Preparation and properties of a liquid crystalline segmented block copolyester

✍ Scribed by Jing Wang; Robert W. Lenz

• Publisher: Society for Plastic Engineers
• Year: 1991
• Tongue: English
• Weight: 337 KB
• Volume: 31
• Category: Article
• ISSN: 0032-3888
• DOI: 10.1002/pen.760311009

✦ Synopsis

Abstract

A segmented block copolyester with a liquid crystalline (LC) “hard block” and poly(tetramethylene glycol) (PTMG) “soft block” was prepared and characterized by intrinsic viscosity [η], by gel permeation chromatography (GPC) for number average molecular weight and molecular weight distribution, by differential scanning calorimetry (DSC), and by dynamic mechanical thermal analysis (DMTA). The “soft block” had a melting transition at about −30°C and the hard block had a glass transition at about 70°C and a nematic‐to‐isotropic transition at 260°C. Mechanical testing, which included tensile testing, hysteresis analysis and stress relaxation at small strains, revealed that the block copolyester was a flexible rubbery material with an elongation at break of about 1000% and showed reversible extension below 50% strain.