Main content area

Microcellular Foam from Ethylene Vinyl Acetate/Polybutadiene Rubber (EVA/BR) Based Thermoplastic Elastomers for Footwear Applications

Maiti, Madhuchhanda, Jasra, Raksh Vir, Kusum, Suraj K., Chaki, T. K.
Industrial & Engineering Chemistry Research 2012 v.51 no.32 pp. 10607-10612
abrasion resistance, chemistry, engineering, ethylene-vinyl acetate, foams, hardness, rubber, thermoplastics
Thermoplastic elastomer (TPE) from ethylene vinyl acetate (EVA) and synthetic general purpose rubber, polybutadiene rubber (BR), which can improve set, wear, and tear properties of virgin EVA without any coloring problem, was developed. EVA-BR blend ratio and processing parameters were optimized based on physicomechanical properties. It was found that EVA:BR 80:20 blend forms TPE of high strength (20 MPa) and low hardness (71 Shore A). This TPE shows 58 and 40% improvement in tension and compression set compared to virgin EVA. Tear strength and abrasion resistance of TPE was also improved by 9 and 35% respectively compared to EVA. The observed properties of TPE were explained in terms of morphology and interaction parameter. Microcellular foam of this TPE was developed using organic and inorganic blowing agents. Dinitrosopentamethylene tetramine at 3 phr loading forms closed cell microcellular foams with an average cell diameter of 100 μm. EVA:BR microcellular foam showed overall properties comparable with commercial EVA:NR microcellular foam.