Blends of polyamide 6 and epichlorohydrin elastomers. II. Thermal, dynamic mechanical, and mechanical properties

Abstract

The mechanical blending of polyamide 6 and epichlorohydrin elastomers, polyepichlorohydrin, PEPI, and poly(epichlorohydrin-co-ethylene oxide), ECO, is accompanied by grafting copolymerization. In this work the influence of the graft copolymer on the thermal and mechanical properties of the blends is investigated. The blends are immiscible and the crystallinity degree normalized to the polyamide 6 contents in the blends is higher than expected. The X-ray diffraction results show that the grafting copolymer is also crystalline; hence, the presence of crystalline phase of copolymer can be responsible for the apparent enhancement of crystallinity. The DMA analysis reveals the presence of a shoulder in the peak corresponding to the PA 6 glass transition, as observed by loss modulus curves, which was assigned to relaxations of the grafting copolymer. Tensile tests show that the blends are more fragile than the PA 6, despite the graft copolymer. These results were attributed to the mechanical fragile interface constituted by a network type structure of the graft copolymer. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1835–1841, 1999