1、Designation:D441990(Reapproved 2015)Standard Test Method forMeasurement of Transition Temperatures of PetroleumWaxes by Differential Scanning Calorimetry(DSC)1This standard is issued under the fixed designation D4419;the number immediately following the designation indicates the year oforiginal adop
2、tion or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the transition temperatures ofpetroleum waxes,including
3、 microcrystalline waxes,by differ-ential scanning calorimetry(DSC).These transitions mayoccur as a solid-solid transition or as a solid-liquid transition.1.2 The normal operating temperature range extends from15 C to 150 C(Note 1).1.3 The values stated in SI units are to be regarded as thestandard.1
4、.4 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.Referenced Docume
5、nts2.1 ASTM Standards:2D87 Test Method for Melting Point of Petroleum Wax(Cooling Curve)D1160 Test Method for Distillation of Petroleum Products atReduced PressureD3418 Test Method for Transition Temperatures and En-thalpies of Fusion and Crystallization of Polymers byDifferential Scanning Calorimet
6、ryE472 Practice for Reporting Thermoanalytical Data(With-drawn 1995)3E473 Terminology Relating to Thermal Analysis and Rhe-ologyE474 Method for Evaluation of Temperature Scale for Dif-ferential Thermal Analysis(Withdrawn 1986)33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Dif
7、ferential Scanning Calorimetry(DSC)A tech-nique in which the difference in energy inputs into a substanceand a reference material is measured as a function oftemperature,while the substance and a reference material aresubjected to a controlled temperature program.The record isthe DSC curve.Two modes
8、,power-compensation DSC andheat-flux DSC,can be distinguished depending on the methodof measurement used.For additional background informationrefer to Practice E472,Terminology E473,and Test MethodE474.4.Summary of Test Method4.1 Separate samples of petroleum wax and a referencematerial or blank(emp
9、ty sample container)are heated at acontrolled rate in an inert atmosphere.A sensor continuouslymonitors the difference in heat flow to the two samples.TheDSC curve is a record of this difference versus temperature.Atransition in the wax involves the absorption of energy relativeto the reference,resu
10、lting in an endothermic peak in the DSCcurve.While the transition occurs over the temperature rangespanned by the base of the peak,the temperature associatedwith the peak apex is designated the nominal transitiontemperature(Note 1).NOTE1Test Method D87 also monitors energy transfer between waxand a
11、standard environment.The highest temperature DSC transition maydiffer from the melting point because the two methods approach thesolid/liquid phase transition from different directions.5.Significance and Use5.1 DSC in a convenient and rapid method for determiningthe temperature limits within which a
12、 wax undergoes duringtransitions.The highest temperature transition is a solid-liquidtransition associated with complete melting;it can guide thechoice of wax storage and application temperatures.Thesolid-solid temperature transition is related to the properties ofthe solid,that is,hardness and bloc
13、king temperature.NOTE2For a relatively narrow cut petroleum wax,the lowesttransition will be a solid-solid transition.Anarrow cut wax is one obtainedby deoiling a single petroleum distillate with a maximum range of 120 Fbetween its 5%and 95%vol in accordance with Test Method D11601This test method i
14、s under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricantsand is the direct responsibility ofSubcommittee D02.10.0A on Physical/Chemical Properties.Current edition approved April 1,2015.Published May 2015.Originallyapproved in 1984.Last previous edition approved
15、in 2010 as D4419 90(2010).DOI:10.1520/D4419-90R15.2For referenced ASTM standards,visit 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.3The last approv
16、ed version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 boiling points(converted to 760 torr).The DSC method cannot differen-tiate between solid-liquid and solid-solid transitions.Such informationmust be predetermined by other techniques.In the case of blends,thelower temperature transition may be envelopes of both solid-liquid andsolid-solid transitions.5.2 Since petroleum w
