Designation:D4473-08 INTERNATIONAL Standard Test Method for Plastics: Dynamic Mechanical Properties: Cure Behavior1 This standard is issued under the fixed designation D4473; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the U.S. Department of Defense. 1. Scope* 1.8 The values stated in SI units are to be regarded as the standard. 1.1 This test method covers the use of dynamic-mechanical- 1.9 This standard does not purport to address all of the oscillation instrumentation for gathering and reporting the thermal advancement of cure behavior of thermosetting resin. safetyconcerns,if any,associated withitsuse.Itisthe It may be used for determining the cure properties of both responsibility of the user of this standard to establish appro- unsupported resins and resins supported on substrates sub- priate safety and health practices and determine the applica- bility of regulatory limitations prior to use. Specific precau- jected to various oscillatory deformations. tionary statements are given in Note 5. 1.2 This test method is intended to provide a means for determining the cure behavior of supported and unsupported Nore 1—There is no known ISO equivalent to this standard. thermosetting resins over a range of temperatures by free 2. Referenced Documents vibration as well as resonant and nonresonant forced-vibration techniques,in accordance with Practice D4065.Plots of 2.1 ASTM Standards:2 modulus, tan delta, and damping index as a function of D4000 Classification System for Specifying Plastic Materi- time/temperature are indicative of the thermal advancement or als D4065 Practice for Plastics: Dynamic Mechanical Proper- cure characteristics of a resin. ties: Determination and Report of Procedures 1.3 This test method is valid for a wide range of frequencies, D4092 Terminology for Plastics: Dynamic Mechanical typically from 0.01 to 100Hz.However,it is strongly Properties recommended that low-frequency test conditions,generally ASTM/IEEE SI-1O Standard for Use of the International below 1.5 Hz, be utilized as they generally will result in more System of Units (SI): The Modern Metric System definitive cure-behavior information. 1.4 This test method is intended for resin/substrate compos- 3. Terminology ites that have an uncured effective elastic modulus in shear 3.1 Definitions-For definitions applicable to this test greater than 0.5 MPa. method refer to Terminology D4092. 1.5 Apparent discrepancies may arise in results obtained under differing experimental conditions. These apparent differ- 4.Summary ofTest Method ences fromresults observed in anotherstudycan usually be 4.1 Aknown amount of thermosetting liquid resin or resin- reconciled, without changing the observed data, by reporting in impregnated substrate is placed in mechanical oscillation at full (as described in this test method) the conditions under either a fixed or natural resonant frequency or by free vibration which the data were obtained. and at either isothermal conditions, with a linear temperature 1.6 Due to possible instrumentation compliance, especially increase or using a time-temperature relation simulating a in the compressive mode, the data generated may indicate processing condition.The elastic or loss modulus, or both, of relative and not necessarily absolute property values. the composite specimen are measured in shear or compression as a function of time. The point in time when tan delta is 1.7 Test data obtained by this test method are relevant and maximum,and the elastic modulus levels off after an increase appropriate for use in engineering design. is calculated as the gel time of the resin under the conditions of the test. 1 This test method is u