1、Designation: D721 15Designation: 158/69(85)Standard Test Method forOil Content of Petroleum Waxes1This standard is issued under the fixed designation D721; 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method covers the determination of o
3、il inpetroleum waxes having a congealing point of 30 C (86 F) orhigher as determined in accordance with Test Method D938,and containing not more than 15 % of oil.2NOTE 1With some types of waxes, of oil contents greater than 5 %,there may be an incompatibility with MEK resulting in the formation oftw
4、o liquid phases. If this occurs, the test method is not applicable to thematerial under test.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered s
5、tandard.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 determine the applica-bility of regulatory limitations prior to use.2. Refe
6、renced Documents2.1 ASTM Standards:3D938 Test Method for Congealing Point of PetroleumWaxes, Including PetrolatumE1 Specification for ASTM Liquid-in-Glass ThermometersE128 Test Method for Maximum Pore Diameter and Perme-ability of Rigid Porous Filters for Laboratory Use2.2 Energy Institute Standards
7、:Specification for IP Standard Thermometers43. Summary of Test Method3.1 The sample is dissolved in methyl ethyl ketone, thesolution cooled to 32 C (25 F) to precipitate the wax, andfiltered. The oil content of the filtrate is determined byevaporating the methyl ethyl ketone and weighing the residue
8、.4. Significance and Use4.1 The oil content of a wax may have significant effects onseveral of its properties, such as strength, hardness, flexibility,scuff resistance, coefficient of friction, coefficient of expansion,melting point, and oil straining. The importance of these effectsmay be dependent
9、 upon the ultimate 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 delivery nozzle. Itis provided with a
10、ground-glass joint to fit a 25 mm by 170 mmtest tube. The dimensions for a suitable filtration assembly areshown in Fig. 1.NOTE 2A metallic filter stick may be employed if desired. A filterstick made of stainless steel and having a 12.7 mm (12 in.) disk of 10 mto 15 m maximum pore diameter, as deter
11、mined by Test Method E128,has been found to be satisfactory.5The metallic apparatus is inserted intoa 25 mm by 150 mm test tube and held in place by means of a cork.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct
12、responsibility ofSubcommittee D02.10.0A on Physical/Chemical Properties.Current edition approved June 1, 2015. Published June 2015. Originallyapproved in 1943. Last previous edition approved in 2011 as D721 06 (2011).DOI: 10.1520/D0721-15.In the IP, this test method is under the jurisdiction of the
13、StandardizationCommittee. This test method was issued as a joint ASTM-IP tentative in 1964.This test method was prepared jointly by the Technical Association of Pulp andPaper Industry and ASTM International.This test method has been adopted for use by government agencies to replaceMethod 5431 of Fed
14、eral Test Method Standard No. 79lb.2This test method is being used by some laboratories for products of higher oilcontent.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, ref
15、er to the standards Document Summary page onthe ASTM website.4Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K.5The sole source of supply of a suitable metal filter stick with designatedporosity G known to the committee at this time is the Pall Corporation, 2200Northern Bou
16、levard East Hills, NY 11548. A list of United Kingdom suppliers canbe obtained from Energy Institute, 61 New Cavendish St., London, W1G 7AR,United Kingdom. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful
17、consideration at a meeting of the responsible technical committee,1whichyou 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 States15.2 Cooling Bath, consisting of an
18、 insulated box with30 mm 6 5 mm (1.2 in. 6 0.2 in.) holes in 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
19、 to accommodatethree test tubes is shown in Fig. 2.5.3 Pipet, or equivalent dispensing device capable of deliv-ering 1 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 thefi
