This test method outlines the use of dynamic mechanical instrumentation for determining and reporting the visco-elastic properties of thermoplastic and thermosetting resins and composite systems in the form of rectangular bars molded directly or cut from sheets, plates, or molded shapes. The data generated, using three-point bending techniques, may be used to identify the thermomechanical properties of a plastic material or compositions using a variety of dynamic mechanical instruments.
This test method is intended to provide means for determining the viscoelastic properties of a wide variety of plastics materials using nonresonant, forced-vibration techniques in accordance with Practice D4065. Plots of the elastic (storage) modulus; loss (viscous) modulus; complex modulus and tan delta as a function of frequency, time, or temperature are indicative of significant transitions in the thermomechanical performance of polymeric material systems.
This test method is valid for a wide range of frequencies, typically from 0.01 to 100 Hz.
Apparent discrepancies may arise in results obtained under differing experimental conditions. These apparent differences from results observed in another study can usually be reconciled, without changing the observed data, by reporting in full (as described in this test method) the conditions under which the data were obtained.
Due to possible instrumentation compliance, the data generated are intended to indicate relative and not necessarily absolute property values.
Test data obtained by this test method are relevant and appropriate for use in engineering design.
The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.
NOTE 1-This test method is equivalent to ISO 6721, Part 5.
*A Summary of Changes section appears at the end of this standard