1、Designation: D 4350 00 (Reapproved 2005)Standard Test Method forCorrosivity Index of Plastics and Fillers1This standard is issued under the fixed designation D 4350; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method is designed for use in o
3、btaining thespecific conductance of a water extract of plastics and fillers.The magnitude of this conductance may be taken as an indexof the likelihood that, in a humid atmosphere, metal surfaces incontact with these materials may become corroded due togalvanic action or direct chemical attack; this
4、 is called thecorrosivity index.NOTE 1There is no similar or equivalent ISO standard.1.2 The values stated in SI units are to be regarded asstandard.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 s
5、tandard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 1193 Speci
6、fication for Reagent WaterE1 Specification for ASTM ThermometersE11 Specification for Wire-Cloth Sieves for Testing Pur-posesE 145 Specification for Gravity-Convection and Forced-Ventilation OvensE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Summ
7、ary of Test Method3.1 Specimens of plastics or fillers are immersed in distilledwater and exposed to specified conditions of temperature andtime. The specific resistance of each of the solutions extractedfrom the test specimens is measured by using the specifiedconductivity cell. The specific conduc
8、tance is calculated fromthe data and is called the corrosivity index of the material.4. Significance and Use4.1 This test method provides a means for comparing thecorrosive potential of plastics and fillers in humid atmospheres.4.2 This test method is intended for use in research andevaluation.5. Ap
9、paratus5.1 Conductance Bridge, Wheatstone type, with a rangefrom 1 to 250 000-V measured resistance, a built-in potenti-ometer, a 1000 6 50-cycles per second oscillator, and asensitive null point indicator. The bridge shall be capable ofmeasuring resistance with an accuracy of 62%.5.2 Conductivity C
10、ell, dip-type, micro, for solutions ofmedium conductance. The cell should have a cell constant ofapproximately 1.0 cm1. The borosilicate glass shall have amaximum outside tube diameter of 12.7 mm, overall length of177.8 mm, chamber inside diameter of 9.5 mm, and chamberdepth of 50.8 mm.35.3 Drill, e
11、lectric, capable of holding a 10.54-mm drill bit,and rotating at 500-r/min maximum speed.5.4 Mill, such as laboratoryWiley cutting mill or equivalent.5.5 Sieves, standard (alternative) sieve designations 425 m(No. 40), and 250 m (No. 60) in accordance with Specifica-tion E11.5.6 Analytical Balance,
12、capable of determining mass to thenearest 1.0 mg.5.7 Oven, forced-ventilation type, with uniformity of tem-perature within 61 % of the differential between oven andambient temperature, with a rate of ventilation of 100 to 200 airchanges per hour, in accordance with Specification E 145,TypeIIA.1This
13、test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.16 on Thermosetting Materi-als.Current edition approved Nov. 1, 2005. Published January 2006. Originallyapproved in 1984. Last previous edition approved in 2000 as D 4350 - 00.2
14、For 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.3The sole source of supply of the conductivity cell (Model No.
15、 3403) known tothe committee at this time is Yellow Springs Instrument Co., Inc., P.O. Box 279,Yellow Springs, OH 45387. If you are aware of alternative suppliers, please providethis information to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the r
16、esponsible technical committee,1whichyou may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.8 Thermometer, solid-stem, precision, ASTM No. 63C, inaccordance with Specification E1.5.9 Chemical Glassware:5.9.1 Borosilicate Gl
17、ass Flask, nominally 1000-mL size,with ground glass stopper.5.9.2 Borosilicate Glass Erlenmeyer Flask, 65-mL actualcapacity to bottom of stopper (nominally 50-mL size), withground glass stopper No. 19.5.9.3 Pipet, volumetric, 50-mL capacity, calibrated “to de-liver.”6. Reagents and Materials6.1 Dist
18、illed Water, Type III, reagent water as defined inSpecification D 1193. When stored in borosilicate glass bottlesat 23 6 2C, the water shall have a calculated specificconductance of less than 2.0 3 106, ohm1,cm1.6.2 Potassium Chloride Solution, consisting of 0.7453 g ofreagent grade potassium chlori
19、de, previously dried at 105 63C for at least 24 h, dissolved in 1000 g of distilled water. Thesolution shall be stored in a borosilicate glass stoppered bottle.The specific conductance of this 0.0100 Demal KCl solution is0.0007736 ohm1,cm1at 0C, 0.0012205 ohm1,cm1at18C, and 0.0014087 ohm1,cm1at 25C.
