INTERCHAIN CROSS-LINKING BETWEEN NBR AND POLYACRYLIC RUBBER AND EFFECT ON (I) PROCESSIBILITY AND BLEND-MORPHOLOGY

Flow behaviour of NBR and polyacrylic rubber blends have been studied throughout the entire composition ranges. The effect of preheating of the blends is also studied in order to understand the interchain cross linking. Viscosity, extrudate swell, power law indices, have been stud ied as a function of shear rate and blend ratio. The shearing accompan ied by blend ratio has a predominent effect on the rheological behavio ur of the preheated blends due to microgel formation. From the rheolog ical behaviour it appears that there is a phase inversion at around 50 % of NBR, however, preheating does not change this trend. (C) 1994 Joh n Wiley & Sons, Inc.