ASTM_D_1109_-_21.pdf

Designation:D110921Standard Test Method for1%Sodium Hydroxide Solubility of Wood1,2This standard is issued under the fixed designation D1109;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 covers the determination of the solu-bility of wood in a hot dilute alkali solution.A1%solution ofsodium hydroxide(NaOH)is used.One application is indetermining the degree of fungus decay that has taken place ina given wood sample.As the wood decays,the percentage ofalkali-soluble material increases in proportion to the decreasein pulp yield caused by the decay.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3 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.Significance and Use2.1 Hot alkali extracts low molecular weight carbohydratesconsisting mainly of hemicellulose and degraded cellulose inwood.This solubility of wood is an indication of the degree offungal decay,or degradation by heat,light,oxidation,and soforth.The more decay or degradation,the higher the solubility.3.Apparatus3.1 Water BathThe water bath shall be designed so thatthe temperature of the material during treatment is uniformlymaintained at 97 to 100 C.When a new bath is used thetemperature shall be checked to ensure the use of properconditions(see Note 1).NOTE1The type of bath recommended is one that is covered and thathas holes in the top of such size that beakers may be set down in the bathuntil they are supported by the flared rim of the beakers.The top of thebeaker is recommended to be nearly level with the cover of the bath.Byusing this type of bath the sides of the beakers are entirely surrounded byboiling water or steam.The water level in the bath is recommended to bemaintained above the level of the liquid in the beakers.3.2 BeakersThe beakers shall be tall-form,200-mL,alkali-resistant glass3beakers.3.3 Filtering CruciblesAlundum or fritted-glass cruciblesof medium porosity are recommended for filtering the treatedsawdust.4.Reagents4.1 Sodium Hydroxide Solution(1.0%)Allow a chemi-cally pure NaOH solution(50%)to stand about 1 week in astoppered vessel to permit settling of Na2CO3and otherinsoluble impurities.Dilute the supernatant clear solution withdistilled water free of CO2(see Note 2)and adjust to between0.9 and 1.1%NaOH.NOTE2It is difficult to make water totally free of CO2and deareatedwater is recommended since a high CO2content will convert NaOH toNa2CO3which will alter the titration value.A titration against a standardHCl solution can check the NaOH content,Water with very low CO2highcontent can be made by boiling the water and keeping it in a stopperedvessel.4.2 Acetic Acid(10%).5.Test Specimen5.1 The test specimen shall consist of air-dried sawdust ormilled wood that has been ground to pass a 425-m(approx.40mesh)sieve and be retained on a 250-m(approx.60 mesh)sieve.The weight of the test specimen shall be such that it willbe equivalent to 2 6 0.1 g of moisture-free wood.6.Procedure6.1 Place two test specimens in 200-mL,tall-form beakersand add to each 100 mL of NaOH solution(1%)measuredcarefully with a graduated cylinder.After stirring well,placethe covered beakers in the water bath,which shall be boilingsteadily.Leave the beakers in the bath for exactly 1 h,stirringthe contents three times,at periods of 10,15,and 25 min afterthe beakers are placed in the bath.6.2 At the end of 1 h,filter the contents of each beaker bysuction using a tared crucible.Wash the wood with 100 mL of1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.01 on Fundamental TestMethods and Properties.Current edition approved April 1,2021.Published April 2021.Originallyapproved in 1950.Last previous edition approved in 2013 as D1109 84(2013).DOI:10.1520/D1109-21.2Based upon Technical Association of the Pulp and Paper Industry StandardMethod T 212 om-18.One percent sodium hydroxide solubility of wood and pulp.3Borosilicate glass has been found satisfactory for this purpose.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 Deci