20、4This specificconductance versus temperature is plotted in Fig. 1.6.3 Grease, silicone, not soluble in water nor containing anywater-soluble constituents. In the control specimens, waterexposed to the grease on the stopper shall have a specificconductance less than 7 3 106, ohm1,cm1.7. Safety Hazard
21、s7.1 Some plastics and fillers are known to contain toxiccomponents and special precautions are required in handling.4Specific conductance values are based on the work of Jones, G., and Bradshaw,B. C., J. Amer. Chem. Soc., 55 (1933) 1780. For more detailed information on theuse of Demal KCl, see“ El
22、ectrolyte Solutions,” by Robinson, R. A., and Stokes, R.H., Academic Press, Inc., New York, 1955, pp. 9496.FIG. 1 Specific Conductance of 0.0100 Demal KClD 4350 00 (2005)2The manufacturers precautionary instructions and sound labo-ratory safety practices should be diligently followed.8. Sampling8.1
23、Because of the diverse nature of plastics and fillers, andthe various forms and packages commercially available, nostandard methods of sampling have been established. Anadequate amount of material, representative of each ingredient,shall be selected from each lot to permit preparation ofspecimens as
24、 agreed upon between the buyer and the seller.9. Specimen Preparation9.1 Plastics, either prepared in accordance with the manu-facturers directions, or as received from the manufacturer,shall be drilled with a sharp drill at a rate not exceeding 27.5mm/s (10.54-mm diameter drill at 500 r/min), and t
25、he drillingsshall be ground in a mill. Care shall be exercised so as not tooverheat the material when drilling or grinding, as overheatingmay cause changes in the characteristics of the material. Thatfraction of ground plastics that passes a 425-m sieve, but isretained by a 250-m sieve, is used for
26、the test.9.2 Fillers, shall be used as received from the manufacturer.10. Conditioning10.1 Unless otherwise specified, condition all specimens fora minimum of 40 h at the standard laboratory atmosphere (236 2C, 50 6 5 % relative humidity), in accordance withProcedure A of Practice D 618.11. Number o
27、f Test Specimens11.1 At least three specimens shall be tested for eachmaterial.12. Procedure12.1 Place 0.50 6 0.01 g of the test material in each of threeErlenmeyer flasks. Prepare at least three flasks, without mate-rial, as controls for the water and grease.12.2 Add 50.0 mL of distilled water with
28、 a pipet to eachflask.12.3 Grease the flask stopper with silicone grease andstopper flasks tightly. Agitate the flasks until the specimenparticles are thoroughly wetted.12.4 Place the stoppered flasks in an oven at 71 6 3C fora total of 288 h (12 days). At the end of the first day of ovenstorage, ex
29、amine the flasks to determine that no stoppers havebecome loose or blown off, with consequent loss of liquid (inwhich event the specimen shall be discarded). Agitate theflasks in order to break up large aggregates of the test specimenand to dislodge air bubbles that tend to float particles of the te
30、stspecimen, thus preventing proper wetting.12.5 At the end of 288 6 2 h, remove the stoppered flasksfrom the oven and allow them to cool to 23 6 2C. Againagitate the flasks thoroughly and allow the solids to settle.12.6 Determine the cell constant of the conductivity cell.12.6.1 Pipet 50.0 mL of 0.0
31、100 Demal KCl into each ofthree Erlenmeyer flasks, and allow to come to 23 6 2C.12.6.2 Use a thermometer to determine the temperature tothe nearest 0.1C of the liquid in the flask immediately prior tothe time of specific resistance measurements.12.6.3 Dip the conductivity cell vertically into the li
32、quiduntil the bottom edge of the cell rests on the bottom of theflask.12.6.4 Measure the specific resistance in ohms of each ofthe solutions with a conductance bridge at 1000 6 50 cyclesper second.12.7 Determine the specific resistance of the specimens andcontrols. Use the same technique and the sam
33、e conductivitycell used in 12.6.3 and 12.6.4. Measurements shall be made atthe same temperature determined in 12.6.2. Measurementsshall be made within 4 h after removal from oven.13. Calculation13.1 Calculate the cell constant. The conductivity cellconstant K is given by K = kR, where k is the speci
