ASTM_D_3876_-_96_2021.pdf

Designation:D387696(Reapproved 2021)Standard Test Method forMethoxyl and Hydroxypropyl Substitution in Cellulose EtherProducts by Gas Chromatography1This standard is issued under the fixed designation D3876;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is applicable to the determination ofmethoxyl and hydroxypropyl substitution content in celluloseether products by a Zeisel-gas chromatographic technique.1.2 This test method is not suitable for use for the analysisof hydroxypropyl-cellulose due to its very high substitutionlevel.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific hazard statements,see Section 2,11.1.4,and11.1.7.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Summary of Test Method2.1 When methyl cellulose or hydroxypropyl methyl cellu-lose is reacted with hydriodic acid,1 mol of methyl iodide and1 mol of isopropyl iodide are liberated for each mole ofmethoxyl and hydroxypropoxyl that is substituted on thecellulose chain.The methyl iodide and isopropyl iodide areextracted in situ with o-xylene and quantitated by gas chroma-tography using an internal standard technique.3.Significance and Use3.1 This test method determines the methoxyl and hydroxy-propoxyl content of cellulose ethers by a Zeisel-gas chromato-graphic technique.3.2 Substitution levels affect solution properties,rheology,viscosity,and many other properties of the polymer.4.Apparatus4.1 Gas Chromatograph,2with thermal conductivity detec-tor and heated injection port.4.2 Electronic Integrator.34.3 Stainless Steel Tubing,49.5 mm in outside diameter and1981 mm in length,packed with reagent in 5.8.4.4 Syringes,10 and 100 L.4.5 Reaction Vials,Caps,and Heating Block.55.Reagents5.1 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 o-Xylene,ACS.5.3 Toluene,ACS.5.4 Iodomethane,99%min.5.5 2-Iodopropane,97%min.5.6 Hydriodic Acid(sp.gr.1.69 to 1.70)57%.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved June 1,2021.Published June 2021.Originallyapproved in 1979.Last previous edition approved in 2013 as D3876 96(2013).DOI:10.1520/D3876-96R21.2Hewlett-Packard Model 5700,available from Hewlett-Packard,Route 41,StarrRd,P.O.Box 900,Avondale,PA19311,has been found satisfactory for this purpose.3Hewlett-Packard Model 3380 has been found satisfactory for this purpose.4Tubing from Supelco,Inc.,Supelco Park,Bellefonte,PA16823 has been foundsatisfactory for this purpose.5Reacti-therm Heating module,Reacti-Block Reacti-vials and Mininert valvetops from Pierce Chemical Co.,Box 117,Rockford,IL 61105 have been foundsatisfactory for this purpose.6ACS Reagent Chemicals,Specifications and Procedures for Reagents andStandard-Grade Reference Materials,American Chemical Society,Washington,DC.For suggestions on the testing of reagents not listed by the American ChemicalSociety,see Analar Standards for Laboratory Chemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeia and National Formulary,U.S.Pharma-copeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.15.7 Acetone.5.8 Packing Material.76.Hazards6.1 Safety precautions must be taken for handling of hydri-odic acid.6.2 During the reaction,the glass vials are under pressure.Exercise caution in handling the hot vials.7.Samplin