1、Designation: E2425 11Standard Test Method forLoss Modulus Conformance of Dynamic MechanicalAnalyzers1This standard is issued under the fixed designation E2425; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. 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 describes the performance confirma-tion or measurement of conformance for the loss modulus scaleof a commercial
3、or custom-built dynamic mechanical analyzer(DMA) at 21 C using ultra-high molecular weight polyethyl-ene as a reference material.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 There is no ISO standard equivalent to this
4、 test method.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 to determine theapplicability of regulatory limitations prior to use.2
5、. Referenced Documents2.1 ASTM Standards:2E473 Terminology Relating to Thermal Analysis and Rhe-ologyE1142 Terminology Relating to Thermophysical PropertiesE1867 Test Method for Temperature Calibration of Dy-namic Mechanical Analyzers3. Terminology3.1 DefinitionsSpecific technical terms used in this
6、 testmethod are defined in Terminologies E473 and E1142 includ-ing Celsius, dynamic mechanical analysis and loss modulus.4. Summary of Test Method4.1 The loss modulus signal measured by a dynamic me-chanical analyzer for an elastic material is compared to thereported loss modulus for that reference
7、material. A linearrelationship is used to correlate the experimental loss modulussignal with the reported value of the reference material.4.2 The mode of deformation (for example, tensile, flexure,compression, shear. etc.) shall be reported.5. Significance and Use5.1 This test method demonstrates co
8、nformity of a dynamicmechanical analyzer at an isothermal temperature of 21 C.5.2 Dynamic mechanical analysis experiments often uselinear temperature change. This test method does not addressthe effect of that change in temperature on the loss modulus.5.3 This test method may be used in research and
9、 develop-ment, specification acceptance, and quality control or assur-ance.6. Apparatus6.1 The essential instrumentation required to provide theminimum dynamic mechanical capability for this test methodincludes:6.1.1 Drive Actuator, to apply force (or displacement) to thespecimen in a periodic manne
10、r. This actuator may also becapable of providing static force or displacement to thespecimen.6.1.2 Coupling Shaft, or other means to transmit the forcefrom the motor to the specimen.6.1.3 Clamping System(s), to fix the specimen between thedrive shaft and the stationary clamp(s).6.1.4 Position Sensor
11、, to measure the change in position ofthe specimen during dynamic motion, or6.1.5 Force Sensor, to measure the force developed by thespecimen.6.1.6 Temperature Sensor, to provide an indication of thespecimen temperature to within 61 C.6.1.7 Furnace, to provide controlled heating or cooling of aspeci
12、men at a constant temperature or at a constant rate withinthe applicable temperature range of 100 to +300 C.6.1.8 Temperature Controller, capable of executing a spe-cific temperature program by operating the furnace between100 and +300 C and at a constant temperature within thatrange.1This test meth
13、od is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.10 on Funda-mental, Statistical and Mechanical Properties.Current edition approved April 1, 2011. Published May 2011. Originallyapproved in 2005. Last previous edition approv
14、ed in 2005 as E2425 05. DOI:10.1520/E2425-11.2For 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
15、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.9 Data Collection Device, to provide a means of acquir-ing, storing, and displaying measured or calculated signals, orboth. The minimum output signals required for dynamicmechanical analysis are st
16、orage modulus, loss modulus, tandelta, temperature, and time.6.2 Auxiliary instrumentation considered necessary in con-ducting this method near or below ambient temperature:6.2.1 Cooling capability to sustain a constant temperature ator below ambient temperature or to provide controlled cooling.6.2.
