1、Designation:D132916(Reapproved 2021)Standard Test Method forEvaluating Rubber PropertyRetraction at LowerTemperatures(TR Test)1This standard is issued under the fixed designation D1329;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,
2、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 describes a temperature-retractionprocedure for rapid evaluation of crystallization effects an
3、d forcomparing viscoelastic properties of rubber and rubber-likematerials at low temperatures.This test method is useful whenemployed in conjunction with other low-temperature tests forselection of materials suitable for low-temperature service.1.2 The values stated in SI units are to be regarded as
4、 thestandard.The values given in parentheses are for informationonly.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,health,and environmental practices and det
5、er-mine the applicability of regulatory limitations prior to use.1.4 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-mendat
6、ions issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D832 Practice for Rubber Conditioning For Low Tempera-ture TestingD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black Manufacturi
7、ngIndustries3.Summary of Test Method3.1 This test method is carried out by(1)elongating thespecimen,(2)locking it in the elongated condition,(3)freezingit to a state of reduced elasticity,(4)releasing the frozenspecimen and allowing it to retract freely while raising thetemperature at a uniform rate
8、,(5)measuring the length of thespecimen at regular temperature intervals while it is retracting,and(6)computing the percentage retraction at these tempera-tures from the data obtained.In practice,the temperaturescorresponding to 10%and 70%retraction are of particularimportance,and are designated as
9、TR10 and TR70,respec-tively.4.Significance and Use4.1 The difference between the temperature at which avulcanizate retracts 10%(TR10)and the temperature at whicha vulcanizate retracts 70%(TR70)increases as the tendency tocrystallize increases.4.2 TR70 correlates with low-temperature compression set.
10、4.3 TR10 has been found to correlate with brittle points invulcanizates based on polymers of similar type.4.4 In general,the retraction rate is believed to correlatewith low-temperature flexibility of both crystallizable andnoncrystallizable rubbers.5.Apparatus5.1 Specimen Rack,designed to maintain
11、a slight tension onthe specimen of 7 to 21 kPa(1 to 3 psi),and to permit it to bestretched and anchored at any elongation desired up to amaximum to 350%.Means of measuring the length of thespecimen at any time during the test within an accuracy of 61mm(60.04 in.)shall be provided.The rack may be des
12、ignedto hold a number of specimens at the same time.5.2 InsulatedCoolingBath,equippedwithstirrer,thermometer,and an immersion heater.A rheostat shall beincluded in the heater circuit.A suitable thermocouple-potentiometer measuring system may be substituted for thethermometer.5.3 Temperature Measurem
13、ent,may be conducted in one oftwo ways:(a)a typical glass thermometer with appropriaterange and sensitivity(61C(62F);or(b)a more modernthermocouple or resistive element,electronic temperature mea-suring system,accurate to 61C.1This test method is under the jurisdiction of ASTM Committee D11 on Rubbe
14、rand Rubber-like Materials and is the direct responsibility of Subcommittee D11.10on Physical Testing.Current edition approved May 1,2021.Published June 2021.Originallyapproved in 1954.Last previous edition approved in 2016 as D1329 16.DOI:10.1520/D1329-16R21.2For referenced ASTM standards,visit the
15、 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 Stat
16、esThis 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.15.4 Liquid Coolant,which does not attack the test specimenunder the conditions of the test.Methanol cooled with dry iceis satisfactory for most samples.Where methanol-dry icecombinati
