In this study the apparent rate constant model was used to determine the mechanism of termination and other rate constants for free radical copolymerizations that are chemically controlled with no penultimate effect. The data required were the number average molecular weight and the conversion obtained at various initial initiator concentrations and monomer compositions, and two rate constants of propagation of the homopolymerizations of its two monomers. The bulk free radical copolymerization of methyl methacrylate (MMA) and styrene(St) at 60°C was studied. Three published literature values of the propagation rate constants k11 and k22. 750, 150; 515, 145; 705, 145, were used for the determination. The unit of the rate constants used was liter/mole/s. The modes of the termination reaction obtained, depending on k11, k22 used, are given as follows: (Table presented) The modes of termination obtained by the case of k11 = 750 and k22 = 150 are in good agreement with those shown by Bevington, Melville, and Taylor (1).
All Science Journal Classification (ASJC) codes
- Polymers and Plastics
- Materials Chemistry