1、Designation: D5870 11D5870 16Standard Practice forCalculating Property Retention Index of Plastics1This standard is issued under the fixed designation D5870; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers procedures for the calculation of a property retention index (PRI) of thermoplastic and thermosetplastics aft
3、er exposure to thermal aging, natural or artificial accelerated weathering, or chemical exposures.1.2 This practice is not intended to establish a fixed procedure for conducting the exposure test, but it is intended to providea set of specific procedures used to calculate the retention index of a ch
4、aracteristic property of the material after it has beenexposed. Selection of the specific exposure test conditions depends on the material being tested and the property being measured.It is up to the user to determine which exposure test conditions are most relevant to the specific material and the
5、service conditionbeing used. The exposure test used must be conducted in accordance with conditions described in specific exposure standards.1.3 This practice does not describe procedures for sampling the materials to be tested. These procedures are described in thestandards and specifications appli
6、cable to the material being evaluated.1.4 The procedure used to calculate the PRI depends on whether the test used to characterize the materials being exposed isdestructive or nondestructive.The PRI can be useful in describing short-term mechanical, electrical, and other properties of plasticsat spe
7、cified temperatures after the materials have been subjected to an exposure test.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and det
8、ermine the applicability of regulatorylimitations prior to use.NOTE 1There is no similar or equivalent ISO standard. ISO DIS 11248 ISO 11248 is significantly different since it pertains only to thermosettingresins.2. Referenced Documents2.1 ASTM Standards:2D543 Practices for Evaluating the Resistanc
9、e of Plastics to Chemical ReagentsD618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1435 Practice for Outdoor Weathering of PlasticsF1499D1499 Specification for Coextruded Composite Drain, Waste, and Vent Pipe (DWV)Practice for Filtered Open-FlameCarbon-Arc Exp
10、osures of PlasticsD1898 Practice for Sampling of Plastics (Withdrawn 1998)3D2565 Practice for Xenon-Arc Exposure of Plastics Intended for Outdoor ApplicationsD3045 Practice for Heat Aging of Plastics Without LoadD4329 Practice for Fluorescent Ultraviolet (UV) Lamp Apparatus Exposure of PlasticsD4364
11、 Practice for Performing Outdoor Accelerated Weathering Tests of Plastics Using Concentrated SunlightD4459 Practice for Xenon-Arc Exposure of Plastics Intended for Indoor ApplicationsD4674 Practice for Accelerated Testing for Color Stability of Plastics Exposed to Indoor Office EnvironmentsD6360 Pra
12、ctice for Enclosed Carbon-Arc Exposures of PlasticsG113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials1 This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.50 on Durability of Plastic
13、s.Current edition approved Feb. 1, 2011April 1, 2016. Published March 2011April 2016. Originally approved in 1995. Last previous edition approved in 20032011 asD5870 - 95D5870 - 11.(2003). DOI: 10.1520/D5870-11.10.1520/D5870-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or
14、contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is in
15、tended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the cur
16、rent versionof the standard as published by ASTM is to be considered the official document.*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 States12.2 ISO Standards:4ISO 291 Pla
17、sticsStandard Atmospheres for Conditioning and TestingISO 877 PlasticsMethods of Exposure to Direct Weathering, to Weathering Using Glass Filtered Daylight, and to IntensifiedWeathering by Daylight Using Fresnel MirrorsSolar Radiation, Part 1: General Guidance, Part 2: Direct Weathering andExposure
18、Behind Window Glass, and Part 3: Intensified Weathering Using Concentrated Solar RadiationISO 4892 PlasticsMethods of Exposure to Laboratory Light Sources Part 1: General Guidance, Part 2: Xenon ArcExposures,Lamps, Part 3: Fluorescent UV Exposures,Lamps, and Part 4: Filtered Open Flame Carbon Arc Ex
19、posuresISO DIS 11248ISO 11248 PlasticsThermosetting Molding Materials, Evaluation of Short-Term Performance at ElevatedTemperatures3. Terminology3.1 Definitions: The terminology given in Terminologies D883 and G113 is applicable to this practice.4. Significance and Use4.1 The property retention inde
20、x (PRI) determined by this practice is intended primarily to provide relative durabilityperformance information on materials for design engineers. It is up to the user to ensure that appropriate sampling procedures areused for the selection of specimens to be exposed so that the PRI data obtained is
21、 actually representative of the material beingevaluated.4.2 The PRI obtained depends on the material being tested, property being evaluated, and exposure condition used. A PRIobtained for one property will probably not be the same as the PRI for a different property of the same material, even if the
22、 sameexposure test is used.4.3 Plastics exposed to a combination of environmental and thermal treatments may undergo a change in functionalperformance. Any laboratory-accelerated aging procedure, especially those that use only a single stress, may not realisticallyindicate the changes a plastic may
23、undergo in actual use conditions. This practice provides a means for expressing the changes inproperties as a function of time exposed in a wide variety of tests. The PRI data obtained is best used for comparing theperformance of materials subjected to the same exposure test simultaneously.4.3.1 Bot
24、h laboratory-accelerated and outdoor exposure testing can be highly variable, and the PRI data will be influenced bythis variability. For example, PRI data from outdoor exposures can vary depending on the exposure location and the time of yearwhen the exposure is conducted. Variability in laboratory
25、-accelerated exposure tests can result in large differences in PRI data fromtwo laboratories running supposedly identical tests. PRI data obtained from exposure to laboratory-accelerated tests cannot be usedto predict the PRI for exposure to natural weathering or actual use conditions unless there i
26、s a sufficient amount of data from bothtypes of exposure to allow valid statistical comparisons.4.4 Anumber of different exposure techniques can be used to provide information on the effects of environmental stresses suchas light, heat, and water on plastics (see Practices D1435, F1499D1499, D2565,
27、D4329, D4364, and D4459; Test Method D4674;and ISO 877 and ISO 4892).When it is desirable to evaluate the effects of heat alone, exposures should be conducted in accordancewith Practice D3045. When it is desirable to evaluate the effects of chemical exposures, the exposures should be conducted inacc
