Mechanical properties, morphology, Mullins effect and its reversibility of thermoplastic vulcanizates based on ethylene-acrylic acid copolymer/chloroprene rubber blends

Thermoplastic vulcanizates (TPVs) of ethylene-acrylic acid copolymer (EAA)/chloroprene rubber (CR) were prepared by dynamic vulcanization, and the mechanical properties, microstructure, Mullins effect and reversible responses of the prepared EAA/CR TPVs were investigated systematically under the compression mode. Experimental results showed that the EAA/CR TPV with 40/60 weight ratio had the excellent mechanical properties. The crosslinked CR particles with average diameter of 3 ~ 6 µm were dispersed evenly in the etched surface of EAA/CR TPV. Mullins effect could be observed in the stress–strain curves of TPVs during the uniaxial loading–unloading cycles. Compared with the EAA/CR TPV with 30/70 weight ratio, the EAA/CR TPV with 40/60 weight ratio had the relatively larger maximum stress, residual deformation, internal friction loss, degree of stress softening effect and tanδ value at specific strain. Meanwhile, the reversibility of the Mullins effect showed a temperature-dependent feature and was enhanced with increasing heat treatment temperature.