1、Designation:D 1398 93(Reapproved 1998)Standard Test Method forFatty Acid Content of Alkyd Resins and Alkyd ResinSolutions1This standard is issued under the fixed designation D 1398;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the
2、year 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.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This test method covers the gravi
3、metric determinationof the total fatty acids in alkyd resins and alkyd resin solutions.The test method is not applicable to alkyd resins containingmodifying agents such as urea,melamine,phenols,rosin,andstyrene.1.2 This standard does not purport to address all of thesafety concerns,if any,associated
4、 with its use.It is theresponsibility of whoever uses this standard to consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 563 Test Method for Phthalic Anhydride Content ofAlky
5、d Resins and Resin Solutions2D 1193 Specification for Reagent Water3D 1615 Test Methods for Glycerol,Ethylene Glycol,andPentaerythritol in Alkyd Resins2D 2245 Test Method for Identification of Oils and OilAcidsin Solvent-Reducible Paints43.Significance3.1 This test method is used to determine total
6、fatty acidcontent of alkyl resins and this solution,in the absence ofinterfering compounds,as a means whereby the relativeapplicability of the alkyd resin to the particular end use may beestimated by buyer and seller.4.Apparatus4.1 Beakers,having capacities of 150 and 400 mL.4.2 Desiccator,4.3 Filte
7、r Paper,rapid,low-ash filter paper,to fit thefiltering funnel.4.4 Filtering Funnel,75-mm diameter,long-stem.4.5 Flask,250-mL,flat-bottom,with standard taper open-ing.4.6 Nitrogen Gas Supply.4.7 Separatory Funnels,three 500-mL capacity glass-stoppered,fitted with standard-taper ground-glass stoppers
8、andstopcocks.4.8 Steam Bath.4.9 Water Bath.4.10 Vacuum Drying Oven,small,laboratory-size,thermo-statically controlled to operate at 606 2C.A water-aspiratorvacuum source is satisfactory.4.11 Cotton,absorbent,USP.5.Reagents and Materials5.1 Purity of ReagentsReagent grade chemicals shall beused in al
9、l tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.5Other grades may beused,provided it is first ascertained that the reagent is ofsuf
10、ficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Type IV of Specification D 1193.5.3 Ether,anhydrous.5.4 Hydrochloric Acid(sp gr 1.19)Conc
11、entrated hydro-chloric acid(HCl).5.5 Indicator Paper,universal-type.5.6 Sodium Sulfate(Na2SO4),anhydrous.6.Procedure6.1 Saponify a portion of resin or resin solution in accor-dance with Test Method D 563.After filtering the potassium1This test method is under the jurisdiction of ASTM Committee D-1 o
12、n Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.33 on Polymers and Resins.Current edition approved April 15,1993.Published June 1993.Originallypublished as D 1398 56.Last previous edition D 1398 84.2Annual Book of ASTM Standards,Vol 06.03.3A
13、nnual Book of ASTM Standards,Vol 11.01.4Annual Book of ASTM Standards,Vol 06.01.5Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for Laboratory
14、Chemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.phthalate alcoholate(6.3),transfer the comb
15、ined filtrate andwashings to the 400-mL beaker with the aid of 25 mL of waterfrom a wash bottle.Concentrate to a volume of approximately25 mL on the steam bath under a blanket of nitrogen to preventoxidation of the fatty acids.(CautionBe sure to use a hood.)Transfer to a 500-mL separatory funnel wit
16、h the aid of waterfrom a wash bottle,dilute with water to approximately 300 mL,and add 10 mL of alcohol.6.2 Extract the unsaponifiable and volatile thinners withsuccessive 50-mL portions of ether(not less than three,or untila colorless ether extract is obtained),combining the etherextracts in the first separatory funnel and using the other twofunnels for the successive extractions(Note 1).Finally,washthe combined ether extracts with three 15-mL portions ofwater,adding the water washes to the mai
