1、Designation:D387696(Reapproved 2013)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
2、 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 substitu
3、tion 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 w
4、ith 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 specific hazardstatements,see Section 2,11.1.4,and 11.1.7.2.Summary of Test Method2.1 When methyl cellulo
5、se 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
6、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
7、,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 Re
8、action 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 s
9、pecifications 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 Aci
10、d(sp.gr.1.69 to 1.70)57%.5.7 Acetone.5.8 Packing Material.76.Hazards6.1 Safety precautions must be taken for handling of hydri-odic acid.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcom
11、mittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved June 1,2013.Published June 2013.Originallyapproved in 1979.Last previous edition approved in 2007 as D3876 96(2007).DOI:10.1520/D3876-96R13.2Hewlett-Packard Model 5700,available from Hewlett-Packard,Route 41,StarrRd,P.O.Bo
12、x 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 an
13、d Mininert valvetops from Pierce Chemical Co.,Box 117,Rockford,IL 61105 have been foundsatisfactory 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 Societ
14、y,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.7Columns packed with 10%SP2100 on 100/120 Supelcoport have been foundsatisfactory for this purpose.Copyright ASTM In
15、ternational,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2 During the reaction,the glass vials are under pressure.Exercise caution in handling the hot vials.7.Sampling7.1 A specific sampling method is currently under study bythe subcommittee.8.Apparatus Preparat
16、ion and Conditioning8.1 Install prepackaged columns in the chromatograph andcondition them by heating to 150C over 1 h and then holdingat temperature for 16 h.Then set the chromatograph asfollows:8Oven temperature130C isothermalInjection port temperature200CDetector temperature250CDetector current170 mAAttenuation1Carrier gasheliumColumn A20 mL/minColumn B20 mL/minNOTE1The conditions used here were determined to be optimum forthe column used.Optimum conditions should be determined for eachcolumn