1、Designation: D3235 16Standard 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 number in
2、parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of solventextractables in petroleum waxes.1.2 The values stated in SI units are to be regarded asstand
3、ard.1.2.1 ExceptionThe values given in parentheses are forinformation only.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 establish appro-priate safety and health practices and determin
4、e the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1 Specification for ASTM Liquid-in-Glass ThermometersE128 Test Method for Maximum Pore Diameter and Perme-ability of Rigid Porous Filters for Laboratory Use3. Summary of Test Method3.1 The sample
5、is dissolved in a mixture consisting of 50 %by volume methyl ethyl ketone and 50 % by volume toluene.The solution is cooled to 32 C (25 F) to precipitate thewax, then filtered. The solvent extractables content is deter-mined by evaporating the solvent from the filtrate and deter-mining the mass of t
6、he residue.4. Significance and Use4.1 The solvent extractables in a wax may have significanteffects on several of its properties such as strength, hardness,flexibility, scuff resistance, coefficient of friction, coefficient ofexpansion, melting point, and staining characteristics. Whetherthese effec
7、ts are desirable or undesirable depends on theintended use of the wax.5. Apparatus5.1 Filter Stick and Assembly, consisting of a 10 mm diam-eter sintered glass filter stick of 10 m to 15 m maximum porediameter as determined by the method in Appendix X1,provided with an air pressure inlet tube and de
8、livery nozzle. Itis provided with a ground-glass joint to fit a 25 mm by 170 mmtest tube. The dimensions for a suitable filtration assembly areshown in Fig. 1.NOTE 1A metallic filter stick may be employed if desired. A filterstick3made of stainless steel and having a 12.7 mm (0.50 in.) disk of10 nm
9、to 15 nm maximum pore diameter, as determined by Test MethodE128, has been found to be satisfactory. The metallic apparatus is insertedinto a 25 mm by 150 mm test tube and held in place by means of a cork.5.2 Cooling Bath, consisting of an insulated box with30 mm 6 5 mm (1.2 in. 6 0.2 in.) holes in
10、the center toaccommodate any desired number of test tubes. The bath maybe filled with a suitable medium such as kerosine, and may becooled by circulating a refrigerant through coils, or by usingsolid carbon dioxide. A suitable cooling bath to accommodatethree test tubes is shown in Fig. 2.5.3 Droppe
11、r Pipet, dispensing device capable of delivering0.5 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 thefiltration assembly (8.5) at sufficient pressure to give an evenflow
12、of filtrate. Either a conventional pressure-reducing valveor a mercury bubbler-type regulator has been found satisfac-tory. The latter type, illustrated in Fig. 3, consists of a 250 mLglass cylinder and a T-tube held in the cylinder by means of arubber stopper grooved at the sides to permit the esca
13、pe ofexcess air. The volume and pressure of the air supplied to thefiltration assembly is regulated by the depth to which theT-tube1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.
14、10.0A on Physical/Chemical Properties.Current edition approved July 1, 2016. Published July 2016. Originally approvedin 1973. Last previous edition approved in 2015 as D3235 15. DOI: 10.1520/D3235-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Servic
15、e 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 a suitable metal filter stick with designatedporosity G known to the committee at this time is the Pall Trinity Micro Corp.,Route 2
16、81, Cortland, NY13045.Alist of United Kingdom suppliers can be obtainedfrom Energy Institute, 61 New Cavendish St., London, W1G 7AR, United King-dom. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consi
17、der-ation at a meeting of the responsible technical committee,1which you may attend.*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 States1is immersed in mercury at the bottom
18、of the cylinder. Absor-bent cotton placed in the space above the mercury prevents theloss of mercury by spattering. The air pressure regulator isconnected to the filter stick and assembly by means of rubbertubing.5.6 Temperature Measuring Devices:5.6.1 Thermometers, two, having a range as shown belo
19、wand conforming to the requirements as prescribed in Specifi-cation E1 or in the specifications for IP Standard Thermom-eters. One thermometer is required for the cold bath and asecond thermometer is required for the sample solution.Thermometer NumberTemperature Range ASTM IP37 C to +21 C 71C 72C35
