1、Designation: E1640 13 (Reapproved 2018)Standard Test Method forAssignment of the Glass Transition Temperature ByDynamic Mechanical Analysis1This standard is issued under the fixed designation E1640; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se 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 a glasstransition temperature (Tg) of materials
3、using dynamic me-chanical analyzers.1.2 This test method is applicable to thermoplasticpolymers, thermoset polymers, and partially crystalline mate-rials which are thermally stable in the glass transition region.1.3 The applicable range of temperatures for this testmethod is dependent upon the instr
4、umentation used, but, inorder to encompass all materials, the minimum temperatureshould be about 150C.1.4 This test method is intended for materials having anelastic modulus in the range of 0.5 MPa to 100 GPa.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurem
5、ent are included in thisstandard.1.6 This standard is similar to IEC 61006 except thatstandard uses the peak temperature of the loss modulus peak asthe glass transition temperature while this standard uses theextrapolated onset temperature of the storage modulus change.1.7 This standard does not pur
6、port 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.8 This international standa
7、rd was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Ref
8、erenced Documents2.1 ASTM Standards:2D4092 Terminology for Plastics: Dynamic MechanicalPropertiesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1142 Terminology Relating to Thermophysical PropertiesE1363 Test Method for Temperature Calibration of The
9、rmo-mechanical AnalyzersE1545 Test Method for Assignment of the Glass TransitionTemperature by Thermomechanical AnalysisE1867 Test Methods for Temperature Calibration of Dy-namic Mechanical AnalyzersE2254 Test Method for Storage Modulus Calibration ofDynamic Mechanical AnalyzersE2425 Test Method for
10、 Loss Modulus Conformance ofDynamic Mechanical Analyzers2.2 Other Standards:IEC 61006 Methods of Test for the Determination of theGlass Transition Temperature of Electrical Insulating Ma-terials33. Terminology3.1 Definitions:3.1.1 Specific technical terms used in this document aredefined in Terminol
11、ogies D4092 and E1142 including Celsius,dynamic mechanical analyzer, glass transition, glass transitiontemperature, loss modulus, storage modulus, tangent delta, andviscoelasticity.4. Summary of Test Method4.1 Aspecimen of known geometry is placed in mechanicaloscillation at either fixed or resonant
12、 frequency and changes inthe viscoelastic response of the material are monitored as afunction of temperature. Under ideal conditions, duringheating, the glass transition region is marked by a rapid1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the dire
13、ct responsibility of Subcommittee E37.10 onFundamental, Statistical and Mechanical Properties.Current edition approved March 15, 2018. Published March 2018. Originallyapproved in 1994. Last previous edition approved in 2013 as E1640 13. DOI:10.1520/E1640-13R18.2For referenced ASTM standards, visit t
14、he 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
15、 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles
16、for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1decrease in the storage modulus and a rapid increase in the lossmodulus and tangent delta. The glass transition of the testspecimen is indicat
17、ed by the extrapolated onset of the decreasein storage modulus which marks the transition from a glassy toa rubbery solid.5. Significance and Use5.1 This test method can be used to locate the glasstransition region and assign a glass transition temperature ofamorphous and semi-crystalline materials.
