ASTM_D_7028_-_07_2015.pdf

Designation:D702807(Reapproved 2015)Standard Test Method forGlass Transition Temperature(DMA Tg)of Polymer MatrixComposites by Dynamic Mechanical Analysis(DMA)1This standard is issued under the fixed designation D7028;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.Scope1.1 This test method covers the procedure for the determi-nation of the dry or wet(moisture conditioned)glass transitiontemperature(Tg)of polymer matrix composites containinghigh-modulus,20 GPa(3 106psi),fibers using a dynamicmechanical analyzer(DMA)under flexural oscillation mode,which is a specific subset of the Dynamic MechanicalAnalysis(DMA)method.1.2 The glass transition temperature is dependent upon thephysical property measured,the type of measuring apparatusand the experimental parameters used.The glass transitiontemperature determined by this test method(referred to as“DMA Tg”)may not be the same as that reported by othermeasurement techniques on the same test specimen.1.3 This test method is primarily intended for polymermatrix composites reinforced by continuous,oriented,high-modulus fibers.Other materials,such as neat resin,may requirenon-standard deviations from this test method to achievemeaningful results.1.4 The values stated in SI units are standard.The valuesgiven in parentheses are non-standard mathematical conver-sions to common units that are provided for information only.1.5 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.2.Referenced Documents2.1 ASTM Standards:2D3878 Terminology for Composite MaterialsD4065 Practice for Plastics:Dynamic Mechanical Proper-ties:Determination and Report of ProceduresD4092 Terminology for Plastics:Dynamic MechanicalPropertiesD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1309 GuideforIdentificationofFiber-ReinforcedPolymer-Matrix Composite Materials in Databases(With-drawn 2015)3E1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Databases(Withdrawn2015)3E1471 Guide for Identification of Fibers,Fillers,and CoreMaterials in Computerized Material Property Databases(Withdrawn 2015)3E1640 Test Method for Assignment of the Glass TransitionTemperature By Dynamic Mechanical AnalysisE1867 Test Method for Temperature Calibration of DynamicMechanical Analyzers3.Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto polymer matrix composites.Terminology D4092 definesterms relating to dynamic mechanical property measurementson polymeric materials.3.2 Symbols:E=storage modulusE”=loss modulustan =E”/E=tangent deltaDMA Tg=glass transition temperature defined from dy-namic mechanical analysis measurementL=length of specimenW=width of specimenT=thickness of specimenTt=peak temperature from tangent delta curve1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.04 onLamina and Laminate Test Methods.Current edition approved Aug.1,2015.Originally approved in 2007.Lastprevious edition approved in 2007 as D7028-071.Published August 2015.DOI:10.1520/D7028-07E01R15.2For 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 last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Test Method4.1 Aflat rectangular strip of laminate is placed in the DMAequipment and oscillated at a nominal frequency of 1 Hz.Thespecimen is heated at a rate of 5C/min(9F/min).The sameloading frequency and heating rate is used for both dry and wetspecimens(moisture conditioned)to allow for comparison.The temperature at which a significant drop in storage modulus(E)begins is assigned as the glass transition temperature(DMA Tg).The peak temperature of the tangent delta curve(Tt)is identified along with DMATg for comparison purposes.5.Significance and Use5.1 This test method is designed to determine the glasstransition temperature of continuous fiber reinforced polymercomposites using the DMA method.The DMA Tg value isfrequently used to indicate the upper use temperature o