ASTM_D_3971_-_89_2010.pdf

Designation:D397189(Reapproved 2010)Standard Test Method forDichloromethane-Soluble Matter in Cellulose1This standard is issued under the fixed designation D3971;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 Thistestmethodcoversthedeterminationofdichloromethane-soluble matter in cellulose and is applicableto dissolving-type cellulose pulps prepared from cotton orwood.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.2.Referenced Documents2.1 ASTM Standards:2D1348 Test Methods for Moisture in Cellulose3.Summary of Test Method3.1 Asample is extracted with dichloromethane in a Soxhletapparatus as a measure of the waxes,fats,resins,and oilspresent.4.Significance and Use4.1 Dichloromethane-soluble materials are typically re-ferred to as extractives.These extractives are comprised oforganic materials that originated in the wood or cotton.Themeasure is an indication of the efficiency of removal of thesesubstances during pulping and bleaching.The extractive levelis of concern to dissolving pulp users since the presence oflarge amounts of extractives could inhibit the processing ofcellulose into the desired derivative.5.Apparatus5.1 Extraction Apparatus:5.1.1 Soxhlet.5.1.2 Flask,250-mL.5.1.3 Extractor Tube,with standard taper 45/50 top joint.5.1.4 Allihn Standard Taper,45/50 or5.1.5 Friedrichs Standard Taper,45/50 type condenser.5.2 Extraction Thimble,either(1)standard thickness paper,43 by 123 mm,(2)aluminum oxide,34 by 100 mm,mediumporosity,or(3)glass with coarse-porosity fritted-glass disk,45by 130 mm.5.3 Heating DeviceSteam bath or heating mantle.5.4 Oven,maintained at 105 6 3C.5.5 Dish,evaporating,disposable,light aluminum,63 mmin diameter by 17.5 mm deep.5.6 Desiccator with efficient desiccant.6.Reagent6.1 Dichloromethane,ACS,99%CH2Cl2,having a residueafter evaporation of less than 0.002%.7.Procedure7.1 Weigh 8 to 12 g of loose pulp,to the nearest 0.01 g,intoan extractor thimble that has previously been extracted withdichloromethane.For sheet pulp,cut a sample into strips about10 mm wide and 70 mm long,and weigh about 20 g into athimble.Weigh a separate portion for a moisture determinationin accordance with Test Methods D1348.7.2 Place the extraction thimble with sample in the extractorand connect the flask.Pour 250 mLof the dichloromethane intothe body of the extractor.Connect the assembled extractor tothe condenser and place the flask in the heating device.Turn onthe cooling water to the condenser and adjust the heating rateto cause siphoning 6 to 8 times per hour.Continue theextraction for 5 h.7.3 Heat the evaporating dish in the oven at 105C for 30min,cool in a desiccator,and weigh to the nearest 0.1 mg.7.4 When the extraction is complete,disconnect the flask ata time when most of the solvent has collected in the extractor.Partially evaporate the solvent in the extraction flask to a1This 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 1,2010.Published July 2010.Originally approvedin 1980.Last previous edition approved in 2004 as D3971 89(2004).DOI:10.1520/D3971-89R10.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 volume of 15 to 20 mL.Transfer the extract to the taredweighing dish by washing with three 5-mL portions of freshsolvent.7.5 Place the dish on a steam hot plate and evaporate just todryness.Then place the dish in the oven at 105C for 1 h,coolin a desiccator,and weigh to the nearest 0.1 mg.(WarningCare must be taken to keep the steam hot plate surface cleanin order to prevent contamination of the bottom of thealuminum dish and a subsequent unmeasured increase in tareweight.)7.6 Run a blank determination with the solvent used in thetest.Evaporate 250 mL of the solvent to dryness and weigh theresidue to the nearest 0.1 mg.Correct the weight of the driedextract by the weight of residue found.8.Calculation8.1 Calculate the percent of dichloromethane-solublematter,D,on the dry basis as follows:D 5We2 Wb!/Ws1002 M!/1003100w