Synergetic effect of aramid nanofiber‐graphene oxide hybrid filler on the properties of rubber compounds for tire tread application

Graphene-Based Hybrid Fillers for Rubber Composites

Graphene and its derivatives have been confirmed to be among the best fillers for rubber due to their excellent properties, such as high mechanical strength, improved interface interaction, and strain-induced crystallization capabilities. Graphene rubber materials can be widely used in tires, shoes, high-barrier conductive seals, electromagnetic shielding seals, shock absorbers, etc. In order to reduce the graphene loading and endow more desirable functions to rubber materials, graphene-based hybrid fillers are extensively employed, which can effectively enhance the performance of rubber composites. This review briefly summarizes the recent research on rubber composites with graphene-based hybrid fillers consisting of carbon black, silica, carbon nanotubes, metal oxide, and one-dimensional nanowires. The preparation methods, performance improvements, and applications of different graphene-based hybrid fillers/rubber composites have been investigated. This study also focuses on methods that can ensure the effectiveness of graphene hybrid fillers in reinforcing rubber composites. Furthermore, the enhanced mechanism of graphene- and graphene derivative-based hybrid fillers in rubber composites is investigated to provide a foundation for future studies.

Preparation and Mechanical Properties of UV-Curable Epoxy Acrylate/Modified Aramid Nanofiber Nanocomposite Films

In order to enhance the mechanical properties of UV-curable epoxy acrylate (EA)-based coatings, 3-(trimethoxysilyl)propyl methacrylate modified aramid nanofibers (T-ANFs) were synthesized and used as nanofillers to prepare EA/T-ANF nanocomposite films. The morphology of T-ANFs was characterized by transmission electron microscopy. The chemical structure of T-ANFs was analyzed via infrared spectroscopy, confirming successful grafting of methyl methacryloyloxy groups onto the surface of aramid nanofibers (ANFs). Real-time infrared spectroscopy was employed to investigate the influence of ANFs and T-ANFs on the photopolymerization kinetics of the EA film. The results revealed that the addition of ANFs and T-ANFs led to a decrease in the photopolymerization rate during the initial stage but had little impact on the final double bond conversion, with all samples exhibiting a conversion rate of over 83%. The incorporation of ANFs improved the tensile strength of the films while significantly reducing their Young's modulus. In contrast, the addition of T-ANFs led to a substantial increase in both tensile stress and Young's modulus of the films. For instance, the tensile strength and Young's modulus of the 0.1 wt% of T-ANF film increased by 52.7% and 41.6%, respectively, compared to the pure EA film. To further study the dispersion morphology and reinforcement mechanism, the cross-sectional morphology of the films was characterized by scanning electron microscopy.

The Influence of Styrene Content in Solution Styrene Butadiene Rubber on Silica-Filled Tire Tread Compounds

In tire tread applications, achieving enhanced abrasion resistance, wet grip, and rolling resistance is crucial for optimizing overall performance. To realize improvements in these attributes for silica-filled tire tread compounds, it becomes imperative to improve the dispersity of silica filler by investigating the effect of each component in the tire tread compound. In this work, we study the effect of styrene content within solution styrene butadiene rubber (SSBR) on the properties of tire tread compounds. A higher styrene segment within SSBR contributes to increased silica dispersion and crosslink density. Thus, tire tread compounds featuring SSBR with increased styrene content not only improve physical and mechanical properties, but also enhance major characteristics tailored for tire tread applications. These findings provide valuable insights into advancing the reinforced performance of tire tread compounds through the strategic utilization of SSBR enriched in styrene content.

Cellulose nanocrystal functionalized aramid nanofiber reinforced epoxy nanocomposites with high strength and toughness

The mechanical properties of polymer nanocomposites can be improved by incorporating various types of nanofillers. The hybridization of nanofillers through covalent linkages between nanofillers with different dimensions and morphology can further increase the properties of nanocomposites. In this work, aramid nanofibers (ANFs) are modified using chlorinated cellulose nanocrystals (CNCs) and functionalized with 3-glycidoxypropyltrimethoxysilane to improve the chemical and mechanical interaction in an epoxy matrix. The integration of CNC functionalized ANFs (fACs) in the epoxy matrix simultaneously improves Young's modulus, tensile strength, fracture properties, and viscoelastic properties. The test results show that 1.5 wt% fAC reinforced epoxy nanocomposites improve Young's modulus and tensile strength by 15.1% and 10.1%, respectively, and also exhibit 2.5 times higher fracture toughness compared to the reference epoxy resin. Moreover, the glass transition temperature and storage modulus are found to increase when fACs are incorporated. Thus, this study demonstrates that the enhanced chemical and mechanical interaction by the CNC functionalization on the ANFs can further improve the static and dynamic mechanical properties of polymer nanocomposites.