ASTM_D_1981_-_11_2015.pdf

Designation:D198111(Reapproved 2015)Standard Test Method forMeasuring Color After Heating of Tall Oil Fatty Acids1This standard is issued under the fixed designation D1981;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.Scope1.1 This test method covers the measurement of the Gardnercolor of tall oil fatty acids after heating in an atmosphere ofnitrogen at 205C for one or two hours,depending on whetherits iodine value is over or under 15,respectively.The specimenmay be heated using either an aluminum heating block or an oilbath.This method is applicable to all tall oil fatty acids.Applicability of this method to other types of fatty acids hasnot been determined.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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.Referenced Documents2.1 ASTM Standards:2D1544 Test Method for Color of Transparent Liquids(Gard-ner Color Scale)D6166 Test Method for Color of Pine Chemicals and Re-lated Products(Instrumental Determination of GardnerColor)E1 Specification for ASTM Liquid-in-Glass Thermometers3.Significance and Use3.1 The color of a tall oil fatty acid is readily affected byheat and oxidization.Variations in degree of heat,time of heat,and exposure to atmosphere during heating have a markedeffect on the color obtained;therefore,conformity to theequipment and procedure outlined in this test method isessential to accuracy and precision.4.Heating ApparatusMethod A,Aluminum Block4.1 Forced Draft Oven,maintained at 205 6 2C.4.2 Aluminum Heating Block(see Fig.1).Wrap the outersurface with an appropriate insulating material.5.Heating ApparatusMethod B,Oil Bath5.1 Oil BathA 5-L steel beaker equipped with a mechani-cal stirrer and containing any light-colored alkali-refined oilsuch as hydrogenated cottonseed oil.5.2 Heat SourceAn electric immersion heater with suit-able thermostatic control may be used.The heater shall be ofsufficient capacity so that when placing several tubes in thebath,the bath temperature does not drop by more than 5Cbelow the minimum bath temperature and the recovery time toreach 205C does not exceed 5 min.5.3 Test Tube Holder(see Fig.2).6.Materials6.1 Thermometer Measuring DeviceA thermometer con-forming to the requirements of Specification E1 or an elec-tronic temperature measuring device,such as a resistancethermometer or thermocouple.The device must exhibit thesame temperature response as the thermometers specified inSpecification E1.6.2 Tubes,25 mm(1 in.)in diameter,240 mm(912in.)inlength with ground-glass joints(see Fig.3)and adapter.6.3 Timer,capable of registering up to 135 min.6.4 Nitrogen,a source of nitrogen capable of being regu-lated to a pressure of 7 to 14 kPa(1 to 2 psi).6.5 Bubble Counter for NitrogenAs a liquid,use a portionof tall oil fatty acid,instead of water or mercury.6.6 Gardner Color Tubes or 1 cm CuvetSee Test MethodsD1544 or D6166.7.ProcedureMethod A,Aluminum Block7.1 Insert the thermometer into the aluminum block.Placethe block in a forced-draft oven maintained at a temperature of205 6 2C.7.2 Fill a clean,dry tube to a depth of approximately 125mm with the specimen.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.34 on Pine Chemicals and Hydrocarbon Resins.Current edition approved Dec.1,2015.Published December 2015.Originallyapproved in 1961.Last previous edition approved in 2011 as D1981 11.DOI:10.1520/D1981-11R15.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.3 Place a fitted adapter in each tube.Adjust the flow ofnitrogen through the side arm of the adapter at a rapid rate for3 to 5 min to displace the air,then reduce the flow to a gentlerate of 2 or 3 bubbles per second so that the surface of thespecimen is blanketed by nitrogen at all times.Place the tubein one of the wells of the heating block.The temperature of theblock should not drop more than 5C when the specimens areplaced in it.Set the timer for 75 min if the specimen has aniodine value greater than 15,or for 135 min if the specimen hasan iodine value of 15 or less.NOTE1The extra 15 min heating time is spec