Plastic pollution poses a significant global challenge, with traditional waste management methods proving inadequate. This study introduces a novel three-stage framework for sustainable plastic waste management, integrating artificial intelligence (AI) with literature-based microbial degradation guidance. In Stage 1, three Convolutional Neural Network (CNN) models, namely Custom CNN, EfficientNetV2, and MobileNetV2, were used to classify waste images into 34 categories and identify whether each item was plastic or non-plastic. Among them, MobileNetV2 achieved the highest accuracy, reaching 96.8% in multi-class classification and 98.8% in binary plastic versus non-plastic classification. In Stage 2, Support Vector Machine (SVM), Random Forest, and a one-dimensional Convolutional Neural Network (1D-CNN) were applied to Fourier Transform Infrared (FTIR) spectroscopy data to identify six common plastic types. The 1D-CNN model demonstrated superior performance, achieving 99.50% accuracy, outperforming the other models. Stage 3 provides a conceptual, literature-driven recommendation module for the management of non-recyclable plastics by associating polymer types with reported microbial degradation pathways, including microorganisms such as Ideonella sakaiensis for polyethylene terephthalate (PET) and Pseudomonas species for polystyrene (PS). This stage does not involve experimental biodegradation, simulation, or computational validation, and is intended to highlight potential end-of-life treatment directions informed by existing studies. Overall, the framework combines experimentally validated AI-based material classification and polymer identification with conceptual biodegradation recommendations, supporting informed decision-making across the plastic waste management pipeline. By aligning with the United Nations Sustainable Development Goal 12 (UN SDG 12), the proposed approach provides a structured and extensible foundation for advancing sustainable plastic waste management.
This work contributes to the understanding of material changes during the repeated recycling of glass fibre-reinforced styrene maleic anhydride (SMA). The present study investigates the influence of repeated recycling on its mechanical, rheological and thermal properties. The injection-moulded SMA was shredded, regranulated and subsequently injection-moulded. This was repeated five times in order to compare the material behaviour after multiple recycling runs with respect to the virgin material. In order to distinguish between the influence of polymer degradation and that of reinforcing fibre deterioration, pure SMA was also investigated. Tensile properties, melt volume rate (MVR) and fibre length were evaluated after each recycling run. Gel permeation chromatography (GPC) and infrared spectroscopy (IR) provided insight into the structural changes. The IR spectra and GPC analyses show that the chemical structure of the material is largely retained. The rheological tests show a decrease in the MVR values after each recycling path, indicating an increase in polymer viscosity. It was observed, that the tensile strength of the pure SMA under investigation increased after each recycling path, which could be attributed to the increase in the average molecular weight, as evidenced by the GPC analysis. Despite this increase in strength, the tensile tests of the fibre reinforced polymer showed a significant decrease in strength with each recycling run, while the elongation at break remained relatively constant. The impact strength decreases by 45% compared to the initially processed material. The deterioration in mechanical properties was mainly attributed to the shortened glass fibres. This is supported by the fibre length measurements, which show an average length reduction from 284 & micro;m for the virgin material to 104 & micro;m after five recycling runs. The research results show that SMA with and without glass fibre reinforcement can be mechanically recycled with little loss in mechanical performance.
A new sustainable and environmentally friendly composite material has been developed from coconut fibre particles and recycled polystyrene dissolved in chloroform. Three particle sizes and four reinforcement ratios were used. The composite was moulded by cold pressing without measuring the pressure but by fixing the thickness. The density (592.53 - 723.03) kg.m-3 shows the lightness of the material. The moisture content (6.63 - 8.35%), water absorption rate (54.06 - 109.42) % and thickness swelling rate (2.86 - 16.09) % are within the acceptable range of <= 16% for use in dry and wet areas, except for formulations with a 55% reinforcement rate. The absorption kinetics of the composites produced show hydrophilicity and correlate with Page's model. Microscopic examination shows better interfacial cohesion with low visible porosity for composites with the lowest particle content and reinforcement rate. Young's modulus (129.29 - 530.95) MPa and mechanical stress at break (1.26 - 6.508) MPa are relatively low compared to structural materials. Thermal conductivity (0.22 - 0.347) W.m-1.k-1 and thermal effusivity (571.9 - 856.7) J.m-2.K-1.S-1/2 are within the range of thermally insulating materials. Smaller particles show better cohesion with the matrix. These materials are intended for use in furniture, false ceilings, house partitions, computer stands and telephone booth doors.
