Factors Affectin Adhesion of Tie Layers between Polypropylene and Polyamides

摘要

Adhesion properties were determined on five-layer coextruded cast films.With a few exceptions,the cap layers consisted of polypropylene,the tie layers consisted of blends of polypropylene and maleic anhydride-grafted polypropylene,and the center layer consisted of various polyamides. The adhesion generally increased as the overall film thickness and the level of maleic anhydride-grafted polypropylene were increased.The molecular weight of the grafted rewin had a small effect on adhesion.Homoploymer diluent outperformed random copolymer diluents.Adhesion did not vary much when different types of polyamides were used as the center layer,but each exhibited much greater adhesion than an ethylene-vinyl alcohol center layer.