Study on the morphology, rheology and surface of dynamically vulcanized chlorinated butyl rubber/polyethylacrylate extrudates: effect of extrusion temperature and times

Abstract

A high-damping thermoplastic vulcanizate (TPV) composed of chlorinated butyl rubber (CIIR) and polyethylacrylate (PEA) was prepared by using a twin-screw extruder. The effect of extrusion temperature and times on the morphology, rheology and surface of the extrudates was examined and attempts were made to correlate the extrudate surface with the evolution of two-phase morphology and the rheological behavior. CIIR gel content of each extrudate was also analyzed. The result shows that CIIR gel content increases with increasing extrusion temperature or times; furthermore, extrusion at high temperature can produce numerous PEA and CIIR macromolecular radicals, thus chemical links take place between PEA and CIIR molecules. Morphological analysis indicates that phase inversion occurs at a gel content of around 68%, and with increasing extrusion times at high temperature the dispersed particles become larger and the particle edges become blurrier. All CIIR/PEA extrudates show pseudoplastic flow behavior. The extrusion temperature or extrusion times have a significant effect on melt viscosity of the extrudates. Surface analysis exhibits that co-continuous nature of the two-phase morphology results in melt fracture and periodic distortions on the extrudate surface, but with the increasing extrusion temperature or times the surfaces of the extrudates become gradually smooth.