1、Designation: D3235 16D3235 161Standard Test Method forSolvent Extractables in Petroleum Waxes1This standard is issued under the fixed designation D3235; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1 NOTECorrected misplaced figures editorially in December 2016.1. Scope*1.1 This test method covers the determination of solvent extractables in pet
3、roleum waxes.1.2 The values stated in SI units are to be regarded as standard.1.2.1 ExceptionThe values given in parentheses are for information only.1.3 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
4、 standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1 Specification for ASTM Liquid-in-Glass ThermometersE128 Test Method for Maximum Pore Diameter and Permeability of Rigid P
5、orous Filters for Laboratory Use3. Summary of Test Method3.1 The sample is dissolved in a mixture consisting of 50 % by volume methyl ethyl ketone and 50 % by volume toluene. Thesolution is cooled to 32 C (25 F) to precipitate the wax, then filtered. The solvent extractables content is determined by
6、evaporating the solvent from the filtrate and determining the mass of the residue.4. Significance and Use4.1 The solvent extractables in a wax may have significant effects on several of its properties such as strength, hardness,flexibility, scuff resistance, coefficient of friction, coefficient of e
7、xpansion, melting point, and staining characteristics. Whetherthese effects are desirable or undesirable depends on the intended use of the wax.5. Apparatus5.1 Filter Stick and Assembly, consisting of a 10 mm diameter sintered glass filter stick of 10 m to 15 m maximum porediameter as determined by
8、the method in Appendix X1, provided with an air pressure inlet tube and delivery nozzle. It is providedwith a ground-glass joint to fit a 25 mm by 170 mm test tube. The dimensions for a suitable filtration assembly are shown in Fig.1.NOTE 1A metallic filter stick may be employed if desired. A filter
9、 stick3 made of stainless steel and having a 12.7 mm (0.50 in.) disk of 10 nm to15 nm maximum pore diameter, as determined by Test Method E128, has been found to be satisfactory. The metallic apparatus is inserted into a 25 mmby 150 mm test tube and held in place by means of a cork.1 This test metho
10、d is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.10.0A on Physical/Chemical Properties.Current edition approved July 1, 2016. Published July 2016. Originally approved in 1973. Last previous editio
11、n approved in 2015 as D3235 15. DOI:10.1520/D3235-16.10.1520/D3235-16E01.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the A
12、STM website.3 The sole source of supply of a suitable metal filter stick with designated porosity G known to the committee at this time is the Pall Trinity Micro Corp., Route 281,Cortland, NY13045.Alist of United Kingdom suppliers can be obtained from Energy Institute, 61 New Cavendish St., London,W
13、1G 7AR, United Kingdom. If you are awareof alternative suppliers, please provide this information toASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1 which you may attend.This document is not an ASTM standard and is
14、intended 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 c
15、urrent 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 States15.2 Cooling Bath, consisting
16、 of an insulated box with 30 mm 6 5 mm (1.2 in. 6 0.2 in.) holes in the center to accommodateany desired number of test tubes. The bath may be filled with a suitable medium such as kerosine, and may be cooled by circulatinga refrigerant through coils, or by using solid carbon dioxide. A suitable coo
17、ling bath to accommodate three test tubes is shown inFig. 2.5.3 Dropper Pipet, dispensing device capable of delivering 0.5 g 6 0.05 g of molten wax.5.4 Transfer Pipet, or equivalent volume dispensing device, capable of delivering 15 mL 6 0.06 mL.5.5 Air Pressure Regulator, designed to supply air to
18、the filtration assembly (8.5) at sufficient pressure to give an even flow offiltrate. Either a conventional pressure-reducing valve or a mercury bubbler-type regulator has been found satisfactory. The lattertype, illustrated in Fig. 3, consists of a 250 mL glass cylinder and a T-tube held in the cyl
19、inder by means of a rubber stoppergrooved at the sides to permit the escape of excess air. The volume and pressure of the air supplied to the filtration assembly isregulated by the depth to which the T-tube is immersed in mercury at the bottom of the cylinder. Absorbent cotton placed in thespace abo
