1、Designation: E 1867 06Standard Test Method forTemperature Calibration of Dynamic Mechanical Analyzers1This standard is issued under the fixed designation E 1867; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes the temperature calibrationof dynamic mechanical analyzers (DMA) from 150 to 500C.1.2 SI units are
3、the standard1.3 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. Sp
4、ecific precau-tionary statements are given in Note 7.2. Referenced Documents2.1 ASTM Standards:2E 473 Terminology Relating to Thermal Analysis and Rhe-ologyE 1142 Terminology Relating to Thermophysical Properties3. Terminology3.1 Definitions:3.1.1 The technical terms used in this test method aredefi
5、ned in Terminology E 473 and Terminology E 1142.4. Summary of Test Method4.1 An equation is developed for the linear correlation ofexperimentally observed program or sensor temperature andthe actual melting temperature for known melting referencematerials. This is accomplished by loading melting poi
6、ntreference materials into a polymer tube, or wrapping them withpolymer tape and subjecting it to a mechanical oscillation ateither fixed or resonant frequency. The extrapolated onset ofmelting is identified by a rapid decrease in the ordinate signal(the apparent storage modulus, stress, inverse str
7、ain or probeposition). This onset is used for temperature calibration withtwo melting point reference materials.5. Significance and Use5.1 Dynamic mechanical analyzers monitor changes in theviscoelastic properties of a material as a function of tempera-ture and frequency, providing a means to quanti
8、fy thesechanges. In most cases, the value to be assigned is thetemperature of the transition (or event) under study. Therefore,the temperature axis (abscissa) of all DMA thermal curvesmust be accurately calibrated by adjusting the apparent tem-perature scale to match the actual temperature over thet
9、emperature range of interest.6. Interferences6.1 An increase or decrease in heating rates or change inpurge gas type or rate from those specified may alter results.6.2 Once the temperature calibration procedure has beenexecuted, the measuring temperature sensor position shall notbe changed, nor shal
10、l it be in contact with the specimen orspecimen holder in a way that would impede movement. If thetemperature sensor position is changed or is replaced, then theentire calibration procedure shall be repeated.6.3 Once the temperature calibration has been executed, thegeometry deformation (bending stu
11、dy, versus tensile, and thelike) shall not be changed. If the specimen testing geometrydiffers significantly from that of the calibrants, then thecalibration shall be repeated in the geometry matching that ofspecimen testing.6.4 This method does not apply to calibration for shear orcompressive geome
12、tries of deformation.7. Apparatus7.1 The function of the apparatus is to hold a specimen ofuniform dimension so that the specimen acts as the elastic anddissipative element in a mechanically oscillated system. Dy-namic mechanic analyzers typically operate in one of severalmodes as outlined in Table
13、1.7.1.1 The apparatus shall consist of the following:7.1.1.1 ClampsAclamping arrangement that permits grip-ping of the specimen. This may be accomplished by clampingat both ends (most systems), one end (for example, torsionalpendulum) or neither end (for example, free bending betweenknife edges).1Th
14、is test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.01 on TestMethods and Recommended Practices.Current edition approved Sept. 1, 2006. Published November 2006. Originallyapproved in 1997. Last previous edition app
15、roved in 2001 as E 186701.2For 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.1Copyright ASTM International, 100
16、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.1.1.2 Device to Apply Oscillatory Stress or StrainAdevice for applying an oscillatory deformation (strain) oroscillatory stress to the specimen. The deformation may beapplied and then released, as in freely vibrating d
17、evices, orcontinually applied, as in forced vibration devices.7.1.1.3 DetectorA device or devices for determining thedependent and independent experimental parameters, such asforce (stress), deformation (strain), frequency, and temperature.Temperature shall be measurable with an accuracy of 6 0.1 C,
18、force to 6 1 % and frequency to 6 1%.7.1.1.4 Temperature Controller and OvenA device forcontrolling the specimen temperature, either by heating, cool-ing (in steps or ramps), or by maintaining a constant experi-mental environment. The temperature programmer shall besufficiently stable to permit meas
