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Preparation and properties of a liquid crystalline segmented block copolyester
Author(s) -
Wang Jing,
Lenz Robert W.
Publication year - 1991
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760311009
Subject(s) - copolyester , materials science , differential scanning calorimetry , dynamic mechanical analysis , glass transition , gel permeation chromatography , liquid crystal , thermal analysis , thermogravimetric analysis , composite material , polymer chemistry , polymer , chemical engineering , thermodynamics , thermal , polyester , physics , optoelectronics , engineering
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.