1、Designation: D1240 02 (Reapproved 2006) D1240 12Standard Test Methods forRosin Acids Content of Naval Stores,Pine Chemicals,Including Rosin, Tall Oil, and Related Products1This standard is issued under the fixed designation D1240; the number immediately following the designation indicates the year o
2、foriginal 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 These test methods cover the determination of rosin acids
3、in tall oil, tall oil fatty acid, tall oil rosin, and other navalstorespine chemicals products.1.2 These test methods may not be applicable to adducts or derivatives of rosin, fatty acid, or other naval storespine chemicalsproducts.1.3 The values stated in SI units are to be regarded as the standard
4、. The values given in parentheses are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicabil
5、ity of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1585 Test Methods for Fatty Acids Content of Naval Stores, Including Rosin, Tall Oil, and Related ProductsE70 Test Method for pH of Aqueous Solutions With the Glass ElectrodeE177 Practice for Use of the Terms Preci
6、sion and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Summary of Test Method3.1 The rosin acids content is determined by one of threetwo procedures; by selective esterification of fatty acids to form methylesters followe
7、d by titration of the unreacted rosin acids, by selective esterification of fatty acids to form butyl esters followed bytitration of the unreacted rosin acids, or by selective esterification of fatty acids to form methyl esters followed by extraction ofthe sulfuric acid catalyst and titration of the
8、 unreacted rosin acids.4. Significance and Use4.1 This is revision of the method for measuring rosin acids content combines the three major ways of determining the rosinacids content of naval storespine chemicals products into a single method.4.1.1 For materials containing less than 15 % rosin, the
9、modified Glidden procedure has gained acceptance over theHerrlinger-Compeau. acceptance. For materials containing more than 15 % rosin the modified Wolfe Method is preferred. Themodified Wolfe and modified Glidden procedures differ only in their details. They have been combined here into a singlepro
10、cedure. This procedure can be run using either a potentiometer or an internal indicator to determine the end point of the titration.Use of a potentiometer is preferred and is the referee method. Use of an internal indicator is the principal alternative method. Theywill be referred to as the Potentio
11、metric Method and the Internal Indicator Method to distinguish them from the Herrlinger-Compeau and Linder-Persson methods.Method.4.1.2 The Herrlinger-Compeau Method is limited in application to materials containing less than 15 % rosin. It is little used inthe industry today. Much early work is bas
12、ed on this test method so it is included here to provide a historical basis for the overalltest method.1 These test methods are under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and are the direct responsibility ofSubcommittee D01.34 on Naval Sto
13、resPine Chemicals and Hydrocarbon Resins.Current edition approved Nov. 1, 2006Nov. 1, 2012. Published November 2006December 2012. Originally approved in 1952. Last previous edition approved in 20022006as D1240 02.D1240 02 (2006). DOI: 10.1520/D1240-02R06.10.1520/D1240-12.2 For referenced ASTM standa
14、rds, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an A
15、STM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as publishe
16、d by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.3 The Linder-Persson Method is also little used in the industry today. It is applicable for measuring the rosin acids contentof na
17、val stores products containing greater than 60 % rosin. Like the Herrlinger-Compeau, it is included here to provide a historicalbasis for the test method. In those instances where they are used, the Herrlinger-Compeau and Linder-Persson methods are oftenin conjunction to cover the whole range of ros
18、in content.5. Reagents5.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society wheresuch specifications are availa
19、ble.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.5.2 Unless otherwise indicated, references to water shall be understood to mean deionized or distilled water.6. Prepar
20、ation of Sample6.1 Homogeneous liquid materials may be used without further preparation.6.2 Nonhomogeneous liquid materials should be heated until they are homogeneous, then a portion taken for analysis.6.3 Solid samples are subject to surface oxidation which may affect the results. Prepare the samp