This work focuses on optimising the thermal expansion and dimensional stability of calcium-borosilicate (CaO-B2O3-SiO2) glass fibre R-12 reinforced epoxy-934 laminates. Due to their superior mechanical strength, thermal performance, and durability, these laminates are widely used in the aerospace industry. R-12 glass fibre offers high tensile strength and enhanced thermal resistance, while Epoxy 934 resin ensures excellent adhesion and stability under thermal and mechanical stresses. The temperature of interest was selected as 80 degrees C, representing the service limit, which is typical of operational simulations in aerospace conditions with an extreme working range of around 70 degrees C. The fibre orientations tested were [+/- 0 degrees](5S), [+/- 15 degrees](5S), [+/- 30 degrees](5S), [+/- 45 degrees](5S), [+/- 60 degrees](5S) in a series of 13 experiments designed using Response Surface Methodology (RSM) and Central Composite Design (CCD) in Design-Expert software, to determine their effect on thermal expansion and dimensional stability. The model was experimentally validated, confirming its accuracy and demonstrating its reliability in optimising fibre-reinforced epoxy composites for aerospace applications.
In order to improve the oil and water resistance of the lunch box, wheat straw was used to produce the lunch box, while chitosan and beeswax served as raw materials for the oil- and water-resistant coating. The surface of the food box is coated by spraying. Firstly, a single chitosan solution is sprayed onto the surface of the wheat straw food box, and oil and water resistance tests are conducted. Subsequently, a composite oil and water resistant agent was prepared by adding beeswax to the chitosan solution. Optimization experiments were conducted on the dosage of the composite oil and water resistant agent from the perspectives of coating solution concentration and coating amount. The results showed that under the conditions of chitosan concentration of 2.0 wt%, beeswax solid content of 50 wt%, and coating amount of 2 g/m2, the oil resistance level of the food box could reach level 9 or above, and the water absorption rate decreased to 11.3%. The food box met the requirements for oil and water resistance, providing a promising green alternative to traditional plastic tableware.
The uniformity of rubber products is one of the important indicators of the quality of rubber products. For some special rubber products, such as rubber bladders, uniformity becomes a decisive indicator of their quality. There are many factors affecting the uniformity of rubber products, but the effects of elastic modulus and Mooney viscosity of rubber materials on the uniformity of rubber products have not been systematically studied. To avoid the chance of experimental results, this paper uses different molding processes to prepare the same kind of rubber products. Then the effects of elastic modulus and Mooney viscosity on the uniformity of rubber products are observed by comparing the results of different kinds of rubber products. The results show that for cylindrical rubber products such as rubber bladders, there exists an optimal interval between the homogeneity and the material's Mooney viscosity and elastic modulus, with the optimal interval for the Mooney viscosity being [40, 60] and the optimal interval for the elastic modulus being [6.63, 8.40] MPa.
Additive manufacturing (AM) is an innovative production technology used to create parts using a layer-by-layer production method. The Fused Deposition Modeling (FDM) AM technique is particularly preferred due to its ability to provide flexible production and the availability of inexpensive materials. This method is frequently used in the automotive industry, medical and biomedical applications, and prototype production. However, despite its flexible production capabilities, it requires specific processing steps to improve post-production surface quality and dimensional accuracy. As a result of these processes, undesirable outcomes such as delamination, surface roughness, and high temperature formation may occur, depending on both the processing parameters and the production parameters. Therefore, it is necessary to examine both the AM production parameters and the processing parameters. The aim of this study is to examine the drilling performance of samples produced at different raster angles using the FDM technique made from polylactic acid (PLA) material. Therefore, three different samples were produced at raster angles of 0-45-90 degrees and drilled at three different feed rates (0.1-0.15-0.2 mm/rev). The thrust force, delamination, temperature formation, and surface roughness changes were examined. The results showed that the thrust force increased with the increase in feed rate and raster angle, which in turn led to an increase in the amount of delamination. The increase in raster angle and feed rate also raised the temperature during drilling. Additionally, chips became wrapped around the chip evacuation channels of the cutting tool, and as the cutting tool attempted to push and remove the chips, it increased the surface roughness of the hole's inner walls. Finally, the relationship between the dependent and independent variables in the experimental results was examined using ANOVA analysis, and it was found that the effects of feed rate and raster angle on thrust force were significant (p < 0.05).