28、ordance with Test Method D543.4.5 There are a number of factors influencing the physical properties and the retention of these properties after exposure. Inaddition to a complete description of the exposure test conditions used, the following information shall be included in any reportreferencing th
29、is practice: (1) complete description of the material tested, including the type, source, manufacturers code number,form, and previous history; (2) methods of preparation for the material and individual test specimens; (3) procedure used forspecimen conditioning prior to and after exposure; (4) comp
30、lete description of the environment in which the physical propertieswere determined (for example, temperature and relative humidity); (5) complete description of the procedure used to determinethe physical properties tested, including the rate at which specimens were tested, if applicable; (6) if ap
31、plicable, void content ofthe specimens tested and the method used to measure void content.NOTE 2It is not the intent of this practice to require users to divulge proprietary information regarding composition. To avoid divulging proprietaryinformation, generic descriptions may be used to provide info
32、rmation on material composition.4.6 When destructive tests are used to determine a physical or chemical change, or both, which occurs as a result of exposure,the amount of change is expressed as a function of the value obtained for the material tested at a specified test environment (forexample, tem
33、perature and humidity). The exposed and reference specimens are measured at the same time in the specified testenvironment.4.7 When nondestructive tests are used to determine a physical or chemical change, or both, which occurs as a result ofexposure, the amount of change is expressed as a function
34、of the value obtained on the specimens prior to exposure. Propertymeasurement tests on the specimens before and after exposure shall be conducted at the same conditions (for example, temperatureand humidity).4 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, Ne
35、w York, NY 10036, http:/www.ansi.org.D5870 1624.8 The property or properties to be measured may be specified in anASTM, ISO, or other appropriate standard for the materialbeing tested, or by any prior agreement between interested parties. If the method used to measure the property being evaluated is
36、not described in an ASTM, ISO, or other appropriate standard, a description of the test method shall be included in the report oftest results.4.9 It is realized that a material cannot be tested without specifying the method of preparation. To have any meaning incomparative testing, specimens of each
37、 material being evaluated by these test procedures should be prepared or molded from thesame lot under identical processing conditions and randomized prior to testing at the conditions desired. It must be realized thatlot-to-lot variation in the material may cause additional variability in results.N
38、OTE 3For those plastics with a Tg greater than ambient, the slow collapse of free volume, with attendant significant changes in mechanicalproperties such as fatigue resistance, impact resistance, yield stress, and vapor transmission, etc. will be accelerated at elevated temperatures below theTg but
39、will be reversed at temperatures above the Tg. Therefore, incubation of material at elevated temperatures in the Tg range may be erraticallysusceptible to oven fluctuation effects.4.10 The results depend on which side of the test specimen is exposed with some tests. In bending tests, for example, di
40、fferentresults are obtained in accordance with whether the exposed surface or the unexposed surface of the test specimen is placed undertension. Care must be taken to ensure that all specimens being exposed have the same orientation in the test fixture used to holdthe specimens during exposure. In a
41、ddition, the results also depend on the orientation of test specimens during the procedure usedto measure the property being monitored. This is especially true with impact tests. During the procedure used to measure thecharacteristic property, care must be taken to ensure that all specimens are orie
42、nted the same way in the test fixture.4.11 Before proceeding with this practice, reference should be made to the specification of the material being tested. Any testspecimen preparation, conditioning, or dimensions, or some combination thereof, and testing parameters covered in the materialsspecific
43、ation shall take precedence over those mentioned in this practice. The default conditions described in this practice applyif there are no material specifications.5. Apparatus5.1 The apparatus used for exposure and measurement of the property desired will depend on the particular exposure used andpro
44、perty being measured. Refer to the appropriate ASTM or ISO standards for requirements on the apparatus needed.6. Sampling6.1 Sampling of materials for testing is covered under applicable standards or specifications for the material being tested.6.2 It is important to select samples for testing that
45、are representative of the material being evaluated. Procedures for samplingplastics are described in Practice D1898.7. Test Specimens7.1 The test specimens shall be in accordance with the appropriate test method used for the properties being measured.7.2 All test specimens shall be prepared in accor
46、dance with the pertinent material standards and other relevantASTM standards.7.3 Annealing of thermoplastic materials and post-curing of thermosetting materials has a significant effect on many properties.To minimize errors caused by these effects, annealing and post-curing shall be conducted accura
47、tely in accordance with pertinentmaterial standards or, if not available, in accordance with the material manufacturers recommendations. The conditions used forany annealing or post curing of specimens shall be reported.7.4 The number of specimens tested shall be in accordance with the test method f
48、or the particular properties being measured.Large numbers of test specimens should be used in cases of extreme variability, in which the standard deviation of test results ismore than 20 % of the mean value. If the test method used does not require a specific number of test specimens, a minimum offi
49、ve replicate specimens of each material shall be used.8. Procedure8.1 Exposure of Test Specimens8.1.1 When determining the PRI for materials exposed to natural weathering, conduct exposures in accordance with PracticeD1435.8.1.2 When the PRI for exposure to concentrated natural sunlight is to be determined, conduct exposures in accordance withPractice D4364.8.1.3 When the PRI for exposure to laboratory light sources is to be determined, conduct exposures in accordance with one ofthe following ASTM standards:(1) Practice F1499D1499 for exposures to filtered open-flame carb
