PHOTODEGRADATION OF HIGH POLYMERS IN SOLUTION. PART II. SOLVENT EFFECTS IN THE PHOTOLYSIS OF POLYSTYRENE.
Abstract
Polystyrene photolysis in solution under ultraviolet irradiation by low-pressure and medium-pressure mercury lamps was studied in the presence and absence of air at about 25C. Both intrinsic viscosity and ultraviolet spectral changes were followed during the exposures. In the absence of air, crosslinking is a major process; a measurable decrease in viscosity occurred only in dioxane and carbon tetrachloride and, at sufficiently high doses, insoluble material was formed. In the presence of air, viscosity decreases were observed in all solvents; apparent quantum yields for random scission ranged from 0.0002 in cyclohexane to 0.11 in carbon tetrachloride. In the latter solvent, quantum yield decreased with increasing polymer concentration and intensity of absorbed radiation. Carbon tetrachloride sensitized the degradation in cyclohexane, and small amounts of cyclohexane acted as an inhibitor in carbon tetrachloride solutions. Spectral changes were similar to those observed earlier for poly(alpha-methylstyrene). Mechanisms are suggested. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 21, 1965
- Accession Number
- AD0624593
Entities
People
- R. B. Fox
- T. R. Price
Organizations
- United States Naval Research Laboratory