1、Designation:E260209(Reapproved 2015)Standard Test Methods forthe Assignment of the Glass Transition Temperature byModulated Temperature Differential Scanning Calorimetry1This standard is issued under the fixed designation E2602;the number immediately following the designation indicates the year ofor
2、iginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods describe the assignment of the glasstransition te
3、mperature of materials using modulated tempera-ture differential scanning calorimetry(MTDSC)over thetemperature range from 120 to+600C.The temperaturerange may be extended depending upon the instrumentationused.1.2 The values stated in SI units are to be regarded asstandard.No other units of measure
4、ment are included in thisstandard.1.3 There are no ISO equivalents to this standard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and de
5、termine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E473 Terminology Relating to Thermal Analysis and Rhe-ologyE967 Test Method for Temperature Calibration of Differen-tial Scanning Calorimeters and Differential Thermal Ana-lyzersE968 Practice
6、for Heat Flow Calibration of DifferentialScanning CalorimetersE1142 Terminology Relating to Thermophysical PropertiesE1356 Test Method for Assignment of the Glass TransitionTemperatures by Differential Scanning CalorimetryE1545 Test Method for Assignment of the Glass TransitionTemperature by Thermom
7、echanical AnalysisE1640 Test Method for Assignment of the Glass TransitionTemperature By Dynamic Mechanical Analysis3.Terminology3.1 DefinitionsSpecific technical terms found in these testmethods are defined in Terminologies E473 and E1142 includ-ing differential scanning calorimetry,glass transitio
8、n,glasstransition temperature,specific heat capacity,and thermalcurve.3.2 Definitions of Terms Specific to This Standard:3.2.1 extrapolated end temperature(Te),nthe point ofintersection of the tangent drawn at the point of greatest slope(that is,the inflection point)in the transition region with the
9、extrapolated baseline following the transition.3.2.2 extrapolated onset temperature(Tf),nthe point ofintersection of the tangent drawn at the point of greatest slope(that is,the inflection point)in the transition region with theextrapolated baseline prior to the transition.3.2.3 midpoint temperature
10、(Tm),nthe point on the ther-mal curve corresponding to the average of the extrapolatedonset and extrapolated end temperatures.3.2.4 modulated,na prefix indicating that a parameterchanges in a periodic manner during the experiment.3.2.5 modulated heat flow,nthe heat flow resulting froman applied modu
11、lated temperature program.3.2.6 modulated temperature differential scanning calorim-etry(MTDSC),na method of differential scanning calorim-etry(DSC)that varies the temperature sinusoidally or with aperiodic step-and-hold or pulse program to the test specimenover a traditional isothermal or temperatu
12、re ramp program.Results from the experiment include reversing and nonrevers-ing heat flow and specimen temperature.3.2.7 nonreversing heat flow,nthe kinetic component ofthe total heat flow.That is,the portion of the heat flow thatresponds to temperature and not to the temperature rate ofchange.3.2.8
13、 reversing heat flow,nthe portion of the total heatflow that responds to the temperature rate of change.3.2.9total heat flow,nthe value of the modulated heatflow averaged over one modulation period or impulse.1These test methods are under the jurisdiction of ASTM Committee E37 onThermal Measurements
14、 and is the direct responsibility of Subcommittee E37.01 onCalorimetry and Mass Loss.Current edition approved May 1,2015.Published May 2015.Originallyapproved in 2009.Last previous edition approved in 2009 as E2602 09.DOI:10.1520/E2602-09R15.2For referenced ASTM standards,visit the ASTM website,www.
15、astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.9.1 Discus
16、sionThe total heat flow is equivalent to theheat flow signal of conventional differential scanning calorim-etry.3.2.9.2 DiscussionThe total heat flow is equal to the sumof the reversing and nonreversing heat flows.4.Summary of Test Method4.1 The determination of the glass transition by differentialscanning calorimetry using Test Method E1356 is difficultwhen kinetic events such as the cure exotherm of a thermosetresin occur at or near the glass transition.In MTDSC,the totalheat flow signal is se