ASTM_D_3591_-_97_2011.pdf

Designation:D359197(Reapproved 2011)Standard Test Method forDetermining Logarithmic Viscosity Number of Poly(VinylChloride)(PVC)in Formulated Compounds1This standard is issued under the fixed designation D3591;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 determination of the loga-rithmic viscosity number of poly(vinyl chloride)(PVC)ho-mopolymers after compounding or processing.1.2 It is the basic assumption of this technique that theformulation of the compounded resin is known and that anyadditives present can be separated from the resin by extractionwith diethyl ether.This is necessary to permit adjustment of theamount of sample used in the test to give a resin concentrationin cyclohexanone of 0.2 6 0.002 g/100 mL.1.3 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.Specific precau-tionary statements are given in 7.3 and 8.4.1.NOTE1This test method and ISO 1628-2 are not equivalent.2.Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids(and Calculation of Dynamic Viscos-ity)D446 Specifications and Operating Instructions for GlassCapillary Kinematic ViscometersD1243 Test Method for Dilute Solution Viscosity of VinylChloride PolymersD2124 Test Method for Analysis of Components in Poly(Vi-nyl Chloride)Compounds Using an Infrared Spectropho-tometric TechniqueE1 Specification for ASTM Liquid-in-Glass ThermometersE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodIEEE/ASTM SI-10 Standard for the Use of InternationalSystem of Units(SI)2.2 ISO Standard:1628-2 PlasticsDetermination of Viscosity Number andLimiting Viscosity NumberPart 2:Poly(Vinyl Chlo-ride)Resins33.Terminology3.1 Units and symbols used in this test method are thoserecommended in IEEE/ASTM SI-10.3.2 Definitions of Terms Specific to This Standard:3.2.1 The term logarithmic viscosity number is defined bythe equation is 9.1.4.Summary of Test Method4.1 The sample is pressed into a thin film and extracted toremove the plasticizer.4.2 The plasticizer-free film is dissolved in cyclohexanoneand centrifuged to remove insoluble matter.4.3 The viscosity of the cyclohexanone solution is measuredin accordance with Test Method D1243.5.Significance and Use5.1 The logarithmic viscosity number provides informationon the effect of compounding or processing of PVC.5.2 Exposure of PVC compositions to shear or to hightemperatures can result in a change in the logarithmic viscositynumber of the resin.6.Apparatus6.1 Centrifuge,capable of 2500 rpm with 100-mL samplecontainer.6.2 Heated Hydraulic Press,capable of 620-kN ram forceand a temperature of 165C.6.3 Soxhlet Extraction Apparatus with a 150-mL flask and a27 by 100-mm thimble.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved Feb.1,2011.Published March 2011.Originallyapproved in 1977.Last previous edition approved in 2003 as D3591 97(2003).DOI:10.1520/D3591-97R11.2For 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,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.4 Volumetric Flasks,100-mL.6.5 Viscometers.46.6 Infrared Spectrophotometer,see 5.4 of Method D2124.7.Reagents7.1 Cyclohexanone,high-purity(see Annex A1).7.2 Diethyl Ether,anhydrous,reagent grade.7.3(WarningSafety precautions should be taken to avoidpersonal contact,to eliminate toxic vapors,and to guardagainst explosive hazards in accordance with the hazardousnature of the particular reagent being used.)8.Procedure8.1 Prepare the PVC sample for extraction by pressing afilm.The film should be 0.02 to 0.5 mm(1 to 2 mil)thick.Prepare two films in order to make duplicate runs.8.1.1 Heat the hydraulic press to 165C(330F).8.1.2 Place 2 g of sample between two sheets of aluminumfoil and insert into the press.8.1.3 Allow the sample to come to temperature for 2.5 min.During the next 0.5 min,increase the force on the sample to620 kN.Maintain the force for 3 min,then cool whilemaintaining the force.8.2 Weigh,to 60.2 mg,approximately 1 g of pressed filminto a 27 by 100-mm extra