19、urement of specimen tempera-ture to 6 0.1 C.7.1.1.5 Output DeviceCapable of displaying the storagemodulus (either linearly or logarithmically) on the Y-axis(ordinate) increasing in the upwards direction and temperatureon the X-axis (abscissa) increasing to the right.NOTE 1Some instruments, suitable
20、for this test, may display onlylinear or logarithmic storage modulus while others may display linearand/or logarithmic storage 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.7.2 PTFE (Polytet
21、rafluoroethylene), tubing of 3 mm diam-eter and wallthickness of 0.5 mm (0.002 in.)3inner diametermay be used for low temperature standards. The tubing may besealed with suitable melting temperature wax plugs, or similarsealant.NOTE 2PTFE tubing is selected for its flexibility and inert nature forth
22、e solvents in use at the temperatures of interest. Furthermore itstransitions should not produce any interference in the DMA signal withinthe range of the suggested calibrant materials. For other temperatureranges, a suitable replacement for the PTFE tubing may be used.7.3 Where the melting material
23、 is to be confined to a tube7.4 PTFE Tape, for wrapping metal point standards.7.5 Calibration MaterialsOne or more suitable materialspresented in Table 2.7.6 Calipers or other length measuring device capable ofmeasuring dimensions (or length) within 6 10 m.8. Reagents and Materials8.1 Dry nitrogen,
24、helium, or other inert gas supplied forpurging purposes and especially to ensure that moisture con-densation and ice formation is avoided when measurementsinvolve temperatures below the dew point.9. Calibration and Standardization9.1 Prepare the instrument for operation as dexcribed by themanufactur
25、er in the operations manual10. Procedure10.1 Two Point CalibrationFor the purposes of this pro-cedure, it is assumed that the relationship between observedextrapolated onset temperature (To) and actual specimen tem-perature (Tt) is a linear one governed by the equation:Tt5 To3 S! 1 I (1)where: S and
26、 I are the slope and intercept of a straight line,respectively.10.2 Select two calibration standards near the temperaturerange of interest. The standards should be as close to the upperand lower temperature limits used for the subsequent testmaterials as practical.NOTE 3In some testing geometries it
27、 may be possible to perform thetest directly on the metal melting point reference materials withoutencapsulation.10.2.1 Encapsulation technique for low temperature (liquid)standards where the melting temperature does not exceed 100C.10.2.1.1 Fill the PTFE tubing with the calibration materialor wrap
28、a solid calibrant with PTFE tape. Calibrant mustextend to the ends of the clamping geometry and must haveuniform dimensions with respect to width.NOTE 4For solid calibrants, a wire of dimensions suitable for testingshould be used.10.3 Measure the length and for solid calibrants the diam-eter as well
29、, of specimens.10.4 Mount the specimen in accordance with the procedurerecommended by the manufacturer.NOTE 5For specimen clamping arrangements where the specimen isnot gripped on either end (for example, free bending between knife edges)the specimen must be rigid enough at the test start temperatur
30、e to sustain3Lotti, C., Canevarolo. S.V., Polymer Testing, 1998, Vol 17, pp. 523530.“Temperature Calibration of a Dynamic Mechanical Thermal Analyzer”.TABLE 1 Dynamic Mechanical Analyzer Modes of OperationModeMechanical ResponseTension Flexural Torsion CompressionFree/decA. . X .Forced/res/CAA. X X
31、.Forced/fix/CAAXX XForced/fix/CSAX X . XAFree = free oscillation; dec = decaying amplitude; forced = forced oscillation;CA = constant amplitude; res = resonant frequency; fix = fixed frequency; CS =controlled stress.TABLE 2 Calibration MaterialsMaterialTransition TemperatureAReferenceC KCyclopentane
32、 (solid-solid) -151.16 121.99 X1.1Cyclopentane (solid-solid) -135.06 138.09 X1.1n-Heptane -90.56 182.65 X1.2Cyclohexane -87.06 186.09 X1.3n-Octane -56.76 216.39 X1.1n-Decane -26.66 246.49 X1.1n-Dodecane -9.65 263.5 X1.1Water 0.01 273.16 X1.4Cyclohexane 6.54 279.69 X1.3Indium 156.5985 495.7485 X1.4Ti
33、n 231.928 505.078 X1.4Lead 327.462 600.612 X1.5ZincB419.527 692.677 X1.4AThe values in this table were determined under special, highly accurate testconditions that are not attainable or applicable to this test method. The actualprecision of this test method is given in Section 13.BAmalgamates with
34、aluminum. Do not heat above 430C.E1867062initial loading. Alternatively, the calibration specimen, without encapsu-lation, can be placed between the knife edge and a substrate.10.5 Maximum strain amplitude should be within the linearviscoelastic range of the specimens to be subsequently ana-lyzed. S
