Vinyl Polymerization. 269. Polymerization of Methyl Methacrylate Initiated by p,p'-Dimethoxydiphenyldiazomethane

Abstract Using p,p'-dimethoxydiphenyldiazomethane (DMDM) as initiator, the polymerization of methyl methacrylate (MMA) in benzene or in bulk was carried out. The initial rate of polymerization, Rp, was found to be expressed by the following equation: Rp = k[DMDM]0.53 [MMA]0.84 The polymerization was confirmed to proceed by a radical mechanism. The over-all activation energy for the polymerization in benzene was calculated as 19.3 kcal/mole. The rate of thermal decomposition of DMDM was also measured in benzene and the rate equation was obtained as follows: kd (sec−1) = 1.0 × 1015 exp (−29.1 kcal/RT) (for 50-80°C) Explanations of these observations are discussed in connection with those of the preceding papers.