1、Designation: E1640 09Standard 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 case of revision, th
2、e 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 using dynamic me-c
3、hanical analyzers.1.2 This test method is applicable to thermoplastic poly-mers, thermoset polymers, and partially crystalline materialswhich are thermally stable in the glass transition region.1.3 The applicable range of temperatures for this testmethod is dependent upon the instrumentation used, b
4、ut, inorder to encompass all materials, the minimum temperatureshould be about 150 C.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 measurement are included
5、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 purport to address a
6、ll 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:2D4092 Terminology f
7、or 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 Ther-momechanical AnalyzersE1545 Test Method for Assignment
8、 of the Glass TransitionTemperature by Thermomechanical AnalysisE1867 Test Method for Temperature Calibration of Dy-namic Mechanical AnalyzersE2254 Test Method for Storage Modulus Calibration ofDynamic Mechanical Analyzers2.2 Other Standards:IEC 61006 Methods of Test for the Determination of theGlas
9、s Transition Temperature of Electrical Insulating Ma-terials33. Terminology3.1 Definition:3.1.1 Specific technical terms used in this document aredefined in Terminology D4092 and E1142 including Celsius,dynamic mechanical analyzer, glass transition, glass transitiontemperature, loss modulus, storage
10、 modulus, tangent delta andviscoelasticity.3.1.2 dynamic mechanical analyzerany of various com-mercial or experimental devices used to study the viscoelasticresponse of a specimen under a forced or free resonantoscillatory load. The force may be applied in torsion, flexure,or a combination of tensio
11、n and compression.4. Summary of Test Method4.1 Aspecimen of known geometry is placed in mechanicaloscillation at either fixed or resonant frequency and changes inthe viscoelastic response of the material are monitored as afunction of temperature. Under ideal conditions, during heat-ing, the glass tr
12、ansition region is marked by a rapid decrease inthe storage modulus and a rapid increase in the loss modulusand tangent delta. The glass transition of the test specimen is1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subco
13、mmittee E37.10 on Funda-mental, Statistical and Mechanical Properties.Current edition approved Sept. 1, 2009. Published October 2009. Originallyapproved in 1994. Last previous edition approved in 2004 as E1640 04. DOI:10.1520/E1640-09.2For referenced ASTM standards, visit the ASTM website, www.astm.
14、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
15、.1Copyright ASTM International. 100 Barr Harbor Drive PO box C700 West Conshohocken, Pennsylvania 19428-2959, United StatesCopyright by ASTM Intl (all rights reserved); Tue May 8 22:06:30 EDT 2012Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized
16、.indicated by the extrapolated onset of the decrease in storagemodulus which marks the transition from a glassy to a rubberysolid.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 ma
17、terials.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
18、A glass 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 mechan
19、ical andelectrical 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 tha
20、t each specimen be homogeneous and/or represen-tative of the material as a whole.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
21、 transition temperature increases with increasingfrequency.) Extrapolation to a common frequency may beaccomplished using a predetermined frequency shift factor orassuming the frequency shift factor of about 8 C per decade offrequency.47. Apparatus7.1 The function of the apparatus is to hold a speci
22、men 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, a clamping arrangement that pe
23、rmits grippingof the specimen. Samples may be mounted by clamping at bothends (most systems), one end (for example, torsional pendu-lum), or neither end (free bending between knife edges).7.2.2 Oscillatory Stress (Strain), for applying an oscillatorydeformation (strain) or oscillatory stress to the
24、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-placement (or strain), frequency,
25、and temperature. Tempera-tures should be measurable with an accuracy of 60.5 C, 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 constant experimental environ-ment
26、. The temperature programmer shall be sufficiently stableto permit measurement of specimen temperature to 60.5C.The precision of the required temperature measurement is61.0 C.7.2.5 Data Collection Device, to provide a means of acquir-ing, storing, and displaying measured or calculated signals, orbot
27、h. The minimum output signals require for dynamic me-chanical analysis are storage modulus, loss modulus, tangentdelta, temperature and time.NOTE 1Some instruments suitable for this test may display onlylinear or logarithm storage modulus while others may display either linearand/or logarithm storag
28、e modulus. 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 capable ofmeasuring dimensions (o
29、r length within)6 0.01 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 secondary to the primarygl
