Oxidative aging of natural rubber vulcanizates. Part I. The scission of peroxide vulcanizates

✍ Scribed by C. L. M. Bell; R. Tiller

• Publisher: John Wiley and Sons
• Year: 1967
• Tongue: English
• Weight: 415 KB
• Volume: 11
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1967.070110725

✦ Synopsis

A new method has been developed for measuring the number of molecules of oxygen required ( 6 ) to cause a main chain scission in peroxide vulcanisates of natural rubber. This method is based on experimentally derived relationships and is not dependent on statistical theories of rubber elasticity. The value E is only slightly temperature dependent, ranging from 28 a t 65°C. to 22 at 100°C. The effectsof several types of antioxidant have been examined, in all cases e was greatly reduced. The effect of antioxidant 2246 has been studied in more detail and the results indicate that there is a high probabbility of scission occurring a t the termination step in the oxidation chain.

* Some confusion has arisen in the past from the use of the term scission efficiency which, although usually defined as number of cuts per molecule of oxygen absorbed, has also been defined w the reciprocal of this.616 To avoid further confusion the term scission efficiency is not used at all. 1289