RHEO-OPTICAL STUDIES OF THE THERMOTROPIC AROMATIC COPOLYESTERS OF POLY(ETHYLENE TEREPHTHALATE) AND p-ACETOXYBENZOIC ACID.

In our laboratory, we have investigated both groups of copolyesters for their processability in the melt state and particularly for producing multiaxially oriented morphologies using curvilinear flow conditions under compression. During our studies with the aromatic copolyesters of poly(ethylene terephthalate) with 60 and 80 mole % of p-acetoxybenzoic acid, we conducted, concurrently, rheo-optical observations which elucidate their unusual flow behaviour.