1、Designation: D3971 89 (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
2、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 covers the determination ofdichloromethane-soluble matter in cellulose and is applicableto dissolving-type
3、 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 o
4、f 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 dich
5、loromethane 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
6、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 App
7、aratus: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, me
8、diumporosity, 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 Di
9、chloromethane, 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
10、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
11、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 desiccat
12、or, and weigh to the nearest 0.1 mg.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, 2010. Publish
13、ed 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,
14、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.7.4 When the extraction is complete, disconnect the flask ata time when most of the solvent has collected in the extracto
15、r.Partially evaporate the solvent in the extraction flask to avolume 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
16、h, coolin a desiccator, and weigh to the nearest 0.1 mg. (WarningCare must be taken to keep the steam hot plate surface clean inorder to prevent contamination of the bottom of the aluminumdish and a subsequent unmeasured increase in tare weight.)7.6 Run a blank determination with the solvent used in
17、 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-soluble mat-ter, D, on the dry basis as follows:D 5 We2 Wb!/Ws100 2 M!/100
18、 3 100where:We= oven-dry weight of extract, g,Wb= oven-dry weight of solvent blank determined in 7.6,g,Ws= weight of sample, g, andM = moisture in sample, % (Test Methods D1348).9. Report9.1 Report the dichloromethane-soluble matter to the near-est 0.01 %.10. Precision and Bias10.1 Results of a roun
19、d robin study by five laboratoriesshowed that for a content of 0.20 % extractives the relativestandard deviation was 10 %. For samples at the 0.15 % levelthe relative standard deviation was 7 %.10.2 No statement of bias can be made as no suitablereference material exists for determining bias.11. Key
20、words11.1 dissolving types of cellulose pulps; extractives; fat;removal efficiency of bleaching and pulping; resin; soxhlet;waxASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are
21、expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not re
22、vised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you
23、may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United S
24、tates. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3971 89 (2010)2