20、F to +70 F 71F 72F5.6.2 Temperature measuring devices other than those de-scribed in 5.6.1 are satisfactory for this test method, providedthey exhibit the same temperature response as the equivalentmercury-in-glass thermometers.5.7 Weighing Bottles, glass-stoppered, having a typical ca-pacity of 15
21、mL to 25 mL.5.8 Evaporation Assembly, consisting of an evaporatingcabinet and connections, essentially as illustrated in Fig. 4, andcapable of maintaining a temperature of 35 C 6 1 C (95 F6 2 F) around the evaporation flasks. Construct the jets withan inside diameter of 4 mm 6 0.2 mm for delivering
22、a streamof clean, dry air vertically downward into the weighing bottle.Support each jet so that the tip is 15 mm 6 5 mm above thesurface of the liquid at the start of the evaporation. Supplypurified air at the rate of 2 Lmin to 3 Lmin per jet. One wayto purify the air is to pass it through a tube of
23、 approximately1 cm bore packed loosely to a height of approximately 20 cmwith absorbent cotton. Periodically check the cleanliness of theair by evaporating 4 mLof the solvent mixture described in 6.3by the procedure specified in 8.5. When the residue does notexceed 0.1 mg, the evaporation equipment
24、is operating satis-factorily.NOTE 2Investigations by the European World Federation have indi-cated that improved precision may be achieved by individually calibratingeach nozzle to deliver a flow rate of 2 L min to 3 L min.5.9 Analytical Balance, capable of reproducing masses to0.1 mg.5.10 Wire Stir
25、rerA piece of stiff made of iron, stainlesssteel, or Nichrome wire of about No. 20 Bands (0.9 mm indiameter) or 16 swg. gage, 250 mm long. A 10 mm diameterloop is formed at each end, and the loop at the bottom end isbent so that the plane of the loop is perpendicular to the wire.6. Solvent6.1 Methyl
26、 Ethyl Ketone, conforming to the specifications ofthe Committee onAnalytical Reagents of theAmerican Chemi-cal Society.46.2 Toluene, conforming to the specifications of the Com-mittee on Analytical Reagents of the American ChemicalSociety.46.3 Solvent MixturePrepare a mixture of 50 % by vol-ume meth
27、yl ethyl ketone and 50 % by volume toluene.6.4 Store the solvent mixture over a suitable drying agent,such as anhydrous calcium sulfate (five mass percent of thesolvent). Filter prior to use.7. Sample7.1 Obtain a representative portion by melting the entiresample and stirring thoroughly. This is nec
28、essary because theextractables may not be distributed uniformly throughout thesolidified sample.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual St
29、andards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.All dimensions are in millimetres.FIG. 1 Filter StickD3235 1628. Procedure8.1 Melt a representative portion of the sample
30、, using awater bath or oven maintained at 70 C to 100 C (158 F to212 F). As soon as the wax is completely melted, thoroughlymix. Preheat the pipet or equivalent measuring device in orderto prevent the solidification of wax in the tip, and withdraw aportion of the sample as soon as possible after the
31、 wax hasmelted. The mass of wax transferred to the test tube must be1.00 g 6 0.05 g. Allow the test tube to cool, and determine themass to at least the nearest 1 mg.NOTE 3The mass of a test tube which is cleaned by means of solventwill not vary to a significant extent. Therefore, a tare mass may beo
32、btained and used repeatedly.8.2 Pipet 15 mLof the solvent mixture into the test tube andplace the latter just up to the level of its contents in a hot wateror steam bath. Heat the solvent-wax mixture, stirring up anddown with the wire stirrer, until a homogeneous solution isobtained. Exercise care t
33、o avoid loss of solvent by prolongedboiling.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 icewater and continue to stir until the contents are cold. Removethe
34、stirrer. Remove the test tube from the ice bath, wipe dry onthe outside with a cloth, and determine the mass to at least thenearest 0.1 g.NOTE 5During this operation the loss of solvent through vaporizationshould be less than 1 %. The mass of the solvent is, therefore, practicallya constant, and aft
35、er the masses of a few samples are determined, this masscan be used as a constant factor.All dimensions are in millimetres (inches).FIG. 2 Cooling BathD3235 1638.3 Place the test tube containing the wax-solvent slurry inthe cooling bath, which is maintained at 34.5 C 6 1.0 C(30.0 F 6 2.0 F). During
