1、Designation:D211522Standard Practice forOven Heat Stability of Poly(Vinyl Chloride)Compositions1This standard is issued under the fixed designation D2115;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A num
2、ber in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This practice lists procedures for determining the rela-
3、tive thermal stability of sheet or molded poly(vinyl chloride)compounds as indicated by discoloration due to exposure to anelevated temperature at controlled oven conditions.1.2 A specimen preparation technique using a two-roll millis provided for compositions that are not in molded or sheetedform.1
4、.3 This practice is not intended for use in purchasingspecifications because the conditions of processing plasticcompounds vary widely,and the degree of correlation of dataobtained by this practice to process exposure has not beendetermined.However,despite this limitation,this practice doesyield dat
5、a of value in judging the comparative service qualityof poly(vinyl chloride)compositions.1.4 The values stated in SI units are to be regarded as thestandard.The values in parentheses are given for informationonly.1.5 This standard does not purport to address all of thesafety concerns,if any,associat
6、ed 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 standard is similar in content,but not technicallyequivalent to ISO 3051990.1.6 T
7、his 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
8、(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-tics2.2 ISO Standard:ISO3051990 PlasticsDetermination of Thermal Stabilityof Poly(Vinyl Chloride),Related Chlorine-ContainingPolymers and Copolymers a
9、nd Their CompoundsDiscoloration Method33.Terminology3.1 GeneralDefinitions are in accordance with Terminol-ogy D883 and abbreviations with Terminology D1600,unlessotherwise indicated.4.Significance and Use4.1 Poly(vinyl chloride)compositions degrade by discolor-ation on prolonged exposure to heat.Th
10、e degree of discolor-ation is related to the condition of exposure,such as length ofperiod and temperature.When the conditions of exposure arefixed and controlled,then the relative resistance to discolor-ation due to heat of two or more compositions is able to bedetermined.The precision of heat stab
11、ility testing is alsodependent on the thickness of the specimens and the history ofheat exposure prior to testing.This practice allows for controlor the reporting of these variables.4.2 This practice is particularly applicable for determininggross differences in the heat stabilities of poly(vinyl ch
12、loride)compositions that are detectable as a color change.It is notintended to measure absolute thermal stability.This testmethod applies when observed changes are evidence of1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20
13、.15 on Thermoplastic Materials.Current edition approved July 15,2022.Published July 2022.Originallyapproved in 1962.Last previous edition approved in 2017 as D2115-17.DOI:10.1520/D2115-22.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceast
14、m.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036.*A Summary of Changes section appears at the end of this standardCopyright A
15、STM 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 Standar
16、ds,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1degradation,molecular degradation phenomena such as chain-scission or cross-linking are not identifiable.4.3 While discoloration caused by exposure to elevatedtemperature is commonly regarded as evidence of degradationin poly(vinyl chloride)compositions,some vinyl compositionsundergo substantial change in color without appreciable loss ofmechanical strength,chemical resistance,etc.,whe
