- Author
-
Hirata, T.
|
Kashiwagi, T.
|
Brown, J. E.
- Title
- Thermal and Oxidative Degradation of Poly(methyl methacrylate): Weight Loss.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Journal
-
Macromolecules,
Vol. 18,
No. 7,
1410-1418,
July 1984
- Keywords
-
oxygen
|
weight loss
|
polymethyl methacrylate
|
thermogravimetry
- Abstract
- The effects of gas-phase oxygen on the weight loss of poly(methyl methacrylate) (PMMA) were studied by comparing weight loss behavior of PMMA degraded in nitrogen with that of PMMA degraded in air. Thermogravimetry (TG) and isothermal heating experiments were conducted to obtain kinetic constants for the degradation of PMMA. The results show that there are two distinct effects of oxygen on the weight loss of PMMA; one is an increase in PMMA stability at low temperatures and the other is a destabilization of PMMA at high temperatures by enhanced random scission. there are two reaction stages for the weight loss from PMMA degraded in nitrogen and four reaction stages for PMMA degraded in air. These four reaction stages are, however, caused mainly by impurities in the sample. The effects of purification of the commercial PMMA on the weight loss are small for samples degraded in nitrogen, but they are significant for samples degraded in air.