Solid state 13C NMR spectroscopy on EPDM/PP/oil based thermoplastic vulcanizates in the melt

Influence of Rubber Ratio and Crosslinking Agent on Mechanical Properties, Crystallization and Rheological Behaviors of EPDM/PP Thermoplastic Elastomer

The ethylene-propylene-diene monomer/polypropylene (EPDM/PP) thermoplastic elastomer is prepared by dynamic vulcanization. The effects of different rubber ratios and crosslinking agent contents on the static and dynamic mechanical properties, crystallization and rheological behaviors are investigated and discussed. EPDM/PP with the rubber ratio from 40 to 50 % and crosslinking agent content of 1.2 wt% has the highest tensile strength and elongation at break. The fracture morphologies indicate that EPDM/PP with high rubber ratios and crosslinker contents is over vulcanized to harden, which results in that some large particles cannot be fragmented by shear force. The crystallinity obtained from differential scanning calorimetry (DSC) shows a decrease with increasing rubber ratio and a very slight variation with increasing the crosslinking content. The dynamic mechanical analysis (DMA) results display a decrease trend in storage modulus and tan δ with increasing crosslinking density. The rheological behaviors show that the complex viscosity also increases with increasing crosslinking density, indicating that the elastic deformation becomes superior to viscous flow in EPDM/PP.

HIGH-TEMPERATURE THERMOPLASTIC ELASTOMERS FROM RUBBER–PLASTIC BLENDS: A STATE-OF-THE-ART REVIEW

This article reviews different types of high-temperature thermoplastic elastomers and thermoplastic vulcanizates from rubber-plastic blends. Preparation, structure, and properties of these materials are discussed briefly. Strategies to further improve the high-temperature performance of these materials are presented herein. A synopsis of the applications of these high-performance materials in the automotive industry is reported, pointing out the gaps to motivate potential research in this field.

Influence of process parameters on property of PP/EPDM blends prepared by a novel vane extruder

In this study, thermoplastic elastomers based on polypropylene (PP) and ethylene-propylene-diene terpolymer (EPDM) were prepared via direct melt blending in a novel vane extruder. The influence of processing temperature and rotor speed on the degree of cross-linking of the EPDM phase, the tensile properties, the melting behavior and the crystallization morphology of PP/EPDM blends was investigated. It was observed that the volume fraction (Vr) of the vulcanizate arriving swelling equilibrium reached the maximum value when the processing temperature was 190°C. The tensile properties showed better performance at 195°C, at which the PP/EPDM blend obtained good dispersive mixing performance. Moreover, the Vr of the vulcanizate arriving swelling equilibrium reached the maximum value when the rotor speed was 60 rpm, at which the dispersive mixing performance and tensile properties of the PP/EPDM blend were better.

Microstructure and properties of bromo-isobutylene–isoprene rubber/polyamide 12 thermoplastic vulcanizate toward recyclable inner liners for green tires

Bromo-isobutylene–isoprene rubber (BIIR)/polyamide 12 (PA 12) thermoplastic vulcanizate (TPV) were prepared by dynamic vulcanization (DV) and the microstructure and properties of BIIR/PA 12 TPV toward recyclable green inner liners were studied.

Efeito de EPDM modificado nas propriedades mecânicas e no processamento de composições de EPDM contendo resíduo de EPDMR

Neste trabalho foi estudado o efeito de três agentes na recuperação de resíduos de borracha, copolímero de etileno-propylene-dieno (EPDMR) contendo negro de fumo. Os três agentes preparados foram: EPDM modificado com 1-dodecanotiol (EPDMSDD), EPDM modificado com ácido esteárico (EPDMAE) e EPDM modificado com ácido graxo linolênico (EPDMAG). Os resultados de propriedades mecânicas mostraram que o EPDMSDD fornece a melhor combinação de resistência à tração e rasgamento associado à processabilidade. A adição dos agentes EPDMAE e EPDMAG melhorou a processabilidade da mistura por extrusão, mantendo suas propriedades mecânicas. Este resultado indica que o EPDMAE e o EPDMAG atuam como auxiliares de processamento.