21、le for analysis by chippingsmall pieces from a freshly exposed surface of a lump or lumps and crush to a coarse powder to facilitate weighing and solution.Prepare fresh on the same day, prior to weighing, in order to avoid changes due to surface oxidation of crushed rosin on exposureto the air.ROSIN
22、 ACIDS CONTENT BY THE POTENTIOMETRIC METHOD(Referee Method)7. Scope7.1 This test method covers the determination of rosin acids content of tall oil rosin, tall oil fatty acid, and other naval storespinechemicals products, where the most reproducible results are desired. By using the potentiometric i
23、nflection end points, the errordue to colorimetric end points is avoided.8. Summary of Test Method8.1 A sample is refluxed with methyl sulfuric acid to esterify the fatty acids. The rosin acids and sulfuric acid are then titratedpotentiometrically, and the rosin acids content calculated from the dif
24、ference between the two inflection points obtained.9. Apparatus9.1 pH MeterAn indicating potentiometer having a limit of error not greater than 60.1 pH over a range from pH 1 to pH 13,using an alkali-resistant glass electrode and a saturated calomel half-cell. The pH meter shall conform to the requi
25、rements of TestMethod E70. Alternatively, an automatic potentiometric titrator may be used.9.2 Stirrer, magnetic, equipped with poly(tetrafluoroethylene)-coated stir bar.9.3 Buret, 50-mL capacity, with 0.1-mL divisions. The so-called automatic buret is preferable as its use minimizes errors dueto ev
26、aporation. The automatic buret should be guarded with soda-lime tubes against the absorption of CO2 from the air.9.4 Erlenmeyer Flask, 250-mL or larger of a chemically resistant glass with a standard-taper 24/40 joint.9.5 Condenser, water-cooled, equipped with a joint fitting the flask described in
27、accordance with 9.4.10. Reagents10.1 Alcoholic Alkali, Standard Solution (0.5 N)Dissolve 33 g of potassium hydroxide (KOH), preferably in pellet form, inmethanol (CH3OH) and dilute to 1 L with methanol. Standardize to 60.001 N with potassium acid phthalate (C6H4COOKCOOH)in 60 mL of water followed by
28、 40 mL of methanol; 2.553 g of potassium acid phthalate will be neutralized by 25.00 mL of 0.5N KOH solution. Protect the standardized solution against evaporation and absorption of carbon dioxide (CO2) from the air.Restandardize the solution frequently, either potentiometrically or colorimetrically
29、, using phenolphthalein as the indicator.10.1.1 For fatty acids containing low concentrations of rosin acids, 0.1 N alcoholic potassium hydroxide may give superiorresults.10.2 Ethanol (95 %)Denatured alcohol conforming to Formula No. 3A or No. 30 of the U.S. Bureau of Internal Revenue,neutralized by
30、 the addition of KOH.3 Reagent Chemicals, American Chemical Society Specifications ,Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagentsnot listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset
31、, U.K., and the United States Pharmacopeia andNational Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.D1240 12210.3 Methanol (99.5 %).10.4 Methyl Sulfuric Acid SolutionSlowly pour 100 g of concentrated sulfuric acid (H2SO4 sp gr 1.82 to 1.84), while stirringconstantly, into 40
32、0 g of methanol. Extreme caution should be taken while preparing the methyl sulfuric acid. Adding sulfuric acidtoo rapidly may cause the methanol to flash out of its container. Store the methyl sulfuric acid in a glass-stoppered bottle.10.5 Toluene.11. Procedure11.1 Weigh the sample to the nearest 0
33、.001 g in a 250-mL flask. Choose the amount of sample so that the second titration willconsume between 10 and 30 mL of KOH solution. For rosin acids, this will be about 5 g of material. For fatty acids containingless than 15 % rosin, this will be about 40 g of material. For fatty acids containing le
34、ss than 3 % rosin acids titrating with 0.1 NKOH may give superior results. Table 1 gives suggested amounts of material to use.11.2 Dissolve the sample in 100 mL of methanol in a 250-mL flask. If the sample has a high rosin content it may be helpfulfirst to dissolve it in 25 mL of toluene before addi
35、ng the methanol. For material believed to contain lessmore than 15 % fattyrosinacid, that is, high in rosin, add 5 mL of methyl sulfuric acid, connect the flask assembly, and reflux the solution for 2 to 20 min.(Solid samples must be in solution before beginning reflux.) For materials believed to co
