Synthesis and polymerization of 8,9-benzo-2-methylene-1,4,6-trioxaspiro[4,4]nonane (BMTN)

8,9-Benzo-2-methylene-1,4,6-trioxaspiro[4,4]nonane (BMTN) was prepared by the reaction of phthalide with epichlorohydrin, followed by dehydrochlorination. BMTN was polymerized with di-t-butyl peroxide (DTBP) to give a solyble polymer with a high molecular weight and good thermal stability. The infrared (IR) and nuclear magnetic resonance (NMR) spectra indicated that the polymer structure contained aromatic ester and ketone in the backbone. T_g and T_m of homopolymer of BMTN were, respectively, 98 and 282°C. BMTN was also readily copolymerized with such vinyl monomers as methyl methacrylate (MMA), acrylonitrile (AN), and maleic anhydride (MA), but not with styrene, in the presence of radical initiators. AN and MA, in particular, were spontaneously copolymerized with BMTN in the absence of radical initiators at 40°C. From the results of ultra violet (UV) spectra it is suggested that spontaneous copolymerization proceeds via a charge-transfer complex between BMTN as an electron donor and AN or MA as an acceptor.