1、Designation: D 1981 02 (Reapproved 2006)Standard Test Method forMeasuring Color After Heating of Tall Oil Fatty Acids1This standard is issued under the fixed designation D 1981; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 atmosp
3、here ofnitrogen at 205C for one or two h, depending on whether itsiodine 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
4、 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
5、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:2D 1544 Test Method for Color of Transparent Liquids(Gardner Color Scale)D 6166 Test Method for Color of Naval Stores
6、and RelatedProducts (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 durin
7、g 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
8、). 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
9、 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 Holde
10、r (see Fig. 2).6. Materials6.1 Thermometer, range 95 to 255C, 0.5 subdivisions, 100mm partial immersion, conforming to the requirements forThermometer 42C as prescribed in Specification E1.6.2 Tubes, 25 mm (1 in.) in diameter, 240 mm (912 in.) inlength with ground-glass joints (see Fig. 3) and adapt
11、er.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 Cuv
12、etSee Test MethodsD 1544 or D 6166.7. 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.7.3 Place a fitted ad
13、apter 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 th
14、e wells of the heating block. The temperature of the1This 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 Naval Stores.Current edition approved Nov. 1, 2006. Published Nove
15、mber 2006. Originallyapproved in 1961. Last previous edition approved in 2002 as D 1981 02.2For 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 Su
16、mmary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.block 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
17、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 block 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 thecont
18、ents of the tubes slightly in a water-bath before removingthe stoppers. Immediately fill a Gardner color tube or 1 cmcuvet with the specimen, and read the color in accordance withTest Method D 1544 or Test Method D 6166, respectively.Alsomeasure the color of the unheated specimen.8. ProcedureMethod
19、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 of205 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
20、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 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.
21、Set the timer forFIG. 1 Eight Hole Aluminum Heating BlockD 1981 02 (2006)260 min if the specimen has an iodine value greater than 15, orfor 120 min if the specimen has an iodine value of 15 or less.8.4 At the end of the applicable time remove the tubes fromthe bath while still allowing the nitrogen
22、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 specimen, and read the color in accordance withTest Method D 1544 or Method D 6166, respectively. Alsomeasure the color of the unheated specimen.9.
23、 Report9.1 Report the Gardner color of the specimen after heating,the color of the unheated specimen and report the method ofmeasurement (Test Method D 1544 or Test Method D 6166)used.10. Precision and Bias10.1 No statement available.NOTE 11 in. = 25.4 mm.FIG. 2 Tube Holder (Aluminum or Stainless St
24、eel) for Color-After-Heating TestNOTE 11 in. = 25.4 mm.FIG. 3 Details of Color-After-Heating TubeD 1981 02 (2006)311. Keywords11.1 color after heating; fatty acid colorASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin t
25、his standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must
26、be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of there
27、sponsible 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 ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700,
28、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).D 1981 02 (2006)4
