Premium
Multiple molecular relaxations of hot‐drawn and quenched polymers above their glass transition temperatures
Author(s) -
Kato T.,
Yanagihara N.
Publication year - 1981
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1981.070260702
Subject(s) - polycarbonate , glass transition , shrinkage , materials science , relaxation (psychology) , polymer , quenching (fluorescence) , thermal , methyl methacrylate , polymer chemistry , composite material , thermodynamics , polymerization , optics , physics , psychology , social psychology , fluorescence
Thermal shrinkage of highly hot‐drawn and quenched poly(methyl methacrylate) and polycarbonate of bisphenol A were measured. PMMA shows three‐step thermal shrinkage under suitable experimental conditions above its glass transition temperature ( T g ). Polycarbonate exhibits four kinds of molecular relaxation associated with shrinkage around and above its T g . The effect of hot‐drawing and quenching conditions on shrinking behavior is discussed. Almost all of the molecular relaxations are observed above T g . The molecular origins of the relaxations are discussed in relation with the so‐called T 11 transitions of polymers.