Thermotropic liquid crystalline polymer reinforced with polyimide sized carbon fibers
OwnerRobert Edelman, Richard D. Orwollinventors
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Abstract
A thermotropic liquid crystalline polymer matrix having sized carbon fibers incorporated therein for reinforcement. The carbon fibers are coated on their surface with a sizing composition comprising a rigid polyimide coating which is derived from the reaction of at least one aromatic diamine, at least one dianhydride, and at least one aromatic tetracarboxylic acid diester in which the carboxylic acid groups and ester groups are ortho disposed. By the use of appropriate amounts of heat and pressure, multifilamentary bundles of carbon fibers are readily impregnated with thermotropic liquid crystalline polymer to form a prepreg having a uniform distribution of carbon fiber throughout.
Claims40
A composite structure comprising a thermotropic liquid crystalline polymer matrix having carbon fibers incorporated therein, the carbon fibers having been coated on their surface with a sizing composition comprising a rigid polyimide coating which is derived from the reaction of at least one aromatic diamine, at least one aromatic dianhydride, and at least one aromatic tetracarboxylic acid diester in which the carboxylic acid groups and ester groups are ortho disposed, wherein a polyamic acid oligomer is formed as an intermediate during the formation of the rigid polyimide coating and is present within a flexible coating comprising the reactants which facilitates impregnation of the coated carbon fibers with the matrix during the formation of the composite structure.
A prepreg comprising a thermotropic liquid crystalline polymer matrix having carbon fibers incorporated therein, the carbon fibers having been coated on their surface with a sizing composition comprising a rigid polyimide coating which is derived from the reaction of at least one aromatic diamine, at least one aromatic dianhydride, and at least one aromatic dianhydride, and at least one aromatic tetracarboxylic acid diester in which the carboxylic acid groups and ester groups are ortho disposed, wherein a polyamic acid oligomer is formed as an intermediate during the formation of the rigid polyimide coating and is present within a flexible coating comprising the reactants which facilitates impregnation of the coated carbon fibers with the matrix during the formation of the prepreg.
Dependencies are inferred from the claim text.