inorganic and organic UV‐shielding NPs. We then summarize the various processing techniques used to disperse NPs in polymer matrices to obtain polymer composites with improved UV‐shielding…

Abstract Natural biopolymers (carbohydrates and proteins) are the family of natural polymers that are widely used in wound healing. This is due to their biocompatibility and their chemical structural similarity to the extracellular matrix (ECM). Wound healing is a complex process and requires a multidisciplinary approach and appropriate treatment product to enable a full recovery. Chronic nonhealing wounds significantly caused the reduction. Currently, diabetic and nonhealing wounds are considered the unmet clinical need and a new effective treatment will benefit patients and the economy. This research was aimed to critically review both literature as well as industrial products that used carbohydrates and proteins in wound dressing for the treatment of the wound. The outcome was chitosan (CS), as a carbohydrate, has the most clinical application as it is readily available and affordable, and has shown excellent antibacterial activity. Among proteins, keratin (Kr) can be an option with similar characteristics, however, Kr has not yet found clinical use when compared with CS.

Abstract Viscoelastic materials are commonly utilized in seismic vibration suppression of building structures. Supramolecular modification can extend the effective damping temperature range and improve the damping performance of viscoelastic materials. In present work, the mechanical behaviors of the nitrile rubber viscoelastic material are investigated by dynamic thermomechanical analyzer (DMA) with different strain amplitudes, excitation frequencies and environmental temperatures. The supramolecular interaction and molecular structures modified fractional Kelvin (SMF Kelvin) model taking into account the temperature and frequency impacts is proposed and verified with the DMA test results of the nitrile rubber viscoelastic material. The test results of the viscoelastic damper with different temperatures are employed to further prove the effectiveness of the new proposed SMF Kelvin model.

Abstract Advanced materials are among the prime drivers for technological revolutions and transformation in quality of lives. Over time, several modification techniques have emerged enabling development of novel materials with extraordinary features. The present review aims to introduce various promising chemical and physical surface modification techniques instrumental for tailoring the characteristics of thin films and membranes. Meticulous discussions are provided over chemical vapor deposition (CVD) techniques evolved for addressing the demands for materials with desired functionalities. Also, essential criteria for the selection of substrates, modifying and precursor materials for an effective CVD modification are elaborated. Investigations are extended to unraveling the role of various process parameters on the quality and properties of deposition. Special attention is paid to the significance and performance of CVD‐based membranes and thin films for industrial applications ranging from desalination and water treatment to energy and environment, biomedical and life science as…

Abstract Polymeric dielectrics with high dielectric permittivity (ɛ′) and low loss have momentous applications in energy storage devices. In this study, to concurrently improve the ɛ′ and restrain the loss of original Zn (Zinc)/poly(vinylidene fluoride, PVDF), the core@double‐shell structured Zn@ZnO(zinc oxide)@PS(polystyrene) particles were prepared and composited with the PVDF. The impacts of the dual shells on the dielectric properties and polarization mechanism of composites were explored by fitting the experimental data with a Havriliak–Negami (H–N) equation. The Zn@ZnO@PS/PVDF exhibit remarkably higher ɛ′ in comparison to the raw Zn and Zn@ZnO fillers owing to the induced multiple polarizations originating from the combined contributions of the α relaxation of PVDF, slow interparticle polarization and fast intraparticle polarization. More importantly, the ɛ′ of the composites remarkably increases with the PS shell’ thickness, while the loss is still kept at rather low levels owing to the PS shell’ barrier effect on long‐range charges migration. So, the introduction of the PS…

Abstract The present study aims to develop a novel waterborne chitosan‐based coating formulation for slow‐release urea fertilizer. Coating formulations were elaborated by blending chitosan (Cs) and polyvinyl alcohol (PVA) (50/50, wt/wt) followed by the addition of lignin nanoparticles (LNPs) at various loadings (1, 2, 3, and 5 wt% LNPs) to yield viscous coating formulations. Formulations were cast to obtain coating films on which several structural, thermal, morphological, mechanical, and physicochemical characterizations were performed. Results showed that the Cs/PVA‐LNPs (3%) formulation exhibited suitable physicochemical characteristics in terms of the hydrophobic–hydrophilic balance, reduced water vapor permeability, and tolerated elasticity making it suitable to be used for fertilizer coating. Urea granules were coated by Cs/PVA and Cs/PVA‐LNPs formulations under controlled spraying and drying conditions until a good adhesion between the fertilizer and coating was obtained. Coated granules showed a good slow‐release N property over time and results indicated that the…

Abstract Catheters are commonly used in hospital treatment, but most of the medical materials used in the production of catheters are hydrophobic, with high surface friction and weak antibacterial properties, so a large amount of money is spent on the treatment of catheter‐related urinary tract infections worldwide every year. To improve the comfort of patients, weaken the friction and damage between urinary catheters and urethra, and reduce economic burden, coating the urethral catheter surface is a good strategy. Because of the softness, lubricity and functional network structure (load or graft different substances) of hydrogel, it has a wide range of applications for medical devices. In recent years, the studies of hydrogel coatings in urethral catheters have received more and more attention. This review mainly summarized the research progress of hydrogel coating in recent years, including its function and the method of guiding the grafting of hydrogel to the substrate, and the prospects in the future.

