Abstract: A nanocomposite composition is disclosed which comprises clay and an effective amount of a benzoxazine monomer, oligomer, and/or polymer. In one embodiment, the presence of the benzoxazine monomer, oligomer, and/or polymer in the clay results in an at least about 5% increase in the spacing between the platelets of the clay. In another embodiment, the presence of the presence of the benzoxazine monomer, oligomer, and/or polymer in the clay results in at least about 5 wt. % of the clay being exfoliated. Also disclosed are a method for making (1) an intercalated nanocomposite clay composition which comprises clay and an effective amount of a benzoxazine monomer, oligomer, and/or polymer; (2) an exfoliated nanocomposite clay composition which comprises clay and an effective amount of a benzoxazine monomer, oligomer, and/or polymer; and (3) a method for making a nanocomposite clay composition that is both exfoliated and intercalated.

Abstract: Cationic polymerization of mono and polyfunctional benzoxazine monomers is described. The chemical structure of the polymers from cationic polymerization of benzoxazine monomers has been identified and distinguished from thermally polymerized products from the same monomers. The controllable microstructure of the polymers from benzoxazines prepared by cationic polymerization offers opportunities to prepare and optimize the polymer structure for specific applications.

Abstract: Low viscosity ternary mixtures of benzoxazine, epoxy and phenolic resins have been developed. The blends render homogeneous and void free cured specimen with a wide range of properties. Melt viscosity values as low as 0.3 Pa.s at 100° C. can be achieved. The phenolic resin acts as a cure accelerator to the system, besides its typical function as a hardener of epoxy resin. Glass transition temperatures Tg as high as 170° C. can also be obtained.

Abstract: A low viscosity high thermal conductivity polymer-based boron nitride composition and a surface-treated boron nitride material for use as a filler in this composition, and methods of preparation is described.

Abstract: Arylamines with electron donating groups such as alkyl and alkoxy groups in the meta position on the aromatic ring change the polymerization temperature of the benzoxazine prepared therefrom and offer an opportunity for an additional crosslinking site (the para position on the aromatic amine can couple to a Mannich base generated by the opening of the oxazine ring of the benzoxazine or a methylene bridge generated by a degradation reaction). Naphthenic amines with an alkyl or alkoxy substituent on the 5.sup.th through the 8.sup.th carbon atom on the naphthalene ring can function similarly. The polymers for benzoxazines prepared from at least 10% substituted aromatic or naphthenic amines are useful due to low polymerization temperatures and higher Tg (glass transition temperature).

Abstract: Benzoxazine monomers, oligomers and polymers are desirably modified by adding pendant functional groups to either the amine or phenolic reactants. These pendant functional groups can be activated at temperatures generally from about 25.degree. C. to about 300.degree. C. to form chemical bonds between said benzoxazine monomers, oligomers and polymers. The additional chemical bonds increase the thermal stability of benzoxazine polymers such that they can withstand higher use temperature, act as more effective flame barriers, or result in higher amounts of char if used as a precursor to high temperature (600-1000.degree. C. reaction condition) chars.

Abstract: The present invention relates to a composition and method for forming a high thermal conductivity polybenzoxazine-based material. The composition comprises at least one benzoxazine resin and a filler material which includes particles of boron nitride in an amount sufficient to establish a thermal conductivity of between about 3 W/mK and 37 W/mK in the polybenzoxazine-based material.

Abstract: A method for preparing a desired benzoxazine compound comprises preparing a substantially homogeneous reaction mixture that includes a phenolic compound; a primary amine; and an aldehyde, but no solvent other than for the solvency which the reactants may have for each other. Following its preparation, the reaction mixture is maintained at a temperature, and for a period sufficient to cause the reactants to combine chemically to form the desired compound.

Abstract: An improved pultrusion process for preparing composites comprises combining polymer precursors in a mixer and continuously introducing the resulting mixture, together with reinforcing fibers, into an impregnation chamber maintained under conditions such that the mixture remains in liquid form of low viscosity. The impregnated fibers are continuously withdrawn from the chamber through a die in which polymerization of the precursors takes place to form the desired composite.

Abstract: The compounds are of the class of multi-functional benzoxazine compounds, useful in forming carbon-carbon composites by means of the pyrolysis of carbon fibers impregnated with such compounds.

Abstract: A method for forming carbon-carbon composites consists of impregnating structures with carbon-forming precursor compounds comprising multi-functional benzoxazine compounds. The impregnated structures are pyrolyzed to form carbonaceous char which serves to fill the interstices in the structure, thus densifying the composites. The process of impregnation and pyrolysis is repeated as many times as required to obtain the composite density desired. Unusually high char yields are produced by multi-functional benzoxazine compounds in which benzoxazine are joined to each other through a bridge characterized by having conjugated unsaturation associated therewith. A number of preferred compounds providing unexpectedly high yields of char are shown, enabling the desired densification to be achieved with a minimum number of impregnation and pyrolysis cycles, thereby reducing the costs of forming the composites.