The mechanical performance of the Fused Deposition Modeling (FDM) printed polylactic acid (PLA) parts is influenced by the printing and filament extrusion parameters. In this regard, this work focusses on the investigation of the effects of filament extrusion zonal temperatures and printing temperatures on the porosity and mechanical strength of the printed parts. Firstly, the working temperature range of the PLA is estimated as 180 degrees C to 220 degrees C using the Differential Scanning Calorimetry (DSC). Based on this, the filament is extruded using a single screw extruder with varying zonal temperatures in the increments of 5,10 and 15 degrees C. Followed by that, the filaments are printed at various nozzle temperatures between 180 degrees C and 220 degrees C. The results showed that the zonal temperature difference of 10 degrees C and the nozzle temperature of 200 degrees C yields the lowest porosity of 1.2% and highest tensile strength of 49.18 MPa, highest compression strength of 60.89 MPa and flexural strength of 70.19 MPa. This enhanced performance is attributed to the gradual thermal gradient, proper polymer chain alignment and randomized layer bonding in the material. The results provide understandings on the significance of thermal parameters on the structural integrity and mechanical performance of the printed parts.
This study presents an integrated approach to minimize warpage and shrinkage in automotive A-pillar plastic components fabricated via injection moulding. The research systematically investigates the effect of key process parameters mould temperature, injection pressure, and melt temperature alongside three distinct gate configurations: single middle, double middle, and two-end double gates. Simulations were conducted using Autodesk Moldflow Adviser, and the Taguchi method was employed to design experiments and analyse the significance of each factor using signal-to-noise (S/N) ratios and ANOVA. Results indicate that melt temperature is the most influential parameter, contributing up to 96.25% to warpage formation, followed by mould temperature and injection pressure. Among the gate designs, the double middle gate configuration demonstrated the best balance between reduced deflection and structural integrity. Optimized parameters (melt temperature: 190 degrees C, mould temperature: 20-40 degrees C, injection pressure: 90-130 MPa) effectively reduced deflection by up to 4.50%. Furthermore, an Artificial Neural Network (ANN) model trained with experimental data accurately predicted deflection values with less than 15% deviation from simulated and actual results. The integration of simulation, statistical optimization, and machine learning provides a robust framework for enhancing dimensional accuracy and process efficiency. This study offers a scalable methodology for automotive part manufacturers seeking to optimize injection moulding processes and ensure higher product quality with reduced material waste.
The study investigates the combined effects of airflow rate (AR) and layer thickness (LT) on the mechanical and thermal behavior of 3D-printed Acrylonitrile Butadiene Styrene (ABS). A series of tensile and compressive tests were performed, varying the LT and AR to understand their influence on mechanical robustness. In parallel, thermal properties were analyzed using thermal imaging and differential scanning calorimetry (DSC). It was observed that decreasing LT from 0.3 mm to 0.05 mm significantly increased tensile properties, with comparatively less impact on compressive strength. The AR's influence was more pronounced at thinner layers, affecting both mechanical and thermal properties. Thermal analyses provided a dynamic view of temperature changes, with swift cooling leading to dramatic temperature drops. The DSC highlighted variations in glass transition and thermal degradation temperatures between extruded ABS and its filament form, with higher cooling rates elevating the glass transition temperatures. This study elucidates the complex relationship between 3D printing parameters and the resulting properties of ABS, offering insights that could revolutionize the printing process and material customization, particularly for applications demanding high mechanical strength and thermal stability.
Mycelium-based foam is a sustainable alternative to synthetic polymers, produced biologically using the vegetative part of fungi, known as mycelium. This study examines the impact of fabrication conditions on the morphology and mechanical, water-related, and thermal properties of mycelium-based foams. Pleurotus citrinopileatus and Pleurotus djamor were cultivated on ground paddy straw at 25 degrees C for 21 days under dark conditions. The samples were subjected to hot pressing at 150 degrees C, cold pressing at 25 degrees C, or left unpressed as a control. Scanning electron microscopy (SEM) analysis revealed that cold-pressed P. citrinopileatus foam (YCP) exhibited the most compact hyphal structure, contributing to superior mechanical properties, with the highest tensile strength (4.324 +/- 0.857 MPa), elongation at break (0.260 +/- 0.040), and modulus (16.459 +/- 2.552 MPa). Additionally, YCP showed the lowest water absorption (0.126 +/- 0.190), indicating enhanced resistance to moisture. Thermogravimetric analysis showed that YCP retained structural integrity up to 600 degrees C, with major mass loss occurring above this temperature, indicating high thermal stability suitable for demanding applications. These findings highlight the potential of mycelium-based foam as a biodegradable, high-performance material for packaging and insulation applications.