Abstract Poly(ether ketone ketone) (PEKK) is a thermoplastic of the poly(aryl ether ketone) (PAEK) family, with excellent mechanical and thermal performances and high chemical resistance properties. This makes it an appealing material in high‐performance applications as a replacement for poly (ether ether ketone) (PEEK). PEKK was thus selected in this study as a base material for application in 3D printing. The effects of nozzle temperature, layer orientation and layer thickness on the final properties of 3D‐printed PEKK parts were investigated. Furthermore, we assessed the mechanical and morphological features of printed samples through tensile tests and scanning electron microscope, respectively. Thermal properties of samples were also evaluated through DSC and DMA analysis. Optimum printing parameters were found at 0.15 mm layer thickness, 380°C nozzle temperature, and [45/−45°] layer orientation. The printed PEKK samples were annealed at various temperatures to allow the relaxation of residual stress and enhance the degree of crystallinity. Samples annealed for 1 h at 240°C have…

Abstract The present work is an attempt to study the effect of different surface treatments of flax fiber on the mechanical properties of the natural fiber reinforced natural rubber (NR) composites. In this study, flax fiber was chopped to 1, 1.25, and 1.5 cm in length and mixed with NR in two roll mill. The composite of 20%, 30%, 40%, and 50% fiber loading was prepared from each fiber length. Tensile analysis showed that a 1.25 cm fiber length composite of volume 40% has higher tensile strength compared to others. Hence, this optimized the fiber length and loading has opted for further study. Flax fiber was treated with NaOH and laccase and reinforced into an NR matrix. Properties like tensile strength, hardness, relative density, water diffusion, scanning electron microscope (SEM) and Fourier‐transform infrared spectroscopy (FTIR) for surface treated and untreated natural fiber‐reinforced NR composites have been investigated and compared. The reduction in the hydrophilic characteristics of the NaOH and laccase treated fiber was evident from FTIR analysis and increase in the…

Abstract This research article aimed to assist the works conducted to save water resources, which are rapidly depleted as a result of climate change by eliminating toxic chromium ions Cr(VI) from simulated solution. In this regard, chitosan/Na‐alginate/polyacrylic acid (CS/Na‐Alg/PAAc) and Ni/chitosan/Na‐alginate/polyacrylic acid (Ni@CS/Na‐Alg/PAAc) were created as eco‐friendly hydrogel composites via gamma radiation. The hydrogel matrix served as a basin for the in‐situ formation of Ni nanoparticles. The prepared composites were characterized by the FTIR and XRD analyses. The surface morphology of the nanocomposite was also verified via the SEM. It exhibited a dense packing of the Ni nanoparticles representing about 2.5% of the atomic percentage depicted by the EDX analysis. The swelling performance was investigated versus different pH values and the maximum swelling percent was attained as a non‐Fickian character at pH = 13 and 5 for CS/Na‐Alg/PAAc and Ni@CS/Na‐Alg/PAAc, respectively. Furthermore, the surface topographies of CS/Na‐Alg/PAAc and Ni@CS/Na‐Alg/PAAc loaded with Cr(VI)…

Abstract Epoxy resin (EP) has excellent comprehensive properties, but its inherent flammability limits its further application in high‐end industries. The present study focuses on the preparation of an efficient phosphorus/silicon‐containing flame retardant for improving the flame retardancy and smoke suppression of EP. The intermediate product ED was first obtained by the addition reaction of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) with eugenol, and then the target flame retardant DPSi‐ED was synthesized by the Williamson etherification reaction between ED and dichlorodiphenylsilane. The flame retardant was further incorporated into EP/4,4′‐diaminodiphenylmethane (DDM) system to prepare the modified epoxy thermosets. The flame‐retardant performance and mechanism were investigated by limiting oxygen index (LOI) test, vertical combustion test, cone calorimetry, thermogravimetric analysis‐infrared spectroscopy (TG‐IR), and so forth. At the same phosphorus content (0.5 wt%), EP/DPSi‐ED thermosets exhibited superior flame‐retardant properties to EP/ED thermosets.…

Abstract To obtain clean gasoline, a new nanohybrid catalyst (TPA@PAN@CH) was synthesized by immobilizing tungstophosphoric acid (TPA) on the surface of polyaniline (PAN) and chitosan (CH) polymers. The features of the materials were detected by FT‐IR, UV/vis, XRD, FE‐SEM, and EDX methods. The XRD patterns demonstrate that the average crystallite size of the TPA@PAN@CH is estimated to be approximately 45 nm, which corresponds to the results of the FE‐SEM. The catalytic performance of the TPA@PAN@CH was tested in the nano‐catalytic oxidative desulfurization (Ncat‐ODS) of gasoline and model fuels by H2O2/AcOH (volume proportion of 2:1) oxidizing agent. The best desulfurization outcomes were achieved by 0.1 g of the TPA@PAN@CH as a nanocatalyst at 35°C under mild reaction conditions. Based upon the above findings, the sulfur content could be declined from 0.4986 to 0.0193 wt%, which corresponds to performance of 96%. Mercaptan concentration decreased from 98 to 4 ppm, and the removal efficiency of model fuels declined in the order of DBT ≥ BT > Th. The high catalytic activity of…

Abstract This work evaluated the reprocessing of PLA with a high melt flow index (MFI). PLA samples were prepared by extrusion using a chain extender (Joncryl ADR‐4368) and subjected to two additional extrusion cycles with or without exposure to accelerated weathering. The results showed drastic affectations of PLA properties by weathering. The MFI increased from 65 to 137 g/10 min by reprocessing, while reprocessed and weathered samples reached a MFI of 417 g/10 min after three extrusion cycles. The addition of Joncryl prevented PLA degradation (MFI of 170 g/10 min after three extrusion cycles, even when weathering was performed). Additionally, the tensile strengths of weathered samples were substantially decreased (67%) compared to only reprocessed samples (14%). In this sense, PLA mechanical recycling is a good alternative if it is not exposed to harsh weathering conditions, in which case a chain extender is needed to get reasonable properties. Otherwise, reprocessing accelerated the composting of PLA, and the chain extender addition did not limit it.

