Polyphenylene sulfide (PPS) is becoming increasingly valuable in the electrical, electronic, and automotive industries. In particular, PPS composites reinforced with glass fiber (GF) have better dimensional stability and mechanical properties than conventional PPS materials and can be used in applications like electric vehicle capacitor housing. In the electric vehicle industry, the epoxy-molding process is essential for manufacturing capacitor housings, where the bonding strength between the PPS/GF composites and epoxy significantly affects the durability of the product. However, the inert surface characteristics of polymers like PPS limit their interaction with epoxy, decreasing the bonding strength. This study was aimed at enhancing the bonding strength between PPS/GF composites and epoxy by modifying the PPS surface using atmospheric-pressure plasma treatment. The surface modification resulted in increased surface roughness and the introduction of polar functional groups, which improved both mechanical interlocking and chemical affinity to the epoxy. Surface changes were analyzed using atomic force microscopy and scanning electron microscopy, and chemical characterization was conducted using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Surface energy was determined via contact angle measurements, and bonding strength was evaluated through single-lap shear tests. The results showed a 55% increase in surface energy and a 24.8% improvement in bonding strength due to the surface modification.

Polyetheretherketone (PEEK) is widely used across various industries due to its high thermal stability, chemical resistance, and superior mechanical properties. However, its tribological and electrical properties require enhancement for advanced applications. This study investigates the effect of graphene coating on PEEK microspheres to improve their performance. Functionalized graphene oxide (CMG+) and graphene nanoplatelets (GnPs) were introduced onto the PEEK surface via an electrostatic self-adsorption process, followed by high-speed mixing and hot-pressing to fabricate PEEK–graphene nanocomposites. The structural, thermal, tribological, and electrical properties of the composites were systematically analyzed. The results show that graphene acts as a nucleating agent, enhancing the crystallinity of the nanocomposites. Tribological tests indicate that CMG+ significantly reduces the friction coefficient, with CMG1.0 and CMG2.0 samples showing friction reductions of 54% and 63%, respectively, compared to pure PEEK. Moreover, electrical property evaluations reveal that surface resistance decreases with increasing graphene content, achieving optimal conductivity at 1.0 wt.% CMG+ and further enhancement with the addition of GnPs. These findings demonstrate that the functionalized graphene-coated PEEK microspheres exhibit superior tribological and electrical performance due to nanoscale interactions, making them suitable for electrostatically dissipative and wear-resistant applications.

This study investigated the lifetime prediction of polyphenylene sulfide (PPS)/glass fiber (GF) composites used in film capacitor housings through accelerated thermal aging tests. The accelerated aging tests were conducted at temperatures of 200, 230, and 260 degrees C for aging times ranging from 250 to 5000 h. The mechanical properties deteriorated with increasing aging time, with higher degradation rates observed at elevated temperatures. During the initial phase of aging, a temporary increase in the tensile strength was observed, likely due to postcrosslinking and chain scission within the PPS molecular structure. However, prolonged aging leads to excessive thermal oxidation and chain breaking, accelerating polymer degradation and causing a significant decline in the composite properties. Furthermore, crystallinity analysis revealed that, as the degradation progressed, the crystal structure became looser and the crosslinking structure was disrupted, leading to a decrease in the melting enthalpy and, consequently, a gradual decline in crystallinity. Notably, after 2000 h, the crystallinity of PPS disappeared completely, indicating that the duration and temperature of the accelerated aging significantly affected the crystallization of PPS. These findings provide valuable insights into the degradation mechanisms of PPS/GF composites and contribute to the long-term durability and reliability of materials used in electric vehicles.

Fogging in automotive headlamps is a significant issue that affects both aesthetics and functionality. This study investigates the use of graphene-based nanocomposites to mitigate fogging by enhancing the hygroscopic properties of Polybutylene Terephthalate/Acrylonitrile Styrene Acrylate (PBT/ASA) composites commonly used in headlamps. The incorporation of functional-ized graphene improved the tensile and flexural strength of the nanocomposites, though it led to a reduction in elongation and melt flow. Additionally, the solid lubrication properties and increased surface hardness of the graphene contributed to enhanced wear resistance. The presence of gra-phene in the nanocomposites also reduced moisture diffusion, lowering the rates of both hygro-scopic and desorption when compared to commercial PBT/ASA composites. Furthermore, the nanocomposites exhibited a reduction in maximum moisture uptake. These improvements are expected to reduce the absolute humidity inside the headlamp, thereby effectively mitigating the fogging issue.

