1、Designation:D 5510 94(Reapproved 2001)Standard Practice forHeat Aging of Oxidatively Degradable Plastics1This standard is issued under the fixed designation D 5510;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revi
2、sion.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice is intended to define the exposure condi-tions of plastics at various temperatures when exposed solely tohot air for
3、extended periods of time.Only the procedures forheat exposure are specified,not the test method or specimen.The effect of heat on any particular property may be deter-mined by selection of the appropriate test method and speci-men;however,it is recommended that Practice D 3826 be usedto determine th
4、e embrittlement endpoint,which is defined asthat point in the history of a material when 75%of thespecimens tested have a tensile elongation at break of 5%orless at an initial strain rate of 0.1 mm/mm min.1.2 This practice should be used as a guide for comparingthe thermal-aging characteristics of m
5、aterials as measured bythe change in some property of interest(that is,embrittlementby means of loss of elongation).It is very similar to PracticeD 3045 but is intended for use in evaluating plastics designedto be oxidized easily after use.The exposure times used for thispractice will be significant
6、ly shorter than those used forPractice D 3045.1.3 The type of oven used can affect the results obtainedfrom this practice.The user can use one of two methods foroven exposure.The results based on one method should not bemixed with those based on the other.1.3.1 ProcedureA:Gravity-ConvectionOvenRecom
7、mended for film specimens having a nominal thicknessnot greater than 0.25 mm(0.010 in.).1.3.2 ProcedureB:Forced-VentilationOvenRecommended for specimens having a nominal thicknessgreater than 0.25 mm(0.010 in.).1.4 This practice recommends procedures for comparing thethermal aging characteristics of
8、 materials at a single tempera-ture.Recommended procedures for determining the thermalaging characteristics of a material at a series of temperaturesfor the purpose of estimating time to a defined property changeat some lower temperature are also described.This practicedoes not predict thermal aging
9、 characteristics where interac-tions between stress,environment,temperature,and timecontrol failure.1.5 The values stated in SI units are to be regarded as thestandard.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of th
10、e user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE1There is no ISO standard that is equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:D 618 Practice for Conditioning Plastics fo
11、r Testing2D 883 Terminology Relating to Plastics2D 1870 Practice for Elevated Temperature Aging Using aTubular Oven3D 2436 Specification for Forced-Convection LaboratoryOvens for Electrical Insulation4D 3045 Practice for Heat Aging of Plastics Without Load5D 3593 Test Method for Molecular Weight Ave
12、rages andMolecular Weight Distribution of Certain Polymers byLiquid Size-Exclusion Chromatography(Gel PermeationChromatography GPC)Using Universal Calibration5D 3826 Practice for Determining Degradation End Point inDegradable Polyolefins Using a Tensile Test5E 145 Specification for Gravity-Convectio
13、n and Forced-Ventilation Ovens63.Terminology3.1 DefinitionsThe definitions used in this practice are inaccordance with Terminology D 883.4.Significance and Use4.1 The correlation of results obtained from this practice toactual disposal environments(for example,composting)hasnot been determined,and,a
14、s such,the results should be usedonly for comparative and ranking purposes.4.2 Degradable plastics exposed to heat may be subject tomany types of physical and chemical changes.The severity of1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of
15、Subcommittee D20.96 on Environmentally DegradablePlastics.Current edition approved Feb.15,1994.Published April 1994.2Annual Book of ASTM Standards,Vol 08.01.3Discontinued;see1997 Annual Book of ASTM Standards,Vol 08.01.4Annual Book of ASTM Standards,Vol 10.01.5Annual Book of ASTM Standards,Vol 08.02
16、.6Annual Book of ASTM Standards,Vol 14.02.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.the exposures in both time and temperature determines theextent and type of change that occurs.Short exposure times atelevated temperatures generally serve to shorten the inductionperiod of oxidatively degradable plastics during which thedepletion of antioxidants and stabilizers occurs.Physical prop-erties,such as tensile and impact strength and