Abstract Fluorinated graphene (FG) is a derivative of graphene with excellent insulating properties, however, the dispersion performance of FG in organic coatings is still a challenge in anti‐corrosion applications. This study aims to propose a simple strategy to effectively improve the dispersion of FG towards enhancing its interfacial compatibility with epoxy resins. FG was modified with amino‐containing 3‐aminopropyl triethoxysilane (APTES) and epoxy terminated 3‐glycidoxypropyl trimethoxysilane (GPTMS). The chemical compositions and microstructures of FG and the silane‐modified FGs were effectively characterized. Moreover, the corrosion resistance and anticorrosion mechanisms of the epoxy coatings modified by FG and silane‐modified FG were systematically studied, and the results showed that the silane coupling agent effectively improved the dispersion of FG in the epoxy coating and enhanced the interface interaction between FG and the epoxy resin, thereby improving the barrier properties of the epoxy coating and preventing the penetration of the corrosive medium. Electrochemical…

Abstract In this work, a novel functional polylactic acid (PLA) was prepared by melt blending using epoxy Joncryl ADR 4468 (ADR) as chain extender. The effects of the epoxy chain expander ADR on the molecular structure, crystallization properties, rheological properties, and mechanical properties of PLA were studied. Furthermore, the chain expansion mechanism was analyzed. It was found that the epoxy group of the epoxy chain extender reacted with the terminal hydroxyl and terminal carboxyl groups of PLA in the molten state, thus significantly increasing the molecular weight of PLA. Meanwhile, the weight average molecular weight of PLA increased by 42.51% when the maximum additional amount of epoxy chain extender was 1.2 wt%. The dynamic rheological experiments also confirmed that ADR can effectively improve the storage modulus, loss modulus and complex viscosity of PLA systems and the Cole‐Cole diagram reveals the branched structure of PLA chain expansion systems. The formation of this branched structure will destroy the regularity of the PLA chain, reduce the crystallization…

Abstract An increasing trend in creating materials with a greater extent of sustainability from an ecological and financial perspective involves usage of bio resources and industrial residues. In this paper, leftover bamboo micro particles (BMP) from bamboo factories were collected and used as fillers with polyvinylidene fluoride (PVDF) matrix in varying concentrations (1, 3, 5, 7, and 9 wt.%) to fabricate low‐cost composite films using solvent casting route for mechanical energy harvesting purpose. Out of the prepared samples, PVDF with 5 wt.% BMP showed maximum electroactive phase content (82%), tensile strength (34.23 MPa), and piezoelectric voltage (6.5 V) among the untreated samples. PVDF with 5 wt.% BMP is then subjected to NaOH treatment for further enhancement in overall performance. PVDF with 5 wt.% treated BMP also showed 467% increment in output voltage and 235% increment in output current as compared to pure PVDF. The piezoelectric output voltage of PVDF with 5 wt.% treated BMP is then measured under impact loading conditions to determine its suitability as an impact…

Abstract In tissue engineering technique, a biological scaffold with appropriate composition and structure for promoting growth and differentiation of cells thereby regenerating damaged tissue, is a prime necessity. In this paper, 3D‐printed scaffolds comprising sodium alginate (SA) and chitosan (CH) biopolymers of natural origin are reported. Bioinks with varying ratios of SA and CH were prepared and scaffolds were fabricated by 3D printing. The fabricated scaffolds possess many desired properties that are vital for tissue regeneration purposes. The scaffolds possess open pore microstructures with interconnected pores and desired pore size as revealed by scanning electron microscopic image analysis. The polyelectrolyte complex formation (PEC) between SA and CH as revealed by Fourier‐transform‐infrared spectroscopic analysis is favorable as it offers a better surface for cell attachment and proliferation, and an ideal microenvironment for bone regeneration. Among the scaffolds, SA/CH with 60:40 showed controlled swelling and degradation behavior, with higher tensile strength of…

Abstract Additive manufacturing technique fused filament fabrication (FFF) has found widespread usage in a variety of sectors, because of its ability to produce parts with arbitrary geometries and intricate internal structures. This study focuses on the characterization of polylactic acid (PLA) and polyethylene terephthalate glycol (PETG) composites under compressive force to learn more about how various nozzle diameter (ND) and infill pattern (IP) affect the fabricated specimens. The specimens are created with various combination of IPs (triangular, honeycomb, and rectilinear) and NDs (0.2, 0.4, and 0.6 mm) utilizing three polymer composites namely carbon fiber filled PLA (CF‐PLA), carbon fiber filled PETG (CF‐PETG), and multi walled carbon nano tubes filled PLA (MWCNTs‐PLA). According to the findings, the higher ND improves the compressive properties of the polymer composites. The IP also has significant impact on the compressive properties of the fabricated specimens. The overall minimum compressive strength of 14.612 MPa at ND 0.2 mm and honeycomb IP for CF‐PLA specimen. The…

Abstract The packaging insulation material was a crucial component to guarantee the stable and safe operation of electronic devices. Epoxy resin, one of the most popular packaging materials, was widely used as an electronic packaging material because of its good corrosion resistance and electrical insulation, low price, and easy processing and molding. However, the unsatisfied heat resistance cannot meet the requirements of the rapid development of third‐generation power semiconductors, so it was meaningful to modify the epoxy resin with both excellent heat resistance and insulation. In this paper, tetrafunctional epoxy resin AG70 and phenolic epoxy resin F51 was blended in different proportions to combine their individual advantages, and the microstructure and electrical/thermal properties of epoxy resin blends had been systematically studied. The results showed that with the increase of blending ratio of AG70 with F51, both high glass transition temperature of 213.3°C and electric breakdown of 206.1 kV/mm were achieved when the blending ratio was 5:5, displaying excellent overall…

