MEMORY EFFECTS IN POLYMERS .1. ORIENTATIONAL MEMORY IN THE MOLTEN STATE - ITS RELATIONSHIP TO POLYMER STRUCTURE AND INFLUENCE ON RECRYSTALLIZATION RATE AND MORPHOLOGY

The influence of polymer structure on the orientational memory in the molten state has been studied by observing the crystallization behavior of the molten polymer through differnetial scanning calorimetry. It is shown that polymers with strong intermolecular forces (e. g. , H-bonding) retain the orientation memory even at temperatures above their equilibrium melting temperatures. The retained orientation memory of the polymer melt is shown to influence its recrystallization rate and the morphology. Some of the polymers covered include nylon polymers, polyethylenes, and polyethylene terephthalate.