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Ethylene-propylene-diene monomer rubber, grafted with maleic anhydride functions (EPDM-g-MA) was organically reinforced by reactive extrusion from the in situ synthesis of a polyimide (PI) phase. The blends were reactively processed at 200[degrees]C in a twin-screw extruder, with the PI content varying from 5 to 40 wt%. Transmission Electron Microscopy (TEM) revealed a very fine nodular dispersion of the PI phase with diameters ranging from 130 to 240 nm depending on the PI concentration. The reinforcement of the elastomer was evidenced with a sharp increase of the Young's modulus and the tensile strength, and the stiffness of the material was further increased with the PI content. The linear viscoelastic regime, as measured by the variation in storage modulus as a function of strain, was unaffected by this organic reinforcement, thus opening up an original way of controlling the Payne effect. Additionally, the cross-linking of the blend with 20 wt% of PI with dicumyl peroxide (DCP) showed that the PI phase did not impact the creation of the cross-linked network. The decrease of the swelling ratio and the improvement of the elastic recovery suggested that EPDM-g-PI copolymers can create a second network in the material, resulting in a higher apparent cross-linking density. The mechanical properties of the cured blend showed a doubling of the Young's modulus and maximal stress values compared to those obtained for the pure matrix as well as a constant strain at break. Highlights * Ethylene-propylene-diene monomer rubber, grafted with maleic anhydride functions (EPDM-g-MA) was organically reinforced by reactive extrusion. * The reinforcement was obtained from the in situ synthesis of a polyimide (PI) phase. * The Young's modulus of cross-linked EPDM containing 20 wt% PI was doubled. * The linear viscoelastic regime was unaffected by this organic reinforcement. * This original way of reinforcement opens the control of the Payne effect. KEYWORDS EPDM, in situ polymerization, polyimide, reactive extrusion, reinforcement, 1 | INTRODUCTION Ethylene-propylene-diene monomer rubber (EPDM) is one of the most widely used synthetic rubbers. The presence of diene enables sulfur vulcanization or peroxide cross-linking with a high efficiency. [...]

Herein, the impact modifier of poly(butyl acrylate) grafted poly(styrene-coacrylonitrile) (PBA-g-SAN) with 60% rubber content was prepared by emulsion grafting polymerization and subsequently blended with styrene-acrylonitrile copolymer (SAN) resin to construct acrylate styrene acrylonitrile (ASA) resins. The effects of acrylonitrile content of PBA-g-SAN copolymer and PBA size on the ASA resins' mechanical properties were investigated. Experimental results revealed that ASA resin's highest impact strength reached 27.75 kJ/[m.sup.2]. The lap shear adhesion test suggested that the PBA-g-SAN copolymer with 21% AN content exhibited excellent interfacial adhesion with SAN resin. The PBA-g-SAN particles with 100 and 400 nm poly (butyl acrylate) as core rubbers demonstrated a synergistic toughening effect for SAN resin. The high blackness ASA resin with excellent impact resistance was obtained when the 100 nm and the 400 nm poly (butyl acrylate) particle mass ratio reached 8/2. Highlights * The ASA resin with 27.75KJ/[m.sup.2] impact strength was prepared. * The synergistic toughening mechanisms were investigated. * The high blackness ASA resin was constructed. KEYWORDS ASA resin, high blackness, impact modifier, interfacial adhesion, particle size distribution, synergistic toughening, 1 | INTRODUCTION Toughening of polymer materials, such as polycarbonate (PC) and styrene-acrylonitrile copolymer (SAN), has been widely studied, and these materials have been rapidly developed in recent decades due [...]