The development of a heavy metal adsorbent was successfully achieved through a crosslinked polymer nanocomposite system consisting of 70 wt% polyacrylamide (PAM), 30 wt% polyethylenimine (PEI), 3 phr nano-hydroxyapatite (nHA), and 15 phr cellulose. The nanocomposite was crosslinked using 10 phr N,N-methylenebisacrylamide (MBA) and prepared via solution casting. This study investigated the effects of the initial Pb2+ concentration and contact time on the adsorption capacity. This specific combination of dual fillers (cellulose + nHA) and crosslinking provided a synergistic enhancement in structural stability, active site accessibility, and Pb2+ adsorption efficiency, achieving a maximum adsorption capacity of 404.5 mg/g (at pH 5 with an initial Pb2+ concentration of 100 ppm and a contact time of 2 h using 10 mg of the adsorbent). The findings revealed that the PAM/PEI/Cel/nHA/MBA-10 nanocomposite followed the Freundlich isotherm and exhibited pseudo-second-order kinetics, indicating that the adsorption process is primarily governed by multilayer chemisorption. The findings demonstrate a distinct improvement over previously reported PAM/PEI or single-filler systems, highlighting the novelty and potential of PAM/PEI/Cel/nHA/MBA-10 for heavy metal (e.g., Pb2+) removal applications.
With Additive Manufacturing (AM) technology such as Fused Deposition Modeling (FDM) technique being used to produce functional components, it is necessary to understand the combined effect of significant printing process parameters over the mechanical properties of printed parts. The present work employed the full factorial technique to investigate the effect of printing process parameters such as infill density, infill pattern, layer height, and nozzle size over the tensile strength of the printed parts. Analysis of Variance (ANOVA) was conducted and it identified the nozzle size as the most significant factor influencing tensile strength, followed by infill density. Layer height and infill shape had a smaller individual impact on tensile strength. However, with specific combinations of nozzle size and infill densities, noticeable variations in tensile strength were observed. Increasing the infill density enhances tensile strength proportional to the rise in mass due to the additional material. Although infill patterns had minimal effect on tensile strength, the specific strength varied, with the triangle pattern showing the highest specific strength of 7.11 MPa/g, which is 5.20% and 21.65% higher than the rectilinear and wiggle patterns. The highest tensile strength of 43.63 MPa was achieved using the wiggle pattern at 80% infill which is due to print orientation of wiggle pattern with the tensile load. Further, increasing the layer height and nozzle size significantly improved specific strength because of higher print quality and reduced defects. The experimental investigation proved the optimal nozzle to layer height ratio (N/L) for to achieve greater strength is 1.66. With the extensive datasets obtained using experimental investigation, a machine learning model was trained for predicting the tensile strength for the given printing process parameters. Due to its adaptability, efficiency and robustness, the Gaussian Process Regression was proved to estimate the tensile strength of the Polylactic Acid (PLA) material with more accuracy. The predictive performance and corresponding residuals of the training and testing datasets resulted with MAE of 3.17, MAPE of 11.66, and an accuracy of 88.34%.
This study investigates the effect of recycling and nanofiller incorporation on the morphological, rheological, and mechanical properties of various injection moulded polyesters. The research compares the behaviour of two types of bio-based (polylactic acid (PLA) and polybutylene succinate (PBS)) and two types of petroleum-based (polyethylene terephthalate (PET) and polybutylene terephthalate (PBT)) polyesters, including polymers with aliphatic and aromatic structures. Recycling was simulated by repeated extrusion for both unreinforced and 6 wt% montmorillonite (MMT) reinforced nanocomposites. Although in all cases the rheology measurements resulted in shear-thinning behaviour, the complex viscosity range and shape of the curves varied differently for each material depending on the MMT reinforcement and the number of extrusions. The melt flow index (MFI) values showed that neither reprocessing nor MMT had a significant effect on the results of PBT, PBS, and PLA. A sharp increment was observed when PET was processed with MMT, indicating the polymer's notable degradation. Non-isothermal crystallization was used to investigate the extent of overcooling, and the results were compared at 10 degrees C/min and at cooling rates extrapolated to 1 degrees C/min. The undercooling of PBS and PBT barely changed with reprocessing and MMT content, but degradation in PET also modified the crystallization tendency, while in PLA MMT reinforcement inhibited molecular ordering. The wide-angle X-ray diffraction (WAXD) study showed an intercalated structure for all types of polyester nanocomposites, with minor differences in the layer-stack number. Dynamic mechanical analysis (DMA) indicated changes in the glass transition temperature and storage modulus with reprocessing and the addition of MMT. While below the glass transition temperature, the glassy amorphous phase has a more pronounced effect on the storage modulus, above this temperature the crystalline phase tends to dominate, as the contribution of the amorphous phase in the rubbery state is minor to the stiffness. The homogeneous distribution of MMT was confirmed by the shape of the Cole-Cole diagrams.