Abstract High‐performance fibers developed since the 1960s have a wide range of applications including firefighters' protective clothing. Firefighters' protective clothing made of inherently flame‐resistant high‐performance fibers offers excellent protection in the new condition. However, these fibers experience aging as any polymer material. The situation is amplified due to the severe conditions associated with the firefighters' activities. And the consequences of a loss in the performance of the protective clothing can be dramatic for the firefighter's safety. This article provides a comprehensively review of the aging behavior of high‐performance fibers used in firefighters' protective clothing. Residual performance data have been identified both for used firefighter garments as well as fabric specimens subjected to accelerated aging. Research shows that different aging conditions affect the different fibers to a different degree. The specific conditions in which the aging is applied also affects the outcome in terms of loss in performance. Techniques successfully used to…

Abstract In the proton exchange membrane fuel cell, proton exchange membrane (PEM) serves as both the main conductor of protons and the fuel‐blocking membrane. Thus, high proton conductivity and excellent stability are expected for PEMs at the same time. According to chemical structure, this review divides PEM into three groups. Recently, high‐performance PEM has been made possible by controlling chemical structure, organic–inorganic hybrid composite membranes, and nanofiber composite membranes. One of them, nanofiber composite membranes, is distinguished by long‐range order and is capable of achieving both strong proton conductivity with exceptional stability. The high‐performance PEM has been accomplished by the presence of an acid‐rich layer, acid–base interaction, and proton transport channel in PEMs are also summarized in this paper. We believe that our discussion will help the researcher create high‐performance PEM and pave the way for further developments in the field of energy materials as a whole.

Abstract The synthesis and application of the bio‐derived flame retardant can meet the current requirements for the high‐efficient and sustainable development of flame retardants. Therefore, using phytic acid (PA), 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO), and piperazine as raw materials, a PA‐derived flame retardant (PAPDOPO) was prepared. Fourier transform infrared spectroscopy and x‐ray diffraction techniques were applied to characterize the structure of the PAPDOPO. In the prepared flame‐retardant epoxy resin (FEP), PAPDOPO showed high flame retardancy. When 4% PAPDOPO was added into epoxy resin (EP), the prepared FEP (EP‐PAPD‐4) passed the V‐0 level in the UL‐94 test, and the limited oxygen index value of EP‐PAPD‐4 reached 35.3%. Microcombustion calorimetry test was also applied to demonstrate the performance of PAPDOPO. The peak heat release rate of EP‐PAPD‐4 was reduced by 30.4% compared with that of the pure EP. Due to the low addition amount of PAPDOPO in FEP, the mechanical properties of the FEP using PAPDOPO as flame retardant were hardly decreased…

Abstract Varying graphene nanoplatelet (GNP) and hexagonal boron nitride (h‐BN) based fillers were integrated to an aerospace grade epoxy resin typically used as matrix to obtain or repair structural parts of aerospace platforms. The three‐roll milling approach was used for this purpose. Five cycles were performed for the mixing while the gap between rollers was 50 μm. Microstructure and thermal properties of the nanocomposites were studied. Moreover, mechanical and transport (electrical as well as thermal) performances were investigated. Results show that certain fillers yield multifunctional properties, that is, enhanced flexural strength by up to 69% in combination with high electrical conductivities with orders of magnitude of approximately and improved thermal conductivities up to 9.3%. For instance, the hybrid nanocomposite sample produced with 0.5 wt% GNP and 0.5 wt% h‐BN added to the epoxy matrix exhibits an electrical conductivity which increased fold, a flexural strength increased by 69% and thermal conductivity increased by 7% in comparison the neat epoxy. Hence, in this…

Abstract In this work, a novel UV‐curable polyurethane acrylate (PUA) oligomer was developed from castor oil (CO). Reaction monitoring and structures of the PUA oligomer were characterized by Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR). Subsequently, a series of UV‐curable resins were prepared by combining PUA with different reactive diluents, and their effect on thermal and mechanical properties was investigated. From the overall characterization trend, it was observed that the formulation containing trimethylolpropane triacrylate (TMPTA) showed the highest mechanical strength and thermal stability. Whereas the formulation containing isobornyl acrylate (IBOA) showed the least performance, and dipropyleneglycol diacrylate (DPGDA) showed properties ranging between TMPTA and IBOA. Furthermore, incorporating 1% TiO2 into the formulation increases the resin's viscosity and mechanical properties without disturbing its thermal stability. This work offered a simple method to prepare vegetable oil‐based high‐performance PUA resins that could be used in the 3D…

Abstract It is crucial and significant to boost the utilization of renewable resources and exploitation of biodegradable materials alternative to petrochemical plastics. Waste paper, mainly composed of cellulose (82–95 wt%) and derived from the lignocellulose, is a type of abundant, renewable, and biodegradable resource, whose recycling use and conversion to high value‐added products can reduce the pressure on the environment and exert immense economic benefits. Herein, four kinds of common waste paper (e.g., printing paper, newspaper, straw paper and roll paper) were converted into cellulose‐based bioplastic membranes by using ionic liquid 1‐butyl‐3‐methyl‐imidazolium chloride as solvent. The cellulose‐based membranes are smooth and compact, and their mechanical strength is prominently improved about 3–100 times comparison with the original paper. The maximum tensile strength of the film (F4) is over 127 Mpa and its optical transmittance reaches 80% at 450–800 nm wavelength. Besides, this kind of cellulose‐based films have excellent biodegradability. Thus, the results demonstrated…

