Liquid‐crystalline thermosets by the curing of dimeric liquid‐crystalline epoxyimine monomers with 2,4‐toluene diisocyanate

Abstract

We studied the curing processes of several series of dimeric liquid‐crystalline epoxyimine monomers with 2,4‐toluene diisocyanate (TDI) alone or with added catalytic proportions of 4‐(N,N‐dimethylamino)pyridine. We obtained isotropic materials or liquid‐crystalline thermosets with different degrees of order, which depended on the structures of the monomers. To fix ordered networks, we had to do the curing in two steps when TDI was used alone as the curing agent. However, when a tertiary amine was added in catalytic proportions, the ordered networks were fixed in just one step. In this way, we were able to fix both nematic and smectic mesophases. The significance of the polarization of the mesogen for obtaining liquid‐crystalline thermosets was demonstrated. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2521–2530, 2003

Liquid crystalline polymer networks based on a nematic epoxy resin with azoxy group

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Curing behavior of Azo‐containing twin liquid crystalline epoxy resins with anhydride

“…Although a few models were employed to study the curing kinetics and phase changes, none of them is on the curing reaction of twin LC epoxy resins, which are prone to form a smectic mesophase [16–18]. Twin LC epoxy resins containing azomethine [19, 20] and aromatic ester [21] were synthesized respectively by Ribera and Ober. Most of their attentions were paid for the mesophase behavior of monomers and final mesophase after cross‐linking.…”

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