ASTM_D_1469_-_93.pdf

Designation:D 1469 93Standard Test Method forTotal Rosin Acids Content of Coating Vehicles1This standard is issued under the fixed designation D 1469;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.1.Scope1.1 This test method covers the determination of total rosinacids content of rosin esters,varnishes,and alkyd resins,unmodified by such materials as maleic or fumaric acid,orphenols.Total rosin acids determined include free rosin,esterified rosin,and metallic salts of rosin.1.2 This test method is primarily designed for materialcontaining 0.5 to 5%rosin on the nonvolatile basis.1.3This standard does not purport to address all of thesafety problems,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 1193 Specification for Reagent Water2D 1259 Test Methods for Nonvolatile Content of ResinSolutions3D 1644 Test Methods for Nonvolatile Content of Varnishes33.Summary of Test Method3.1 The specimen is saponified with potassium hydroxide-ethylene glycol reagent and acidified with hydrochloric acid.Heat is applied to hydrolyze metallic driers.This is necessary,especially when metallic rosinates are present.3.2 The mixture described in 3.1 is extracted with benzene(Note 1).The rosin and fatty acids and unsaponifiables passinto the benzene layer.The aqueous layer will contain certaindibasic acids,polyhydric alcohols,and other water-solubleproducts of saponification.NOTE1While it has not been evaluated for this procedure,toluene hasbeen found to be an acceptable alternative in similar procedures.3.3 The benzene is removed by evaporation,the residueweighed,and the rosin acids are determined by a selectiveesterification and titration method.44.Apparatus4.1 Air Condenser,30 in.(760 mm),with a 24/40 standard-taper joint.4.2 Buret,automatic type,having a capacity of 25 mL,forthe standard potassium hydroxide solution,fitted with soda-lime traps to protect against absorption of atmospheric carbondioxide(CO2).4.3 Erlenmeyer Flasks,250 and 500-mL capacity,with24/40 ground joint.4.4 Separatory Funnels,three of 1-L capacity.4.5 Steam Bath,located in a fume hood,for evaporation ofvolatile solvents.4.6 Moisture Collection Trap,constructed according todetails shown in Fig.1.Wrap with12-in.(12.7-mm)asbestostape.4.7 Pipet,automatic,50-mL capacity.55.Reagents and Materials5.1 Purity of ReagentsReagent 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.6Other 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.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type II of Specification D 1193.5.3 Benzene(Toluene may be an acceptable substitute,seeNote 1.)5.4 Butyl Alcohol-Sulfuric Acid Esterification ReagentAdd 500 mL of n-butyl alcohol,500 mL of benzene,and 3.3mL(6 g)of sulfuric acid(H2SO4)to a 2-L round-bottom flaskwith ground joint,connect to a moisture trap and condenser,and reflux on a hot plate for 30 min to distill out the water and1This test method is under the jurisdiction of ASTM Committee D-1 on 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 D1469 57 T.Last previous edition D1469 73(1988)e1.2Annual Book of ASTM Standards,Vol 11.01.3Annual Book of ASTM Standards,Vol 06.01.4Linder,A.,and Persson,V.,“Determination of Rosin Acids in Mixtures withFattyAcids,”Journal,Am.Oil Chemists Soc.,Vol XXXIV,No.1,1957,pp.2427.5Pipets obtainable from the Arthur H.Thomas Co.,W.Washington Square,Philadelphia,PA 19105 Catalog No.8212,or from the Scientific Glass ApparatusCo.,Catalog No.JP-6000,have been found satisfactory for this purpose.6Reagent 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.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.to form butyl-sulfuric acid.Cool and store in a glass-stopperedbottle.5.5 Ethyl Alcohol,c