Abstract In this study, the extrusion process of PLA/P(3HB)(4HB) blends was studied and the effect on mechanical, thermal and physical properties of the blends containing increasing amounts of P(3HB)(4HB) was evaluated. The blends were prepared by means of a twin screw extruder and subsequently film samples were manufactured using a lab scale cast extruder. A potential industrial application of the studied materials was also validated by testing the films on a pilot thermoforming machine for the production of food containers. The extrusion process demonstrated good processability of blends containing 10%, 20%, and 30% of P(3HB)(4HB). Increasing the amount of P(3HB)(4HB) up to 40% and 50%, processability problems occurred related to tackiness of the materials both during extrusion compounding and during cast extrusion. Both granules and films were characterized and thermo‐physical and mechanical properties of the samples are hereinafter reported. The novel polymeric blends are found to be suitable for extrusion compounding, cast extrusion and thermoforming processes. Moreover, the…

Abstract Polymers offer unique functional properties that lead to some novel applications every other day. Bioactive polymers with high degree of biodegradability, nonimmunogenicity, and biocompatibility are considered for applications in wound healing. The most basic form of wound protection is by gauge dressing that isolates the wound from contaminants. Natural polymers for example, cellulose, alginate, chitosan, starch, dextran, gelatin, hyaluronic acid, glycan, collagen, and synthetic polymers including polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP) are candidates for these applications. Biopolymers, when applied as wound dressing promote tissue healing and repair by (i) regulating the moist environment, and (ii) providing the needed growth factors, while offering anti‐inflammatory, immune‐modulatory, and cell proliferative properties. It induces hemostasis via direct interaction with erythrocytes and platelets. These polymers in cross linked state offer a scaffold for cell proliferation, differentiation, and cell…

Abstract In vanadium redox flow battery (VRFB). Sulfonated poly(ether ether ketone) (SPEEK) is viewed as a promising alternative to Nafion as a material for vanadium liquid flow battery membrane, due to its low cost and high proton conductivity. However, SPEEK membranes have a Trade‐Off effect of proton conduction and ion selectivity, which limits the performance of VRFB. Here, we exploited the Donnan effect of imidazole cations in ionic liquids (ILs) to improve the ion selectivity of SPEEK membrane. In addition, used porous covalent organic framework materials (COF) with sulfonic acid functional groups to immobilize ionic liquids, which reduced the loss of ILs. The ion selectivity of the SPEEK membrane was further improved. As a result, the cell performance of the composite membrane is improved. At a constant current density of 40 mA cm−2, SPEEK/IL‐5@TpPa‐SO3H‐3 membrane exhibits high coulombic efficiencies (CE: 98.43%) and energy efficiencies (EE: 91.7%). Furthermore, the energy efficiency of the SPEEK/IL‐5@TpPa‐SO3H‐3 membrane decreases only 2.1% after 60 charge/discharge cycles…

Abstract Based on the irresistible inherent trade‐off between the mechanical and self‐healing performances of cross‐linked polyurethane materials, there is still an intractable challenge to design efficient self‐healing and tough elastomers, especially in flexible sensors. Herein, a tough, efficient self‐healing, and recyclable cross‐linked polyurethane elastomer (DTPU) was prepared by integrating oxime‐carbamate bonds and thiourethane bonds into the network. The extraordinary mechanical properties and self‐healing performances of DTPU elastomers were related to the synergistic effect of oxime‐carbamate bonds in the main chain and thiourethane bonds in the chemical cross‐linked sites. The existence of dynamic cross‐linked points not only optimized the mechanical properties of DTPU but also provided support for the reversible cleavage and formation of oxime carbamate bond, thus endowing DTPU with efficient self‐healing performance and recyclability. After self‐healing at mild temperatures for 6 h, the self‐healed DTPU elastomers had a tensile strength of 30.27 MPa and a self‐healing…

Abstract In recent years, the widespread use of 3D printing technology in various industries has highlighted the crucial issue of how 3D printed polymers behave mechanically when subjected to stress relaxation. The time‐independent mechanical properties of these polymers, as well as their stress relaxation behavior, are both affected by the 3D printing parameters used. Therefore, this study examines the stress‐relaxation behavior of PLA under tensile and bending loading modes, specifically investigating how different raster orientations affect this behavior. The findings indicate that the ±45° infill orientation had the least amount of relaxation in both tensile and bending modes compared to the other orientations. Additionally, there was higher stress relaxation in the bending loading mode across all infill orientations. The findings indicate that the experimental duration should exceed 750 s to achieve an accurate model, as both Maxwell‐Weichert elements contribute to stress relaxation during this period. On the other hand, extending the test beyond 20,000 s is not necessary since…

Abstract To comparatively investigate the mechanical, tribological, and interfacial properties of polytetrafluoroethylene (PTFE) strengthened by graphene (Gr) and hexagonal boron nitride (h‐BN) nanosheets, molecular models of PTFE nanocomposites containing a similar weight fraction of Gr and h‐BN nanosheets were established. The constant‐strain approach, the three‐layer friction structures, and the pull‐out simulations were respectively employed to calculate the mechanical, tribological, and interfacial properties of the nanocomposites. Results indicate that the Young's, shear, and bulk moduli of the nanocomposites are increased by 17.22%, 20.72%, and 4.78%, respectively, by introducing h‐BN nanosheets than those by introducing Gr nanosheets. Meanwhile, a decrease of 8.49% in the friction coefficient of the nanocomposites is obtained by incorporating h‐BN nanosheets than that by incorporating Gr nanosheets. In addition, 84.71% and 5.18 times higher in the interfacial cohesive strength and interfacial shear strength, and 91.58% and 128.7% higher in the interfacial fracture toughness…

