1、Designation:D78915Standard Test Methods forDetermination of Solution Viscosities of Polyamide(PA)1This standard is issued under the fixed designation D789;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A nu
2、mber in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 These test methods cover the determination of solutionviscosities as they apply to polyamide(PA).1.2 The values stated in SI units are to be
3、 regarded asstandard.The values given in brackets are for information only.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 t
4、he applica-bility of regulatory limitations prior to use.NOTE1This standard and ISO 307 address the same subject,but thetechnical content is different.2.Referenced Documents2.1 ASTM Standards:2D446 Specifications and Operating Instructions for GlassCapillary Kinematic ViscometersD883 Terminology Rel
5、ating to PlasticsD6779 Classification System for and Basis of Specificationfor Polyamide Molding and Extrusion Materials(PA)2.2 ISO Standards:3ISO 307 Determination of Viscosity Number of Polyamidesin Dilute SolutionsISO 17025 General Requirements for the Competence ofTesting and Calibration Laborat
6、ories3.Terminology3.1 DefinitionsThe definitions used in these test methodsare in accordance with Terminology D883.4.Significance and Use4.1 These test methods are intended for use as control andacceptance tests.They are also applicable in the partialevaluation of materials for specific end uses and
7、 as a means fordetecting changes in materials due to specific deterioratingcauses.4.2 The steps involved in running this method are:4.2.1 Calibration of the viscometers,4.2.2 Preparation of solutions,4.2.3 Determination of efflux time,4.2.4 Calculation of relative viscosity(which requires thefollowi
8、ng),4.2.4.1 Determining the density of the polymer/formic acidsolution,and4.2.4.2 Determining the absolute viscosity of the formicacid used.4.3 Viscosity for groups 03,04,and 05(PA11,PA12,andPA6,12)in Classification System D6779 shall be measuredusing solvents other than formic acid.Relative viscosi
9、ties forGroups 03 and 04 shall be measured using 0.5 g of polymerdissolved in 99.5 g of m-cresol at 25.0 6 0.1C in aCannon-Fenske No.200 viscometer.Inherent viscosity ofGroup 05 shall be measured using 0.5 g of polymer dissolvedin 100 mLof m-cresol at 25.0 6 0.1C in a Cannon-Fenske No.200 viscometer
10、.The inherent viscosity is calculated as follows:Inherent viscosity5lnts/tc!C(1)where:ts=average efflux time for sample solution,tc=average efflux time for solvent,andC=concentration in g/100 mL5.Test Specimen5.1 Test specimens for the various tests shall conform to therequirements prescribed herein
11、.6.Number of Tests6.1 One determination shall be considered sufficient fortesting each molding powder batch or resin lot.Table 1 givesrepeatability and reproducibility statistics for relative viscositytesting.7.Sampling7.1 The material shall be sampled statistically or the sampleshall come from a pr
12、ocess that is in statistical control.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials(Section D20.15.09).Current edition approved April 1,2015.Published May 2015.Originallyapproved in 1944.
13、Last previous edition approved in 2007 as D789-071.DOI:10.1520/D0789-15.2For 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 we
14、bsite.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*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 States
15、1 7.2 Samples in many forms,such as molded powder,molded shapes,or re-grind are permitted.It is recommendedthat molded specimens be cut into smaller parts prior to testing.8.Conditioning8.1 Test ConditionsDo not remove samples from sealed,airtight containers until ready for testing.TEST METHOD9.Rela
16、tive Viscosity9.1 GeneralDetermine the relative viscosity of the poly-amide polymer by ASTM Ubbelohde(Suspended-Level)-typeviscometer.The ASTM Ubbelohde-type viscometer is thereference and referee method.Ostwald-type viscometers,pipetviscometer,and rotational viscometer4,5are acceptable as analternative method.9.2 ASTMUbbelohde(SuspendedLevel)-typeViscometerTo determine the viscosity of formic acid use anASTM Ubbelohde viscometer Size 1 with an inside diameter of0.58 mm 6 2%.For use to determine
