1、Designation: D1981 11Standard 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
2、. 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 20
3、5C 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 bee
4、n 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
5、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(Gardner Color Scale)D6166 Test Method for Color of Naval Stores and RelatedProducts
6、 (Instrumental Determination of Gardner Color)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 ma
7、rkedeffect 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 outersu
8、rface 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 the
9、rmostatic 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. M
10、aterials6.1 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 inSpecificatio
11、n E1.6.2 Tubes, 25 mm (1 in.) in diameter, 240 mm (912 in.) 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 Nitro
12、genAs 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 temperatu
13、re of205 6 2C.7.2 Fill a clean, dry tube to a depth of approximately 125mm with the specimen.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 gentle1This test method is
14、 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 June 1, 2011. Published June 2011. Originallyapproved in 1961. Last previou
15、s edition approved in 2006 as D1981 02 (2006).DOI: 10.1520/D1981-11.2For 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 w
16、ebsite.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.rate 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 temperatur
17、e 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.NOTE 1The extra 15 min heating time is specified to allow thespecimen in the blo
18、ck to reach the prescribed temperature.7.4 At the end of the applicable time remove the tubes fromthe block while still allowing the nitrogen to flow. Cool thecontents of the tubes slightly in a water-bath before removingthe stoppers. Immediately fill a Gardner color tube or 1 cmcuvet with the speci
19、men, and read the color in accordance withTest Method D1544 or Test Method D6166, respectively. Alsomeasure the color of the unheated specimen.8. ProcedureMethod B, Oil Bath8.1 Adjust the oil level so that the tubes will be immersed toa depth of 140 mm (512 in.). Bring the bath to a temperature of20
20、5 6 2C and maintain the temperature within the specifiedrange.8.2 Fill a clean, dry tube to a depth of 127 mm (5.0 in.) withthe specimen, and place it in the oil bath.8.3 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
21、 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. Set the timer for60 min if the specimen has an iodine value greater than 15, orfor 120 min if the specimen has an iodine value of 15 or le
22、ss.8.4 At the end of the applicable time remove the tubes fromthe bath while still allowing the nitrogen to flow. Cool theFIG. 1 Eight Hole Aluminum Heating BlockD1981 112contents of the tubes slightly in a water-bath before removingthe stoppers. Immediately fill a Gardner color tube or 1 cmcuvet wi
23、th the specimen, and read the color in accordance withTest Method D1544 or Method D6166, respectively. Alsomeasure the color of the unheated specimen.9. Report9.1 Report the Gardner color of the specimen after heating,the color of the unheated specimen and report the method ofmeasurement (Test Metho
24、d D1544 or Test Method D6166)used.10. Precision and Bias10.1 No statement available.11. Keywords11.1 color after heating; fatty acid colorNOTE 11 in. = 25.4 mm.FIG. 2 Tube Holder (Aluminum or Stainless Steel) for Color-After-Heating TestNOTE 11 in. = 25.4 mm.FIG. 3 Details of Color-After-Heating Tub
25、eD1981 113ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such r
26、ights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for addition
27、al standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the AS
28、TM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D1981 114
