1、Designation: D 3971 89 (Reapproved 2004)Standard Test Method forDichloromethane-Soluble Matter in Cellulose1This standard is issued under the fixed designation D 3971; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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-t
3、ype cellulose pulps prepared from cotton orwood.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 establish appro-priate safety and health practices and determine the applica-bility of reg
4、ulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1348 Test Methods for Moisture in Cellulose3. Summary of Test Method3.1 A sample is extracted with dichloromethane in a Soxhletapparatus as a measure of the waxes, fats, resins, and oilspresent.4. Significance and Use4.1 D
5、ichloromethane-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 c
6、oncern 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 Standar
7、d 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
8、 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
9、 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
10、 Test Methods D 1348.7.2 Place the extraction thimble with sample in the extractorand connect the flask. Pour 250 mL of 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 conden
11、ser 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 t
12、he solvent has collected in the extractor.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 p
13、lace 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 clean in1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is t
14、he direct responsibility ofSubcommittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved June 1, 2004. Published June 2004. Originallyapproved in 1980. Last previous edition approved in 1999 as D 3971 89 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.or
15、g, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, 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.order to prev
16、ent 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 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 th
17、e 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 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 = moistu
18、re in sample, % (Test Methods D 1348).9. Report9.1 Report the dichloromethane-soluble matter to the near-est 0.01 %.10. Precision and Bias10.1 Results of a round robin study by five laboratoriesshowed that for a content of 0.20 % extractives the relativestandard deviation was 10 %. For samples at th
19、e 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. Keywords11.1 dissolving types of cellulose pulps; extractives; fat;removal efficiency of bleaching and pulping; resin; soxhlet;waxASTM Internat
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23、ds, 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 States. 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).D 3971 89 (2004)2