30、ass 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 Samples may be any uniform siz
31、e 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 noted in the report.9.2 Due to the numerous types of dynamic mechanicalanalyzers, sample size is not fixed by this test metho
32、d. In manycases, specimens measuring between 1 3 5 3 20 mm and1 3 10 3 50 mm are suitable.NOTE 2It is important to select a specimen size appropriate for both4Ferry, D. “Viscoelastic Properties of Polymers,” John Wiley dec = decaying amplitude; forced = forced oscillation;CA = constant amplitude; re
33、s = resonant frequency; fix = fixed frequency;CS = controlled stress.E1640 092Copyright by ASTM Intl (all rights reserved); Tue May 8 22:06:30 EDT 2012Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.the material and the testing apparatus. For
34、example, thick samples may berequired for low modulus materials while thin samples may be requiredfor high modulus materials.10. Calibration10.1 Calibrate the storage modulus and temperature signalsin accordance with Test Methods E1867 and E2254, respec-tively.11. Procedure11.1 Mount the specimen in
35、 accordance with procedurerecommended by the manufacturer.11.2 Measure the length, width, and thickness of the speci-men to an accuracy of 60.01 mm.11.3 Maximum strain amplitude should be within the linearviscoelastic range of the material. Strains of less than 1 % arerecommended and should not exce
36、ed 5 %.11.4 Conduct tests at a heating rate of 1 C/min and afrequency of 1 Hz. Other heating rates and frequencies may beused but shall be reported.NOTE 3The glass transition temperature measured by dynamic me-chanical measurements is dependent upon heating rate and oscillatoryfrequency. The experim
37、ental heating rate and the frequency of oscillationshould be slow enough to allow the entire specimen to reach satisfactorythermal and mechanical equilibration. When the heating rate or oscillatoryrate is high, the experimental time scale is shortened, and the apparent Tgis raised. Changing the time
38、 scale by a factor of 10 will generally result ina shift of about 8 C for a typical amorphous material. The effect of thesevariables on the temperature of the tangent delta peak may be observed byrunning specimens at two or more rates and comparing the results (seeappendix).NOTE 4Where possible in a
39、utomated systems, a minimum of one datapoint should be collected for each C increase in temperature. At low andhigh frequencies, use care in the selection of scanning rate and frequencyrate; select test conditions and a data collection rate that will ensureadequate resolution of the mechanical respo
40、nse of the specimen. Forexample, select a heating rate that allows the specimen to complete at leastone oscillation for each C increase in temperature.11.5 Measure and record the storage modulus, from 30 Cbelow to 20 C above the suspected glass transition region.12. Calculation12.1 For the purpose o
41、f this test method the glass transitionshall be taken as the extrapolated onset to the sigmoidal changein the storage modulus observed in going from the hard, brittleregion to the soft, rubbery region of the material under test.NOTE 5Storage modulus may be displayed on a linear or logarithmicscale.
42、The reported glass transition temperature will differ depending uponthe scale chosen. The scale type (for example, linear or logarithmic) shallbe reported 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
43、.1.2 Construct a tangent to the storage modulus curve atthe inflection point approximately midway through the sigmoi-dal change associated with the 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 sp
44、ecial circumstances agreeable to all parties, othertemperatures taken from the storage modulus, loss modulus, or tangentdelta curve may be taken to represent the temperature range over whichthe glass transition takes place. Among these alternative temperatures arethe peak of the loss modulus (Tl) or
45、 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 frequency measurements at 1 Hz.12.2.1 Report the mean value of duplicate determinations asTg.12.3 For measurements made at frequencies other than 1Hz.12.3
46、.1 Using a predetermined frequency shift factor (k) (seeappendix), calculate the first approximation of the glass tran-sition temperature (Tl8) using equation 1.Tl8 5 T 1T2klogF1Hz(1)12.3.2 Calculate the glass transition temperature usingequation 2:FIG. 1 Storage ModulusE1640 093Copyright by ASTM In
47、tl (all rights reserved); Tue May 8 22:06:30 EDT 2012Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.T15 T 1TT18klogF1Hz(2)where:k = Predetermined Frequency Shift Factor (see Appen-dix X1.1)F = Frequency of Measurement (Hz)T = Glass Transition
48、 Temperature Observed at Fre-quency F (K)Tl8 = First Approximation for the Glass Transition Tem-perature at 1 Hz (K)Tl= Glass Transition Temperature at 1 Hz (K)Example:k = 12,417KF =2HzT = 100 C = 373KFIG. 2 Loss ModulusFIG. 3 Tangent DeltaE1640 094Copyright by ASTM Intl (all rights reserved); Tue M
49、ay 8 22:06:30 EDT 2012Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.T8 =373K 1373K! 373K!212,417Klog 2 5 373K 2 3.37K= 369.62 KT =373 1373K! 369.62K!212,417Klog 2 5 373K 23.34K= 369.66 K = 96.5 C13. Report13.1 The report shall 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.
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