1、Designation:D556595(Reapproved 2011)Standard Test Method forDetermination of the Solidification Point of Fatty AcidsContained in Animal,Marine,and Vegetable Fats and Oils1This standard is issued under the fixed designation D5565;the number immediately following the designation indicates the year ofo
2、riginal 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.Scope1.1 This test method covers determination of the solidifica-tion point
3、of fatty acids contained in animal,marine,andvegetable fats and oils.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is
4、 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.See 5.2 and 5.7 foradditional information.2.Significance and Use2.1 This test method is intended to cover determination ofthe
5、solidification point of fatty acids contained in animal,marine,and vegetable fats and oils used in the softening andstuffing of leather,as well as those used in the manufacture ofproducts for such purpose.3.Apparatus3.1 Griffn Low-Form Beaker,2-L capacity.3.2 Wide Mouth BottleCapacity of 450 mL,heig
6、ht of 190mm,and inside diameter of neck of 38 mm.3.3 Test TubesLength of 100 mm and diameter of 25 mm,with or without rim.These tubes may have an etched markextending around the tube at a distance of 57 mm from thebottom to show the height to which the tube is to be filled.3.4 Saponification VesselA
7、750-or 1000-mL flask.3.5 Stirrer,2-to 3-mm outside diameter,with one end bentin the form of a loop of 19-mm outside diameter.Glass,nichrome,stainless steel,or monel wire shall be used.Theupper end can be formed to accommodate hand stirring or forattachment to a mechanical stirrer.3.6 Laboratory Ther
8、mometer,0 to 150C.3.7 Titer Test ThermometerSpecifications for thermom-eter used in titer test determinations:3.7.1 TypeEtched stem glass.3.7.2 LiquidMercury.3.7.3 Filling Above LiquidEvacuated or nitrogen gas.3.7.4 Temperature Range2 to+68C.3.7.5 Subdivisions0.2C.3.7.6 Total Length385 to 390 mm.3.7
9、.7 Stem Diameter6 to 7 mm.3.7.8 Stem ConstructionPlain or lens front.The crosssection of the lens front type shall be such that it will passthrough an 8 mm ring gage but will not enter a 5 mm slot gage.3.7.9 Bulb Diameter5.5 mm to not greater than that ofstem.3.7.10 Bulb Length15 to 25 mm.3.7.11 Bul
10、b ConstructionCorning normal or equally suit-able thermometric glass.3.7.12 Distance from Bottom of Bulb to 2 Mark50 to60 mm.3.7.13 Distance from 68 Mark to Top of Thermometer20to 35 mm.3.7.14 Length of Unchanged Capillary Between the HighestGraduation and the Expansion Chamber10 mm.3.7.15 Expansion
11、 ChamberTo permit heating to at least85C.3.7.16 Top FinishGlass ring.3.7.17 Longer Graduation LinesAt each 1 mark.3.7.18 GraduationsNumbered at zero and each multipleof 2.3.7.19 Immersion45 mm,a line shall be etched around thestem 45 mm from the bottom of the bulb.3.7.20 Special Marking on Thermomet
12、erA.O.C.S.TiterTest.3.7.21 Maximum Scale Error Permitted at any Point0.2C.3.7.22 Marking on CaseA.O.C.S.Titer Test,2 to+68in 0.2C.3.7.23 StandardizationThe thermometer shall be stan-dardized at the ice point and at intervals of approximately1This test method is under the jurisdiction of ASTM Committ
13、ee D31 on Leatherand is the direct responsibility of Subcommittee D31.08 on Fats and Oils.This testmethod was developed in cooperation with the American Leather Chemists Assn.(Methods H 10 and H 17-1957).Current edition approved Jan.1,2011.Published March 2011.Originallyapproved in 1994.Last previou
14、s edition approved in 2006 as D5565 95(2006).DOI:10.1520/D5565-95R11.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 20C,for the condition of 45 mm immersion,and for anaverage stem temperature of the emergent mercury column of25C.3.8 Filt
15、er Paper,qualitative,rapid filtering grade.4.Reagents4.1 Glycerol-Caustic Solution,prepared by dissolving,withthe aid of heat,250 g of solid potassium hydroxide in 1250 gof glycerin(dynamite or C.P.grade).To avoid foaming,heating shall not exceed 135 to 145C.(Sodium hydroxide cannot be substituted f
16、or potassium hydroxide.)4.2 Sulfuric Acid,30%by weight.5.Procedure5.1 Preparation of the Fatty AcidsWeigh approximately110 g of glycerol-caustic solution into the saponification vesseland heat to 150C with stirring.Then add approximately 50mL of oil or melted fat sample and reheat the whole to 140 to150C.A little additional solution may be necessary to ensurecomplete saponification in some cases.5.2 Continue stirring until the saponification is complete.(WarningDo not heat to above 150C.)5.2.1(T
