OXYGEN BARRIER ENHANCEMENT OF PET BY BLENDING WITH AN AROMATIC POLYAMIDE

摘要

The improvement of oxygen-barrier properties of poly(ethylene terephthalate) (PET) by blending with an aromatic polyamide (MXD6I) based on poly(m-xylylene adipamide) (MXD6) in which 12 mol% of isophthalamide was replaced with adipamide, was examined. The sequentially biaxially oriented blends containing 10 wt% MXD6I had significantly reduced oxygen permeability of PET by a factor of about 3 when tested at 43% relative humidity. Enhanced barrier arose from increased tortuosity of the diffusion pathway provided by the oriented, flat MXD6I platelets of high aspect ratio, which was confirmed by atomic force microscopy.