4.1 These test methods may be used to determine the subnormal temperature stiffening of flexible polymers or fabrics coated with flexible polymers. Temperatures at which the low temperature modulus is a specified multiple or ratio of the modulus at room temperature are interpolated from the twist versus temperature curve. These specified ratios of low-temperature modulus to room-temperature modulus are called relative moduli. These temperatures at the relative moduli encompass the transition region between the glassy and rubbery states of the materials tested.

4.2 These test methods offer only a general guide to stiffness characterization as service conditions of experimental materials may differ greatly from the test conditions.

1.1 These test methods describe the use of a torsional apparatus for measuring the relative low temperature stiffening of flexible polymeric materials and fabrics coated therewith. A routine inspection and acceptance procedure, to be used as a pass-fail test at a specified temperature, is also described.

1.2 These test methods yield comparative data to assess the low temperature performance of flexible polymers and fabrics coated therewith.

1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.4 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.

1.5 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.