PHASE VOLUME AND SIZE EFFECTS ON THE TERMINAL RELAXATION OF ABS MELTS

The dynamical viscoelasticity of ABS melts with different particle siz e was investigated at various levels of rubbery phase contents. The ef fects of the rubber are more pronounced in the terminal zone: a transi tion from viscoelastic liquid to viscoelastic solid behavior was obser ved which can be interpreted as a physical gelation occurring at a cri tical rubbery phase content. This critical content resulted in being s maller in the case of smaller particles. A quantitative explanation of the experimental findings was proposed in terms of the average interp article distance and overlapping of the chains grafted onto the neighb oring rubber particles. The gel-like transition appeared to correspond to an approximately constant level of grafted chains overlapping.