ASTM D87-2009(2014) Standard Test Method for Melting Point of Petroleum Wax &40 Cooling Curve&41 《石蜡熔点的标准试验方法(冷却曲线)》.pdf

1、Designation: D87 09 (Reapproved 2014) Technical Association of Pulpand Paper IndustryStandard Method T 630m-61Method 1402-Federal TestMethod Standard No. 791bBritish Standard 4695Designation: 55/77(83)Standard Test Method forMelting Point of Petroleum Wax (Cooling Curve)1This standard is issued unde

2、r the fixed designation D87; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the

3、last revision or reapproval.1. Scope1.1 This test method covers the determination of the meltingpoint (cooling curve) of petroleum wax. It is unsuitable forwaxes of the petrolatum group, microcrystalline waxes, orblends of such waxes with paraffin wax or scale wax.NOTE 1For additional methods used f

4、or testing petroleum waxes, seeTest Method D127 and Test Method D938. Results may differ, dependingon the method used. For pharmaceutical petrolatum, Test Method D127usually is used.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informati

5、ononly.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. Refer

6、enced Documents2.1 ASTM Standards:2D127 Test Method for Drop Melting Point of PetroleumWax, Including PetrolatumD938 Test Method for Congealing Point of PetroleumWaxes, Including PetrolatumD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate Analytical

7、Measurement System PerformanceE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 melting point (cooling curve) of petroleum waxtemperature at which melted petroleum wax first shows aminimum rate of temperature change when allowed to coolunder prescribed conditi

8、ons.3.1.1.1 DiscussionThe so-called “American MeltingPoint” is arbitrarily 1.65C (3F) above the Melting Point(Cooling Curve) of Petroleum Wax.4. Summary of Test Method4.1 In Procedure A (Manual Method), a specimen of moltenwax in a test tube fitted with a thermometer or equivalenttemperature measuri

9、ng device is placed in an air bath, which inturn is surrounded by a water bath held at 16 to 28C (60 to80F). As the molten wax cools, periodic readings of itstemperature are taken. When solidification of the wax occurs,the rate of temperature change decreases, yielding a plateau inthe cooling curve.

10、 The temperature at that point is recorded asthe melting point (cooling curve) of the sample.4.2 In Procedure B, an automatic analyzer is used. As themolten wax cools, the sample temperature decrease is mea-sured every 15 s in 0.01C (0.1F) readings. The melting pointis considered to be reached when

11、five consecutive measure-ments are constant within a given temperature interval, usually0.1C (0.2F).5. Significance and Use5.1 Melting point (cooling curve) is a test that is widelyused by wax suppliers and consumers. it is particularly appliedto petroleum waxes that are rather highly paraffinic or

12、crystal-line in nature. A plateau occurs with specimens containingappreciable amounts of hydrocarbons that crystallize at thesame temperature, giving up heat of fusion, thus temporarilyretarding the cooling rate. In general, petroleum waxes withlarge amounts of non-normal hydrocarbons or with amorph

13、oussolid forms will not exhibit a plateau.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.10.0A on Physical/Chemical Properties.In the IP, this test method is under the jurisdicti

14、on of the StandardizationCommittee. This test method was adopted as a joint ASTM-IP standard in 1966.Current edition approved May 1, 2014. Published July 2014. Originally approvedin 1921. Last previous edition approved in 2009 as D87 09. DOI: 10.1520/D0087-09R14.2For referenced ASTM standards, visit

15、 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959

16、. United States16. Apparatus6.1 The necessary apparatus for Procedure A is described inAnnex A1.6.2 The automatic instrument consists of a bath (forexample, an aluminum block with two measuring locations,two apertures to place the test tubes, and two apertures for thetemperature probes). The apparat

17、us may have an accessorydigital display and a printer.6.2.1 The temperature of the bath is maintained between 22and 26C (72 and 79F). A heating device is used to increasethe temperature, and a cooling device with cold water circula-tion is used to decrease the temperature.6.2.2 The temperature may b

18、e monitored with a calibratedthermometer or an electronic temperature measuring device ofequivalent precision and accuracy.6.3 Other types of equivalent automatic apparatus are ac-ceptable.7. Test Specimen7.1 Obtain a sample of wax representative of the shipmentto be tested. From each test unit obta

