Spontaneous alternating copolymerization of 1-silyloxy-1,3-dienes and unsaturated cyclic anhydrides

1-Silyloxy-1,3-dienes, i.e., 1-butadienyloxytrimethylsilane (BdTMS) or 1-bu tadienyloxytert -butyldimethylsilane (BdTBDMS) and unsaturated cyclic anhyd rides, containing maleic anhydride (MAn), citraconic anhydride (CAn), and i taconic anhydride (IAn) were found to form charge transfer complexes (CTC) in benzene. Equilibrium constants, K, of the complexes were calculated by t he Benesi-Hildebrand equation using UV spectroscopy to be 0.4 -1.0. Spontan eous copolymerizations of silyloxydienes with unsaturated cyclic anhydrides were established from 25 to 75 mol% of BdTMS in the feed. All polymers obt ained had molar composition of 50/50 irrespective of feed molar ratios. Int erestingly, molar ratio of 1,4- and 3,4-addtion structure seems to be influ enced by K of CTC. Desilylation and successive lactonization of poly(BdTMS- alt-MAn) were conducted. Conversions of lactonization were beyond Flory's l imit (86.5%) being nearly 100% due to intramolecular reactions of neighbori ng hydroxyl groups and cyclic anhydride in alternating copolymers.