ASTM_D_3133_-_01_2005.pdf

Designation:D 3133 01(Reapproved 2005)Standard Test Method forQuantitative Determination of Cellulose Nitrate in AlkydModified Lacquers by Infrared Spectrophotometry1This standard is issued under the fixed designation D 3133;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 quantitative determinationof the content of cellulose nitrate(also known as nitrocellulose)in lacquers containing alkyd resins.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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.For a specifichazard statement,see 7.1.1.2.Referenced Documents2.1 ASTM Standards:2D 1644 Test Methods for Nonvolatile Content of VarnishesD 2372 Practice for Separation of Vehicle from Solvent-Reducible PaintsE 168 Practices for General Techniques of Infrared Quanti-tative AnalysisE 275 Practice for Describing and Measuring Performanceof Ultraviolet,Visible,and Near-Infrared Spectrophotom-eters3.Summary of Test Method3.1 The method of standard additions is employed.Incre-ments of cellulose nitrate,in solution,are added to aliquots ofthe sample.Absorbance measurements are made of the band at11.8 m(848 cm1)for each addition.The original content isthen calculated from absorbance versus concentration.4.Significance and Use4.1 Coating compositions based on a mixture of syntheticresins and cellulose nitrate dissolved in organic solvents arequantitatively analyzed for the cellulosic derivative withoutisolating it.The test method is applicable to lacquers for whichthe grade of nitrocellulose is known and available.Othercellulosics,alkyd resins,many vinyl resins,and solvents do notinterfere.Components,such as acrylic resins and some vinylpolymers,that absorb infrared near 11.8 m(848 cm1)interfere with the determination.High boiling ester solvents,inparticular methyl cellosolve acetate,may also interfere with thedetermination if not removed in the evaporation procedure(see8.3).5.Apparatus5.1 Infrared Spectrophotometer,automatic recording,double-beam.Most infrared spectrophotometers operate from2.5 to 15 m(4000 to 650 cm1),but in this test method onlythe range between 10 to 14 m(1000 and 750 cm1)is used.See Practices E 168.5.2 Absorption Cells,sealed,with sodium chloride(NaCl)windows,0.1-mm path length,one pair approximatelymatched.5.3 Film Vacuum Evaporator,rotary thin or equivalentapparatus,to obtain redissolvable lacquer solids without de-composition of the cellulose nitrate.5.4 Oven,vacuum drying,thermostatically controlled tooperate at 65 6 2 C.6.Reagents6.1 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,1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.55 on Factory Applied Coatings on Preformed Products.Current edition approved May 15,2005.Published June 2005.Originallyapproved in 1972.Last previous edition approved in 2001 as D 3133 01.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.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.6.2 Cellulose Nitrate,of the same grade as in the sample.6.3 N,N-Dimethylacetamide(DMA),spectrograde quality.6.4 Nitrogen Gas,dry.7.Standard Solution7.1 Thoroughly dry a quantity of cellulose nitrate at 65C,in the vacuum oven(7.1.1).Transfer 4000 g,weighed to 0.1mg,to a 200-mLvolumetric flask.Add DMA,shake to dissolvethe cellulose nitrate,and dilute to volume with DMA.Onemillilitre of solution is equivalent to 20 mg of cellulose nitrate.7.1.1 Warning;Every precaution must be exercised in thehandling and drying of cellulose nitrate because of its explo-sive nature.No more than 15 g should be dried at any one time.8.Procedure8.1 If the material is pigmented,remove the pigment quan-titatively in accordance with Practice D 2372,and proceed withthe determina