IMIDE OLIGOMERS AND CO-OLIGOMERS CONTAINING PENDENT PHENYLETHYNYL GROUPS AND POLYMERS THEREFROM

摘要

Controlled molecular weight imide oligomers and co-oligomers containingpendent phenylethynyl groups (PEPIs) and endcappedwith nonreactive or phenylethynyl groups have been prepared by thecyclodehydration of the precursor amide acid oligomers orco-oligomers containing pendent phenylethynyl groups and endcapped withnonreactive or phenylethynyl groups. The amine terminated amideacid oligomers or co-oligomers are prepared from the reaction ofdianhydride(s) with an excess of diamine(s) and diamine containingpendent phenylethynyl groups and subsequently endcapped with a phenylethynylphthalic anhydride or monofunctional anhydride. Theanhydride terminated amide acid oligomers and co-oligomers are prepared fromthe reaction of diamine(s) and diamine containing pendentphenylethynyl group(s) with an excess of dianhydride(s) and subsequentlyendcapped with a phenylethynyl amine or monofunctional amine.The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone and N,N-dimethylacetamide under nitrogenat room temperature. The amide acid oligomers or co-oligomers are subsequentlycyclodehydrated either thermally or chemically to thecorresponding imide oligomers. The polymers and copolymers prepared from thesematerials exhibit a unique and unexpected combinationof properties that includes higher glass transition temperatures after curingand higher retention of neat resin, adhesive and carbon fiberreinforced mechanical properties at temperatures up to 204 °C under wetconditions without sacrificing melt flow behavior and processabilityas compared to similar materials. These materials are useful as adhesives,coatings, films, moldings and composite matrices.