Investigating the Use of a Protective Coating Material as an Antiozonant for Natural Rubber Under Dynamic Deformation

Abstract

Petroleum wax is known to provide ozone protection to natural rubber under static deformation while a combination of chemical antiozonant and wax is normally used for ozone protection under dynamic conditions. The work described in this paper, aims at investigating the effectiveness of a coating material in protecting a natural rubber substrate from ozone cracking under dynamic deformation. Two compounds (without an antiozonant system) and NRAo (with an antiozonant system) were used as substrates while a grade of liquid nitrile-butadiene rubber was applied as a coating on the substrate surface. Dynamic ozone tests were carried out under standard ASTM D430-88 methods with samples strained to 25%. Comparison of cracking under continuous dynamic conditions and intermittent dynamic conditions were made. Initial results showed that the protective coating was more effective as an antiozonant under intermittent conditions where a combination of wax and a chemical antiozonant were incorporated.

(Af. J. of Science and Technology: 2002 3(2): 123-126)