ASTM_D_5492_-_10.pdf

Designation:D549210Standard Test Method forDetermination of Xylene Solubles in Propylene Plastics1This standard is issued under the fixed designation D5492;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 is to be used for determining the 25Cxylene-soluble fraction of polypropylene homopolymers andcopolymers.1.2 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.NOTE1This test method is technically equivalent to ISO 16152.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Standard:ISO 16152 PlasticsDetermination of Xylene Solubles ofPolypropylene33.Terminology3.1 Definitions:3.1.1 For definitions of plastic terms see Terminology D883and for abbreviations see Terminology D1600.3.2 Definitions of Terms Specific to This Standard:3.2.1 soluble-fraction(SS)the percentage of the polymermass that does not precipitate out when the polymer solution iscooled from reflux temperature to+25 6 0.5C and held at thattemperature for a specified period of time.4.Summary of Test Method4.1 A weighed amount of sample is dissolved in xyleneunder reflux conditions.The solution is cooled under con-trolled conditions and maintained at a+25C equilibriumtemperature so that the crystallization of the insoluble fractiontakes place.When the solution is cooled the insoluble portionprecipitates and is isolated by filtration.The xylene is evapo-rated from the filtrate,leaving the soluble fraction in theresidue.The percentage of this fraction in the plastic isdetermined gravimetrically.5.Significance and Use5.1 The results of this test provide a relative measure of thetotal soluble fraction of polypropylene homopolymers andcopolymers.The soluble fraction approximately correlates tothe amorphous fraction in the polypropylene.Xylene is widelyused for determining the soluble fraction in polypropylene as itis more specific to the atactic fraction than other solvents.Theconcentration of a soluble fraction obtained with a specificsolvent has been found to relate closely to the performancecharacteristics of a product in certain applications,for examplefilm and fiber.Data obtained by one solvent and at oneprecipitation time cannot be compared with data obtained byanother solvent or precipitation time,respectively.6.Interferences6.1 It is possible that materials with solubilities similar tothe soluble fraction,such as additives,can interfere with themeasurement of solubles.When present in concentrations thatare judged to impart a significant error to the soluble-fractiondata,the level of interference must be determined and correc-tions made.6.2 It is possible that small-particle fillers and pigments andinsoluble gels present in the polymer can pass through the filterand cause errors in the measurement.6.3 The polymer flakes and spheres must be dried beforetesting to eliminate moisture that can influence the initialweight of sample added to the flask.7.Apparatus7.1 Reflux-Condenser Apparatus,400 mm,with 24/40 glassjoint.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materi-als.Current edition approved Aug.1,2010.Published September 2010.Originallyapproved in 1994.Last previous edition approved in 2006 as D5492-06.DOI:10.1520/D5492-10.2For 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 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 ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.2 Flat-Bottom Boiling Flask,with one or two necks,400mL with 24/40 joint,Erlenmeyer flask,or cylindrical bottle.7.3 Insulation Disk,made of fiberglass or rock wool.7.4 Electromagnetic Stirrer Unit,with temperature-controlled heating plate,thermostatted oil bath,or heater blockcapable of maintaining 145 to 150C.7.5 Stirring Bar.7.6 Pipet,Class A,200 mL or equivalent.7.7 Pipet,Class A,100 mL or equivalent.7.8 Glass-Stoppered Volumetric Flask,250 mL.7.9 Thermostatically Controlled Water Bath,at+25 60.5C.7.10 Electromagnetic Stirrers.7.11 Fil