A Research on Polymerization of o-, m-, and p-Vinylphenol

Abstract

Dependence of radical initiators on polymerizations of o-, m-, and p-vinylphenol (OVP, MVP, and PVP) was investigated. Initiator generating the carbon radical such as AIBN induced polymerizations of these monomers to give fine polymers. That is; MVP and PVP gave polymers with high molecular weight (21,000∼53,000), while OVP gave polymers with relatively low molecular weight (7,600∼9800). The results of the spectroscopic investigations of the polymers thus obtained suggested that all of the polymers consisted of the structure formed through the normal vinyl polymerization mechanism. Initiator generating the oxy radical such as BPO as well as the thio radical such as tetraethylthiuram disulfide did not induce appreciable polymerizability. A reasonable radical polymerization mechanisms for OVP, MVP, and PVP were considered from the results of the kinetic investigations of the polymerization reactions for these monomers. Copolymerizations of OVP, MVP, and PVP with styrene or methyl methacrylate by using AIBN as initiator were investigated. The monomer reactivity ratios and Q-e values for OVP, MVP, and PVP were determined, respectively. The copolymerizations generally gave copolymers with relatively high intrinsic viscosity not only for MVP and PVP but also for OVP without distinction. Cationic polymerizations of OVP, MVP, and PVP with boron trifluoride etherate as initiator were investigated. As the result, it was of interest that on the cationic polymerization only PVP gave polymers with high molecular weight (66,000∼192,000), whereas both OVP and MVP gave polymers with low molecular weight (∼3950 for OVP and ∼710 for MVP, respectively). The results of spectroscopic investigation for the polymers thus obtained indicated that PVP polymers consisted of the structures formed through the normal vinyl polymerization mechanism, while OVP and MVP polymers contain considerable portion of the structures due to the reaction of the vinyl group and the phenol nucleus. The rate of cationic polymerization and the molecular weight of the polymer decreased in the order PVP >> OVP > MVP. Plausible polymerization mechanisms were considered.