Oxidation behavior of isoprene/styrene copolymer and butadiene/styrene copolymer

✍ Scribed by Kazuyuki Sakota; Kenji Okuno; Takuji Okaya; Shizuo Tsuchiya

• Publisher: John Wiley and Sons
• Year: 1976
• Tongue: English
• Weight: 413 KB
• Volume: 20
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1976.070201015

✦ Synopsis

Abstract

The oxidation behavior of emulsion isoprene/styrene copolymer (SIR) and emulsion butadiene/styrene copolymer (SBR) by heat aging of ultraviolet irradiation in air has been investigated from the change of gel fraction, intrinsic viscosity, molecular weight distribution, and mechanical properties. Upon oxidation by heat aging, SIR predominantly undergoes chain scission and shows only a slight change of mechanical properties, whereas SBR predominantly undergoes crosslinking and sharply becomes brittle. Upon oxidation by ultraviolet irradiation, SIR undergoes both chain scission and crosslinking and shows almost no substantial change in mechanical properties, whereas SBR predominantly undergoes crosslinking and sharply becomes brittle. The probability ratio of chain scission to crosslinking with oxidation by heat aging or ultraviolet irradiation was determined by the method of Charlesby et al. The results can reasonably explain the oxidation behavior of the copolymers described above.