Chemorheological study of cured polysulfide liquid polymers

✍ Scribed by P. C. Colodny; A. V. Tobolsky

• Publisher: John Wiley and Sons
• Year: 1959
• Tongue: English
• Weight: 630 KB
• Volume: 2
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1959.070020406

✦ Synopsis

Abstract

The effect of curing agents and their reaction products upon the disulfide interchange reaction of cured liquid polysulfide polymers was studied. The curing process involved the oxidation of the mereaptan terminals of the liquid polymer to disulfide linkages or the reaction of these end groups with some polyfunctional reagent. Several different types of cure were attempted on the same batch of the liquid polymer including oxidation by metallic oxides, organic peroxides, and hydroperoxides, p‐quinonedioxime, and catalyzed air oxidation. Cures were also obtained by the use of diisocyanates. The disulfide interchange was studied by means of stress relaxation. It was found that the rate of exchange was greatly accelerated by the presence of ionic or alkaline materials. In their absence the exchange reaction proceeded quite slowly. The incorporation of excess sulfur also increased the reaction rate. The mechanism of the reaction is believed to be predominantly ionic.