Reclamation of vulcanized rubbers by chemical degradation. VIII. Absorption of oxygen and degradation of cis-1,4-polyisoprene by phenylhydrazine–iron(II) chloride system

✍ Scribed by Shinzo Yamashita; Shin'Ichi Kato; Nariyoshi Kawabata; Takao Okamoto

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 417 KB
• Volume: 22
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1978.070220204

✦ Synopsis

Abstract

Absorption of oxygen and degradation of cis‐1,4‐polyisoprene by the phenylhydrazine–iron(II) chloride system was investigated at 30°C in connection with the mechanism of reclamation of vulcanized rubbers by the system. In the presence of iron(II) chloride, phenylhydrazine rapidly absorbed an equimolar amount of oxygen and evolved an equimolar amount of nitrogen. Gas‐chromatographic analysis of the reaction mixture showed the presence of benzene, phenol, and biphenyl in 37%, 35–60%, and 4–8% yields, respectively, based on phenylhydrazine. When cis‐1,4‐polyisoprene was added to the reaction mixture, additional absorption of oxygen was observed. Molecular weight of the polymer decreased during the oxygen absorption, and the scission efficiency (i.e., number of mole scissions/mole oxygen) was 0.14–0.26.