19、in a portion of waxweighing at least 25 g for each melting point determination.8. Procedure A (Manual Method)8.1 Support the air bath in its proper position in the waterbath. Fill the water bath to within 13 mm (12 in.) of the topwith water at a temperature of 16 to 28C (60 to 80F). Thebath temperat

20、ure is kept within these limits throughout the test.8.2 Heat the wax sample to at least 8C (15F) above itsexpected melting point (see Note 2). To heat the wax sampleuse a suitable container in an oven or water bath which is heldat a temperature not exceeding 93C (200F). Avoid the use ofdirect heat s

21、uch as flame or hot plate. Do not keep the samplein the molten state longer than 1 h.NOTE 2If no estimate of the melting point is available, heat the waxsample to 10C (15F) above the temperature at which the wax iscompletely molten, or to from 90 to 93C (195 to 200F) beforeproceeding to the next ste

22、p.8.3 Fill the test tube to a height of 51 mm (2 in.) with themelted sample. Insert the melting point temperature measuringdevice through the center of a one-holed stopper, such as acork. In the case of a thermometer, position the 79-mm(318-in.) immersion line at the lower surface of the stopper.Ins

23、ert the stopper into the test tube so that the bottom of thethermometer bulb or temperature measuring probe is 10 mm(38 in.) from the bottom of the test tube. Support the test tubeassembly in the air bath, as shown in Fig. A1.1, while thetemperature of the molten wax is still at least 8C (15F) above

24、its expected melting point (Note 2).8.4 Take a temperature reading every 15 s. Record eachreading to at least the nearest 0.05C (0.1F). Monitor theprogress of these sequential readings to determine the appear-ance of the plateau. Identify the plateau as the first fiveconsecutive readings all of whic

25、h agree within 0.1C (0.2F).You may discontinue the test after obtaining these five plateaureadings.NOTE 3If no plateau appears as defined above, the reading procedureis continued until either (1) the temperature reached 38C (100F) or (2)the temperature reaches a point 8C (15F) below a temperature wh

26、ere thewax has solidified (as may be observed through a transparent bath). Ineither of these cases the test is discontinued and the method is judged NotApplicable for the sample (see Note 1 for other methods).9. Procedure B (Automatic Method)9.1 Place a clean test tube held in a PTFE holder ring in

27、theaperture provided in the apparatus.9.2 Insert the temperature probe into a centrally bored,one-holed stopper, and insert it in the test tube. Check theprobe height to reach manufacturers suggested height. Placethe stopper with the probe back in the resting holder provided.9.3 Bring the sample to

28、a temperature at least 8C (15F)above the expected melting point. Heat the sample in a 93C(200F) maximum temperature water bath.9.4 Add the molten sample to the test tube to the fillingmark. Place the stopper with the probe on the test tubeassembly.9.5 Insert the assembly into the aluminum block aper

29、ture,and initiate the analysis in accordance with the manufacturersinstructions.9.6 When the melting point is detected, the analysis willautomatically stop. Per available options on the instrument, theresulting melting point will be displayed on the digital monitor,or printed on a printer, or both.1

30、0. Calculation and Report10.1 When using a manual apparatus, average the first fiveconsecutive temperature readings of the identified plateau,which agree within 0.1C (0.2F). Correct this average forerror in the thermometer scale where necessary.10.2 The automatic apparatus will average the first fiv

31、econsecutive temperature probe readings within 60.1C(60.2F).10.3 Report the result to at least the nearest 0.05C (0.1F)as the Petroleum Wax Melting Point (Cooling Curve), TestMethod D87. Also report whether the test was performedmanually or using automatic apparatus, as applicable.11. Quality Contro

32、l (QC)11.1 Confirm the performance of the instrument or the testprocedure by analyzing a quality control (QC) sample.11.1.1 When QC/Quality Assurance (QA) protocols arealready established in the testing facility, these may be usedwhen they confirm the reliability of the test result.11.1.2 When there

33、 is no QC/QA protocol established in thetesting facility, Appendix X1 can be used as the QC/QAsystem.12. Precision and Bias312.1 PrecisionThe precision of this test method as deter-mined by statistical examination of interlaboratory results is asfollows:3Supporting data have been filed at ASTM Inter

34、national Headquarters and maybe obtained by requesting Research Report RR:D02-1617.D87 09 (2014)212.1.1 RepeatabilityThe difference between two testresults, obtained by the same operator with the same apparatusunder constant operating conditions on identical test material,would in the long run, in t