20、ltration assembly (8.5) at the volume and pressure required togive an even flow of filtrate. Either the conventional pressure-reducing valve or a mercury bubbler-type regulator has beenfound satisfactory. The latter type, illustrated in Fig. 3, consistsof a 250 mL glass cylinder and a T-tube held in
21、 the cylinder bymeans of a rubber stopper grooved at the sides to permit theescape of excess air. The volume and pressure of the airsupplied to the filtration assembly is regulated by the depth towhich the T-tube is immersed in mercury at the bottom of thecylinder. Absorbent cotton placed in the spa
22、ce above themercury prevents the loss of mercury by spattering. The airpressure regulatory is connected to the filter stick and assemblyby means of rubber tubing.5.6 Temperature Measuring Device:5.6.1 Thermometer, having a range as shown below andconforming to the requirements as prescribed in Speci
23、ficationE1, or in the Specification for IP Standard Thermometers.Thermometer NumberTemperature Range ASTM IP37 C to +21 C 71C 72C35 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, providedthat they exhibit the same tem
24、perature response as the equiva-lent mercury-in-glass thermometers.5.7 Weighing Bottles, glass-stoppered, having a typical ca-pacity of 15 mL to 25 mL.5.8 Evaporation Assembly, consisting of an evaporatingcabinet and connections, essentially as illustrated in Fig. 4, andcapable of maintaining a temp
25、erature of 35 C 6 1 C (95 F6 2 F) around the evaporation flask. Construct the jets with aninside diameter of 4 mm 6 0.2 mm for delivering a stream ofclean, 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 star
26、t of the evaporation. Supplypurified air at the rate of 2 L min to 3 L min per jet. One wayto purify the air is by passage through a tube of approximately10-mm bore packed loosely to a height of approximately200 mm with absorbent cotton. Periodically check the cleanli-ness of the air by evaporating
27、4 mL of methyl ethyl ketone bythe procedure specified in 8.5. When the residue does notexceed 0.1 mg, the evaporation equipment is operating satis-factorily.5.9 Analytical Balance, capable of reproducing weights to0.1 mg.5.10 Wire StirrerA piece of stiff wire, made of iron,stainless steel, or Nichro
28、me wire of about No. 20B thenimmediately immerse in the mixture the clean dry filter stickwhich 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
29、airtight seal. Place anunstoppered weighing bottle, previously weighed together withthe glass stopper to the nearest 0.1 mg, under the deliverynozzle of the filtration assembly.NOTE 7Take every precaution to ensure the accuracy of the weight ofthe stoppered weighing bottle. Prior to determining this
30、 weight, rinse theclean, dry weighing bottle and stopper with methyl ethyl ketone, wipe dryon the outside with a cloth, and place in the evaporation assembly to dryfor about 5 min. Then remove the weighing bottle and stopper, place nearthe balance, and allow to stand for 10 min prior to weighing. St
31、opper thebottle during this cooling period. Once the weighing bottle and stopperhave been dried in the evaporation assembly, lift only with forceps. Takecare to remove and replace the glass stopper with a light touch.8.5 Apply air pressure to the filtration assembly, and imme-diately collect about 4
32、 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 weigh to at least the nearest10 mg without waiting for it to come to room temperature.Unstopper the weighing bottl
33、e and place it under one of the jetsin the evaporation assembly maintained at 35 C 6 1 C (95 F6 2 F), with the air jet centered inside the neck, and the tip15 mm 6 5 mm above the surface of the liquid. After thesolvent has evaporated, which usually takes less than 30 min,remove the bottle and stoppe
34、r, and place them near the balance.Allow to stand for 10 min and weigh to the nearest 0.1 mg.Repeat the evaporation procedure, using a 5 min evaporationperiod instead of 30 min, until the loss between successiveweighings is not over 0.2 mg.9. Calculation9.1 Calculate the amount of oil in the wax as
35、follows:Oil in wax, weight % 5 100 AC/BD! 2 0.15 (1)where:A = weight of oil residue, g,B = weight of wax sample, g,C = weight of solvent, g, obtained by subtracting weightof test tube plus wax sample (8.1) from weight oftest tube and contents (8.2),D = weight of solvent evaporated, g, obtained by su
