ASTM D1329-16(2021)

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.

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.

1.3?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.