35、he normal and correct operation ofthe test method, exceed the following values only in one casein twenty:Manual apparatus 0.11CAutomatic apparatus 0.23C12.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on

36、 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:Manual apparatus 0.41CAutomatic apparatus 0.50C12.2 This test method is considered suitable for waxes of amelting point between 38C (100F) and

37、82C (180F). Theseprecision values have been obtained by statistical examinationof interlaboratory test results from 2005. These values arebased on a study among 14 laboratories, using seven paraffinwaxes with a melting point range of 52 to 70C (126 to 158F).12.3 BiasThe bias of this test method cann

38、ot be deter-mined since no generally acceptable standard reference mate-rial is available for this analysis.12.4 Relative BiasThe sample set was analyzed usingboth manual and automatic apparatus. The difference betweenthe two sets of measurements was not very significant. Auto-matic mode results wer

39、e biased very slightly low (averaging0.064 difference).12.4.1 Based on the comparison of analysis of three sets ofwax samples in the melting point range of 115 to 159F (a totalof 70 data points by each method) by both manual andautomatic apparatus in one laboratory, a correlation coefficientof r2of

40、0.9999 was obtained indicating that there is no biasbetween the two modes of measurement.13. Keywords13.1 cooling curve; melting point; petroleum wax; waxANNEX(Mandatory Information)A1. APPARATUSA1.1 Test TubeA standard glass test tube, 25 mm (1 in.)in outside diameter, and 100 mm (4 in.) in length.

41、 It may bemarked with a reference line for sample filling at 51 mm (2 in.)above the bottom, and a reference line for positioning of thebottom of the temperature measuring device at 10 mm (38 in.)above the bottom.A1.2 Air BathAcylinder 51 mm (2 in.) in inside diameterand114mm(412 in.) in depth, equip

42、ped to hold the test tubefirmly in a vertical position in the center of the air bath. Asexamples, a tight-fitting cork having a central opening or ametal plate top with a spring clamp that holds the test tubefirmly in place have been found suitable to use.A1.3 Water BathA suitable cylindrical vessel

43、, 130 mm(518 in.) in inside diameter and 152 mm (6 in.) in depth.Provide a fitted cover equipped to support the air bathvertically so that the sides and bottom of the air bath aresurrounded by a layer of water 38 mm (112 in.) thick. Providethe cover with an opening through which the bath temperature

44、measuring device may be suspended 19 mm (34 in.) from theoutside wall of the water bath.NOTE A1.1The air bath, water bath, and water bath cover may bemade in one assembly as shown in Fig. A1.1.A1.4 Melting Point ThermometerA wax melting pointthermometer having the range shown below and conforming to

45、the requirements as prescribed in Specification E1 or in thespecifications for IP thermometers:Thermometer NumberTemperature Range ASTM IP38 to 82C 14C 17C100 to 180F 14F 17FNOTE A1.2Other means of monitoring the temperature (for example,a resistance temperature detector, in conjunction with a data

46、logger orcomputer) may be used in place of the specified melting pointthermometer, provided that the results are found to be statisticallyequivalent and that the laboratory making the substitution has collectedthe necessary data to demonstrate this equivalency.A1.5 Bath Temperature Measuring DeviceA

47、ny suitablepartial immersion thermometer, or other equivalent device,accurate to at least 1.0C (2F) throughout the required range.A1.6 TimerInterval timer or stop watch.D87 09 (2014)3APPENDIX(Nonmandatory Information)X1. QUALITY CONTROL MONITORINGX1.1 Confirm the performance of the instrument or the

48、 testprocedure by analyzing a quality control (QC) sample(s).X1.2 Prior to monitoring the measurement process, the userof the method needs to determine the average value and controllimits of the QC sample (see Practice D6299 and MNL74).X1.3 Record the QC results and analyze by control chartsor other

49、 statistically equivalent techniques to ascertain thestatistical control status of the total testing process (see PracticeD6299 and MNL74). (In the absence of explicit requirementsgiven in the test method, this clause provides guidance on QCtesting frequency.) Investigate any out of control data for rootcause(s). The results of this investigation may, but notnecessarily, result in instrument recalibration.X1.4 The frequency of QC testing is dependent on thecriticality of the quality being measured,