ASTM_D_1469_-_00.pdf

Designation:D 1469 00Standard 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 the rosinacids content of rosin,unmodified by such materials as maleicor fumaric acid,or phenols.Rosin acids determined by this testmethod include free rosin.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3This 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.Summary of Test Method2.1 The rosin acids content of tall oil rosin and relatedproducts is determined from a titration of the residual acidity ofa specimen after first selectively esterifying any fatty acids,which may be present.2.2 The specimen is refluxed in a solution of cyclohexaneand butylsulfuric acid,with continuous removal of the water ofesterification.The residual acidity,which consists of the rosinacids and the butyl sulfuric acid catalyst,is then titrated;areagent blank is treated in the same manner and titrated todetermne the amount of acid catalyst.The percent rosin acidsis calculated as the difference between the two titrations2.2.3 This test method is applicable over the entire range ofrosin acids-fatty acids concentrations.3.Apparatus3.1 Air Condenser,760 mm(30 in.),with a 24/40 standard-taper joint.3.2 Buret,self-zeroing,ClassA,having a capacity of 25 mL,for the standard potassium hydroxide solution,fitted withsoda-lime traps to protect against absorption of atmosphericcarbon dioxide(CO2).3.3 Erlenmeyer Flasks,250-mLcapacity,with 24/40 groundjoint.3.4 Moisture Collection Trap,Bidwell-Sterling,5mL ca-pacity,with 24/40 joints.Wrap with insulating tape.3.5 Dispensing Pipet,50-mL capacity,repeatability or re-producibility of#0.1%.4.Reagents and Materials4.1 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.3Other 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.4.2 Cyclohexane.4.3 n-Butyl Alcohol.4.4 Butyl Alcohol-Sulfuric Acid Esterification ReagentAdd 500 mL of n-butyl alcohol,500 mL of cyclohexane,and3.3 mL(6 g)of concentrated sulfuric acid(H2SO4)to a 2-Lround-bottom flask with ground joint,connect to a moisturetrap and condenser;then reflux on a hot plate for 30 min todistill out the water and to form butyl-sulfuric acid.Cool andstore in a glass-stoppered bottle.4.5 Potassium Hydroxide,Alcoholic Standard Solution,0.5N(13.3 g/L)Dissolve 13.3 g of KOH pellets in 1 L of ethylalcohol.Standardize against potassium acid phthalate primarystandard.4.6 Sulfuric Acid(sp gr 1.84)Concentrated sulfuric acid(H2SO4).4.7 Thymol Blue Indicator Solution(10 g/L)Mix 1 g ofthymol blue indicator with 100 mL of ethyl alcohol.5.Procedure5.1 Transfer to a 250-mL Erlenmeyer flask 1.0 to 1.2 g ofsample,weighed to the nearest 0.0001 g.5.2 Using a dispensing pipet,accurately measure 50 mL ofthe esterification reagent into the flask.Connect the flask to themoisture collection trap and condenser,place on a hot plate,heat to boiling,and reflux for 20 min AFTER the first drop of1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.34 on Naval Stores.Current edition approved Nov.10,2000.Published January 2001.Originallypublished as D1469 57 T.Last previous edition D1469 93.2Linder,A.,and Persson,V.,“Determination of Rosin Acids in Mixtures withFattyAcids,”Journal,Am.Oil Chemists Soc.,Vol XXXIV,No.1,1957,pp.2427.3Reagent 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.NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.liquid falls