35、trains of less than 1 % are recommended and shouldnot exceed 5 %.10.6 Conduct the calibration runs at the heating rate ofinterest, preferably 1 C/min but no greater than 5 C/min anda frequency of 1 Hz. Other heating rates and frequencies maybe used but shall be reported.NOTE 6Calibration for tempera
36、ture should always be performedunder the conditions of heating rate and frequency at which the unknownspecimens will be tested. This method does not address the issues offrequency affects for polymeric transitions (such as the upwards shift ofTg with increasing frequency), and will only compensate f
37、or thermal lagwithin the measuring device.10.7 Measure and record the ordinate signal, from 30Cbelow to 20C above the melting point of the referencematerial. The calibration specimen may be equilibrated aminimum of 50C below the melting transition, but adequatetime to achieve thermal equilibrium in
38、the specimen must beallowed.11. Calculation11.1 Take the transition temperature as the extrapolatedonset to the sigmoidal change in the ordinate signal observed inthe downward direction (see Fig. 1).11.1.1 Construct a tangent to the ordinate signal curvebelow the transition temperature.11.1.2 Constr
39、uct a tangent to the ordinate signal curve at theinflection point approximately midway through the sigmoidalchange associated with the transition.11.1.3 Report the temperature at which these tangent linesintersect as reported as the observed transition temperature(To).11.2 Two Point Calibration:11.2
40、.1 Using the standard temperature values from Table 2and the corresponding onset temperatures obtained experimen-tally, calculate the slope and intercept using the followingequations:S 5 Tr1Tr2/To1To2 (2)I 5 To1 3 Tr2Tr13 To2!# /To1To2 (3)whereS = slope (nominal value = 1.0000),I = intercept,Tr1 = r
41、eference transition temperature for Standard 1 (inTable 2),Tr2 = reference transition temperature for Standard 2 (inTable 2),To1 = experimentally observed transition onset tempera-tures for Standard 1, andTo2 = experimentally observed transition onset temperaturefor Standard 2.NOTE 7Caution: The slo
42、pe S is a dimensionless number whose valueis independent of which temperature scale is used for I and T. I,inallcases, must have the same units as Tr1, Tr2, To1, and To2 that are, bynecessity, consistent with each other.11.2.2 S should be calculated to 6 0.0001 units while Ishould be calculated to 6
43、 0.1C.FIG. 1 Transition TemperatureE186706311.2.3 Using the determined values for S and I, Eq 1 may beused to calculate the actual specimen transition temperature(Tt) from any experimentally observed transition temperature(To) for the particular DMA instrument employed.11.3 One Point Calibration:11.
44、3.1 In this abbreviated procedure, a relationship betweenthe extrapolated onset temperature as observed and the tem-perature as assigned by a temperature sensor is established. Theoperator should choose a calibration standard that is near thetemperature of the transition or phenomenon under study.11
45、.3.2 Using the specimen handling techniques in 10.2through 10.7, obtain the DMA curve for the calibrationstandard chosen from Table 2.11.3.3 From the known melting temperature of the calibra-tion material (see Table 2), calculate the value and sign of sfrom the following equation:s5Tr To(4)whereTr=
46、reference transition temperature for standard (in Table2),To= experimentally observed transition onset temperaturefor standard, ands = correction factor for converting the observed tempera-ture sensor temperature to actual sample temperature.11.3.4 For the purpose of this abbreviated procedure, it i
47、sassumed that the relationship between the observed extrapo-lated onset temperature (To) and the actual specimen tempera-ture is constant over the temperature range of interest. Thevalue of s is thus added to all observed measurements oftransition temperatures for the particular instrument employed.
48、That is:Tt5 To1s (5)whereTt= temperature of transition to be assigned.12. Report12.1 Report the following information:12.1.1 Description of the instrument (manufacturer andmodel number) as well as the data handling device used inthese tests,12.1.2 Complete identification of the temperature reference
49、materials used including source and purity,12.1.3 Description of the dimensions, geometry, and mate-rial of the specimen. A description of the specimen holdershould be specified as to composition, geometry and dimen-sions,12.1.4 Identification of sample environment by gas flowrate, purity and composition,12.1.5 Heating rate and description of any coolant used, and12.1.6 Results of the calibration procedure including valuesfor S and I. If the abbreviated one point calibration procedurewas used, then the value of s is given.12.1.7 The specific
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