Study on the compatibility of ethylene‐vinyl acetate copolymer/vermiculite in biaxially oriented polypropylene films

A process for preparing expanded vermiculite/ethylene vinyl acetate nanocomposites by ball milling expanded vermiculite (EVMT) in cyclohexane solution of ethylene vinyl acetate copolymer resin (EVA) was presented, and the influence of EVA/EVMT nanocomposites on mechanical, barrier performance of modified biaxially oriented polypropylene (BOPP) films was discussed in this article. By the process, the EVMT is intercalated and exfoliated to obtain a kind of EVMT/EVA nanocomposite, in which EVA serves as both intercalating agent into EVMT and compatibilizer between EVMT and polypropylene (PP); so, when EVMT/EVA was melt blended with PP, platelets of vermiculite can be exfoliated easily and dispersed relatively well in the PP matrix. Compared with original (nonmodified) BOPP, when EVMT loading ranged from 0.1% to 0.5%, both strength and toughness of the modified BOPP films was increased. Moreover, platelets (flakes) of vermiculite dispersed in PP matrix improved barrier properties of modified BOPP films also. The improved barrier properties of BOPP films accorded with Nielsen model. POLYM. COMPOS., 36:78–87, 2015. © 2014 Society of Plastics Engineers