20、ve the mercury prevents the loss of mercury by spattering. The air pressure regulator is connected to the filter stick andassembly by means of rubber tubing.5.6 Temperature Measuring Devices:5.6.1 Thermometers, two, having a range as shown below and conforming to the requirements as prescribed in Sp
21、ecification E1or in the specifications for IP Standard Thermometers. One thermometer is required for the cold bath and a second thermometeris required for the sample solution.Thermometer NumberTemperature Range ASTM IP37 C to +21 C 71C 72C35 F to +70 F 71F 72F5.6.2 Temperature measuring devices othe
22、r than those described in 5.6.1 are satisfactory for this test method, provided theyexhibit the same temperature response as the equivalent mercury-in-glass thermometers.5.7 Weighing Bottles, glass-stoppered, having a typical capacity of 15 mL to 25 mL.5.8 Evaporation Assembly, consisting of an evap
23、orating cabinet and connections, essentially as illustrated in Fig. 4, and capableof maintaining a temperature of 35 C 6 1 C (95 F 6 2 F) around the evaporation flasks. Construct the jets with an insidediameter of 4 mm 6 0.2 mm for delivering a stream of clean, dry air vertically downward into the w
24、eighing bottle. Support eachjet so that the tip is 15 mm 6 5 mm above the surface of the liquid at the start of the evaporation. Supply purified air at the rateof 2 Lmin to 3 Lmin per jet. One way to purify the air is to pass it through a tube of approximately 1 cm bore packed looselyAll dimensions
25、are in millimetres.FIG. 1 Filter StickD3235 1612to a height of approximately 20 cm with absorbent cotton. Periodically check the cleanliness of the air by evaporating 4 mL of thesolvent mixture described in 6.3 by the procedure specified in 8.5. When the residue does not exceed 0.1 mg, the evaporati
26、onequipment is operating satisfactorily.NOTE 2Investigations by the European World Federation have indicated that improved precision may be achieved by individually calibrating eachnozzle to deliver a flow rate of 2 L min to 3 L min.5.9 Analytical Balance, capable of reproducing masses to 0.1 mg.5.1
27、0 Wire StirrerA piece of stiff made of iron, stainless steel, or Nichrome wire of about No. 20 Bands (0.9 mm in diameter)or 16 swg. gage, 250 mm long. A 10 mm diameter loop is formed at each end, and the loop at the bottom end is bent so that theplane of the loop is perpendicular to the wire.6. Solv
28、ent6.1 Methyl Ethyl Ketone, conforming to the specifications of the Committee on Analytical Reagents of the American ChemicalSociety.46.2 Toluene, conforming to the specifications of the Committee on Analytical Reagents of the American Chemical Society.44 Reagent Chemicals, American Chemical Society
29、 Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeia
30、l Convention, Inc. (USPC), Rockville, MD.All dimensions are in millimetres (inches).FIG. 2 Cooling BathD3235 16136.3 Solvent MixturePrepare a mixture of 50 % by volume methyl ethyl ketone and 50 % by volume toluene.6.4 Store the solvent mixture over a suitable drying agent, such as anhydrous calcium
31、 sulfate (five mass percent of the solvent).Filter prior to use.7. Sample7.1 Obtain a representative portion by melting the entire sample and stirring thoroughly. This is necessary because theextractables may not be distributed uniformly throughout the solidified sample.8. Procedure8.1 Melt a repres
32、entative portion of the sample, using a water bath or oven maintained at 70 C to 100 C (158 F to 212 F).As soon as the wax is completely melted, thoroughly mix. Preheat the pipet or equivalent measuring device in order to preventthe solidification of wax in the tip, and withdraw a portion of the sam
33、ple as soon as possible after the wax has melted. The massof wax transferred to the test tube must be 1.00 g60.05 g.Allow the test tube to cool, and determine the mass to at least the nearest1 mg.NOTE 3The mass of a test tube which is cleaned by means of solvent will not vary to a significant extent
34、. Therefore, a tare mass may be obtainedand used repeatedly.8.2 Pipet 15 mL of the solvent mixture into the test tube and place the latter just up to the level of its contents in a hot wateror steam bath. Heat the solvent-wax mixture, stirring up and down with the wire stirrer, until a homogeneous s
35、olution is obtained.Exercise care to avoid loss of solvent by prolonged boiling.NOTE 4Very high-melting wax samples may not form clear solutions. Stir until the undissolved material is well dispersed as a fine cloud.8.2.1 Plunge the test tube into an 800 mL beaker of ice water and continue to stir u
