MECHANICAL-PROPERTIES OF A POLYMER BLEND OBTAINED THROUGH IN-SITU CROSS-LINKING OF THE DISPERSED PHASE

Blends of a polypropylene matrix and a miscible phase of ethylene viny l acetate and ethylene methyl acrylate copolymers were produced by twi n-screw extrusion. The miscible phase can be crosslinked in, situ thro ugh a catalyzed transesterification reaction. Mechanical properties of reactive and nonreactive blends were characterized. Impact properties increase with the concentration of elastomeric phase and are improved by the crosslinking reaction. Yield stress and Young modulus are not modified by the reaction, but tensile stress and elongation at break a re improved, which suggests the development of network structure at th e interface. (C) 1997 John Wiley & Sons, Inc.