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Dielectric properties of bisphenol‐A novolac type epoxide oligomer as a parameter for cure monitoring
Author(s) -
Koike Tsuneo,
Ishizaki Noritoshi
Publication year - 1998
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.10353
Subject(s) - bisphenol a , diglycidyl ether , oligomer , epoxy , materials science , branching (polymer chemistry) , dielectric , epoxide , curing (chemistry) , polymer chemistry , bisphenol , glass transition , ether , polymer , composite material , organic chemistry , chemistry , optoelectronics , catalysis
Dielectric properties above the glass transition temperature ( T g ) have been investigated for three bisphenol‐A novolac type epoxide oligomers (PGEBANs) that have some branching in each molecule in comparison with the diglycidyl ether of bisphenol‐A (DGEBA) oligomer without branching. The relationship between the dielectric relaxation time (τ) and T g for the branched PGEBAN oligomers is expressed by a modified Williams‐Landel‐Ferry (WLF) equation taking T g as a variable at fixed temperatures from 70 to 100°C. The WLF‐type relationships between τ and T g for the two types of uncured epoxide oligomers, the branched PGEBAN and the nonbranched DGEBA, were found to be useful for predicting the T g of a branched DGEBA‐alicyclic amine system during the middle stage of curing.