36、ntil the contents are cold. Remove the stirrer.Remove the test tube from the ice bath, wipe dry on the outside with a cloth, and determine the mass to at least the nearest 0.1 g.NOTE 5During this operation the loss of solvent through vaporization should be less than 1 %. The mass of the solvent is,
37、therefore, practically aconstant, and after the masses of a few samples are determined, this mass can be used as a constant factor.8.3 Place the test tube containing the wax-solvent slurry in the cooling bath, which is maintained at 34.5 C61.0 C (30.0 F6 2.0 F). During this chilling operation, stir
38、the contents of the tube by means of a temperature measurement device placed inthe tube. It is important that stirring by means of the temperature measurement device be almost continuous, in order to maintaina slurry of uniform consistency as the wax precipitates. Do not allow the wax to set up on t
39、he walls of the cooling vessel nor permitany lumps of wax crystals to form. Continue stirring until the temperature reaches 31.7 C 6 0.3 C (25.0 F 6 0.5 F).8.4 Remove the temperature measurement device from the tube and allow it to drain momentarily into the tube, thenimmediately immerse in the mixt
40、ure the clean, dry filter stick, which has previously been cooled by placing it in a test tube andholding at 34.5 C 6 1.0 C (30.0 F 6 2.0 F) in the cooling bath for a minimum of 10 min. Seat the ground-glass joint of thefilter so as to make an airtight seal. Place an unstoppered weighing bottle, the
41、 mass of which was previously determined, togetherwith the glass stopper to the nearest 0.1 mg, under the delivery nozzle of the filtration assembly.All dimensions are in millimetres.FIG. 3 Air Pressure RegulatorD3235 1614NOTE 6Take every precaution to ensure the accuracy of the mass of the stoppere
42、d weighing bottle. Prior to determining this mass, rinse the clean,dry weighing bottle and stopper with the solvent mixture described in 6.3, wipe dry on the outside with a cloth, and place in the evaporation assemblyto dry for about 5 min. Then remove the weighing bottle and stopper, place near the
43、 balance, and allow to stand for 10 min prior to determining the mass.Stopper the bottle during this cooling period. Once the weighing bottle and stopper have been dried in the evaporation assembly, lift only with forceps.Take care to remove and replace the glass stopper with a light touch.8.5 Apply
44、 air pressure to the filtration assembly and immediately collect about 4 mL of filtrate in the weighing bottle. Releasethe air pressure to permit the liquid to drain back slowly from the delivery nozzle. Remove the weighing bottle immediately, andstopper and determine the mass to at least the neares
45、t 10 mg without waiting for it to come to room temperature. Unstopper theweighing bottle and place it under one of the jets in the evaporation assembly maintained at 35 C 6 1 C (95 F 6 2 F), withthe air jet centered inside the neck, and the tip 15 mm 6 5 mm above the surface of the liquid. After the
46、 solvent has evaporated,which usually takes less than 30 min, remove the bottle, stopper, and place near the balance. Allow to stand for 10 min anddetermine the mass to the nearest 0.1 mg. Repeat the evaporation procedure, using 5 min evaporation periods, until the lossbetween successive determinati
47、ons is not over 0.2 mg.All dimensions are in millimetres (inches).FIG. 4 Evaporation AssemblyD3235 16159. Calculation9.1 Calculate the amount of extractables in the wax as follows:Solvent extractables,percent by mass5100 AC/BD (1)where:A = mass of extractables residue, g,B = mass of wax sample, g,C
48、= mass of solvent, g, obtained by subtracting mass of test tube plus wax sample (8.1) from mass of test tube and contents(8.2), andD = mass of solvent evaporated, in g, obtained by subtracting mass of weighing bottle plus extractables residue from mass ofweighing bottle plus filtrate (8.5).10. Repor
49、t10.1 Report the result as solvent extractables, Test Method D3235, to the nearest 0.1 % by mass. If the result is negative, reportas zero.11. Precision and Bias11.1 The precision of this test method as determined by statistical examination of interlaboratory results is as follows:11.1.1 RepeatabilityThe difference between two test results, obtained by the same operator with the same apparatus underconstant operating conditions on identical test material would, in the long run, in the normal and correct operation
