TRANSPORT-PROPERTIES OF POLY(ETHYLENE-TEREPHTHALATE) RODRUN-3000 BLENDS

The transport properties of incompatible blends of poly(ethylene terep hthalate) (PET) and a thermotropic liquid crystalline polymer (TLCP) c omposed of 40 mol% of PET and 60 mol% of p-hydroxybenzoic acid (Rodrun 3000) have been investigated using dichloromethane as permeant. Films , obtained by a blown film extrusion process, were analyzed and compar ed with the same samples stored 2 and 15 days at 60 degrees C. With re spect to the as-blown films, blends submitted to physical aging show a decrease in permeability by a percentage that increases with the amou nt of the LC phase present and a larger contribution derived from the polymeric matrix. The decrease of permeability is essentially attribut ed to a lowering of sorption because diffusional behavior for the diff erent samples is the same.