This study aims to analyze tire wear particulate matter (TWP) from tread rubber with different formulations and to compare the concentration of TWP with different wear devices. The TWP generated during the abrasion of truck and bus radial (TBR) tires were examined, and the effect of using different types of rubber and carbon black (CB) were investigated. When natural rubber (NR) was solely used as the tire tread rubber material, there was a higher concentration of 5–10 µm TWP. However, when the tread formulation consisted of NR mixed with butadiene rubber, the TWP concentration decreased. Changing the type of CB also reduced the amount of TWP in the 2.5 µm size range. The TWP concentration in the specimens increased with increasing speed and vertical load. The TWP generated during the abrasion tests using wear testers and tire simulators exhibited similar trends. These findings suggest that modifying tire tread formulations can effectively control the distribution and amount of TWP generation.

Polypropylene (PP) is used as a housing material in automotive headlamps but can cause fogging as a result of absorbed moisture and temperature differences between the exterior and interior of the housing. In this study, PP was combined with a graphene/montmorillonite hybrid (MMT-G) to yield a nanocomposite with reduced moisture absorption. Crucially, the modified nanofiller had low hydrophilicity and good compatibility with the PP matrix. Notably, the water contact angle of the MMT-G improved by 676%. Furthermore, the maximum moisture absorption of the PP/MMT-G nanocomposites was reduced by up to 11.22% compared to that of commercial PP composites, and the weight of the headlamp housing was decreased by 3.6%. Therefore, the designed nanocomposites are expected to help mitigate headlamp fogging while slightly reducing the housing weight.

This study aimed to analyze the trend of particulate matter (PM) generation from tires by nonexhaust systems. These types of PM are lesser known than the airborne PM generated from automotive exhaust systems. Specimens with rubber formulations similar to commercial tires for trucks and buses were artificially abraded, and the generated PM was analyzed. Abrasion of a specimen made of butadiene rubber, which is a synthetic rubber, generated lesser PM than a natural rubber specimen. This reduction of PM generation was particularly significant for PM10. Furthermore, using carbon black (a filler in tires) having small sized particles, the generation of PM2.5 was reduced to a large extent. To study the influence of tire aging on the increased generation of PM, rubber specimens were analyzed after prolonged exposure to a high temperature.

This study investigated the service life prediction of fluorocarbon elastomers that are used in automotive vapor fuel hoses under thermal environments. The changes in mechanical properties such as the tensile strength, elongation, compression set (CS), and hardness according to thermal aging were investigated for two types of ternary fluoroelastomers. Destructive tests of the tensile strength and elongation showed large variations in the mechanical properties under the same condition because there is no continuity of samples. In contrast, nondestructive tests of the CS and hardness showed little variations in the mechanical properties under the same condition. The elongation, CS, and hardness were selected as the physical parameters for service life prediction as they showed a tendency according to the aging temperature, which is an accelerating factor. The effective activation energy derived using each physical parameter was 74.91–159.6 kJ mol−1, and the service life was 17.8–140 × 103 h based on B10. In this study, hardness, which has a small deviation between samples, is considered appropriate as mechanical parameter for predicting the service lifetime.

Owing to stringent international environmental and fuel efficiency requirements for lightweight automotive systems, polymer composites have attracted widespread attention. Polypropylene (PP) is a widely employed commercial polymer because of its lightweight and low cost. In this study, PP nanocomposites were fabricated to reduce the moisture absorption of PP composites in automotive headlamp housings. Alkylated chemically modified graphene (CMG-R) was synthesized to reduce the surface hydrophilicity of graphene and increase compatibility with the PP matrix. Fourier transform-infrared spectroscopy and scanning electron microscopy were performed to analyze the nanofillers. X-ray diffraction was performed to determine the interlayer spacing of the nanofiller resulting from surface treatment. Differential scanning calorimetry was used to analyze the crystallinity of the nanocomposites. The results indicated that the improved hydrophobicity of the nanofiller due to alkylation reduced the maximum moisture absorption of the PP nanocomposites by 15% compared to PP composites. The findings of this study are useful for reducing fogging in automotive headlamps.

Polyamide 46 (PA46) is used in various automotive parts because of its excellent heat resistance and mechanical properties. This study aims to improve the frictional properties of PA46 using the lubricating ability of graphene. Nanocomposites are prepared via two mixing methods: Graphene powder is compounded directly with PA46 pellets through a twin-screw extruder, or PA46 powder is added to graphene dispersion for self-adsorption, and subsequently, it is dried and compounded with PA46 through the twin-screw extruder. Application of the nanocomposite in the friction field is evaluated via the pin-on-disk method. The coefficient of friction of the nanocomposite prepared by self-adsorption is lower than that of the nanocomposite prepared by direct compounding. The mechanical properties of the nanocomposite fabricated by self-adsorption are superior to those of other materials. This can be attributed to the uniform dispersion of graphene and the strong attractive force between the PA46 matrix and graphene.

