BEHAVIOR OF A LIQUID CRYSTAL POLYMER AFTER ELONGATION FLOW TREATMENT

Abstract

Crystallization behavior of a liquid crystal copolyester of 4-hy-droxybenzoic acid (HBA) and 6-hydroxy-2-naphthoic acid (HNA) after an elongation flow treatment was investigated by differential scanning calorimeter (DSC), polarized light microscopy (PLM), and an instrument capable of generating elongation flow. DSC heating scans of the elongation flow treated samples exhibit an additional high temperature endothermic peak, suggesting that the high degree of molecular orientation achieved by elongation flow results in a formation of new kind of crystalline structure. The annealing effect including different temperature and time on such stretched samples has also been studied.

Keywords:

• Liquid Crystal Polymer
• Crystallization
• Elongation Flow

ACKNOWLEDGEMENTS

J. Lin takes pleasure in acknowledging his gratitude to the Austria Science Foundation for awarding a Lise–Meitner fellowship.