ASTM_D_1109_-_84_2013.pdf

Designation:D110984(Reapproved 2013)Technical Association of Pulp and Paper IndustryStandard Method T 212 os-76Standard Test Method for1%Sodium Hydroxide Solubility of Wood1This 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 and health practices and determine the applica-bility of regulatory limitations prior to use.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 100C.When a new bath is used thetemperature shall be checked to ensure the use of properconditions.The type of bath recommended is one that iscovered and that has holes in the top of such size that beakersmay be set down in the bath until they are supported by theflared rim of the beakers.The top of the beaker shall be nearlylevel with the cover of the bath.By using this type of bath thesides of the beakers are entirely surrounded by boiling water orsteam.The water level in the bath shall be maintained abovethe level of the liquid in the beakers.3.2 BeakersThe beakers shall be tall-form,200-mL,alkali-resistant glass2beakers.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 CO2and adjust to between 0.9 and 1.1%NaOH.4.2 Acetic Acid(10%).5.Test Specimen5.1 The test specimen shall consist of air-dried sawdust thathas been ground to pass a 425-m sieve and be retained on a250-m sieve.The weight of the test specimen shall be suchthat it will be 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 graduate.After stirring well,place the coveredbeakers in the water bath,which shall be boiling steadily.Leave the beakers in the bath for exactly 1 h,stirring thecontents three times,at periods of 10,15,and 25 min after thebeakers are placed in the bath.6.2 At the end of 1 h,filter the contents of each beaker bysuction on a tared crucible.Wash the sawdust with 100 mL ofhot water,then with 50 mL of acetic acid(10%),and thenthoroughly with hot water.Dry the crucible and contents toconstant weight at 100 to 105C,cool in a desiccator,andweigh in a stoppered weighing bottle.7.Calculation and Report7.1 Report the results as weight percentage of matter solublein 1%sodium hydroxide solution,on the moisture-free basis,calculated as follows:1This 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 Aug.1,2013.Published August 2013.Originallyapproved in 1950.Last previous edition approved in 2007 as D1109 84(2007).DOI:10.1520/D1109-84R13.2Borosilicate glass has been found satisfactory for this purpose.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Matter soluble in caustic soda,%5W12 W2!/W1#3100(1)where:W1=weight of moisture-free wood in specimen prior totest(Section 5),andW2=weight of dried specimen after treatment with theNaOH solution(6.2).7.2 Base the results on the average of at least two determi-nations.8.Precision and Bias38.1 Results obtained from an interlaboratory study by ninelaboratories on four woods indicate a repeatability of 0.45 andreproducibility of 1.96.The solubility of the wood samplesranged from 11.2 to 17.0%.8.2 Bias is unknown.9.Keywords9.1decay;fungal decay;sodium hydroxide;solubilityASTM International takes no position respectin