In this study, dynamically vulcanized thermoplastic elastomer nanocomposites consisting of polypropylene (PP) as the thermoplastic matrix, ethylene propylene diene monomer (EPDM) rubber as the dispersed phase, and needle-like cellulose nanocrystals (CNC) were investigated. The two polymers were melt blended in a ratio of 70/30 (PP/EPDM) and 60/40% w/w (PP/EPDM) together with CNC (2, 3, and 5 phr) and sulfur-curing system. The potential of EPDM-g-MA and PP-gMA's as interfacial compatibilizers for enhancing interfacial interactions between components and partitioning of CNC between the two polymer phases was examined by measuring the decrease in the size of EPDM particles. The resulting thermoplastic vulcanizates (TPV) were characterized using a melt rheometric mechanical spectrometer (RMS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and tensile tests. The inclusion of any type of interfacial compatibilizers led to enhanced tensile properties when compared to the samples lacking compatibilizers in both TPVs and TPEs in different ratios. EPDM-g-MA was found to be more effective for 60/40% w/w (PP/EPDM) TPVs, while PP-g-MA showed higher potential for 70/30% w/w TPVs. The CNCreinforced TPVs displayed higher melt elasticity than their unloaded counterparts. These nanocomposites also showed reduced EPDM particle size, enhanced Young modulus, and a higher degree of crystallinity. Highlights * Nanocomposite thermoplastic vulcanizates (TPVs): polypropylene (PP)/ ethylene propylene diene monomer (EPDM)/cellulose nanocrystals (CNC) with matrix-dispersed morphology. * Interfacial enhancement: Compared EPDM grafted maleic anhydride (EPDM-g-MA) and PP-g-MA potentials. * Tensile properties: EPDM-g-MA is more effective in higher rubber content TPVs. * Mechanical enhancements: Improved properties and Young's modulus in CNC-filled TPVs. * Diverse applications: PP/EPDM/CNC nanocomposites in auto, electrical, electronic, and packaging industries. KEYWORDS cellulose nanocrystal, dynamically vulcanized, ethylene propylene diene monomer, interfacial compatibilizer, polypropylene, thermoplastic elastomer, 1 | INTRODUCTION A 'polymer blend' refers to a material resulting from the combination of two or more structurally different polymers, this blending technique, commonly employed for cost-effective enhancement of [...]

Sortation is a crucial step in the mechanical recycling of post-consumer plastics (PCR) whereby properties such as density or spectral signature are used to separate plastics. However, it is difficult to sort polyolefin flakes at high throughput by these properties. We ask whether the frictional properties of plastics as a function of temperature may be used as an alternate sorting property. However, fundamental studies of friction at temperatures near their melting points are limited. Here we measure the temperature dependence of kinetic friction for three common polyolefins (high and low-density polyethylene and polypropylene) as well as polyethylene terephthalate (PET), focusing on the softening/melting regime. The results are augmented by differential scanning calorimetry and temperature-dependence measurements of both dynamic modulus and probe tack. For the polyolefins, we find strong increases in the coefficients of kinetic friction during temperature ramps in the melting/ softening regime. For the PET, we report a notable peak in the kinetic friction which we associate with the glass transition and cold-crystallization. We discuss the enhanced friction in the context of rubber friction, which exhibits comparable coefficients of kinetic frictions. Highlights * Significant upturn in kinetic friction coefficient of polyolefins near melting point * Strong peak in kinetic friction coefficient of polyethylene terephthalate (PET) above glass transition * Correlation of upturns with thermal and mechanical properties and tack * High friction state is analogous to rubber friction * High friction state is a possible mechanism for plastics sortation. KEYWORDS friction, polyolefins, recycling, sorting, thermoplastics, 1 | INTRODUCTION The international efforts to increase plastics recycling rates are driven by the need to reduce plastic pollution, to keep valuable materials within the working economy, and to [...]

