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Liquid crystalline thermosets from triaromatic azomethine group containing diepoxides and 4,4′‐methylenedianiline
Author(s) -
Mormann Werner,
Bröcher Markus
Publication year - 1998
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/(sici)1521-3935(19980901)199:9<1935::aid-macp1935>3.0.co;2-2
Subject(s) - thermosetting polymer , monomer , epoxide , polymer chemistry , curing (chemistry) , chemistry , amine gas treating , diamine , epoxy , organic chemistry , polymer , catalysis
Five triaromatic azomethine‐linked diepoxides have been cured by reaction with 4,4′‐methyl‐enedianiline (MDA) in a molar ratio epoxide/amine of 1:1 and 2:1. The influence of the structure of monomers, of the molar ratio epoxide/amine, and of the curing conditions on the formation of liquid crystalline networks was studied. Initially a decrease of the clearing temperature was caused by mixing with the nonmesogenic diamine. The clearing point of the mixture increased with conversion, and thermosets with a liquid crystal order of the monomers were obtained from the 2:1 combinations. Curing occurs in two stages as revealed by DSC: first epoxy/amine reaction occurs, and at higher temperature homopolymerisation of residual oxirane takes place. This is due to non‐homogeneous melting of the diepoxides in dynamic curing.