PHOTODEGRADATION OF HIGH POLYMERS. PART VII - PHOTOLYSIS OF POLY(N-BUTYL METHACRYLATE) IN VACUUM,
Abstract
The photodegradation of poly(n-butyl methacrylate) from three sources has been studied. At 100 C, samples lost 90 to 95% of their original weight after about 30 hr of exposure and left about 4% insoluble polymer. At 50 C, about half as much material was volatilized, and one fourth was left insoluble. Most of the volatile products consisted of n-butul methacrylate (monomer), n-butyl formate, and 1-butene; lesser amounts of n-butyraldehyde, 1-butanol, n-butane, and carbon dioxide were also produced. Increasing the temperature increased the relative yield of monomer, and, except for 1-butene, decreased the relative yields of the other products. Although films degraded at 100 C showed nearly complete volatilization, a sample exposed at 50 C and then re-exposed at 100 C showed little additional volatilization at the higher temperature. This suggests that more crosslinking occurs at the lower temperature. The volatile products other than monomer are accounted for by cleavage reactions of the pendent ester groups, with subsequent hydrogen abstraction or disproportionation of the free radicals. Monomer results from main chain cleavage followed by depolymerization; this reaction predominates at the higher temperature. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 14, 1965
- Accession Number
- AD0624303
Entities
People
- L. G. Isaacs
- R. B. Fox
Organizations
- United States Naval Research Laboratory