Ethylene-propylene-diene monomer (EPDM) rubber has widespread uses in various applications due to its ozone and oxidation stability, weatherability, electrical insulation, and elasticity. However, its further use is limited by low flame retardancy and low thermal stability. This study incorporated metal hydroxide flame retardant to enhance flame retardancy and electron beam cross-linking to simultaneously enhance mechanical properties, thermal stability, and flame retardancy. The utilization of electron beam irradiation resulted in an increase in gel content and a decrease in swelling ratio with increasing absorbed doses, indicating the successful formation of cross-linked network structures. The hot-set elongation was significantly reduced to 0.6%-0.8%, while the decomposition temperature increased with increasing absorbed doses, indicating improved thermal stability. The results from limiting oxygen index measurements and burning tests demonstrate that the flame retardancy of EPDM was improved by the combined effect of metal hydroxide flame retardant and electron beam cross-linking. Highlights * EPDM/metal hydroxide composites were prepared via electron beam irradiation. * Metal hydroxide flame retardants were incorporated to enhance flame retardancy. * EBI simultaneously enhanced mechanical property and thermal stability. KEYWORDS cross-linking, electron beam irradiation, ethylene-propylene-diene monomer rubber, gel content, limiting oxygen index, mechanical property, thermal stability, 1 | INTRODUCTION Ethylene-propylene-diene-monomer (EPDM) rubber is a versatile synthetic rubber composed of ethylene, propylene, and a small amount of unsaturated dienes, such as ethylidene norbornene (ENB), dicyclopentadiene (DCPD), and [...]

Abstract This study investigated novel methods for treating the surface of nitrilebutadiene rubber to enhance its stability and resistance to thermal oxidation and aggressive media. The rubber surface was modified [...]

The self-healing performance of epoxidized deproteinized natural rubber (EDPNR) and EDPNR/graphene oxide (GO) composites was investigated. Composites of EDPNR25 and EDPNR50 with GO contents of 0.5 and 1.0 phr were prepared by adding a GO dispersion into a EDPNR latex and the product was subsequently cast into films. Tensile strengths of the original samples and after self-healing were used to evaluate self-healing performance. The tensile strength of EDPNR25 after self-healing achieved about 65% of tensile strength of original EDPNR25. The recovery of tensile strength for the composite increased to 81% for EDPNR25/GO0.5 and 105% for EDPNR25/GO1.0 for self-healing at 25[degrees]C for 24 h. At 70[degrees]C, EDPNR25/GO0.5 and EDPNR25/GO1.0 composite achieved ~100% recovery after 24 h. On the other hand, the tensile strength recoveries of EDPNR50, EDPNR50/GO0.5, and EDPNR50/GO1.0 were relatively low (33%, 28%, and 24%, respectively) at 25[degrees]C. At 70[degrees]C, recoveries increased to 63%, 67%, and 52%, respectively. This result demonstrated that the interdiffusion of epoxidized natural rubber molecules plays a key role in the self-healing performance rather than hydrogen bonds between GO and functional groups on EDPNR molecules. KEYWORDS epoxidized deproteinized natural rubber, graphene oxide, hydrogen bonds, interdiffusion, self-healing, 1 | INTRODUCTION In recent years, humans have been facing environmental problems of discharging thermoset plastics and vulcanized natural rubber (VNR) products since these materials are difficult to be recycled [...]

Thermoplastic materials have received extensive attention for their excellent mechanical properties and reproducibility, and have been emerging in lightweight accessories. However, for the traditional thermoplastic vulcanized (TPV) rubber, the dynamic vulcanization process makes it difficult to achieve low density and good compression performance. Herein, lightweight propylene butene copolymer/ethylene propylene diene monomer (PPB/EPDM) blend foam was prepared by static vulcanization of PPB and EPDM blend and supercritical nitrogen (sc-[N.sub.2]) foaming technology. The minimum density and compression set of the PPB/EPDM blend foam were 0.065 g/[cm.sup.3] and 13.6% respectively, a significant improvement was obtained compared with TPV. In addition, the PPB/EPDM blends retained the mechanical properties after seven times reprocessing, and the blend foam had similar cell structures to that of dynamic vulcanized TPV foam because of the phase transition of PPB/EPDM blend during reprocessing. This work provided an idea for the preparation of high-performance, lightweight, and recyclable thermoplastic materials. KEYWORDS mechanical properties, polymer blends, reprocessing, supercritical foam, vulcanization, 1 | INTRODUCTION Plastic and rubber are two important branches of polymer materials. [1-3] Based on the excellent mechanical properties of vulcanized rubber and the thermoplasticity of plastics, [4] rubber/plastic [...]

