Preparation of Highly Rubber-toughened Nylons.

Nylon 6 and 66 were toughened with EPDM-g-MA and SEBS-g-MA and steadystate rheological behaviour of rubbers, nylons and their blends and mechanical properties of nylons and their rubber-toughened blends were investigated. The EPDM maleic grafting preparation was performed in the framework of this study where SEBS-g-MA was obtained from a commercial source. The results showed the ultratoughened SEBS-g-MA blends, whereas EPDM blends under the same blending conditions did not show a significant improvement in toughness. In case of EPDM toughened blends an average of some micrometers was observed for the dispersed EPDM particles. Impact and tensile properties of the toughened blend with 20% of SEBS-gMA rubber showed about 1540% improvement in impact and 240% in elongation-atbreak of the blend as compared with those of neat nylon, whereas these properties only showed 30% reduction in Young s modulus of the blends. Rheological measurements revealed the closeness of the viscosity of SEBS-g-MA and nylon 66, whereas the viscosities of EPDM rubber and nylons were found very far from each other under the blending conditions. Morphological observations using SEM technique revealed a co-continuous and a probable nano-scale-dispersed SEBS-g-MA in nylon matrix.