PARTICLES VERSUS FIBRILLAR MORPHOLOGY IN POLYOLEFIN TERNARY BLENDS

PP/EPR binary and PP/(EPR/PE) ternary blends were prepared based on th e viscosity ratio, using a corotating twin-screw extruder. Both fibril lar structures and particle-in-matrix morphologies were created depend ing on the viscosity ratio of rubber domain to the matrix PP(eta(EPR)/ eta(PP), Or eta(EPR-PE)/eta(PP)) With fibril formation, mechanical pro perties of the blends, especially the flexural modulus and notched imp act strength, were significantly increased and the increase was more p ronounced with the ternary blends. The fractured surfaces obtained fro m the impact test showed compressed welded grains for fibrillar morpho logy and filled-out particles for particle-in-matrix morphology. (C) 1 996 John Wiley & Sons, Inc.