POLYMERIZATION OF ALPHA-METHYLENEINDANE - A CYCLIC ANALOG OF ALPHA-METHYLSTYRENE

Alpha-Methyleneindane (MI), a cyclic analog of alpha-methylstyrene which does not undergo radical homopolymerization under standard conditions, was synthesized and subjected to radical, cationic, and anionic polymerizations. MI undergoes radical polymerization with alpha,alpha'-azo-bis (isobutyronitrile) in contrast to alpha-methylstyrene, owing to its reduced steric hindrance, though the polymerization is slow even in bulk. Cationic and anionic polymerizations of MI with BF3OEt2 and n-butyllithium, respectively, proceed rapidly. The thermal degradation behavior of the polymer depends on the polymerization conditions. The anionic and radical polymers are heteortactic-rich. Reactivity ratios in bulk radical copolymerization of MI (M2) with methyl methacrylate (MMA, M1) were determined at 60-degrees-C (r1 = 0.129 and r2 = 1.07). In order to clarify the copolymerization mechanism, radical copolymerization of MI with MMA was investigated in bulk at temperatures ranging from 50 to 80-degrees-C. The Mayo-Lewis equation has been found to be inadequate to describe the results due to depolymerization of MI sequences above 70-degrees-C.