18、5.2 Dynamic mechanical analyzers monitor changes in theviscoelastic properties of a material as a function of tempera-ture and frequency, providing a means to quantify thesechanges. In ideal cases, the temperature of the onset of thedecrease in storage modulus marks the glass transition.5.3 A glass
19、transition temperature (Tg) is useful in charac-terizing many important physical attributes of thermoplastic,thermosets, and semi-crystalline materials including their ther-mal history, processing conditions, physical stability, progressof chemical reactions, degree of cure, and both mechanical ande
20、lectrical behavior. Tgmay be determined by a variety oftechniques and may vary in accordance with the technique.5.4 This test method is useful for quality control, specifica-tion acceptance, and research.6. Interferences6.1 Because the specimen size will usually be small, it isessential that each sp
21、ecimen be homogeneous or representativeof the material as a whole, or both.6.2 An increase or decrease in heating rates from thosespecified may alter results.6.3 A transition temperature is a function of the experimen-tal frequency, therefore the frequency of test must always bespecified. (The trans
22、ition temperature increases with increasingfrequency.) Extrapolation to a common frequency may beaccomplished using a predetermined frequency shift factor orassuming the frequency shift factor of about 8C per decade offrequency.4Such extrapolation shall be reported.7. Apparatus7.1 The function of th
23、e apparatus is to hold a specimen ofuniform dimension so that the sample acts as the elastic anddissipative element in a mechanically oscillated system. Dy-namic mechanical analyzers typically operate in one of severalmodes. See Table 1.7.2 The apparatus shall consist of the following:7.2.1 Clamps,
24、a clamping arrangement that permits grippingof the specimen. Samples may be mounted by clamping at bothends (most systems), one end (for example, torsionalpendulum), or neither end (free bending between knife edges).7.2.2 Oscillatory Stress (Strain), for applying an oscillatorydeformation (strain) o
25、r oscillatory stress to the specimen. Thedeformation may be applied and then released, as in freelyvibrating devices, or continuously applied, as in forced vibra-tion devices.7.2.3 Detector, for determining the dependent and indepen-dent experimental parameters, such as force (or stress), dis-placem
26、ent (or strain), frequency, and temperature. Tempera-tures should be measurable with an accuracy of 60.5C, forceto 61 %, and frequency to 60.1 Hz.7.2.4 Temperature Controller and Oven, for controlling thespecimen temperature, either by heating, cooling (in steps orramps), or by maintaining a constan
27、t experimental environ-ment. The temperature programmer shall be sufficiently stableto permit measurement of specimen temperature to 60.5C.The precision of the required temperature measurement is61.0C.7.2.5 Data Collection Device, to provide a means ofacquiring, storing, and displaying measured or c
28、alculatedsignals, or both. The minimum output signals require fordynamic mechanical analysis are storage modulus, lossmodulus, tangent delta, temperature and time.NOTE 1Some instruments suitable for this test may display only linearor logarithm storage modulus while others may display either linear
29、orlogarithm storage modulus, or both. Care must be taken to use the samemodulus scale when comparing unknown specimens, and in the compari-son of results from one instrument to another.7.3 Nitrogen, Helium or other gas supplied for purgingpurposes.7.4 Calipers or other length measuring device capabl
30、e ofmeasuring dimensions (or length within) 60.01 mm.8. Precautions8.1 Toxic and corrosive, or both, effluents may be releasedwhen heating some materials and could be harmful to person-nel and to apparatus.8.2 Multiple TransitionsUnder some experimental condi-tions it is possible to have transitions
31、 secondary to the primaryglass transition. Secondary transitions may be related to theglass transition of a second polymeric phase, melt processes,crystallization, chemical reactions, the motion of groups pen-dent to the main backbone or the crankshaft motion of thepolymer backbone.9. Samples9.1 Sam
32、ples may be any uniform size or shape, but areordinarily analyzed in rectangular form. If some heat treatmentis applied to the specimen to obtain this preferred analyticalform, such treatment should be reported.9.2 Due to the numerous types of dynamic mechanicalanalyzers, sample size is not fixed by
33、 this test method. In many4Ferry, D., Viscoelastic Properties of Polymers, John Wiley dec = decaying amplitude; forced = forced oscillation;CA = constant amplitude; res = resonant frequency; fix = fixed frequency;CS = controlled stress.E1640 13 (2018)2cases, specimens measuring between 1520 mm and1