Abstract This study aims to enhance the flame retardant efficiency and thermal stability of low density polyethylene (LDPE) by using halogen‐free inorganic additives. To prepare the highly loaded flame retardant polymer composites, LDPE melt mixes with magnesium hydroxide and magnesium carbonate at different weight ratios using a twin‐screw extruder. The composites are characterized by thermogravimetric analysis, crystallinity degree, tensile strength, morphological analysis, limiting oxygen index and UL‐94 vertical burning test. An optimum MH/MC weight ratio of 60/40 provides satisfactory composite properties with increased maximum thermal degradation temperature from 472.3 to 483.5°C, the highest LOI value of 32.5% and a UL‐94 V‐0 rating without melt dripping. The homogeneity of this composite is improved by using a polymeric compatibilizer, MAH‐g‐PE and an enhancement in tensile strength, elongation at break and elastic modulus values of 33.68%, 33.02% and 23.55%, respectively, are obtained. In order to create synergism between the flame retardant additives, 1, 3 and 5 wt% zinc…

Abstract DOPO based flame retardants demonstrate exceptional flame retardancy efficiency when applied to epoxy resins. However, the crosslinking degree of epoxy resin may decrease due to the addition of DOPO, leading to a deterioration in flame retardancy and mechanical properties. Herein, a reactive DOPO derivative flame retardant 6‐((1H‐benzo[d]imidazol‐2‐yl) amino) dibenzo oxaphosphinine 6‐oxide (BADO) was successfully synthesized, which contains multiple reactive sites, thus ensuring a higher degree of crosslinking in the system. As a result, the modified epoxy resin exhibits excellent flame retardancy. The limiting oxygen index value of the modified epoxy resins increased from 19.8% to 29.7% by adding 7.5 wt% BADO, and its UL‐94 test passed V‐0. Flame retardancy mechanism analysis reveals that BADO exhibits both gas‐phase and condensed‐phase flame retardant effects. In particular, the formation of a porous inside‐char layer is a significant factor in reducing smoke release. The 7.5% BADO/EP composite exhibited a 43.2% reduction in total smoke production and a 43.6% reduction in…

Abstract In this work, the biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT)/poly(lactic acid) (PLA) blend (ECOVIO®) and lignin, a renewable and biodegradable natural polymer with high UV absorption and modified by gamma radiation were used to produce agriculture mulch films. Lignin was gamma‐irradiated at 30 and 60 kGy. The irradiated and non‐irradiated lignin content of 2 wt% was incorporated into PBAT/PLA blend matrix using a twin‐screw extruder and extrusion blown film to prepare flexible films. PBAT/PLA/LIGNIN films were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), x‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), tensile tests, contact angle, and UV–Vis analysis. FTIR spectra showed partial miscibility between PBAT/PLA and lignin, being intensified in irradiated lignin compounds. The DSC and XRD results confirmed that the degree of crystallinity of the blends was not significantly influenced by lignin addition. FE‐SEM images showed better dispersion and miscibility in…

Abstract Membrane separation is one of the techniques used for biogas upgradation. Mixed matrix membranes (MMMs) are currently being explored to overcome the trade‐off of selectivity‐permeability inherent in polymer membranes used for gas separation. A significant challenge associated with MMMs is the poor polymer‐metal–organic framework (MOF) filler interfacial compatibility, reducing the selectivity or permeability of gas. To address this issue, the present study focuses on the effect of the amine functionalization of ZIF‐8 to enhance the CO2 gas permeation without reducing the CO2/CH4 selectivity. MMMs were fabricated using unmodified ZIF‐8 and amine‐modified ZIF‐8 nanofillers dispersed in polysulfone at 5, 10, and 15 wt% loadings. MMMs were characterized by FTIR, DSC, TGA, and FESEM. X‐ray diffraction and FTIR analysis was conducted to verify the amine modification of ZIF‐8. Further, the performance of MMMs was tested with pure gasses (CO2 and CH4) and a model mixture of CO2 and CH4. In the mixed gas permeation test, the 10 wt% ZIF‐8 MMM exhibited the highest CO2 permeability of…

Abstract The low melt viscosity and melt strength of polyglycolic acid (PGA) severely limit its application. In this work, high melt viscosity PGA/PLA blends are prepared by reactive extrusion of bifunctional isocyanate (HDI) and multifunctional epoxy oligomer (ADR) as chain extenders. The use of hybrid chain extender (hCE) containing 2 wt% HDI and 1 wt% ADR results in a long chain branched/cross‐linked structure, thus increasing melt viscosity more effectively than HDI or ADR alone. The complex viscosity, storage modulus and loss modulus of the PGA/PLA/hCE blends are significantly higher than those of the PGA/hCE. The 60PGA/40PLA/hCE has the highest complex viscosity of 72,115 Pa s, which is 69 times of that of PGA/hCE. The modification of hCE significantly improved the mechanical performance of PGA/PLA blend, with the 60PGA/40PLA/hCE having the highest tensile strength and flexural strength. The crystallization temperature and crystallinity of the PGA component in the PGA/PLA/hCE blend are significantly reduced in comparison to that of the PGA/hCE. The PGA/PLA/hCE has the best…

Abstract Ternary blends of polypropylene (PP), high‐density polyethylene (HDPE), and a random copolymer with 85% propylene and 15% ethylene (trade name Vistamaxx 6202, abbreviated here as VM) have been investigated to elucidate the efficiency of this additive in the management of recycling streams. Differential scanning calorimetry showed that VM will induce simultaneous crystallization of PP and HDPE. Polarized Optical Microscopy revealed a breakdown in the spherulitic structure already at 10% of additive (for blends with ratio PP: HDPE = 1:1), respectively 17%, (for PP/HDPE = 7:3). A similar threshold was found in the impact strength, and stress–strain‐curves. This means that VM is also advantageous for recycling of PP: HDPE blends, especially those with high PP content.

