1、Designation: D4350 13Standard Test Method forCorrosivity Index of Plastics and Fillers1This standard is issued under the fixed designation D4350; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method is designed for use in obtaining thespe
3、cific 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 is called thec
4、orrosivity index.NOTE 1There is no known ISO equivalent to this 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 standard to e
5、stablish 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:2D618 Practice for Conditioning Plastics for TestingD1193 Specification for R
6、eagent WaterE1 Specification for ASTM Liquid-in-Glass ThermometersE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE145 Specification for Gravity-Convection and Forced-Ventilation OvensE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. S
7、ummary 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 con
8、ductance 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.
9、 Apparatus5.1 Conductance Bridge, Wheatstone type, with a rangefrom 1 to 250 000- measured resistance, a built-inpotentiometer, 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 and1This test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.16 on T
13、hermosetting Materi-als.Current edition approved Dec. 15, 2013. Published December 2013. Originallyapproved in 1984. Last previous edition approved in 2005 as D4350 - 00 (2005).DOI: 10.1520/D4350-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
14、 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. 3403) known tothe committee at this time is Yellow Springs Instrument Co., Inc., P.O. Box 279,Yello
15、w 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 responsible technical committee,1whichyou may attend.*A Summary of Changes section appears at the end
16、 of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1ambient temperature, with a rate of ventilation of 100 to 200 airchanges per hour, in accordance with Specification E145, TypeIIA.5.8 Thermometer, solid-stem, precision,
17、 ASTM No. 63C, inaccordance with Specification E1. Temperature measuringdevices with equivalent accuracy and characteristics, such asRTDs and thermistors, may be used. In addition, ASTM No.S63C in accordance with Specification E2251 may be used.5.9 Chemical Glassware:5.9.1 Borosilicate Glass Flask,
18、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 Distilled Water
19、, Type III, reagent water as defined inSpecification D1193. When stored in borosilicate glass bottlesat 23 6 2C, the water shall have a calculated specificconductance of less than 2.0 106, ohm1,cm1.6.2 Potassium Chloride Solution, consisting of 0.7453 g ofreagent grade potassium chloride, previously
20、 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,cm1atFIG. 1 Specific Conductance of 0.0100 Demal KClD
21、4350 13218C, and 0.0014087 ohm1,cm1at 25C.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 le
22、ss than 7 106, ohm1,cm1.7. Safety Hazards7.1 Some plastics and fillers are known to contain toxiccomponents and special precautions are required in handling.The manufacturers precautionary instructions and sound labo-ratory safety practices should be diligently followed.8. Sampling8.1 Because of the
23、 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 agreed upon b
24、etween 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 the drillingssh
25、all be ground in a mill. Care shall be exercised so as not tooverheat the material when drilling or grinding, as overheatingshall 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 the test.9.2
26、 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 10 % relative humidity), in accordance withProcedure A of Practice D618.11. Number of Test Speci
27、mens11.1 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, withoutmaterial, as controls for the water and grease.12.2 Add 50.0 mL of distilled water with a pipet to ea
28、chflask.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, examine the flas
29、ks 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 testspecimen, th
30、us 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 0.0100 Demal KCl
31、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 liquiduntil the
32、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 same conductivity
33、cell 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 specificconductance
34、 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 cm1.The three
35、cell constant values shall be averaged as follows:K 5 K11K21K3!/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 13.1, andR = measu
36、red 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:4Specific conductance values are based
37、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“ Electrolyte Solutions,” by Robinson, R. A., and Stokes, R.H., Academic Press, Inc., New York, 1955, pp. 9496.5The k value may be obtained from Fig. 1.D4350 13
38、3corrosivity index 5 S11S21S3!/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 o
39、f test exposure,14.1.4 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 calcul
40、ated corrosivity index for each material inohms1,cm1106.15. 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 eachlaboratory prepared the individual spe
41、cimens 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 Sris the within-laboratory standard de
42、viation 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, obtained by the same operator using the
43、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 using differ-ent equipment on different da
44、ys, 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 with 15.2.3 and 15.2.4will have an app
45、roximate 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 E691.15.4 There are no recognized standards on which to base anestimate of bias for this test method.16
46、. Keywords16.1 corrosivity; plastics; fillersSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D4350 - 00(2005) that may impact the use of this standard. (December 15, 2013)(1) Revised to make editorial changes and to remove permis-
47、sive language.ASTM 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 validity of any such patent rights, and the riskof infringement of su
48、ch 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 comments are invited either for revision of this standard or for addi
49、tional 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 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 multiple copies)
