1984 Volume 41 Issue 7 Pages 371-375
Although thiols, having large chain transfer constants are generally used as a regulator of polymerization degree, mercaptocarboxylic acid (MCA), such as mercaptoacetic acid (MAc) or mercaptosuccinic acid (MSuc), was found to initiate the radical polymerization of methyl methacrylate (MMA) in methanol. The overall activation energies for polymerization were 10. 9 kcal/mol (for MAc system) and 10.0 kcal/mol (for MSuc system), respectively. The following rate equations were obtained :
Rp=k [MMA]1.50 [MAc]0.35
Rp=k [MMA]1.45 [MSuc]0.42
The results indicated that the initiating radical was produced through the complex of MMA and MCA. The rate constants for chain transfer to MCA were evaluated as 0.48 for MAc and 0.42 for MSuc at 60°C, respectively.