The prevalent presence of microplastics in marine environments poses major ecological risks requiring innovative approaches to their management and reduction. This study addresses a knowledge gap in biodegradable microplastic alternatives by looking at the biodegradability and properties of reclaimed microplastic polypropylene (PP) blended with polylactic acid (PLA). The study lies in the systematic exploration of various PP/PLA formulations, evaluating their potential for enhanced biodegradability without significantly compromising mechanical performance. Microplastic PP and PLA blends were prepared in various ratios using the melt blending method. The blend was characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) to confirm the presence and morphology of the components. The mechanical properties were evaluated using tensile strength tests. A blend of 90% PP and 10% PLA was found to retain the highest tensile strength even after immersion in seawater. The thermal stability and degradation behavior were analyzed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). This shows that increasing PLA content affects the thermal properties of the blends. Seawater immersion and soil burial tests were used to assess the biodegradability of the blends. The results showed that the blends’ biodegradation was confirmed by increases in conductivity and salinity in the seawater and weight loss in the soil burial. The major findings show that blending PP and PLA improves biodegradability while maintaining adequate mechanical properties. Tests including immersion in saltwater and soil burial were used to assess the biodegradability of the blends. The results showed that the blends’ biodegradation was confirmed by increases in conductivity and salinity in the seawater and weight loss in the soil burial. The major findings show that blending PP and PLA improves biodegradability while maintaining adequate mechanical properties. Finally, this study presents a new approach to reducing microplastic pollution through the blend of reclaimed PP with biodegradable PLA, resulting in a sustainable material with improved environmental performance. Future studies should look into new formulations, biodegradable polymers, and long-term degradation tests under a variety of environmental circumstances.
Di(2-ethylhexyl) terephthalate (DEHTP) is a promising substitute for dioctyl phthalate (DOP, banned in certain countries) as a polyvinyl chloride (PVC) plasticizer. This research endeavors to present findings about the synthesis of DEHTP through the depolymerization of polyethylene terephthalate (PET) with 2-ethyl-1-hexanol, the production and assessment of PVC formulated with this plasticizer, and a comparative analysis with PVC compounded using commercial plasticizers (DOP and DEHTP). Approximately 200 post-consumer PET bottles underwent chemical recycling under various conditions, leading to complete depolymerization (99%) following a six-hour reaction at 300°C. The plasticizers were characterized by infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, and gas chromatography coupled to mass spectrometry. The flexible PVCs were tensile and hardness tested and submitted to dynamic mechanical and thermogravimetric analyses. The resulting plasticizer exhibited properties analogous to commercial DEHTP, producing flexible PVC with even better properties. For instance, the activation energy of the dehydrochlorination reaction of the flexible PVC produced with DHETP from depolymerization was 3.3% to 16.2% higher than those produced with commercial plasticizers.
The mechanical and thermal characteristics of Recycled Polyester Waste (RPW) reinforced in a polypropylene (PP) matrix were investigated to evaluate their feasibility for producing safety helmet components. Five samples with varying PP and RPW ratio weight fractions were prepared (Sample A:90/10, Sample B:80/20, Sample C:70/30, Sample D:60/40, and Sample E:50/50) and compounded by twin-screw extruder and developed using an injection molding machine. The density, hardness, tensile, and flexural properties of all samples, such as stress, strain, modulus, impact resistance, and Vicat softening temperature, were measured and compared. The findings indicated an increase in density as the RPW content increased, ranging from 0.92 g/cm³ for sample A to 1.23 g/cm³ for sample E. The hardness also increased from 69 Shore D in Sample A 87 Shore D in sample D. The tensile stress and modulus increased from 25.5 MPa to 543 MPa, respectively, for sample A to 27.6 MPa and 827 MPa, respectively, for sample D. The flexural strength and flexural modulus increased from 31.2 MPa to 775 MPa, respectively, for sample A to 34.3 MPa and 1250 MPa, respectively, for sample D. The impact resistance increased as the RPW content increased, ranging from 555 J/m for Sample A 656 J/m for sample D. The Vicat softening temperature increased from 73°C for Sample A to 91°C for Sample E. These findings indicate that RPW has the potential to improve the thermal and mechanical properties of PP, rendering it a sustainable and plausible reinforcement option for head band components of safety helmets.
