Abstract
Polybenzoxazine is a novel type of phenolic resin that is prepared by the ring-opening polymerization of a cyclic monomer. Cyclic monomers are easily prepared in high yields from amines, phenols, and formaldehyde. Polybenzoxazines, like typical phenolic resin, have advantageous properties such as excellent thermal properties, inflammability, electrical properties, and so on. They also possess various characteristics, that are not found in the typical phenolic resin, like molecular design flexibility, no evolution of volatiles during the cure process, and excellent dimensional stability. The problems that have to be solved are relatively high curing temperature and the brittleness of the cured materials. Further improvement of thermal properties is also expected. As the method for high performance polybenzoxazines, designing of cyclic monomers, preparation of high molecular weight and soluble precursors, polymer alloys, and organic-inorganic hybrids have been examined, and were found to be effective for the improvement of thermal and mechanical properties and lowering the cure temperatures.
