Oxygen barrier properties of organic montmorillonite modified polyamide 11/Poly (vinyl alcohol) films

Abstract

Organic montmorillonite (OMMT) nano‐platelets were exfoliated and well dispersed in fully bio‐based polyamide 11/Poly(vinyl alcohol) (PA11/PVA) blends. Significantly lower oxygen permeation rates (OTR) were detected for the PA1172.5PVA27.5OMMTx films than those of PA11 and PA1172.5PVA27.5 films. An extremely low OTR of 0.218 cm3/m2·day·atm was found for PA1172.5PVA27.5OMMT1 film modified with 1 PHR optimum concentration of well dispersed OMMT nano‐platelets. Similarly, the free volume characteristics evaluated for PA1172.5PVA27.5OMMTx film series reduced to a minimum as the OMMT concentration reached the optimum value. As revealed by dynamic mechanical and differential scanning calorimetric analyses of PA1172.5PVA27.5OMMTx film series, all dynamic glass transition temperature (Tg), melting temperature (Tm) and percentage crystallinity (Wc) values of PA1172.5PVA27.5OMMTx films were noticeably higher than those of PA1172.5PVA27.5 film without addition of OMMT. In fact, Tgs, Tms and Wcs evaluated for PA1172.5PVA27.5OMMTx films increased to a maximum, as their OMMT reached the optimum concentration. The considerably enhanced oxygen barrier resistance found for PA1172.5PVA27.5OMMTx films was ascribed to the considerably reduced free volume characteristics and much longer permeation path caused by impermeably OMMT nano‐platelets well dispersed in PA1172.5PVA27.5OMMTx films.