36、this chilling operation, stir thecontents of the tube by means of a temperature measurementdevice placed in the tube. It is important that stirring by meansof the temperature measurement device be almost continuous,in order to maintain a slurry of uniform consistency as the waxprecipitates. Do not a
37、llow the wax to set up on the walls of thecooling vessel nor permit any lumps of wax crystals to form.Continue stirring until the temperature reaches 31.7 C 60.3 C (25.0 F 6 0.5 F).8.4 Remove the temperature measurement device from thetube and allow it to drain momentarily into the tube, thenimmedia
38、tely immerse in the mixture the clean, dry filter stick,which has previously been cooled by placing it in a test tubeand holding at 34.5 C 6 1.0 C (30.0 F 6 2.0 F) in thecooling bath for a minimum of 10 min. Seat the ground-glassjoint of the filter so as to make an airtight seal. Place anunstoppered
39、 weighing bottle, the mass of which was previouslydetermined, together with the glass stopper to the nearest0.1 mg, under the delivery nozzle of the filtration assembly.NOTE 6Take every precaution to ensure the accuracy of the mass ofthe stoppered weighing bottle. Prior to determining this mass, rin
40、se theclean, dry weighing bottle and stopper with the solvent mixture describedin 6.3, wipe dry on the outside with a cloth, and place in the evaporationassembly to dry for about 5 min. Then remove the weighing bottle andstopper, place near the balance, and allow to stand for 10 min prior todetermin
41、ing the mass. Stopper the bottle during this cooling period. Oncethe weighing bottle and stopper have been dried in the evaporationassembly, lift only with forceps. Take care to remove and replace the glassstopper with a light touch.8.5 Apply air pressure to the filtration assembly and imme-diately
42、collect about 4 mL of filtrate in the weighing bottle.Release the air pressure to permit the liquid to drain backslowly from the delivery nozzle. Remove the weighing bottleimmediately, and stopper and determine the mass to at least thenearest 10 mg without waiting for it to come to room tempera-ture
43、. Unstopper the weighing bottle and place it under one ofthe jets in the evaporation assembly maintained at 35 C 61 C (95 F 6 2 F), with the air jet centered inside the neck,and the tip 15 mm 6 5 mm above the surface of the liquid.After the solvent has evaporated, which usually takes less than30 min
44、, remove the bottle, stopper, and place near the balance.Allow to stand for 10 min and determine the mass to thenearest 0.1 mg. Repeat the evaporation procedure, using 5 minevaporation periods, until the loss between successive deter-minations is not over 0.2 mg.9. Calculation9.1 Calculate the amoun
45、t of extractables in the wax asfollows:Solvent extractables, percent by mass 5 100 AC/BD (1)where:A = mass of extractables residue, g,B = mass of wax sample, g,C = mass of solvent, g, obtained by subtracting mass of testtube plus wax sample (8.1) from mass of test tube andcontents (8.2), andD = mass
46、 of solvent evaporated, in g, obtained by subtract-ing mass of weighing bottle plus extractables residuefrom mass of weighing bottle plus filtrate (8.5).10. Report10.1 Report the result as solvent extractables, Test MethodD3235, to the nearest 0.1 % by mass. If the result is negative,report as zero.
47、11. Precision and Bias11.1 The precision of this test method as determined bystatistical examination of interlaboratory results is as follows:11.1.1 RepeatabilityThe difference between two testresults, obtained by the same operator with the same apparatusunder constant operating conditions on identi
48、cal test materialwould, in the long run, in the normal and correct operation ofthe test method, exceed the following values only in one casein twenty:Range Repeatability15%to55% 2%11.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing
49、in different laboratories on identical test material would, inthe long run, in the normal and correct operation of the testmethod, exceed the following values only in one case intwenty:Range Reproducibility15%to55% 5%11.2 The procedure in this test method has no bias becausethe value of solvent extractables can be defined only in termsof a test method.12. Keywords12.1 petroleum waxes; solvent extractables; waxAll dimensions are in millimetres.FIG. 3 Air Pressure RegulatorD3235 164APPENDIX(Nonmandatory Information)X1. TEST
