Heat-ageing test

Long-term heat-aging tests on Tefzel 280 are in progress. It is expected that its continuous-use temperature will be above 150°C. 

Heat ageing tests are carried out for two distinct purposes. They can be intended to measure changes in the plastic at the elevated service temperature, or else as an accelerated test to estimate the degree of change which would take place over longer times at lower temperatures. Here, we are concerned with the second purpose. 

The reproducibility of heat ageing tests is often relatively poor and it is likely that much of the variability is due to lack of control of the oven and exposure parameters. 

Thermal ageing is a principle factor in the lifetime of rubbers which is critically important for virtually all products. Consequently, there is a vast amount of literature on how estimates of service life can be obtained from heat ageing tests... 

Brown R P, Butler T, Hawley S W. Ageing of Rubber, Accelerated Heat Ageing Test Results, Rapra Technology Ltd, Shawbury, 2001. 

Therefore, additional heat aging tests were conducted to investigate the possibility that hydroquinone-derived phenolic groups might function differently from the monohydric phenols and somehow contribute to the high activity of the phenolic-phosphite systems. Two substituted hydro-quinones, two polymeric phenolic phosphites based on those hydro-quinones, and combinations of the hydroquinones with triphenyl phosphite and tris(nonylphenyl) phosphite were evaluated in the oven-aging test again 0.4% DLTDP was included in the formulations. 

The 39 materials were subjected to accelerated heat ageing for a series of times and temperatures, artificial weathering and exposure to ozone. This report details the results of the accelerated heat ageing tests and their analysis for the prediction of changes after long-term natural ageing. The accelerated weathering and ozone test results have been published separately [2]. 

Ageing of Rubber - Accelerated Heat Ageing Test Results... 

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