36、ntain concentrations of fattyrosin acidhigherless than 15 %, that is, low in rosin, use 10 mL of methyl sulfuric and reflux for 20 min. Measure reflux time from themoment the first drop of solvent returns to the flask from the condenser. Cool and transfer to a 400-mL beaker, using a total of100 mL o
37、f methanol (Note 1) in three successive rinsings.NOTE 1Ethanol is preferable when an automatic titrator is used.11.3 Turn the pH meter on and allow a few minutes for it to come to equilibrium. Balance the meter using a standard buffersolution as described in Test Method E70; then rinse the electrode
38、s thoroughly with water and then with alcohol.11.4 Immerse the electrode in the sample solution. Start the stirrer and adjust its speed for vigorous stirring without splattering.11.5 Titrate the sample solution with 0.5 N KOH to a fixed pH of 4.0, the first end point. If it appears that the buret do
39、es notcontain sufficient KOH to continue the titration to the second end point, refill the buret at this point. Continue the titration to thefixed pH of 10.8, the second point. Record the amount of KOH required for the titration between the first and second end point.If an automatic titrator is used
40、, the end points shall be taken at the inflection points or at the fixed pH of 4.0 and 10.8.12. Calculation12.1 Calculate the percentage of rosin acids as follows:12.1.1 For materials containing less than 15 % rosin:Rosin acids, %5AN/B! 330.24#21.1 (1)where:A = KOH solution required for titration be
41、tween the first and second end points, mL,N = normality of the KOH solution,B = sample used, g, and30.24 = (mol weight of abietic acid 100)/100012.1.2 For materials containing greater than 15 % rosin:Rosin acids, %5AN/B! 330.24 (2)where:A = KOH solution required for titration between the first and s
42、econd end points, mL,N = normality of the KOH solution,B = sample used, g, and30.24 = (mol wt of abietic acid 100)/100012.2 Report the percentage of rosin acids calculated by either 12.1.1 or 12.1.2 to the first decimal place.TABLE 1 Sample Size and TitrantMaterialSample Size,gReflux Time,minKOHNorm
43、ality,NRosin 5 2 0.5Fatty acid, 15 % rosin 40 20 0.5Fatty acid, 3 % rosin 40 20 0.1D1240 123ROSIN ACIDS CONTENT BY THE INTERNAL INDICATOR METHOD(Alternative Method)13. Scope13.1 This test method covers the determination of rosin acids content of tall oil rosin, tall oil fatty acid, and other navalst
44、orespine chemicals products, using an internal indicator for the determination of the end point. It gives good results whenroutinely applied by a skilled analyst. However, where the most reproducible results by different analysts and laboratories aredesired, the referee method (Sections 6 to 11) sho
45、uld be used.14. Summary of Test Method14.1 A sample is refluxed with methyl sulfuric acid to esterify the fatty acids. The rosin acids and sulfuric acid are then titratedin the presence of thymol blue indicator. The rosin acids content is then calculated from the difference between the two color end
46、points obtained.15. Apparatus15.1 The apparatus for the esterification and titration of the sample shall consist of the flask, condenser, and buret described inSection 9.16. Reagents16.1 Alcoholic Alkali, Standard SolutionSee 10.1.16.2 MethanolSee 10.316.3 Methyl Sulfuric Acid SolutionSee 10.4.16.4
47、Thymol Blue Indicator Solution (1 g/L)Dissolve 1 g of thymol blue in 1000 mL of methanol.16.5 Toluene.17. Procedure17.1 Weigh the sample to the nearest 0.001 g in a 250-mL flask. Choose the amount of sample so that the titration will consumebetween 10 and 30 mL of 0.5 N KOH. For rosin acids, this wi
48、ll be about 5 g of material. For fatty acids containing less than 15 %rosin, this will be about 40 g of material. For fatty acids containing less than 3 % rosin acids, titrating with 0.1 N KOH may givesuperior results. Table 1 gives suggested amounts of material to use.17.2 Dissolve the sample in 10
49、0 mL of methanol in a 250-mL flask. If the sample has a high-rosin content it may be helpfulfirst to dissolve it in 25 mL of toluene before adding the methanol. For material believed to contain less than 15 % fatty acid, add5 mL of methyl sulfuric acid, connect the flask assembly, and reflux the solution for 2 min. (Solid samples must be in solutionbefore beginning reflux.) For materials believed to contain concentrations of fatty acid higher than 15 %, use 10 mL of methylsulfuric and reflux for 20 min. Measure reflux time from the moment the first drop of sol
