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Liquid Crystalline Thermosets from Ester, Ester-Imide, and Ester-Amide OligomersMain chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,OOO grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end- capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.
Document ID
20050237934
Acquisition Source
Langley Research Center
Document Type
Other - Patent
External Source(s)
LAR-16079-1
Authors
Theodornus J Dingemans
(Langley Research Center Hampton, United States)
Erik S Weiser
(Langley Research Center Hampton, United States)
Terry L St. Clair
(Langley Research Center Hampton, United States)
Date Acquired
August 23, 2013
Publication Date
September 6, 2005
Subject Category
Composite Materials
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-Patent-6,939,940
Patent Application
US-Patent-Appl-SN-757398
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