ASTM D6604-2017 pdf free download

ASTM D6604-2017 pdf free download.Standard Practice for Glass Transition Temperatures of Hydrocarbon Resins by Differential Scanning Calorimetry
1. Scope
1.1 This practice covers determination of glass transition temperatures of hydrocarbon (HC) resins by differential scan- ning calorimetry (DSC). 1.2 This practice is applicable to HC resins as defined in Terminology D6640. The normal operating temperature range is from the cryogenic region to approximately 180°C. The temperature range can be extended. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 Further discussion of glass transition can be found in Test Method D3418, and Test Method E1356. 1.5 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 appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 Definitions: 3.1.1 differential scanning calorimetry (DSC), n—A tech- nique in which the difference in energy inputs into a substance and a reference material is measured as a function of temperature, while the substance and reference material are subjected to a controlled temperature program. 3.1.1.1 Discussion—The record is the DSC curve. Two modes, power-compensation DSC and heat-flux DSC, can be distinguished, depending on the method of measurement used. 3.2 For other definitions of terms relating to thermal analysis, see Terminology E473.
4. Summary of Practice
4.1 This practice consists of heating or cooling the test material at a controlled rate, in a controlled atmosphere, and continuously monitoring with a suitable sensing device, the difference in heat input between a reference material and a test material due to energy changes in the material. Absorption or release of energy marks a transition in the specimen resulting in a corresponding baseline shift in the heating or cooling curve.
5. Significance and Use
5.1 Thermal analysis provides a rapid method for determin- ing transition temperatures in HC resins that possess them. 5.2 This practice is useful for both quality assurance and research.
6. Apparatus
6.1 Differential Scanning Calorimeter—An instrument ca- pable of heating or cooling at rates up to 20 6 1°C/min and automatically recording the difference in input between the sample and a reference material to the required sensitivity and precision.6.2 Sample Tubes or Pans—Borosilicate glass tubes are used for certain applications and aluminum or other metal pans of high thermal conductivity for other applications. 6.3 Reference Material—Glass beads, indium, alumina, sili- con carbide, or mercury in a hermetically sealed sample pan, or a material known to be unaffected by repeated heating and cooling and free from interfering transitions may be used. The thermal diffusivity should be as close as possible to that of the sample. 6.4 Recording Charts or Software—Temperature recording apparatus with suitable graduations for measurement of either temperature differential or energy differential versus tempera- ture or time.
10. Procedure
10.1 Use a sample weight appropriate for the material to be tested and the instrument used. In most cases, 10 to 20-mg sample weight is satisfactory. N OTE 1—Since milligram quantities of sample are used, it is essential to ensure that samples are homogenous and representative. Also, particle size has an effect on the detected transition temperatures. Therefore particle size should be fairly consistent from sample to sample. 10.2 Perform and record a preliminary thermal cycle up to a temperature high enough to erase previous thermal and strain history, at a heating rate of 10°C/min. N OTE 2—Use an inert gas purge such as nitrogen since the sample may react with oxygen during the temperature cycle causing an incorrect transition. N OTE 3—An increase or decrease in heating rate from those specified may alter the results. 10.3 Hold this temperature for 10 min. 10.4 Quench cool to 50°C below the expected transition temperature of interest. 10.5 Hold this temperature for 10 min. 10.6 Repeat heating on the same sample at a rate of 10°C/min. and record the heating curve until all desired transitions have been completed.