1、Designation: D 5279 08Standard Test Method forPlastics: Dynamic Mechanical Properties: In Torsion1This standard is issued under the fixed designation D 5279; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the use of dynamic mechanicalinstrumentation for gathering and reporting the viscoelasticproperties of th
3、ermoplastic and thermosetting resins and com-posite systems in the form of rectangular specimens moldeddirectly or cut from sheets, plates, or molded shapes. Thetorsional data generated may be used to identify the thermo-mechanical properties of a plastics material or composition.1.2 This test metho
4、d is intended to provide means fordetermining the torsional modulus of plastics as a function oftemperature using nonresonant forced-vibration techniques, asoutlined in Practice D 4065. Plots of the elastic (storage), loss(viscous), and complex moduli and tan delta, as a function offrequency, time,
5、or temperature are indicative of significanttransitions in the thermomechanical performance of the poly-meric material system.1.3 This test method is valid for a wide range of frequencies,typically from 0.01 to 100 Hz.1.4 Apparent discrepancies may arise in results obtainedunder differing experiment
6、al conditions. These apparent differ-ences from results observed in another study can usually bereconciled without changing the observed data by reporting infull (as described in this test method) the conditions underwhich the data were obtained.1.5 Test data obtained by this test method are relevan
7、t andappropriate for use in engineering design.1.6 The values stated in SI units are to be regarded asstandard.1.7 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 safe
8、ty and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1This test method is equivalent to ISO 6721, Part 7.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 4065 Practice for Plastics: Dynamic Mechanical Pro
9、per-ties: Determination and Report of ProceduresD 4092 Terminology for Plastics: Dynamic MechanicalProperties3. Terminology3.1 For definitions applicable to this test method, refer toTerminology D 4092.4. Summary of Test Method34.1 This test method covers the determination of the shearmodulus of pla
10、stics using dynamic mechanical techniques. Atest specimen of rectangular cross section is tested in dynamictorsion. The specimen is gripped longitudinally between twoclamps. The specimen of known geometry is placed in me-chanical torsional displacement at either a fixed frequency, orvariable frequen
11、cies at either isothermal conditions, or with alinear temperature increase. The elastic or loss modulus, orboth, of the polymeric material system are measured in torsion.5. Significance and Use5.1 This test method provides a simple means of character-izing the thermomechanical behavior of plastics m
12、aterialsusing very small amounts of material. The data obtained maybe used for quality control, research and development, andestablishment of optimum processing conditions.5.2 Dynamic mechanical testing provides a sensitivemethod for determining thermomechanical characteristics bymeasuring the elast
13、ic and loss moduli as a function offrequency, temperature, or time. Plots of moduli and tan delta1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved March 1, 2008. Publi
14、shed April 2008. Originallyapproved in 1992. Last previous edition approved in 2001 as D5279 - 01.2For 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 Docu
15、ment Summary page onthe ASTM website.3The particular method for measurement of the elastic and loss moduli and tandelta depends upon the individual instruments operating principles.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive,
16、 PO Box C700, West Conshohocken, PA 19428-2959, United States.of a material versus temperature provide graphical representa-tions indicative of functional properties, effectiveness of cure(thermosetting resin system), and damping behavior underspecified conditions.5.3 This test method can be used to
17、 assess5.3.1 The modulus as a function of temperature,5.3.2 The modulus as a function of frequency,5.3.3 The effects of processing treatment, including orien-tation,5.3.4 Relative resin behavioral properties, including cureand damping,5.3.5 The effects of substrate types and orientation (fabri-catio
18、n) on elastic modulus, and5.3.6 The effects of formulation additives that might affectprocessability or performance.5.4 Before proceeding with this test method, referenceshould be made to the specification of the material being tested.Any test specimen preparation, conditioning, dimensions, ortestin
19、g parameters, or combination thereof, covered in therelevant ASTM materials specification shall take precedenceover those mentioned in this test method. If there are norelevant ASTM materials specifications, then the default con-ditions apply.6. Interferences6.1 Since small test specimen geometries
20、are used, it isessential that the specimens be representative of the materialbeing tested.7. Apparatus7.1 The function of the apparatus is to hold a rectangulartest specimen so that the material acts as the elastic anddissipative element in a mechanically driven torsional system.Dynamic mechanical i
21、nstruments operate at a forced, constantamplitude, and either at a fixed frequency, or variable frequen-cies.7.2 The apparatus shall consist of the following:7.2.1 Fixed MemberA fixed or essentially stationarymember carrying one grip.7.2.2 Movable MemberA movable member carrying asecond grip.7.2.3 G
22、ripsGrips for holding the test specimen betweenthe fixed member and the movable member. The grips shall bemechanically aligned, that is, they shall be attached to the fixedand movable member, respectively, in such a manner that theywill move into alignment as soon as any load is applied, so thatthe
23、long axis of the test specimen will coincide with thedirection of the applied pull through the center line of the gripassembly.7.2.3.1 The test specimen shall be held in such a way thatslippage relative to the grips is minimized.7.2.4 Deformation (Strain Device)Adevice for applying acontinuous linea
24、r deformation (strain) to the specimen. In theforce-displacement device the deformation (strain) is appliedand then released. (See Table 1 of Practice D 4065.)7.2.5 DetectorsDevices for determining dependent andindependent experimental parameters, such as force (stress),deformation (strain), frequen
25、cy, and temperature. Temperatureshould be measurable with a precision of 61C, frequency to61 %, and force to 61%.7.2.6 Temperature Controller and Oven A device forcontrolling the temperature, either by heating (in steps orramps), cooling (in steps or ramps), maintaining a constantspecimen environmen