34、10 50 mm are suitable.NOTE 2It is important to select a specimen size appropriate for boththe material and the testing apparatus. For example, thick samples may berequired for low modulus materials while thin samples may be requiredfor high modulus materials.10. Calibration10.1 Calibrate the storage
35、 modulus, loss modules, andtemperature signals in accordance with Test Methods E1867,E2254, and E2425, respectively.11. Procedure11.1 Mount the specimen in accordance with procedurerecommended by the manufacturer.11.2 Measure the length, width, and thickness of the speci-men to an accuracy of 60.01
36、mm.11.3 Maximum strain amplitude should be within the linearviscoelastic range of the material. Strains of less than 1 % arerecommended and should not exceed 5 %.11.4 Conduct tests at a heating rate of 1C/min and afrequency of 1 Hz. Other heating rates and frequencies may beused but shall be reporte
37、d.NOTE 3The glass transition temperature measured by dynamicmechanical measurements is dependent upon heating rate and oscillatoryfrequency. The experimental heating rate and the frequency of oscillationshould be slow enough to allow the entire specimen to reach satisfactorythermal and mechanical eq
38、uilibration. When the heating rate or oscillatoryrate is high, the experimental time scale is shortened, and the apparent Tgis raised. Changing the time scale by a factor of 10 will generally result ina shift of about 8C for a typical amorphous material. The effect of thesevariables on the temperatu
39、re of the tangent delta peak may be observed byrunning specimens at two or more rates and comparing the results (seeAppendix X1).NOTE 4Where possible in automated systems, a minimum of one datapoint should be collected for each C increase in temperature. At low andhigh frequencies, use care in the s
40、election of scanning rate and frequencyrate; select test conditions and a data collection rate that will ensureadequate resolution of the mechanical response of the specimen. Forexample, select a heating rate that allows the specimen to complete at leastone oscillation for each C increase in tempera
41、ture.11.5 Measure and record the storage modulus, from 30Cbelow to 20C above the suspected glass transition region.12. Calculation12.1 For the purpose of this test method the glass transitionshall be taken as the extrapolated onset to the sigmoidal changein the storage modulus observed in going from
42、 the hard, brittleregion to the soft, rubbery region of the material under test.NOTE 5Storage modulus may be displayed on a linear or logarithmicscale. The reported glass transition temperature will differ depending uponthe scale chosen. The scale type (for example, linear or logarithmic) shallbe re
43、ported and must be the same for all parties comparing results.12.1.1 Construct a tangent to the storage modulus curvebelow the transition temperature.12.1.2 Construct a tangent to the storage modulus curve atthe inflection point approximately midway through the sigmoi-dal change associated with the
44、transitions.12.1.3 The temperature at which these tangent lines inter-sect is reported as the glass transition temperature, Tg(see Fig.1).NOTE 6Under special circumstances agreeable to all parties, othertemperatures taken from the storage modulus, loss modulus, or tangentdelta curve may be taken to
45、represent the temperature range over whichthe glass transition takes place. Among these alternative temperatures arethe peak of the loss modulus (Tl) or tangent delta (Tt) curves as illustratedin Fig. 2 and Fig. 3, respectively. These temperatures are generally in theorder Tg Tl Tt.12.2 For fixed fr
46、equency measurements at 1 Hz.12.3 For measurements made at frequencies other than 1Hz.12.3.1 Using a predetermined frequency shift factor (k) (seeAppendix X1), calculate the first approximation of the glasstransition temperature (Tl) using Eq 1.Tl 5 T1T2klogF1Hz(1)12.3.2 Calculate the glass transiti
47、on temperature using Eq 2:FIG. 1 Storage ModulusE1640 13 (2018)3T15 T1TT1klogF1Hz(2)where:k = predetermined frequency shift factor (see AppendixX1),F = frequency of measurement (Hz),T = glass transition temperature observed at frequency F(K),Tl = first approximation for the glass transition temperat
48、ureat 1 Hz (K), andTl= glass transition temperature at 1 Hz (K).FIG. 2 Loss ModulusFIG. 3 Tangent DeltaE1640 13 (2018)4example:k = 12 417KF =2HzT = 100C = 373KT =373K1373K!373K!212 417Klog25373K23.37K= 369.62KT =3731373K!369.62K!212 417Klog25373K23.34K= 369.66K = 96.5C13. Report13.1 The report shall
49、 include the following:13.1.1 A complete identification and description of thematerial testing including dimensions and any pretreatment.13.1.2 A description of the instrument used to perform thetest.13.1.3 A description of the temperature calibration proce-dure used.13.1.4 Whether linear or logarithmic storage modulus wasdisplayed.13.1.5 The calculated glass transition temperature.13.1.6 The frequency of test and any extrapolation proce-dures used to provide results comparable at 1 Hz.13.1.7 The dynamic mechanical curves recorded.13.1.8 The