Silicone rubber is widely used in industry, dairy products, medical, defense support, and other fields due to its excellent comprehensive properties, which have become one of the most important research objects of high-performance elastomer. Cationic-[pi] dynamic noncovalent bond has attracted more and more attention from material researchers due to its dynamic reversibility and design flexibility and has been applied to different material systems, giving new characteristics to traditional materials. Cationic-[pi]/covalently crosslinked silicone rubber was prepared by one-step method with glycidol propyl terminated polydimethylsiloxane (DMS-E21) as basic polymer, epoxy indole monomer (IN) as crosslinking structure modifier, Europium ion ([Eu.sup.3+]) as cation donor and triethylenetetramine (TETA) as a crosslinking agent. The influence of the reversibility of [Eu.sup.3+]-[pi] interaction on the static and dynamic mechanical behaviors of silicone rubber was studied. The results show that the elongation at break of cationic-[pi]/covalent hybrid crosslinked silicone rubber increases by more than 60% compared with pure covalent crosslinked silicone rubber when the breaking energy reaches the maximum, while the tensile strength increases by more than 100% and the introduction of [Eu.sup.3+]-[pi] dynamic bond can weaken the Mullins effect and the Payne effect on the high temperature of silicone rubber with obvious creep resistance. It shows an excellent mechanical strengthening effect with the characteristic of strengthening and toughening simultaneously and attractive nonlinear mechanical behavior on elastomers. KEYWORDS cation-[pi], mechanical properties, Mullins effect, non-covalent bond, silicone rubber, 1 | INTRODUCTION Silicone rubber is considered an important strategic material because of its superior high and low-temperature adaptability, aging resistance, radiation resistance, and other properties, and occupies an irreplaceable [...]

Highly polar and hydrophilic polymers; ethylene-vinyl acetate (EVA), epichlorohydrin rubber (GECO), and polyethylene oxide (PEO) reinforced with fillers (carbon black (CB) and/or Silica) were used to prepare water-swellable rubber nanocomposites. The study showed that although the high content of the GECO delayed vulcanization of the corresponding compounds, the sample filled with desired ratio of GECO/PEO/EVA or GPE, cross-linked with peroxide exhibited the highest swelling performance of ~150%. The samples exhibited good re-usability performance in the re-swollen test, after drying. At prolonged water swelling, the tensile strength dropped drastically for compounds with high content of the GPE, due to weak filler-matrix interactions. On the other hand, the incorporated GPE also increased the rebound resilience (%) property which is a key requirement in green tire fabrication. For example; peroxide cured sample coded SR3 (GPE-15 phr CB) obtained ~30% resilience in non-swollen state and ~53.5% after 1440 min of water-swelling, which represents a dramatic development of over ~78% in rebound resilience. Thus, a proper balance between the GPE content, curing agent and the reinforcements may guarantee high water-swelling performance and mechanical properties integrity for multifunctional applications such as wound healing, structural works, water collection from oil spillages, and for the development of water-based sensors. KEYWORDS composites, elastomers, mechanical strength and resilient, rubber, swelling, volume expansion, water, 1 | INTRODUCTION The unique properties of visco-elastic polymers which include; strength-to-weight ratio, impact resistance, wear resistance, corrosion resistance, and others can be enhanced when they are reinforced with desired [...]