26、t, or a combination thereof. A tempera-ture controller should be sufficiently stable to permit measure-ment of environmental chamber temperature to within 1C.7.3 Nitrogen or other inert gas supply for purging purposes.8. Test Specimens8.1 The specimens may be cut from sheets, plates or moldedshapes,
27、 or may be molded to the desired finished dimensions.Any rectangular specimen, representative of the material beingtested and within the fixturing capabilities of the specific testinstrument being used, may be used as long as it is clearlystated in the test report.9. Calibration9.1 Calibrate the ins
28、trument using procedures recommendedby the manufacturer.10. Conditioning10.1 ConditioningCondition the test specimens at 23.0 62.0C and 50 6 5 % relative humidity for not less than 40 hprior to testing in accordance with Procedure A of PracticeD 618, unless otherwise specified by the contract or rel
29、evantmaterial specification.11. Procedure11.1 Use an untested specimen for each measurement.Measure the width and thickness of the specimen to the nearest0.03 mm at the center of the specimen and enter thosedimensions into the test program using the instruments soft-ware.11.2 Clamp the test specimen
30、 between the movable andstationary members using shim stock, if necessary, to minimizeslippage within the clamp.11.3 Preload the test specimen so that a positive normalforce is maintained during the test. Monitor the normal forceduring testing to ensure adequate preloading.11.4 Measure the jaw separ
31、ation between the movable andstationary members to the nearest 0.03 mm and enter thatdimension into the test program using the instruments soft-ware.NOTE 2Tests may be conducted in several modes depending on thedesired characterization requirements and the properties of interest.Generally those mode
32、s include a strain sweep during which the tempera-ture and frequency are maintained at constant values; a frequency sweepduring which the temperature and strain are maintained at constant values;a temperature sweep during which the strain and frequency are maintainedat constant values or a frequency
33、temperature sweep during which thestrain is maintained at a constant value and properties are measured acrossa range of frequencies at step increments of temperature.11.5 Based on the type of test being conducted:11.5.1 Select the frequency (or range of frequency) fordynamic-torsional displacement
34、as desired.11.5.2 Select the torsional-displacement amplitude (or rangeof amplitude) as desired, making sure it is within the materialslinear elastic region.D5279082NOTE 3An independent strain sweep test may need to be run toestablish this property.11.5.3 Select the temperature (or range of temperat
35、ure),dwell time and either ramp rate or step increments to be usedif temperature is to be varied.11.5.3.1 Temperature increases should be controlled to 1 to2C/min for linear increases or 2 to 5C/min (with a minimumof 1-min thermal-soak time for step increases). These soaktimes should be set to assur
36、e thermal equilibrium of the testmaterial. Appropriate soak times are generally related to themass of the test specimen and to the ramp rate or stepincrement being used.11.6 Conduct the desired test recording the appropriate data.12. Calculations12.1 The equations listed in Practice D 4065 are used
37、tocalculate the important rheological properties measured inforced, nonresonant dynamic displacement:where:G8 = storage (elastic) modulus in torsion,G9 = loss (viscous) modulus in torsion,G* = complex modulus in torsion, andd* = tan delta.13. Report13.1 Report the following information:13.1.1 Comple
38、te identification of the material tested, includ-ing type, source, manufacturers code, number, form, principaldimensions, and previous history as available,13.1.2 Description and direction of cutting and loadingspecimen, including preload force,13.1.3 Conditioning procedure,13.1.4 Description of the
39、 instrument used for the test,13.1.5 Description of the calibration procedure,13.1.6 Identification of the sample atmosphere by gas com-position, purity, and rate used,13.1.7 Width and thickness of specimen,13.1.8 Jaw separation distance,13.1.9 Frequency of dynamic displacement,13.1.10 Amplitude of
40、displacement,13.1.11 Thermal gradient; heating rate,13.1.12 Number of specimens tested,13.1.13 Table of data including moduli, tan delta, frequency,strain, and temperature as appropriate, and13.1.14 A plot of the modulus (moduli) and tan delta asappropriate. (See Fig. 1.)14. Precision and Bias14.1 T
41、he repeatability standard deviation has been deter-mined for the following materials . Laboratory A evaluated apolyurethane sample and the values in Table 1 were obtainedwith the same test method in the same laboratory by the sameoperator using the same equipment in the shortest practicalperiod of t
42、ime using test specimens taken at random from asingle quantity of homogeneous material. Laboratory B testedthe same material and obtained the results shown in Table 1.15. Keywords15.1 dynamic mechanical rheological properties; elastic;loss; storage; tan delta; torsional shear modulus; viscoelasticbe
43、havior; viscousFIG. 1 Dynamic Mechanical Modulus in Torsion as a Function of TemperatureD5279083SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue (D5279 - 01)that may impact the use of this standard. (March 1, 2008)(1) Revised 1.2,
44、8.1, 10.1, 11.1, 11.2, 11.3, 11.4, 11.5, 13.1.1,13.1.13, and 13.1.14.(2) Added subsections 5.4, 11.5.1, 11.5.2, 11.5.3, 11.5.3.1, and11.6.(3) Deleted old subsections 11.7, 11.8, 13.1.13.(4) Reworded Note 1 to meet D4968 guidelines.ASTM International takes no position respecting the validity of any p
45、atent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised 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 revisi
46、on at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your co
47、mments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If 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 copyrigh
48、ted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e
49、mail); or through the ASTM website(www.astm.org).TABLE 1 DMRT-Torsion, Elastic Modulus, G (E8Pascals) or (E9dynes/cm2) at Selected TemperaturesLaboratory 40C 0C 40C 80CAMean 3.773 0.2038 0.03624 0.03532StandardDeviation0.008 0.0067 0.00032 0.00087BMean 3.568 0.2263 0.03206 0.02758StandardDeviation0.160 0.0461 0.00142 0.00023D5279084
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