ASTM_D_1306_-_88_1996e1.pdf

Designation:D 1306 88(Reapproved 1996)e1Standard Test Method forPhthalic Anhydride Content of Alkyd Resins and EstersContaining Other Dibasic Acids(Gravimetric)1This standard is issued under the fixed designation D 1306;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the 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.e1NOTEKeywords were added editorially in October 1996.1.Scope1.1 This test method covers the gravimetric determinationof phthalic anhydride in alkyd resins and esters that containdibasic acids such as maleic,fumaric,adipic,and sebacic,which would interfere if Test Method D 563 was used.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.2.Referenced Documents2.1 ASTM Standards:D 563 Test Method for Phthalic Anhydride Content ofAlkyd Resins and Resin Solutions2D 1193 Specification for Reagent Water33.Summary of Test Method3.1 The specimen is saponified with alcoholic potassiumhydroxide and benzene to precipitate quantitatively the potas-sium salt of phthalic acid as C6H4(COOH)2C2H5OH.Interfer-ing substances are eliminated by dissolving the precipitate inwater,adjusting the pH of the solution to 2.5 with nitric acid,and filtering.Phthalic acid is then precipitated as nonstoichio-metric lead phthalate and calculated to phthalic anhydride,using a factor obtained when compositions of known puritywere analyzed similarly.4.Significance and Use4.1 The phthalic anhydride content of alkyd resins controlsthe properties of the final film.5.Apparatus5.1 Flask and CondenserA 500-mL Erlenmeyer flaskfitted with an air-cooled glass reflux condenser 30 in.(760 mm)in length.The connection between the flask and condensershall be a standard-taper 24/40 ground-glass joint.5.2 Water Bath.5.3 Guard Tube,filled with soda lime.5.4 Fritted-Glass Filter Crucible,medium porosity,of30-mL capacity.5.5 Filter Flasks,suction-type.5.6 Crucible Holder.5.7 Oven,of gravity convection type.5.8 Desiccator,containing concentrated H2SO4(sp gr 1.84)as the desiccant.5.9 Flash Filtrator.5.10 pH Test Assembly.5.11 Volumetric Flask,100-mL.5.12 Erlenmeyer Flask,250-mL,wide-mouth,with glassstopper not smaller than a No.27.5.13 Delivery Pipet,2-mL.6.Reagents6.1 Purity of ReagentReagent grade chemicals shall beused in all 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.4Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type II of Specification D 1193.6.3 Acetic Acid,Glacial.6.4 Alcohol-Benzene Wash SolutionMix 1 volume ofabsolute ethyl alcohol(Note 1)with 3 volumes of benzene.1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings,Materials,andApplications,and is the direct responsibility ofSubcommittee D01.33 on Polymers and Resins.Current edition approved May 27,1988.Published October 1988.Originallypublished as D 1306 54 T.Last previous edition D 1306 80.2Annual Book of ASTM Standards,Vol 06.03.3Annual Book of ASTM Standards,Vol 11.01.4Reagent 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 LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMNOTE1The alcohol may be denatured Formula 2-B,but must beanhydrous.6.5 Benzene(anhydrous).6.6 Ether(anhydrous).6.7 Lead Acetate SolutionDissolve 25 g of lead acetatetrihydrate in glacial acetic acid and dilute to 100-mL volumewith acetic acid.6.8 Methanol(anhydrous).6.9 Nitric Acid(1+3)Mix 1 volume of concentratednitric acid(HNO3)(sp gr 1.42)with 3 volumes of water.6.10 Potassium Hydroxide Alcoholic,Solution(66 g/L)Dissolve 66 g of potassium hydroxide(KOH)in 1 L ofabsolute ethyl alcohol(Note 1).Allow the solution to standovernight protected against carbon dioxide(CO2)absorption.Filter just before use.7.Procedure7.1 Weigh by difference,from a closed container into t