Polymerization system driven by atomatization energy

Abstract

To investigate the polymerization systems driven by aromatization energy, 5,7-dimethyl-1-vinylspiro[2,5] octa-4,7-dien-6-one(5,7-DM-VSO), 4,7-dimethyl-1-vinylspiro[2,5]octa-4,7-dien-6-one(4,7-DM-VSO), 2-vinyl-2``-methylspiro[cyclopropane-1,4``-(1``-naphthalenone)](2-V-2``-M-SCN), 2-phenyl-2``-methylspiro[cyclopropane-1,4``-(1``-naphthalenone)](2-P-2``-M-SCN), 4-allylidene-2,6-dimethyl-2,5-cyclohexadien-1-one(4-A-CHO), and 4-hydroxydiphenyl-4``-sulfonyl chloride(4-H-DSC) were prepared, and their polymerization behaviors under various conditions and the properties of the resulting polymers were investigated. With cyanide ion 5,7-DM-VSO, 4,7-DM-VSO, 2-V-2``-M-SCN, and 2-P-2``-M-SCN gave white powdery polymers which were soluble in common solvents such as chloroform, dichloromethane, and benzene. The inherent viscosities of polymers were in the range of 0.26-0.60 dl/g(concentration of 0.5 g in 100 ml of dimethysulfoxide). All the spectral data indicate that the polymerization of 5,7-DM-VSO,4,7-DM-VSO, and 2-V-2``-M-SCN which have vinyl substituent on cyclopropane ring took place through aromatization of the cyclohexadienone ring without participation of the vinyl group, suggesting that the aromatization energy is the driving force for the polymerization of these monomers. It was also observed that the substituents on cyclopropane ring with different electronic properties affect the tendency of polymerization. 2-P-2``-M-SCN which has phenyl group on cyclopropane ring is more polymerizable than 2-V-2``-M-SCN which has vinyl substituent. In the postulated mechanism of anionic polymerization, a nucleophile first attacks the carbon possessing vinyl(or phenyl) substituent, accompanied by ring opening of cyclopropane ring and aromatization of cyclohexadienone ring. The resulting phenoxide anion will then propagate by attacking the cyclopropane ring of another monomer molecule. 4-A-CHO showed quite different polymerization behavior depending on the employed polymerization ...