EFFECT OF COMPATIBILIZATION ON THE PROPERTIES OF POLYPROPYLENE POLYAMIDE-66 (75 25WT/WT) BLENDS/

Interfacially compatibilized immiscible blends with an isotactic polyp ropylene matrix (PP) and dispersed polyamide-66 (PA) were prepared by extrusion with anhydride-grafted isotactic PP compatibilizers, one of high-anhydride content (HAC, 2.7 wt % grafted maleic anhydride) and on e of low-anhydride content (LAC, 0.2 wt % anhydride). On a weight basi s, HAC was more efficient than LAC in dispersing PA to submicron domai ns, but on a total weight % anhydride basis, both compatibilizers were equally efficient. Both compatibilizers imparted similar tensile stre ngth improvement compared to an uncompatibilized blend. Maximum fractu re strain was obtained at similar total anhydride content, but much hi gher maximum fracture strain was achieved with LAC than with HAC. Good adhesion in an 11.25 wt % LAC blend was seen at the microscale as fib rillar ligaments connecting PA particles to the drawn PP matrix. Inter facial failure was observed in a lower fracture strain composition, 11 .25 wt % HAC. (C) 1994 John Wiley & Sons, Inc.