This paper presents realistic discrete element method (DEM) simulations of mixtures of sand and rubber grains. The shape of the grains and the deformability of the rubber are accounted for in the model. A set of 1D compression tests and triaxial compression tests are performed on samples with different rubber contents. It is shown that the model can accurately predict the mixture behaviour at macro-scale. The insights from a micro-mechanical analysis of force chain network, coordination number, and side-wall friction indicate that deformability plays a key role in exhibiting realistic behaviour. Finally, a new criterion is presented to determine the limits of sand-like and rubber-like behaviour. Key words: Discrete element method (DEM), sand-tire mixture, deformability, sand-like behaviour, side-wall friction, 1. Introduction The disposal of scrap tires has become a global environmental issue. Dumping is not accepted anymore and new options such as retreating, reusing, and recycling are becoming more [...]

The properties of rubber have allowed it to be utilized across many different industries. One of the industries that use rubber is the tire industry. The rubber used in tires affects the performance of the vehicle such as its fuel consumption and safety. Hence, study on tire performance becomes important from different aspects. This study will look at the calculation of the friction coefficient of tire rubbers, which affects vehicle safety, based on studies conducted by different research groups. By combining different models, we suggest a new simple model to predict the friction coefficient. Several discussions in the article will be for validation of the model and its range of applications. We then implement a parametric analysis to determine which factors critically affect the friction coefficient. By finding the sensitivity of the inputs of the model/ code, the critical factors can be identified and focused on. The parameters that are studied are the storage modulus, loss modulus, surface asperities heights, the surface asperities wavelength, and the adhesive contribution to friction. The adhesion and hysteresis contributions to the friction coefficient are also discussed in this article. It is shown that the adhesive contribution plays a large role in determining the friction coefficient. KEYWORDS friction coefficient, loss modulus, modeling, rubber mechanical behavior, storage modulus, 1 | INTRODUCTION Travel by automotive is one of the most common modes of transportation in the United States of America. Therefore, automotive performance plays a significant role in the [...]

With the development of the recycling economy for waste rubber, the highvalue application of rubber powder, such as the modifier in asphalt mixture and the polyurethane foam, has attracted more and more attention. In the study, the surface characteristics of rubber powder modified by deep eutectic solvents were investigated by infrared spectroscopy, sol fraction, solid surface energy, and scanning electron microscope. The mechanical properties of modified ground tire rubber powder (M-GTR)/SBR/silica composites were studied. Meanwhile, the viscoelasticity of the composites was characterized by the Payne effect and Mullins effect. Compared with the unmodified rubber powder, the rubber powder treated at 105[degrees]C had a higher sol fraction and maximum value of solid surface energy. With the increase of the content of M-GTR, the Payne effect of the M-GTR/SBR/silica composites firstly weakened and then increased. As for the Mullins effect, the vulcanizates showed stresssoftening phenomenon in the process of uniaxial cyclic compression. The recovery ability of the Mullins effect strongly depended on temperature. Besides, the modified rubber powder could improve the dispersity of silica in the SBR matrix, and the Mullins effect of the composite contained modified rubber powder was weak, which would provide potential high-value application for rubber powder. KEYWORDS deep eutectic solvents, dispersity, ground tire rubber powder, interaction, modified, viscoelasticity, 1 | INTRODUCTION With the development of the social economy, the demand for rubber products rises from year to year, resulting in more and more waste rubber. But, due to [...]

This study aims to investigate the effect of ground tire rubber (GTR) treated by acetone on mechanical and morphological properties of ethylene-vinyl acetate (EVA) matrix. Polymeric EVA/GTR (0, 10, 20, 30, and 40 phr) compounds were achieved through extrusion and batch foaming process. TGA and NMR analysis revealed that oils and additives were removed from the GTR after the acetone treatment. Morphological characterization showed cell sizes below 100 [micro]m in the compounds with treated GTR, which improved the mechanical performance of EVA/GTR compounds. The results indicated that the acetone-treated GTR are a suitable raw material to obtain foam compounds useful in vibrations absorber and isolation applications. KEYWORDS EVA-GTR foam compounds, ground rubber, Trigonox 145-B, 1 | INTRODUCTION Today, over 17 million tons of tires per year are produced around the world. However, the worn tires have become a serious issue as residue accumulation due [...]

