ASTM_D_6875_-_12.pdf

Designation:D687512Standard Test Method forSolidification Point of Industrial Organic Chemicals byThermistor1This standard is issued under the fixed designation D6875;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 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 a general procedure for deter-mining the solidification point of most organic chemicalshaving appreciable heats of fusion and solidification pointsbetween 4 and 41C.NOTE1Other test methods for determining freeze point and solidifi-cation point of aromatic hydrocarbons include Test Methods D852,D1015,D1016,D3799,D4493,and D6269.1.2 This test method is applicable to relatively pure com-pounds only.Solidification point depression is dependent onimpurity concentrations.1.3 The following applies to all specified limits in this testmethod:for purposes of determining conformance with appli-cable specifications using this test method,an observed valueor a calculated value shall be rounded off“to the nearest unit”in the last right hand digit used in expressing the specificationlimit,in accordance with the“rounding-off method”of PracticeE29.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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.For a specifichazard statement,see Section 8,Hazards.2.Referenced Documents2.1 ASTM Standards:2D852 Test Method for Solidification Point of BenzeneD1015 Test Method for Freezing Points of High-PurityHydrocarbonsD1016 Test Method for Purity of Hydrocarbons from Freez-ing PointsD3437 Practice for Sampling and Handling Liquid CyclicProductsD3438 Practice for Sampling and Handling Naphthalene,Maleic Anhydride,and Phthalic AnhydrideD3799 Test Method for Purity of Styrene by Freezing PointMethod(Withdrawn 2000)3D3852 Practice for Sampling and Handling Phenol,Cresols,and Cresylic AcidD4297 Practice for Sampling and Handling Bisphenol A(4,4-Isopropylidinediphenol)D4493 Test Method for Solidification Point of Bisphenol A(4,4-Isopropylidenediphenol)D6269 Test Method for Solidification Point of p-Xylene(Withdrawn 2004)3D6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 Other Documents:OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.120043.Terminology3.1 Definitions:3.1.1 solidification point,nan empirical constant definedas the temperature at which the liquid phase of a substance isin approximate equilibrium with a relatively small portion ofthe solid phase.3.1.1.1 DiscussionSolidification point as distinguishedfrom freezing point is described in Test Method D1015.Aninterpretation of mole percent in terms of freezing point isgiven in Test Method D1016.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved Dec.1,2012.Published January 2013.Originallyapproved in 2003.Last previous edition approved in 2008 as D6875 08.DOI:10.1520/D6875-12.2For 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 approved version of this historical standard is referenced onwww.astm.org.4Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.*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 States1 4.Summary of Test Method4.1 The solidification point is measured by noting themaximum temperature reached during a cooling cycle after theappearance of a solid phase.5.Significance and Use5.1 This test method may be used for process control duringthe manufacture of organic chemicals described in Section 1,for setting specifications,for development and research work,and to determine if contamination was introduced duringshipment.6.Apparatus6.1 Ohmmeter,capable of measuring resistance to the near-est 0.1 ohm in the range of 1000 to 10 000 ohms with directtemperature readout.56.2 Specimen Container,thick walled test tube with 18 mmoutside diameter and 14 mm inside diameter and 150 mm long.6.3 Stirrer,consisting of a 1-mm