In this study, life time prediction of fluoroelastomer for automotive vapor fuel hose was investigated using the accelerated thermal aging test. The change in hardness of fluoroelastomer was analyzed as physical parameters for the accelerated life time prediction model. The accelerated aging test was performed at temperatures of 160, 175, 190, and 200 degrees C, and it was confirmed that the hardness gradually increased with the aging time. The accelerated life time pre-diction model was conducted using the curve fitting method and the cumulative density function method based on the Arrhenius relationship. As a result of life time prediction of ternary fluoroelastomer, the curve fitting method showed 5170 hours and the cumulative density function method showed 5577 hours. The activation energy calculated from life time prediction model of fluoroelastomer was ca. 86 kJ mol(-1). The accelerated life time prediction model could be used to predict the relative life time according to material changes.

It is known that particular matter from the vehicle's non-exhaust emission is mainly generated by wear of brakes and tires. Unlike particular matters from exhaust system, the one generated by tire wear on the road is very difficult to accurately analyze due to the absence of traces and low concentration in the atmosphere. In this study, in order to analyze the relationship between tire wear and the amount of particular matters generated, samples were prepared with various recipes and under different mixing conditions. Generated particular matters by abrading tires or specimens were analyzed by aerodynamic particle sizer.

In this study, the lifetime prediction of fluoroelastomers for oil seals and gaskes for preventing automotive lubricant oil was investigated using accelerated aging test. The accelerated thermal aging test was performed at temperature of 160 175 190 and 200.. Tensile strength and hardness of the fluoroelastomer were analyzed as physical parameters for the accelerated lifetime prediction model. As a result, the hardness was more excellent in variation and tendency compared to the tensile strength, so hardness was applied as a parameter of the accelerated lifetime prediction model. It was confirmed that the hardness gradually increased with the aging time, and the accelerated life prediction model of the fluorine rubber could be expressed by the Arrhenius relationship.

In this study, lifetime prediction of natural fiber/polypropylene (NFPP) composites for automotive door trim was investigated using an accelerated aging test. Accelerated lifetime prediction was the key technology to assure the reliability of automotive components. The accelerated thermal aging test was performed at the temperature of 110, 130, and 150 degrees C. As a result of thermal analysis according to the thermal aging temperature, it was confirmed that the thermal decomposition temperature was lowered and the thermal decomposition rate was increased. The measured tensile strengths as a function of thermal aging temperature were used as accelerated lifetime prediction data for the analysis of the NFPP composites lifetime. The lifetime of the NFPP composite was estimated using the Arrhenius-Weibull distribution model. The estimated results exhibited that the B-1 lifetime of the NFPP composites was 684 million hours at room temperature (23 degrees C) and 39.2 thousand hours at 80 degrees C, respectively.

The chemical recycling of postconsumer poly(ethylene terephthalate) (PET) bottles to produce highly thermally stable polyurethane foam (r-PUF) with excellent flame-retardant (FR) performance could be applied on an industrial scale to create a sustainable recycling industry. The advantage of oligo-ester-ether-diol obtained from waste PET glycolysis is its application in r-PUF, generating a durable foam with excellent fire resistance at rather low loadings of phosphorus-nitrogen FRs (P-N FRs), especially in high moisture environments. Compared to polyurethane foam from commercial polyol (c-PUF), r-PUF is notably more thermally stable and efficient in terms of flame retardancy, even without adding FRs. By incorporating 15 php diammonium phosphate (DAP) as a P-N FR, r-PUF/DAP self-extinguished 5 s after the removal of the 2nd flame application with a limited oxygen index value of 24%. However, for c-PUF, a much higher DAP (30 php) loading did not exhibit any rating in the vertical burning test. The aromatic moiety in the oligo-ester-ether-diol structure strongly enhanced the compressive strength and thermal stability. The positive outcomes of this study also confirmed that the r-PUF/DAP prepared from oligo-ester-ether-diol not only satisfied the fire safety requirements of polymer applications but also contained a high percentage of postconsumer PET, which could help reduce the amount of recycled polymer materials and improve waste management.

Polyphenylene sulfide (PPS) is well known semi-crystalline super engineering plastic which is having a very high melting temperature (above 290 degrees C) and strong chemical resistance. Research on replacing metallic materials with PPS is going on due to its superior properties. However, PPS is the material that does not have much attention in Korea as compared to the other developed countries. In this research, the crystallinity of the resin was influenced by the mold temperature, as a result, physical properties such as tensile strength, thermal properties were changed. Analyses were carried out with specimen and automotive molded part.