34、ficconductance of the standard KCl solution at the temperaturedetermined at the time of measurement,5and R is the measuredresistance in ohms of the KCl solution. From the measuredspecific resistance value, calculate the cell constant K for eachof the three KCl samples. K should be approximately 1.0
35、cm1.The three cell constant values shall be averaged as follows:K 5 K11 K21 K3!/3 (1)No single value shall deviate from the mean value by morethan 2 %.13.2 Calculate the specific conductance S in ohm1,cm1for each specimen and control as follows:S 5 K/R (2)where:K = conductivity cell constant from 13
36、.1, andR = measured resistance in ohms of the specimen or controlfrom 12.7.13.3 Calculate the corrosivity index for each material tested.The corrosivity index is the average of the specific conductanceS for the replicate specimens of each material, and is calculatedas follows:corrosivity index 5 S11
37、 S21 S3!/3 (3)where S1, S2, and S3are the calculated specific conductancesof the three replicate specimens from 13.2.14. Report14.1 Report the following information:14.1.1 Dates of test,14.1.2 Identification of plastics or filler material,14.1.3 Temperature and total duration of test exposure,14.1.4
38、 Three cell constant values (K1, K2, and K3) and theaverage cell constant K for the conductivity cell,14.1.5 The measured specific resistance R of each specimenand each control,14.1.6 The calculated specific conductance S of each speci-men and each control, and14.1.7 The calculated corrosivity index
39、 for each material inohms1,cm13 106.5The k value may be obtained from Fig. 1.D 4350 00 (2005)315. Precision and Bias615.1 Table 1 is based on a round robin conducted in 1985,involving three materials tested by five laboratories. For eachmaterial, all the samples were prepared by one source, but each
40、laboratory prepared the individual specimens that it tested.Each test result was based on one individual determination.Each laboratory obtained three test results for each material.15.2 In Table 1, for the materials indicated, and for testresults that are derived from testing three specimens:15.2.1
41、Sris the within-laboratory standard deviation of theaverage; Ir= 2.83 Sr. (See 15.2.3 for application of Ir.)15.2.2 SRis the between-laboratory standard deviation ofthe average; IR= 2.83 SR. (See 15.2.4 for application of IR.)15.2.3 RepeatabilityIn comparing two test results for thesame material, ob
42、tained by the same operator using the sameequipment on the same day, those test results should be judgednot equivalent if they differ by more than the Irvalue for thatmaterial and condition.15.2.4 ReproducibilityIn comparing two test results forthe same material, obtained by different operators usin
43、g differ-ent equipment on different days, those test results should bejudged not equivalent if they differ by more than the IRvaluefor that material and condition. (This applies between differentlaboratories or between different equipment within the samelaboratory.)15.2.5 Any judgment in accordance
44、with 15.2.3 and 15.2.4will have an approximate 95 % (0.95) probability of beingcorrect.15.2.6 Other formulations may give somewhat differentresults.15.3 For further information on the methodology used inthis section, refer to Practice E 691.15.4 There are no recognized standards on which to base ane
45、stimate of bias for this test method.16. Keywords16.1 corrosivity; plastics; fillersASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the
46、 validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your
47、 comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments
48、have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multi
49、ple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).6Supporting data are available from ASTM Headquarters. Request RR:D20-1126.TABLE 1 Precision Values in the Units of 106ohm1cm1Material Average SrSRIrIREpoxy 1 25.5 3.30 8.35 9.3 23.6Epoxy 2 30.0 1.80 7.23 5.1 20.5Epoxy 3 104.0 3.87 19.5 11.0 55.2D 4350 00 (2005)4
