1、Designation: D 5418 07Standard Test Method forPlastics: Dynamic Mechanical Properties: In Flexure (DualCantilever Beam)1This standard is issued under the fixed designation D 5418; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 year of last revision. 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 outlines the use of dynamic mechanicalinstrumentation for determining and reporting the vi
3、scoelasticproperties of thermoplastic and thermosetting resins and com-posite systems in the form of rectangular bars molded directlyor cut from sheets, plates, or molded shapes. The elasticmodulus data generated may be used to identify the thermo-mechanical properties of a plastics material or comp
4、osition.1.2 This test method is intended to provide a means fordetermining the viscoelastic properties of a wide variety ofplastics using nonresonant, forced-vibration techniques asoutlined in Practice D 4065. In particular, this method identi-fies the procedures used to measure properties using wha
5、t isknown as a dual-cantilever beam flexure arrangement. Plots ofthe elastic (storage) modulus, loss (viscous) modulus, andcomplex modulus, and tan delta as a function of frequency,time, or temperature are indicative of significant transitions inthe thermomechanical performance of the polymeric mate
6、rialsystems.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 experimental conditions. These apparent differ-ences from results observed in another study can usually bereconciled, withou
7、t 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 relevant andappropriate for use in engineering design.1.6 The values stated in SI units are to be regarded asstandard.1
8、.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 safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is n
9、o known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 4065 Practice for Plastics: Dynamic Mechanical Proper-ties: Determination and Report of ProceduresD 4092 Terminology for Plastics: Dynamic MechanicalPropertiesD 52
10、79 Test Method for Plastics: Dynamic MechanicalProperties: In Torsion3. Terminology3.1 For definitions applicable to this practice see Terminol-ogy Standard D 4092.4. Summary of Test Method4.1 This test method covers the determination of the elasticmodulus of plastics using dynamic mechanical techni
11、ques. Abar of rectangular cross section is tested as a beam in dynamiclinear displacement or bending. The dual-cantilever beamspecimen is gripped between two clamps. The specimen ofknown geometry is placed in mechanical linear displacement,with the displacement strain or deformation applied at thece
12、nter of the dual-cantilever beam. The forced-strain displace-ment is at either a fixed frequency or variable frequencies, andat either isothermal conditions or with a linear temperaturevariation. The elastic or loss modulus, or both, of the polymericmaterial system are measured in flexure.35. Signif
13、icance and Use5.1 This test method provides a simple means of character-izing the thermomechanical behavior of plastic compositionsusing a very small amount of material. Since small testspecimen geometries are used, it is essential that the specimens1This test method is under the jurisdiction of AST
14、M Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved March 15, 2007. Published April 2007. Originallyapproved in 1993. Last previous edition approved in 2001 as D 5418 - 01.2For referenced ASTM standards, visit the ASTM
15、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.3The particular method for measurement of the elastic and loss moduli and tandelta depends upon the individu
16、al instruments operating principles.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.be representative of the material being tested. The dataobtained can be used for qu
17、ality control and/or research anddevelopment purposes. For some classes of materials, such asthermosets, it can also be used to establish optimum processingconditions.5.2 Dynamic mechanical testing provides a sensitive meansfor determining thermomechanical characteristics by measur-ing the elastic a
18、nd loss moduli as a function of frequency,temperature, or time. Plots of moduli and tan delta of a materialversus these variables can be used to provide a graphicrepresentation indicative of functional properties, effectivenessof cure (thermosetting-resin systems), and damping behaviorunder specifie
19、d conditions.5.3 This test method can be used to assess the following:5.3.1 The modulus as a function of temperature or aging, orboth,5.3.2 The modulus as a function of frequency,5.3.3 The effects of processing treatment, including orien-tation, induced stress, and degradation of physical and chemi-
20、cal structure,5.3.4 Relative resin behavioral properties, including cureand damping,5.3.5 The effects of substrate types and orientation (fabri-cation) on elastic modulus, and5.3.6 The effects of formulation additives that might affectprocessability or performance.5.4 Before proceeding with this tes
21、t method, refer to thespecification of the material being tested. Any test specimenpreparation, conditioning, dimensions, or testing parameters, orcombination thereof, covered in the relevant ASTM materialspecification shall take precedence over those mentioned in thistest method. If there are no re
22、levant ASTM material specifica-tions, then the default conditions apply.6. Apparatus6.1 The function of the apparatus is to hold a rectangularcross-sectional bar so that the material acts as the elastic anddissipative element in a mechanically driven linear displace-ment system. Dynamic mechanical i
23、nstruments described inthis standard generally operate in a forced, constant amplitudemode at either a fixed frequency or variable frequencies.6.2 The apparatus consists of the following:6.2.1 Fixed GripsA fixed or essentially stationary fixtureconsisting of two grips to secure the rectangular speci
24、menhorizontally in a dual cantilever configuration.6.2.2 Movable GripA movable grip applying the lineardisplacement at the center of the rectangular beam.6.2.3 Grip AlignmentsThe grips shall be mechanicallyaligned or centered, that is, they shall be attached in such amanner that they will move into
