COMPATIBILIZATION AND DYNAMIC VULCANIZATION OF PA 6 ISOBUTYLENE METHYLSTYRENE ELASTOMER

The effect of reactive polymer blending on the rheological properties and the deformation of dispersed phase in extruded films is described. Three types of polymer blends are studied: (1) a non-reactive blend of nylon 6 (PA 6)/isobutylene-co-paramethylstyrene elastomer; (2) a compatibilized blend of PA 6/brominated (isobutylene-co-para-methylstyrene) elastomer (XP-50); (3) a compatibilized, dynamically vulcanized blend of PA 6/XP-50 plus curatives. Mixing is performed with a Brabender mixer and a twin screw extruder. Rheological measurements were performed at 240-degrees-C which is above melting temperature of PA 6. The storage moduli and complex viscosities of type (3) are the highest, those of type (2) are the next and those of the mechanically mixed non-reactive components are the lowest. The dispersed phases in extruded films show that the deformation of the dispersed elastomer in type (3) is the smallest. The sizes of the dispersed-elastomer domains in type (2) and type (3) are much smaller than those of type (1). There are large and highly deformed dispersed phases in the film of type (1). Also the interfacial bonding is poor.