Vanillin was found to initiate the polymerization of methyl methacrylate(MMA) in benzene at 85 °C. The effects of the concentrations of vanillin and MMA on the rate of polymerization and on the degree of polymerization of poly-MMA were investigated. A probable initiation mechanism proposed. The polymerization is assumed to proceed through a radical mechanism. The polymeric effect of the polymer containing vanillin units was also studied.

SynopsisBenzaldehyde (PhCHO) is found to be able to initiate the radical polymerization of methyl methacrylate (MMA). The rate of polymerization is expressed by the following equation: R, = const[PhCH0]0.5[MMA]1.5. The overall activation energy is estimated to be 56.3 kJ mole-'. The mechanism of polymerization is discussed.(PhCHO) will be reported. It was concluded that PhCHO is able to initiate the homogeneous radical polymerization in benzene. Styrene (St) could not be polymerized, while acrylonitrile (AN) gave a little conversion under the same condition with the case of MMA. The results obtained is surprising in view of the fact that such a simple compound having aldehyde group as PhCHO can generate the free radicals in benzene solution. = 0 is much more unstable than CsH5-C = 0. O---CH,\ c, CH, \H----O@c\mH, -I // CH,CH,,-C complex "C"

The polymerization of methyl methacrylate(MMA) initiated by poly(formylstyrene) (PFS) was carried out in p-dioxane at 85°C. The rate of polymerization was expressed by the following equation: Rp = const. [PFS]0.43[MMA]1.31. The polymerization proceeded homogeneously through a radical mechanism. The initiating ability of PFS was found to be larger than that of benzaldehyde indicating a macromolecular effect on the polymerization.