17、2 Data Analysis capability to provide loss modulusinformation derived from measured signals.7. Reagents and Materials7.1 A reference material of known loss modulus, formed tothe shape suitable for characterization by the particular dy-namic mechanical analyzer (see Table 1).8. Sampling and Test Spec
18、imens8.1 Test specimens are typically prepared in the form of arectangular test bars or film strips.NOTE 1It is common practice to bevel or “break” edges of machinedparts. This practice shall not be followed in the preparation of testspecimens for this method. The measured loss modulus of such speci
19、mensreads low due to imperfect sample geometry.9. Calibration and Standardization9.1 Perform any loss modulus signal calibration procedurerecommended by the manufacturer of the dynamic mechanicalanalyzer as described in the operations manual.9.2 If not already done so, calibrate the temperature scal
20、e ofthe dynamic mechanical analyzer as near as is practical to thetest temperature (see Table 1) using Test Method E1867.10. Procedure10.1 Prepare the dynamic mechanical analyzer for operationunder the test conditions (for example, specimen clamps, purgegas, etc.) to be used for the characterization
21、 of the testspecimen(s). Unless otherwise indicated the temperature con-dition shall be isothermal at 21 6 1 C (that is, between 20 and22 C).10.2 Ensure that the loss modulus signal is less than 1 MPawith no test specimen loaded and at an oscillation testfrequency to be used in this test (see Table
22、1).NOTE 2Alternatively, a thin specimen of a low modulus material (forexample, a thin piece of paper) may be used. The dimension of the testspecimen shall be used rather than the true dimensions of the thin, lowmodulus material.10.3 Open the apparatus, place the reference material intothe specimen h
23、older, and reassemble the apparatus. Equilibratethe reference material at the test conditions. Unless otherwiseindicated, the test frequency shall be that indicated in Table 1and the temperature shall be isothermal between 20 and 22 C.Ensure that the applied strain (or stress) amplitude is within th
24、elinear viscoelastic region of the sample.10.4 Record the loss modulus observed by the apparatus asEo.10.5 Record the loss modulus of the reference material fromits certificate or from Table 1 as Es.10.6 Calculate and report the value of the slope (S) andconformity (C) of the measurement using Eq 2
25、and Eq 3.11. Calculation11.1 For the purpose of this test method, it is assumed thatthe relationship between the observed loss modulus (Eo) andthe reference loss modulus (Es) is linear and governed by theslope (S)ofEq1.Es5 Eo3 S (1)11.2 By using the loss modulus values taken from 10.4 and10.5, calcu
26、late and report S using Eq 2 to four decimal places.S 5 Es/ Eo(2)11.3 The conformity (C) (that is, the percent differencebetween the experimental slope and unity) of the instrumentloss modulus scale is calculated using the value of S from 11.2and Eq 3.C 5 S 2 1.0000! 3 100 % (3)11.3.1 Conformity may
27、 be estimated to one significantfigure using the following criteria:11.3.1.1 If the value of S is between 0.990 and 0.9999 orbetween 1.0001 and 1.0010, then the conformity is better than0.1 %.11.3.1.2 If the value of S is between 0.9000 and 0.9990 orbetween 1.0010 and 1.0100, then conformity is bett
28、er than 1 %.11.3.1.3 If the value of S is between 0.9000 and 0.9900 orbetween 1.0100 and 1.1000, then the conformity is better than10 %.11.4 Report the value of slope (S) and the conformity (C).12. Report12.1 The report shall include the following information:12.1.1 Details and description of the dy
29、namic mechanicalanalyzer, including the manufacturer and instrument modelnumber, where applicable. Also report the test mode, strainamplitude, frequency and applied static load.12.1.1.1 Whether or not the instrument calibration includedcompliance corrections.12.1.2 The value of slope (S) determined
30、in 11.2, reported toat least four decimal places.12.1.3 The conformity (C), as determined in 11.3.12.1.4 The specific dated version of this test method used.13. Precision and Bias13.1 An interlaboratory study was conducted in 2010 thatincluded participation by 15 laboratories using 7 instrumentmodel
31、s from 4 = manufacturers. A single sample of ultra-highmolecular weight polyethylene was characterized in quintupli-cate.TABLE 1 Reference Material Loss ModulusTemperature(C)MaterialFrequencyHzLoss Modulus(MPa)21 Ultra-High Molecular Weight Polyethylene1 62.0E2425 11213.2 Precision:13.2.1 Within lab
32、oratory variability may be described usingthe repeatability value (r) obtained by multiplying the repeat-ability standard deviation by 2.8. The repeatability value esti-mates the 95 % confidence limit. That is, two results from thesame laboratory should be considered suspect (at the 95 %confidence l
33、evel) if they differ by more than the repeatabilityvalue.13.2.2 The within laboratory repeatability standard devia-tion was 2.3 MPa resulting in a repeatability relative standarddeviation of 3.8 % with 48 degrees of experimental freedomThe repeatability value r is 6.7 MPa.13.2.3 The between laborato
34、ry variability may be describedusing the reproducibility value (R) obtained by multiplying thereproducibility standard deviation by 2.8. The reproducibilityvalue estimates the 95 % confidence level. That is, resultsobtained by two different laboratories, operators or apparatusshould be considered su
35、spect (at the 95 % confidence level) ifthey differ by more than the reproducibility value.13.2.4 The between laboratory reproducibility standard de-viation 8.6 MPa resulting in a reproducibility relative standarddeviation of 14 %. The reproducibility value R is 24 MPa.13.3 Bias:13.3.1 Bias is the di
36、fference between the mean value ob-tained and an acceptable reference value for the same material.To the knowledge of the committee, no acceptable lossmodulus reference material is available. Therefore, bias isunable to be determined.13.3.2 The mean loss modulus value for the ultra-highmolecular wei
37、ght polyethylene was 62.0 MPa.14. Keywords14.1 calibration; conformity; dynamic mechanical analysis;loss modulusASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advis
38、ed that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either r
39、eapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If
40、you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individu
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