ASTM_E_1356_-_08_2014.pdf

Designation:E135608(Reapproved 2014)Standard Test Method for Assignment of theGlass Transition Temperatures by Differential ScanningCalorimetry1This standard is issued under the fixed designation E1356;the number immediately following the designation indicates the year oforiginal 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 This test method covers the assignment of the glasstransition temperatures of materials using differential scanningcalorimetry or differential thermal analysis.1.2 This test method is applicable to amorphous materials orto partially crystalline materials containing amorphous regions,that are stable and do not undergo decomposition or sublima-tion in the glass transition region.1.3 The normal operating temperature range is from 120 to500C.The temperature range may be extended,dependingupon the instrumentation used.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 ISO standards 113572 is equivalent to this standard.1.6 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 determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE473 Terminology Relating to Thermal Analysis and Rhe-ologyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE967 Test Method for Temperature Calibration of Differen-tial Scanning Calorimeters and Differential Thermal Ana-lyzersE1142 Terminology Relating to Thermophysical Properties2.2 ISO Standards:3113572 Differential Scanning Calorimetry(DSC)-Part 2Determination of Glass Transition Temperature3.Terminology3.1 Definitions:3.1.1 DefinitionsThe following terms are applicable tothis test method and can be found in Terminologies E473 andE1142:differential scanning calorimetry(DSC);differentialthermal analysis(DTA);glass transition;glass transitiontemperature(Tg);and specific heat capacity.3.2 Definitions of Terms Specific to This Standard:3.2.1 There are commonly used transition points associatedwith the glass transition region(see Fig.1).3.2.1.1 extrapolated end temperature,(Te),Cthe point ofintersection of the tangent drawn at the point of greatest slopeon the transition curve with the extrapolated baseline followingthe transition.3.2.1.2 extrapolated onset temperature,(Tf),Cthe pointof intersection of the tangent drawn at the point of greatestslope on the transition curve with the extrapolated baselineprior to the transition.3.2.1.3 inflection temperature,(Ti),Cthe point on thethermal curve corresponding to the peak of the first derivative(with respect to time)of the parent thermal curve.This pointcorresponds to the inflection point of the parent thermal curve.3.2.1.4 midpoint temperature,(Tm),Cthe point on thethermal curve corresponding to12the heat flow differencebetween the extrapolated onset and extrapolated end.3.2.1.5 DiscussionMidpoint temperature is most com-monly used as the glass transition temperature(see Fig.1).3.2.2 Two additional transition points are sometimes iden-tified and are defined:3.2.2.1 temperature of first deviation,(To),Cthe point offirst detectable deviation from the extrapolated baseline prior tothe transition.1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.01 on Calo-rimetry and Mass Loss.Current edition approved March 15,2014.Published April 2014.Originallyapproved in 1991.Last previous edition approved in 2008 as E1356 08.DOI:10.1520/E1356-08R14.2For referenced ASTM standards,visit the ASTM website,www.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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.2.2 temperature of return to baseline,(Tr),Cthe pointof last deviation from the extrapolated baseline beyond thetransition.4.Summary of Test Method4.1 This test method involves continuously monitoring thedifference in heat flow into,or temperature between a referencematerial and a test material when they are heated or cooled ata controlled rate through the glass transition region of the testmaterial and analyzing the resultant thermal curve to providethe glass transition temperature.5.Significance and Use5.1 Differential scanning calorimetry provides a rapid testmethod