ASTM_D_7976_-_14_2020.pdf

Designation:D797614(Reapproved 2020)Standard Specification forPurified Terephthalic Acid(PTA)1This standard is issued under the fixed designation D7976;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 specification covers purified terephthalic acid(PTA)for use in the manufacturing of polymers.Someexamples include the production of polyesters for fiber,filament,yarn,film,coating,bottle and resin applications.1.2 The following applies to all specified limits in thisspecification:for purposes of determining conformance withthis specification,an observed value or a calculated value shallbe rounded off to the nearest unit in the last right-hand digitused in expressing the specification limit,in accordance withthe rounding-off method of Practice E29.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 Consult current OSHA regulations,suppliers SafetyData Sheets,and local regulations for all materials used in thisspecification.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 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:2D7881 TestMethodforDeterminationof4-Carboxybenzaldehyde and p-Toluic Acid in PurifiedTerephthalic Acid by Capillary Electrophoresis with Re-verse Voltage ModeD7882 TestMethodforDeterminationof4-Carboxybenzaldehyde and p-Toluic Acid in PurifiedTerephthalic Acid by Capillary Electrophoresis with Nor-mal Voltage ModeD7883 TestMethodforDeterminationof4-Carboxybenzaldehyde and p-Toluic Acid in PurifiedTerephthalic Acid by Weak Anion Exchange High Perfor-mance Liquid ChromatographyD7884 TestMethodforDeterminationof4-Carboxybenzaldehyde and p-Toluic Acid in PurifiedTerephthalic Acid by Reverse Phase High PerformanceLiquid ChromatographyE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE300 Practice for Sampling Industrial Chemicals2.2 Other Documents:OSHA Regulations,CFR 29 paragraphs 1910.1000 and1910.120033.Terminology3.1 Definitions:3.1.1 purified terephthalic acid,n(C8H6O4)molecularweight,166.13;white crystalline solid or powder;sublimes,402 to 404C;abbreviated as PTA(CAS#100-21-0).3.1.2 4-carboxybenzaldehyde,n(C8H6O3)molecularweight,150.13;white to yellow crystalline solid or powder;melting point,247C;abbreviated as 4-CBA(CAS#619-66-9).3.1.3 p-toluic acid,n(C8H8O2)molecular weight,136.15;white crystalline solid or powder;melting point,180 to 181C;abbreviated as p-TOL(CAS#99-94-5).1This specification is under the jurisdiction of ASTM Committee D16 onAromatic,Industrial,Specialty and Related Chemicals and is the direct responsi-bility of Subcommittee D16.02 on Oxygenated Aromatics.Current edition approved Feb.1,2020.Published February 2020.Originallyapproved in 2014.Last previous edition approved in 2014 as D7976 14.DOI:10.1520/D7976-14R20.2For 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.3Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.Copyright 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 Organization Technical Barriers to Trade(TBT)Committee.4.Properties4.1 PTA shall conform to the following requirements:PropertySpecificationASTM Test MethodA4-CBA,max,mg/kg25D7881 or D7882 orD7883 or D78844-CBA plus p-TOL,max,mg/kg190D7881 or D7882 orD7883 or D7884AIf more than one method is listed,the producer and user should agree on thereferee method.5.Sampling5.1 The material shall be sampled in accordance withPractice E300.6.Keywords6.1 purifiedterephthalicacid;p-toluicacid;4-carboxybenzaldehydeASTM International takes no position respecting the validity of any patent rights asserted in connect