25、alignment as soon as any loadis applied.6.2.3.1 The test specimen shall be held in such a way thatslippage relative to the grips is minimized as much as possible.6.2.4 Deformation (Strain) DeviceAdevice for applying acontinuous linear deformation (strain) to the specimen. In theforce-displacement de
26、vice the deformation (strain) is appliedand then released (see Table 1 of Practice D 4065).6.2.5 DetectorsA device or devices for determining de-pendent and independent experimental parameters, such asforce (stress), deformation (strain), frequency, and temperature.Temperature should be measurable w
27、ith a precision of 61C,frequency, strain, and force to 61%.6.2.6 Temperature Controller and Oven A device forcontrolling the temperature, either by heating (in steps orramps), cooling (in steps or ramps), or maintaining a constantspecimen environment, or a combination thereof. A tempera-ture control
28、ler should be sufficiently stable to permit measure-ment of environmental chamber temperature to within 1C.6.3 Nitrogen, or other inert-gas supply for purging purposesif appropriate.7. Test Specimens7.1 The specimens may be cut from sheets, plates, ormolded shapes or may be molded to the desired fin
29、isheddimensions. Any rectangular specimen (representative of thematerial being tested and within the fixturing capabilities of thetest equipment) is permitted as long as it is clearly stated in thetest report.8. Calibration8.1 Calibrate the instrument according to procedures recom-mended by the manu
30、facturer.9. Conditioning9.1 ConditioningCondition the test specimens at 23.0 62.0C and 50 6 5 % relative humidity for not fewer than 40 hprior to test in accordance with Procedure A of Practice D 618unless otherwise specified by contract or relevant ASTMmaterial specification.10. Procedure10.1 Use a
31、n untested specimen for each measurement.Measure the width and thickness of the specimen to the nearest0.03 mm (0.001 in.) at the center of the specimen.10.2 Clamp the test specimen between the movable andstationary members; use shim stock, if necessary, to minimizeslippage within the clamp.10.3 Pre
32、-load the test specimen so that there is a positiveforce. The positive pre-load should be sufficient to maintain apositive deflection during testing unless the test mode allows azero-displacement measurement.10.4 Measure the length of the specimen between thestationary end grips to the nearest 0.03
33、mm (0.001 in.).10.5 Select the desired frequency (or frequencies) for dy-namic linear displacement.10.6 Select the linear displacement amplitude within thelinear elastic region of the material being tested. If the linearelastic region is not known, perform a strain sweep at ambienttemperature to det
34、ermine an appropriate amplitude.10.7 Temperature Sweep:10.7.1 Temperature variations shall be controlled to 1 to2C/min for linear increases or to 2 to 5C/min with aminimum of 1-min thermal-soak time for step increases.10.8 The tan delta peak will coincide with a significantdecrease in the E8 (elasti
35、c or storage) modulus, with increasingtemperature, through the glass-transition region. Another indi-cation of the glass-transition is a maximum value of the E9(loss or viscous) modulus.D541807211. Calculation11.1 The equations listed in Practice D 4065 are used tocalculate the important rheological
36、 properties measured inforced, nonresonant dynamic displacement,where:E8 = storage (elastic) modulus in bending,E9 = loss (viscous) modulus in bending,E* = complex modulus in bending, andd* = tan delta.12. Report12.1 Report the following information:12.1.1 Complete identification of the material tes
37、ted, includ-ing type, source, manufacturers code, number, form, principaldimensions, and previous processing or thermal history, orboth, if available,12.1.2 Description and direction of cutting and loadingspecimen, including pre-load force,12.1.3 Conditioning procedure,12.1.4 Description of the inst
38、rument used for the test,12.1.5 Description of the calibration procedure,12.1.6 Identification of the sample atmosphere by gas com-position, purity, and rate used if appropriate,12.1.7 Width and thickness of specimen,12.1.8 Grip separation distance of the beam,12.1.9 Frequency of dynamic displacemen
39、t,12.1.10 Amplitude of displacement,12.1.11 Thermal gradient; heat rate if appropriate,12.1.12 Number of specimens tested,12.1.13 Table of data and results, including moduli and tandelta as a function of temperature or of time as appropriate, and12.1.14 A plot of the modulus (moduli) and tan delta a
40、s afunction of temperature or of time as appropriate (see Fig. 1).13. Precision and Bias13.1 The repeatability standard deviation has been deter-mined for the following materials. A single laboratory evalu-ated a polyurethane sample and the values in Table 1 wereobtained with the same test method in
41、 the same laboratory bythe same operator using the same equipment in the shortestpractical period of time using test specimens taken at randomfrom a single quantity of homogeneous material. This labora-tory tested the same polyurethane material used for theprecision and bias statement in Test Method
42、 D 5279 andobtained the results in Table 1.14. Keywords14.1 dual cantilever; dynamic mechanical rheological prop-erties; linear displacement; modulus (storage; viscous; lossmodulus; and complex); tan delta; viscoelastic behaviorSUMMARY OF CHANGESCommittee D20 has identified the location of selected
43、changes to this standard since the last issue(D 5418 - 99) that may impact the use of this standard. (March 15, 2007)(1) Punctuation was corrected.(2) Portions were re-worded for clarification.(3) The Significance and Use subsection 5.4 was revised.FIG. 1 Dynamic Mechanical Modulus in Bending as a F
44、unction ofTemperature at Different FrequenciesTABLE 1 DMRTDual Cantilever Beam, Elastic Modulus, E* (E9Pa) or (E10dynes/cm2) at Selected Temperatures40C 0CMean 1.162 0.04953Standard deviation 0.004 0.00373D5418073ASTM International takes no position respecting the validity of any patent rights asser
45、ted 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 revision at any time by
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47、e 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 copyrighted by ASTM Intern
48、ational, 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-mail); or through the ASTM website(www.astm.org).D5418074
