ASTM D1329 – Standard Test Method for Evaluating Rubber Property—Retraction at Lower Temperatures (TR Test)
Description:
Significance and Use
4.1 The difference between the temperature at which a vulcanizate retracts 10 % (TR10) and the temperature at which a vulcanizate retracts 70 % (TR70) increases as the tendency to crystallize increases.
4.2 TR70 correlates with low-temperature compression set.
4.3 TR10 has been found to correlate with brittle points in vulcanizates based on polymers of similar type.
4.4 In general, the retraction rate is believed to correlate with low-temperature flexibility of both crystallizable and noncrystallizable rubbers.
Scope
1.1 This test method describes a temperature-retraction procedure for rapid evaluation of crystallization effects and for comparing viscoelastic properties of rubber and rubber-like materials at low temperatures. This test method is useful when employed in conjunction with other low-temperature tests for selection of materials suitable for low-temperature service.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.