POLYFUNCTIONAL CYANATE MONOMERS AS COMPONENTS OF POLYMER SYSTEMS

Cyclotrimerization of cyanate groups in 2,2-bis(4-cyanatophenyl)propane and other polyfunctional cyanate monomers results in formation of polymer networks with triazine rings. Cyclotrimerization of cyanates in systems containing thermoplastic polymers yields semi-IPNs (interpenetrating Polymer Networks) with elevated heat deflection temperatures. Numerous systems consisting of a poly-functional cyanate monomer and a bismaleimide are described. Such systems can contain, moreover, a third crosslinkable monomer, e.g. an allyl ester or an epoxy resin. Two-component systems consisting of a cyanate monomer and an epoxy resin with corresponding curing agent have been developed. Some other resins and monomers, e.g. phenolics, acrylics and ester imides, were also used in compositions with cyanate monomers. Rubber-flexibilized 2,2-bis(cyanatophenyl)propane polymers have been patented. The author's investigations on IPNS, which were obtained by simultaneous cross-linking of 2,2-bis(4-cyanatophenyl)propane and unsaturated polyester resin, are described.