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Effect of previous thermal history on physical aging of amorphous poly (ethylene terephthalate)
Author(s) -
Cortés P.,
Montserrat S.
Publication year - 1989
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19890270118
Subject(s) - amorphous solid , poly ethylene , materials science , relaxation (psychology) , liquid nitrogen , ethylene , thermal , glass transition , analytical chemistry (journal) , polymer , thermodynamics , composite material , chemistry , crystallography , organic chemistry , physics , catalysis , psychology , social psychology
Physical aging of amorphous PET, at aging temperatures (T a ) of 40 and 60°C and different aging times (t a ), has been studied by DSC using two kinds of samples with different thermal history: Liquid‐Nitrogen‐Quenched samples (LNQ) and DSC cooled samples at a controlled cooling rate of 60 K/min (CC). At T a = 40°C, a sub‐T g peak appears in LNQ samples but is not clearly observed in the CC samples. At T g = 60°C, a superposed peak to T g is observed in both kinds of samples. This different behaviour can be explained considering the distribution of relaxation times in the polymer.