ISSN:
0449-2951
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Thin films of poly(methyl methacrylate) (PMMA) at about 25°C. irradiated with a medium-pressure mercury lamp undergo random scission with a quantum yield of 0.039 and 0.017 scissions/quantum absorbed in vacuum and in air, respectively. Crosslinking in air was not observed. Quantum yields for scission were independent of intensity. Volatile products included methyl formate, methyl methacrylate, and methanol in quantum yields of 0.14, 0.20, and 0.48 molecules per quantum absorbed, respectively. During irradiation in either vacuum or air, the ultraviolet absorption of PMMA increases with a band at 285 mμ, attributed to carbonyl groups in the polymer itself. A mechanism for the photodegradation of PMMA is suggested.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1963.100010321