Based on the Penn's experimental data, a consistently compressible Mooney-Rivlin model is developed for the vulcanized rubber. First, the Penn's experimental data are re-analyzed, which show the near incompressibility. Next, the incompressible Mooney-Rivlin model and three conventional types of compressible model are studied for the vulcanized rubber, which exhibit an apparent inconsistence with the incompressible model due to the dissimilar initial shear modulus. Finally, a consistently compressible model with extra constants is proposed, which obeys the normalization conditions and the consistent conditions, and a procedure to identify model constants is suggested, and then applied to the Penn's experimental data. The consistently compressible Mooney model is eventually established for the vulcanized rubber, and then compared with other four hyper-elastic models. KEYWORDS compressible Mooney-Rivlin model, consistent condition, incompressible Mooney-Rivlin model, normalization condition, 1 | INTRODUCTION The mechanics of rubber-like materials has a long and prolific history. In order to accurately describe the experimental data obtained from material testing, much attention has been [...]

3-Octanoylthio-l-propyltriethoxysilane (a new silane) grafted styrene butadiene rubber/ silica composites were prepared in the present work, where grafting weight percentage of the base rubber (0%, 2%, 4%, and 6%) and filler content of the composites (0, 5, 15, 35, and 50 phr) were varied to investigate dispersion of the filler in the rubber. A detailed quantitative study of morphology-physical property relationship of the composites using dispersion degree parameter was carried out. Pronounced improvement of dispersion was observed with increasing grafting weight percentage of the base rubber. A mechanism of polymer to filler interaction was shown by Fourier transform infrared spectroscopy. The dispersion rate constant from the torque-time curve increased with the grafting percentage. Bound rubber content and Payne effect measurement indicated improved rubber-filler interaction for the grafted rubber compound. A relation between low strain modulus of the composites and grafting percentage was proposed. The nanoindentation studies gave further insight into the results. Other physico-mechanical properties at different grafting weight percentages at particular filler loading (50 phr) and at different filler loadings at a particular grafting weight percentage (4%) were evaluated. The improved mechanical and dynamic mechanical properties with increasing grafting weight percentage are an indication that this methodology could be used in green tire application. KEYWORDS composites, dispersion, morphology, rubber, silica, 1 | INTRODUCTION Organic-inorganic nanohybrids are investigated nowadays for their extraordinary surface and bulk properties. The inorganic compounds are usually layered clays or nanosilicas or other materials with a wide [...]

In this experimental investigation, the authors have fabricated and characterized composites made from pyrolysis oil rubber and epoxy resin. As the dumping of waste scrap tires poses a serious environmental threat, the pyrolysis oil rubber was extracted from these waste tires only. The prepared blend having pyrolysis oil with various weight percentages (wt%) was examined on the basis of various physical, microstructural, mechanical, and thermal tests. The microstructural tests (scanning electron microscopy and X-ray diffraction) analysis complemented with the mechanical tests (tensile, compression, flexural, hardness, and impact) results and confirmed that the 4.4 wt% of pyrolysis oil in epoxy resin sample exhibited the best results in toughening of the polymer network. Furthermore, the thermal analysis (differential thermal analysis and thermogravimetric analysis), electrical conductivity, density, water absorption, gas chromatography-mass spectroscopy, and Fourier-transform infrared tests for the composites were also performed. Low density and high tensile strength than neat epoxy resin makes this composite a potential candidate for fabricating lightweight structures and in polymer coatings for automotive industries., INTRODUCTION In general definition, composite is made up of matrix (is a part which acts as the base) and reinforcement (filler that holds and increases the strength of matrix) [1-4]. [...]