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Author
Martin, J. W. | Dickens, B. | Waksman, D. | Bentz, D. P. | Byrd, W. E. | Embree, E. J. | Roberts, W. E.
Title
Thermal Degradation of Poly(Methyl Methacrylate) at 50 Det C to 125 Deg C.
Coporate
National Bureau of Standards, Gaithersburg, MD
Journal
Journal of Applied Polymer Science, Vol. 34, 377-393, 1987
Keywords
polymethyl methacrylate | thermal degradation | temperature | films | monomers | oxidation
Abstract
Small but significant numbers of chain scissions occur in a commercial poly(methyl methacrylate) sheet exposed to temperatures between 50 and 125 deg C. The scission rate is initially high and then levels off to a constant rate. The short-time rate of chain scissions is temperature dependent, while the long-time rate of chain scissions appears to be temperature independent. Four possible sources of random chain scission initiation were considered: (1) the presence of unreacted initiators of polymerization, (2) free radicals generated from additives in the commercial film, (3) weak links in the polymer chain, and (4) free radicals generated from the thermal decomposition of an oxidation product of methyl methacrylate (MMA) monomer. The source most consistent with our results is the one involving free radicals generated from the oxidation product of MMA monomer.