Comparative Effects of Transition Metal Halide Additives on the Thermal Degradation of Poly(methyl methacrylate

It is well known that poly(methyl methacrylate), PMMA, degrades to produce monomer almost exclusively and that this degradation proceeds from either unsaturated chain ends, head-to-head linkages, or by unzipping of the main chain. The work of both Kashiwagi [1-3] and Manring [4,5] have made it clear that side-chain scission of the carbomethoxy occurs as a part of the unzipping process. Manring suggests that side-chain scission is the initial step while Kashiwagi proposes that an initial main-chain cleavage occurs first and this is then followed by side-chain scission.