ASTM_D_1795_-_13.pdf

Designation:D179513Standard Test Method forIntrinsic Viscosity of Cellulose1This standard is issued under the fixed designation D1795;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 intrin-sic viscosity of purified celluloses such as bleached woodpulps,cotton linters,and regenerated cellulose.It is applicableto all cellulose samples with an intrinsic viscosity of 15 dl/g orless.Most native(unpurified)celluloses have intrinsic viscos-ity values too high for measurement by this test method.NOTE1The use of cuprammonium hydroxide solution for regularviscosity determination is described in Method T 206 m-55 of theTechnical Association of Pulp and Paper Industry on“CuprammoniumDisperse Viscosity of Pulp,”and Joint Army-Navy Specifications JAN-C-206.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.2.Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids(and Calculation of Dynamic Viscos-ity)D629 Test Methods for Quantitative Analysis of TextilesE1 Specification for ASTM Liquid-in-Glass ThermometersE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision Liquids3.Summary of Test Method3.1 Aweighed sample of the material is dissolved in a 0.5 Mcupriethylenediamine hydroxide solution.The viscosity of thissolution,and also that of the solvent,is determined at 25C bymeans of a calibrated glass capillary-type viscometer.Therelative viscosity is calculated and the corresponding intrinsicviscosity is read from a table.4.Significance and Use4.1 This test is a sensitive measure of the degradation ofcellulose resulting from the action of heat,light,acids,alkalies,oxidizing and reducing agents,and the like,used in itsprocessing or purification.The intrinsic viscosity value may beconverted to degree of polymerization(DP)or to intrinsicfluidity,if desired.4.2 Solutions of cellulose are not Newtonian liquids;that is,their viscosity depends upon the rate-of-shear or velocitygradient during measurement.This effect is smaller for samplesof low molecular mass(DP)and at low concentrations than forhigh-DP samples and at high concentrations.For the cellulosesand concentrations included within the limits set forth in thistest method,the effect of rate-of-shear is assumed to benegligible for referee purposes.For other conditions and forresearch purposes this assumption may be invalid,but todiscuss ways of accounting for this effect is beyond the scopeof the present test method.5.Apparatus5.1 Viscometer,Glass,Capillary TypeThe Cannon-Fenske,Ubbelohde,or similar capillary type instrument asdescribed in Test Method D445 is recommended.In order toavoid correction for the kinetic energy effect,choose a viscom-eter with a small enough capillary to give an outflow time of 80s or more for the Cannon-Fenske type.(A size 100 viscometeris normally used for the sample solution and a size 50 for thesolvent.)5.2 ThermometerASTM Kinematic Viscosity Thermom-eter for use at 25C,having a range from 19 to 27C andconforming to the requirement for Thermometer 17C asprescribed in Specification E1.Thermometric devices such asRTDs,thermistors and liquid-in-glass thermometers(as speci-fied in Specification E2251)of equal or better accuracy in thespecified temperature range,may be used.5.3 BathA constant-temperature bath at 25C suitable forimmersion of the viscometer so that the reservoir or the top ofthe capillary,whichever is uppermost,is immersed at least 501This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved June 1,2013.Published July 2013.Originally approvedin 1960.Last previous edition approved in 2007 as D1795 96(2007)1.DOI:10.1520/D1795-13.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 mm,and with provision for visibility of the instrument and thethermometer.Firm supports for the viscometer shall be pro-vided;or the viscometer may be sealed in as