A theoretical study of an expanding monomer and an oxirane Part 2: Oxirane and copolymer reactions

Quantum mechanical calculations were performed on copolymerization reactions for 1,5,7,11-tetraoxaspiro[5.5]undecane (TOSU) and bisphenol A diglycidyl ether (BADGE) to predict products formed. Proton affinities were compared to determine which monomer would most likely become activated. Semiempirical results for a new mechanism that forms 1,3-dioxan-2-one (cyclic carbonate) had preferred energetics to the presumed propagation of TOSU indicating it should be competitive. This was further supported by RHF and DFT calculations. The subsequent reincorporation of this by-product had comparable energetics to further propagation by either monomer according to AM1 calculations. Hydrolysis of BADGE was modeled and the effect of this product as well as a BADGE monomer on crosslinking was also investigated to explain product insolubility following extended dark cure time.