Screening and Evaluation of Antiozonants and Waxes in SB-R Rubber

摘要

The report covers an investigation to determine the effectiveness of various antiozonants and antichecking waxes, both individually and in combination, in preventing ozone cracking and deterioration of SB-R rubbers caused by atmospheric ozone attack and by exposure to extreme climatic conditions. Test sheets, 2 inches by 6 inches by 0.080 inch, of Naugapol 1023, each containing either one of 9 antiozonants or one of 11 waxes were subjected to accelerated ozone exposure and evaluated for resistance to deterioration and cracking. Samples of 18 compounds, each containing various combinations of the most promising antiozonants and waxes selected from the above candidates, were exposed at Fort Belvoir, Virginia; Fort Wainwright, Alaska; and Yuma, Arizona, for 8, 16, and 24 months. The specimens were elongated 0, 10, and 20% during exposure and examined periodically for evidence of cracking. Physical properties determined after each exposure period were compared with initial results and data from other accelerated aging tests performed in the laboratory. The results of all tests were analyzed to ascertain the relative effectiveness of these ozone deterioration inhibiting systems when used in military end items requiring SB-R rubber components. (Author)