ASTM_E_2008_-_08_2014e1.pdf

Designation:E200808(Reapproved 2014)1Standard Test Methods forVolatility Rate by Thermogravimetry1This standard is issued under the fixed designation E2008;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.1NOTEWarning notes were editorially updated throughout in March 2014.1.Scope1.1 These test methods cover procedures for assessing thevolatility of solids and liquids at given temperatures usingthermogravimetry under prescribed experimental conditions.Results of these test methods are obtained as volatility ratesexpressed as mass per unit time.Rates 5 g/min areachievable with these test methods.1.2 Temperatures typical for these test methods are withinthe range from 25C to 500C.This temperature range maydiffer depending upon the instrumentation used.1.3 These test methods are intended to provide a value forthe volatility rate of a sample using a thermogravimetricanalysis measurement on a single representative specimen.It isthe responsibility of the user of these test methods to determinethe need for and the number of repetitive measurements onfresh specimens necessary to satisfy end use requirements.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 There is no ISO method equivalent to this standard.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of these test methods to establishappropriate safety and health practices and determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE473 Terminology Relating to Thermal Analysis and Rhe-ologyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1142 Terminology Relating to Thermophysical PropertiesE1582 Practice for Calibration of Temperature Scale forThermogravimetryE1860 Test Method for Elapsed Time Calibration of Ther-mal AnalyzersE2040 Test Method for Mass Scale Calibration of Thermo-gravimetric Analyzers3.Terminology3.1 Definitions:3.1.1 The following terms are applicable to these testmethods and can be found in Terminologies E473 and E1142:3.1.1.1 thermogravimetric analysis(TGA),3.1.1.2 thermogravimetry(TG),3.1.1.3 volatility.3.2 Definitions of Terms Specific to This Standard:3.2.1 volatility ratethe rate of conversion of a solid orliquid substance into the vapor state at a given temperature;mass per unit time.4.Summary of Test Method4.1 A solid or liquid specimen is confined in an appropriatecontainer with a pinhole opening between 0.33 and 0.38 mm.The confined specimen is heated within a thermogravimetricanalyzer either to a temperature and held constant at thattemperature for a fixed interval of time(Method A,Fig.1)orat a slow constant heating rate between temperature limits(Method B,Fig.2).The mass of the specimen is measuredcontinuously and it or its rate of change is displayed as afunction of time or temperature.The volatility rate at anytemperature is reported either as the average rate of mass lossper unit time from Method A or as the instantaneous rate ofmass loss(first derivative)per unit time from Method B.5.Significance and Use5.1 Volatility of a material is not an equilibrium thermody-namic property but is a characteristic of a material related to athermodynamic property that is vapor pressure.It is influenced1These test methods are under the jurisdiction of ASTM Committee E37 onThermal Measurements and are the direct responsibility of Subcommittee E37.01 onCalorimetry and Mass Loss.Current edition approved March 15,2014.Published April 2014.Originallyapproved in 1999.Last previous edition approved in 2008 as E2008 08.DOI:10.1520/E2008-08R14E01.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandardsvolume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 by such factors as surface area,temperature,particle size,andpurge gas flow rate;that is,it is diffusion controlled.FIG.1 Method A:Rv=Average Volatility RateFIG.2 Method B:Rv=Instantaneous Volatility RateE2008 08(2014)12 5.2 The extent of containment achieved for specimens inthese test methods by means of a pinhole opening between 0.33to 0.38 mm allows for measurement circumstances that arerelatively insensitive to experimental variables other thantemperature.Decreasing the extent of containment by use ofpinholes larger than 0.38 mm will increase the magnitude ofthe observed rate of mass loss but wil