STRUCTURE DEVELOPMENT IN CYANATE ESTER POLYMERIZATION

We present results on the product distribution obtained from the polym erization of the dicyanate monomer of bisphenol A carried out under di fferent reaction conditions. Small quantities of side-products were ob served using both size exclusion chromatography and high-pressure liqu id chromatography for samples polymerized under an inert atmosphere. D espite the presence of side-products, the oligomer distribution from S EC, after correcting for differences in refractive index, was found to agree well with random branching predictions. Results from HPLC also confirm good agreement with the theoretical prediction. Furthermore, a gel conversion of approximately 0.51(-0.01, +0.03) was measured for t he inert atmosphere product, which is within experimental error of the ideal value of 0.50. The monomer content of a polymerization carried out open to the atmosphere, however showed significant disagreement wi th theory.