This investigation fully studied optimizing the thermochemical desulfurization process for carbon black-filled styrene butadiene rubber (SBR) by examining the carbon black type effect and the loading amount on desulfurization performance. The analysis of devulcanization process efficiency required the Horikx-Verbruggen method to evaluate sol fraction and crosslink density relationships. When higher amounts of carbon black are present, the speed of crosslinking interactions increases. An increase in crosslinking rate reached 170% for carbon black N-330, while carbon black N-550 showed an 87% increase in such rates. The size of carbon black particles N-330 and N-550 does not impact the desulfurization performance results. The researchers optimized desulfurization procedures using temperature and time variations as critical variables. The study results indicate that reduced desulfurization temperature combined with shorter periods helps minimize crosslinking formation, improving desulfurization results. The aggregation behavior of the system becomes more pronounced when high-temperature conditions prevail, thus it impacts the operation’s outcome. The analysis demonstrates the necessity to match devulcanization approaches with rubber compound characteristics for enhanced product properties and extended life span in rubber applications.
The fields of dentistry and orthopaedics have demonstrated considerable enthusiasm for Ultra-High Molecular Weight Polyethylene (UHMWPE) composites due to their improved thermal and mechanical properties. This study describes a modified fabrication method for a novel thermoplastic hybrid composite loaded by reduced graphene oxide (rGO) nanoparticles. The composite is designed specifically for biomaterial applications subjected to sustained loading conditions. The fabrication procedure involved the manufacture of specimens with varied percentages of rGO content (0, 0.5, 1, 1.5, 2, and 3 wt%) using liquid-phase ultrasonication (LPU) followed by hot press molding (HPM). The resulting composites were examined using Scanning electron microscopy (SEM), Energy Dispersive X-ray Analysis (EDX), Dynamic mechanical analysis (DMA), Thermogravimetric Analysis (TGA) and Compression testing. A detailed understanding of the relationship between structure and properties is necessary to develop various load-bearing components (Finger joints, knee joints, hip joints). Accordingly, performing an in-depth analysis of the viscoelastic properties of the composite is highly desirable for bio-bearing components. According to DMA results at 37°C, the 1 wt.% rGO /UHMWPE nanocomposite is superior to pure UHMWPE in terms of storage modulus (79.55%) and Compressive modulus of 0.5 GPa. The fracture morphology of the impact samples was examined using a SEM test. The results demonstrated the superior characteristics of the 1wt% rGO/UHMWPE nanocomposite over the pure UHMWPE. The implications of the modified UHMWPE composite, incorporating rGO, extend to applications such as prostheses, joint replacements, and components for Artificial Bio-Bearing (ABB). The loading of rGO into UHMWPE bio-bearing materials has enhanced their dynamic mechanical and compression abilities, allowing them to be used in a wider variety of human body parts.
Graft copolymer from natural rubber grafted with polystyrene (NR-g-PS) was prepared. Influences of polystyrene (PS) content grafted on the natural rubber (NR) were investigated. Prior to compounding and compression molding to vulcanizates, the graft copolymers were prepared by emulsion polymerization. Proton nuclear magnetic resonance confirmed the chemical structure of the graft copolymer as NR-g-PS. Grafting of PS onto NR improved the tensile modulus and tensile strength of the vulcanizate, whereas the elongation at break decreased, depending on the PS content. However, a drastic reduction of tensile strength and elongation at break were seen when the PS content was greater than 20%. Compared to ungrafted NR, the onset strain for deformation-induced crystallization of graft copolymers was reduced, while the crystallinity at a given strain was higher. The improved tensile properties and crystallization ability suggest interfacial interactions of NR and PS phases. Such interactions were also responsible for improved thermal stability of the graft copolymer, having the degradation temperature increased by 17–38°C over the ungrafted NR. The best balance in overall properties was achieved by NR/PS 90/10.
