1、Designation:D 2078 86(Reapproved 1995)e1Standard Test Method forIodine Value of Fatty Quaternary Ammonium Chlorides1This standard is issued under the fixed designation D 2078;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year o
2、f 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.This test method was prepared jointly by the American Society for Testing and Materials and the American Oil Chemists Society.e1NOT
3、EKeywords and an update statement on precision and bias were added editorially in May 1995.1.Scope1.1 This test method covers the determination of the iodinevalue of fatty quaternary ammonium chlorides by the Wijsprocedure.NOTE1This test method is essentially equivalent to Test MethodsD 1959 and D 2
4、075.1.2 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.Specific hazar
5、dsstatements are given in Section 7.2.Referenced Documents2.1 ASTM Standards:D 1959 Test Method for Iodine Value of Drying Oils andFatty Acids2D 2075 Test Method for Iodine Value of Fatty Amines,Amidoamines,and Diamines23.Terminology3.1 Definition:3.1.1 iodine valuea measure of the unsaturation of t
6、healkyl group or groups expressed in terms of percent iodineabsorbed.4.Significance and Use4.1 This test method measures the unsaturation as iodinevalue in fatty quaternary ammonium chlorides by addition ofan iodine/chlorine reagent.The amount of reagent absorbed isdetermined by back titrating the e
7、xcess reagent and comparingit to a blank determination.4.2 This determination is an indication of the source of thefatty component or,if the source is known,the number of thefatty components(for example,1,2,3,or 4),in the quaternaryammonium chloride.5.Apparatus5.1 For apparatus used in this test met
8、hod,see Test MethodD 2075.6.Reagents6.1 For reagents used in this test method,see Test MethodD 2075.6.2 Sodium Lauryl Sulfate3.7.Hazards7.1 Chloroform is a hazardous liquid that can be absorbedthrough the skin.Its vapor is hazardous through inhalation.Itis a narcotic.Use only with adequate ventilati
9、on(in a hood).For further information,see suppliers Material Safety DataSheet.7.2 Wijs Solution,iodine monochloride dissolved in glacialacetic acid,is corrosive and may cause burns to the skin andeyes.Wash clothing before reusing.Do not heat Wijs solutionabove 30C as it may liberate chlorine,which i
10、s a strong,irritating gas.Wijs solution can be purchased commercially orprepared in a hood.See Test Method D 2075 for instructions.8.Procedure8.1 Melt the sample,if not already liquid,in a water bath.Mix thoroughly,and weigh into the flask 1.5 g of sample to 0.1mg by difference.Add 20 mL of chlorofo
11、rm(PrecautionSee7.1)and swirl to dissolve the material.8.2 Pipet 25 mL of Wijs solution(PrecautionSee 7.2)into the flask,allowing the pipet to drain in the same mannerfor both specimens and blanks.8.3 Stopper the flasks immediately and moisten the stopperwith the Potassium iodide(KI)solution so as t
12、o prevent theloss of iodine or chlorine,but guard against the use of aquantity sufficient enough to run down the inside of the flask.Swirl the flask to obtain a good mixture.8.4 Prepare and conduct at least two blank determinations1This test method is under the jurisdiction of ASTM Committee D-1 on
13、Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.32 on Drying Oils.Current edition approved Aug.29,1986.Published October 1986.Originallypublished as D 2078 62 T.Last previous edition D 2078 85.2Annual Book of ASTM Standards,Vol 06.03.3Sodium l
14、auryl sulfate manufactured by K&K Laboratories,Inc.,121 ExpressSt.,Plainview,NY 11803 has been found suitable for this purpose.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMwith each group of sp
15、ecimens simultaneously and similar in allrespects.8.5 Store the flasks for 30 min in a dark place at atemperature of 25 6 5C.Swirl the flasks occasionally,beingcareful not to allow the solution to crawl up the side of the flaskmore than half-way.8.6 Remove the flasks from storage and add 20 mL KIsol
16、ution followed by approximately 2.2 g of sodium laurylsulfate and 40 mL of water.NOTE2Sodium lauryl sulfate is added to prevent the free iodine frombeing tenaciously held by the nonaqueous phase,thus giving a sharper endpoint.8.7 Titrate with 0.1 N Na2S2O3solution,adding it graduallyand with constant vigorous shaking until the tannish color hasalmost disappeared.Add 2 mL of starch indicator solution,rinsing the neck of the flask therewith and continue the titrationuntil the blue to brown color b
