ASTM_D_5279_-_21.pdf

Designation:D527921Standard Test Method forPlastics:Dynamic Mechanical Properties:In Torsion1This standard is issued under the fixed designation D5279;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the 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.Scope*1.1 This test method covers the use of dynamic mechanicalinstrumentation for gathering and reporting the viscoelasticproperties of thermoplastic 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 method is intended to provide means fordetermining the torsional modulus of plastics as a function oftemperature using nonresonant forced-vibration techniques,asoutlined in Practice D4065.Plots of the elastic(storage),loss(viscous),and complex moduli and tan delta,as a function offrequency,time,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 experimental 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 relevant 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 safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1This test method is equivalent to ISO 6721,Part 7.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD4065 Practice for Plastics:Dynamic Mechanical Proper-ties:Determination and Report of ProceduresD4092 Terminology for Plastics:Dynamic MechanicalProperties3.Terminology3.1 For definitions applicable to this test method,refer toTerminology D4092.4.Summary of Test Method34.1 This test method covers the determination of the shearmodulus of plastics 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 frequencies 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 material.Thedata obtained may be used for quality control,research anddevelopment,and establishment of optimum processing con-ditions.5.2 Dynamic mechanical testing provides a sensitivemethod for determining thermomechanical characteristics bymeasuring the elastic and loss moduli as a function of1This 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 July 1,2021.Published August 2021.Originallyapproved in 1992.Last previous edition approved in 2013 as D5279-13.DOI:10.1520/D5279-21.2For 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.3The particular method for measurement of the elastic and loss moduli and tandelta depends upon the individual instruments operating principles.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade