Main-chain benzoxazine oligomers: A new approach for resin transfer moldable neat benzoxazines for high performance applications

A new approach has been developed to enhance the processability of main-chain benzoxazine polymers by synthesizing benzoxazine main-chain oligomers that are low in viscosity while maintaining the major part of the advantages of main-chain type polybenzoxazines. A series of main-chain benzoxazine oligomers have been synthesized using bisphenol-F isomers. The structure of the oligomers has been characterized by nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FT-IR). The molecular weight has been evaluated using size exclusion chromatography (SEC). For a viscosity study, a mixture of benzoxazine monomers derived from the same bisphenol-F isomers has been used as control and a reactive diluent to control the viscosity.