Abstract A new hyperbranched sulfonated poly(arylene aliphatic ketones) (HB‐SPAAK) has been synthesized and loaded with titania nanoparticles to obtain HB‐SPAAK/TiO2 nanocomposites for thermally stable proton‐conducting electrolyte membrane fuel cell (PEMFC) applications. The synthesis of HB‐SPAAKs was carried out through the polycondensation reaction of different aliphatic and aromatic acids with simultaneous loss of H2O, trifluromethane sulfonic acid used as catalyst. The long chain hyperbranched polymers and TiO2‐loaded nanocomposites were characterized by FT‐IR, 1H‐NMR, SEM and HR‐TEM. Proton conductivity (PC), swelling ratio, water uptake and oxidative stability. The SEM image of TiO2 NPs and HB‐SPAAKs/TiO2 nanocomposites membrane clearly showed the spherical of TiO2 and porous structure of HB‐SPAAKs with a pore diameter of 2–50 μm. TEM image reveals the uniform particle size distribution of TiO2 nanoparticles having a nanosize of 100 nm. TiO2 loaded polymer nanocomposites showed lower values of W/U and S/R when compared to the unmodified HB‐SPAAK, while 3% TiO2 loaded…

Abstract This work presents the comprehensive characterization of alkali treated areca fruit husk fiber (AAFHF) an industrial agro‐waste reinforced unsaturated polyester resin (UPR) matrix hybrid composite with silicon carbide (SiC) nanoparticles as filler material. Hybrid composite plates were fabricated with 40 wt% of AAFHF and diverse wt% of SiC nanoparticles ranging from 1 to 4 wt% in steps of 1 wt%. The effect of wt% of SiC nanoparticles in hybrid composite over mechanical, morphological, wear, thermal and water absorption characteristics was investigated. The findings help to conclude that a hybrid composite plate with 3 wt% filler content excels in overall properties. Meanwhile, the accumulation and meager scattering of SiC nanoparticles in composite deteriorated the functional characteristics when the wt% of filler content enhanced to 4 wt%. Also, the failure pattern and interaction between AAFHF, SiC nanoparticle and UPR were understood from the images obtained using Scanning Electron Microscopy (SEM). In addition, the availability of functional groups, crystallite size and…

Abstract In this study, the impact of incorporating a plasticizer on the compatibility between organo‐montmorillonite (OMMt) and polylactic acid (PLA) is investigated, and the resulting barrier and mechanical properties are reported. Four polymers were chosen as plasticizers to prepare the PLA nanocomposite blown films: poly(ethylene glycol), poly(ethylene oxide), polycaprolactone (PCL), and random ethylene‐methyl acrylate‐glycidyl methacrylate terpolymer. Firstly, 5 wt% of each plasticizer and 3 wt% of OMMt (Dellite® D43B) were mixed simultaneously with PLA in a twin‐screw extruder and then introduced into the hopper of a single screw extruder to produce D43B‐PLA/plasticizer nanocomposite films. The compatibilization effect was examined based on microstructure observations and thermodynamic predictions. Crystallinity was evaluated using DSC and XRD measurements. The results obtained for permeability and mechanical testing showed that the improvement of barrier and mechanical properties depends directly on the degree of compatibility between plasticizer, OMMt, and PLA. Indeed, the…

Abstract Biaxially oriented polypropylene (BOPP) is the most favorable commercial dielectric energy storage film due to its low dielectric loss and high electric breakdown strength. However, its low dielectric constant always leads to relatively low energy storage density. In this study, we propose an efficient strategy to increase the dielectric constant of BOPP films by laminating with high dielectric polyvinylidene fluoride (PVDF). Utilizing the high dielectric constant of PVDF and optimizing its thickness and layers, the high‐temperature energy storage density at low‐electric field is significantly improved. When the thickness of interlayer PVDF is 5 μm and the total number of stacked layers is 7, the BOPP/PVDF multilayer films deliver excellent high‐temperature energy storage performance. The dielectric constant of BOPP/PVDF multilayer films increases to 3.54, 1.74 times higher than pure BOPP films. At a low electric field of 200 kV/mm, the discharged energy storage density of BOPP/PVDF multilayer films increases to 1.02 and 0.99 J/cm3 at 100 and 125°C. (BOPP ~0.50 and 0.48…

Abstract Epoxy resin has been widely applied in coating preparation, due to its excellent properties. The anti‐corrosion performance improvement of epoxy‐based coatings has attracted much attention. The synergistic effect of the barrier function of two‐dimensional fillers and the slow release of inhibiter has been proven to be an effective way to improve the anti‐corrosion of coatings. In this work, the phytic acid (PA) intercalated hydrotalcite (HT) was fabricated by a one‐pot method. First, HT was synthesized by magnesium nitrate hexahydrate (Mg(NO3)2·6H2O) and aluminum nitrate nonahydrate (Al(NO3)3·9H2O) in the water solution. Subsequently, PA was added to the dispersion to obtain PA intercalated HT fillers (PA‐HT). The obtained PA‐HT fillers were incorporated into the epoxy resin (EP) to prepare the anti‐corrosion coating (PA‐HT/EP). The prepared PA‐HT/EP coating exhibits excellent anti‐corrosion properties at 1 wt% filler loading that the impedance modulus maintains above 109 Ω cm2 after 30 days of soaking in 3.5 wt% NaCl solution. Moreover, the anti‐corrosion mechanism of the…

