ASTM_D_2081_-_92_1998.pdf

Designation:D 2081 92(Reapproved l998)Standard Test Method forpH of Fatty Quaternary Ammonium Chlorides1This standard is issued under the fixed designation D 2081;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 method was prepared jointly by the American Society for Testing and Materials and the American Oil Chemists Society.1.1Scope1.1 This test method covers the preparation of 5%solutionsof fatty quaternary ammonium chlorides and the determinationof their pH.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 establishappropriate safety and health practices and determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water2D 2079 Test Method for Nonvolatile Matter(Solids)inFatty Quaternary Ammonium Chlorides3E 70 Test Method for pH of Aqueous Solutions With theGlass Electrod43.Apparatus3.1 GlassElectrodepHMeter,conformingtotherequirements of Test Method E 704.3.2 Magnetic Stirrer,with inert plastic-coated stirring bar.4.Reagents4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of theCommittee on Analytical Reagents of the American ChemicalSociety,where such specifications are available.5Other gradesmay be used,provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination.4.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Specification D 1193,Type II.4.3 Isopropyl Alcohol Solution(1+1)Mix equal volumesof isopropyl alcohol(99%)and water.5.Standardization of pH Meter5.1 Carefully follow the manufacturers instructions for theparticular meter used and standardize at a pH of 7.0.6.Procedure6.1 Determine the percent of nonvolatile matter(solids)asdirected in Method D 2079.6.2 Determine the specimen weight based on the percent ofnonvolatile matter needed to make 200 g of a 5%solution asfollows:Grams of sample 5200 3 5!%of nonvolatile matter(1)6.3 Melt the sample if it is not already liquid,in a waterbath.Mix thoroughly,and weigh the proper amount into a250-mL low-form beaker.Add 100 g of isopropyl alcoholsolution and warm,if necessary,to dissolve the specimen.Coolto room temperature and add enough isopropyl alcohol solutioninto the beaker to make a total of 200 g of isopropyl alcoholsolution and specimen.6.4 Adjust the beaker so that the lower half of eachelectrode of the pH meter is immersed in the solution.Start thestirrer and adjust the speed so that there is vigorous stirringwith no spattering.Read the pH as soon as the instrumentshows a steady reading.NOTE1Most commercial fatty quaternary ammonium chlorideproducts contain small amounts of dissolved methyl chloride thathydrolyzes to hydrochloric acid which gradually decreases the pH of agiven material on storage.Differences in pH values determined at differenttimes or in different laboratories may be due in part to this factor.7.Report7.1 Report the results to the nearest 0.1 pH unit.8.Precision and Bias8.1 Precision and bias were not established at the time thistest method was written.An effort is being made to obtain theprecision and,if obtainable,it will be published in future1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.32 on Drying Oils.Current edition approved March 15,1992.Published May 1992.Originallypublished as D 2081 62 T.Last previous edition D 2081 64(1987).2Annual Book of ASTM Standards,Vol 11.01.3Annual Book of ASTM Standards,Vol 06.03.4Annual Book of ASTM Standards,Vol 15.05.5Reagent 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 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 ASTMrevisons.This test method has been in use for many years,andits usefulness has been well established.9.Keywords9.1 pH;quaternary ammonium chloridesThe American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard.Users of this standa