36、b-tracting weight of weighing bottle plus oil residuefrom weight of weighing bottle plus filtrate (8.5),and0.15 = average factor correcting for the solubility of wax inthe solvent at 32 C (25 F).10. Report10.1 Report the result as oil content, Test Method D721. Ifthe result is negative, report as ze
37、ro.11. Precision and Bias11.1 PrecisionThe precision of this test method as deter-mined by statistical examination of interlaboratory results is asfollows:11.1.1 RepeatabilityThe difference between two testresults, obtained by the same operator with the same apparatusunder constant operating conditi
38、ons on identical test material,would in the long run, in the normal and correct operation ofthe test method, exceed the following values only in one casein twenty:0.0618% of the mean11.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-in
39、g 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:0.2111% of the mean11.2 BiasThe procedure in this test method has no biasbecause the value of oil content can be
40、defined only in terms ofa test method.12. Keywords12.1 oil content; petroleum wax; waxAll dimensions are in millimetresFIG. 3 Air Pressure RegulatorD721 154All dimensions are in millimetres (inches)FIG. 4 Evaporation AssemblyD721 155APPENDIX(Nonmandatory Information)X1. TEST METHOD FOR MEASUREMENT O
41、F MAXIMUM PORE DIAMETER OF RIGID POROUS FILTERSX1.1 ScopeX1.1.1 This test method covers the determination of theacceptability of porous filter sticks used for filtration in TestMethod D721. This test method establishes the maximum porediameter and also provides a means of detecting and measuringchan
42、ges which occur form continued use.X1.2 DefinitionX1.2.1 maximum pore diameterthe diameter in microm-eters of the largest opening in the filter.NOTE X1.1It is recognized that the maximum pore diameter asdefined herein does not necessarily indicate the physical dimensions of thelargest pore in the fi
43、lter. It is further recognized that the pores are highlyirregular in shape. Because of the irregularity in shape and otherphenomena characteristic of filtration, a filter may be expected to retain allparticles larger than the maximum pore diameter as defined and deter-mined herein, and will generall
44、y retain particles which are much smallerthan the determined diameter.X1.3 Summary of Test MethodX1.3.1 The filter is cleaned and wetted with water. It is thenimmersed in water and air pressure is applied against its uppersurface until the first bubble of air passes through the filter. Themaximum po
45、re diameter is calculated from the surface tensionof water and the applied pressure.X1.4 ApparatusX1.4.1 Pressure Measuring Device, mercury-filled manom-eter or equivalent, capable of measuring pressures in incre-ments of 0.5 mm of Hg.X1.4.2 Air Supply, clean and filtered.X1.4.3 Air Pressure Regulat
46、or, needle-valve type.X1.4.4 Drying Oven.X1.5 ProcedureX1.5.1 Clean the filter sticks by soaking in concentratedhydrochloric acid, and then wash them with distilled water.Rinse with acetone, air dry, and place in drying oven at 220 F(105 C) for 30 min.X1.5.2 Thoroughly wet the clean filter to be tes
47、ted bysoaking it in distilled water.X1.5.3 Assemble the apparatus as shown in Fig. X1.1.Apply pressure slowly from a source of clean air.X1.5.4 Immerse the filter just below the surface of thewater.NOTE X1.2If a head of liquid exists above the surface of the filter, theback pressure produced must be
48、 deducted from the observed pressure.X1.5.5 Increase the air pressure to about 10 mm Hg (orequivalent pressure value if using different units) below theacceptable pressure limit and then at a slow uniform rateequivalent to about 3 mm Hg/min until the first bubble passesthrough the filter. This can b
49、e conveniently observed byplacing the beaker or test tube over a mirror. Read the pressuremeasuring device when the first bubble passes off the undersideof the filter.X1.6 CalculationX1.6.1 Calculate the pore diameter as follows:D 5 2180/pwhere:D = pore diameter, m, andp = pressure reading, mm Hg.NOTE X1.3From this equation, pressure corresponding to the upperand lower limits of the specified pore diameters can be calculated. Thesepressures may be used for acceptance testing.FIG. X1.1 Assembly of Apparatus for Checking Pore Di