Abstract The food industry's ever‐increasing need to substitute synthetic packaging materials has led to the development of eco‐friendly alternatives with improved physical and mechanical properties. The main objective of this work relates to the effect of adding different weight fractions (1, 3 and 5 wt%) of cellulose nanocrystals (CNC) and cellulose nanofibrils (CNF) on the morphological, thermal, structural, biodegradable and mechanical properties of PVA/Chitosan (CS) bio‐nanocomposites. The DSC and FTIR results reveal that PVA and Chitosan are compatible due to the strong interactions via hydrogen bonding, which are also proved by the tensile test. The water solubility test indicates the biodegradability of nanocomposites. Furthermore, CNF have significantly enhanced the mechanical properties of PVA/CS. Hence, PVA/CS/CNF nanocomposites can be efficiently utilized for bio‐based packaging materials, where good mechanical properties are prime requirements.

Abstract Efficient utilization of pesticides has presented various advantages in the ecological environment, food safety, and agricultural sustainability. Pesticide microcapsule could significantly improve the pesticide utilization ratio, and thus, we prepared a sustained‐release microcapsule from cellulose nanocrystal (CNCs) stabilized Pickering emulsion template. The NaCl was added to overcome the strong electrostatic repulsion among CNCs for forming a stable oil‐in‐water (O/W) CNCs‐based Pickering emulsion template, followed by crosslinking with hexamethylene diisocyanate on the interface. UV–vis and zeta‐potential were used to characterize the as‐prepared Pickering emulsion, and the stability and emulsion fraction were calculated. Results indicated that NaCl contributed to the stability of Pickering emulsion, even at a low concentration. The obtained CNCs‐based microcapsule was characterized by FT‐IR, XRD, SEM, TG‐DTG, and three‐phase contact angles. The microcapsule presented an encapsulation efficiency of 96.76% and sustained release of the imidacloprid for more than 82 h.…

Abstract Polyethylene (PE) is a convenient and inexpensive polymer that is widely used in daily life. However, PE products are recalcitrant to degradation in the environment, leading to increasing plastic pollution. This has inspired the search for effective microorganisms and enzymes that can biodegrade PE. In this study, a fungal strain that degrades PE was isolated from soil contaminated with plastic and identified as Trichoderma harzianum. The strain was cultured with PE as the sole carbon source for 30 days, and the weight loss of PE particles was 3.39 ± 0.3%. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectra showed holes and oxygenated functional groups on the surface of the degraded PE particles. Gas chromatography–mass spectrometry (GC–MS) detected products with different carbon atom numbers. In addition, a potential PE degrading enzyme was screened from T. harzianum and identified as laccase. After PE was incubated with the recombinant laccase for 96 h, SEM, FTIR, and GC–MS showed the degradation of PE particles. The results showed that T.…

Abstract Polyoxymethylene (POM)‐based composites reinforced with pristine short glass fiber (SGF) and surface modified SGF with silane coupling agent (SGF550) were prepared by a twin‐screw extruder, and then injection molded via various processing, including natural air‐cooling, water‐cooling, and oven heat‐treating. The mechanical properties, micro‐structures of tensile fracture surfaces and crystallization behaviors were investigated. The results indicated that the above properties were tightly related to the interfacial bonding ability. POM composites reinforced with SGF550 can significantly improve the tensile strength by 33%–43% and the elongation at break by 50% and 66%, comparing with POM/SGF. Further considering the thermal post‐treatments, prompt water‐cooling can induce insufficient crystallization and form tough amorphous regions beneficial to lock firmly with SGF550, thus enhancing the mechanical properties. This work commits to propose an idea to improve performance by means of screening different processing techniques, and provide a route to tailor some nature of…

Abstract Flexible capacitive sensors based on silicone rubber have gained importance in both academic and industrial fields due to their advantages, including low power consumption and high stability to temperature, and humidity. However, pristine silicone rubber has a low dielectric constant (), requiring the use of dielectric additives such as TiO 2 , BaTiO 3 , or Sb 2 O 3 ‐doped SnO 2 rutile‐modified particles (ATO) to enhance electrical properties, but they also increase Young's modulus ( E ). To overcome this problem, liquid silicone rubbers (LSR) are commonly used in academic research due to their low E, but they often compromise mechanical integrity. In contrast, high‐consistency silicone rubbers (HCR), the industry commodity, maintain mechanical integrity even at high filler loadings but are limited in their use in dielectrics due to high E values. This paper explores the potential of vinyl‐terminated HCR for developing dielectric composites with high electromechanical response, with an improved and a reduced E while retaining mechanical and processability properties. The…

Abstract An anticorrosive organic coating of epoxy on carbon steel (CS) was modified with uniformly dispersed graphene oxide (GO) after functionalization with ionic liquid (FGO). The ionic liquid (IL) used was 1‐butyl‐3‐methylimidazolium acetate which possess higher solubility and the graphene oxide was prepared by improved Hummer's method. The successful grafting of IL on the GO was confirmed by various techniques including Fourier‐transform infrared spectroscopy, Raman, XPS, x‐ray diffraction, thermogravimetric analysis, BET, field emission scanning electron microscope, and fidle emission transmission electron microscope. The surface characterization studies revealed that uniform dispersion of FGO is achieved in the epoxy matrix. Further, electrochemical studies such as potentiodynamic polarization, and electrochemical impedance spectroscopy showed higher corrosion protection efficiency (~99%) against corrosive fluid (3.5 wt% NaCl solution). This approach may offer an easy, ecologically benign way to create a new candidate coating for the protection of CS.