1、Designation:D 2998 89(Reapproved 1996)e1Standard Test Method forPolyhydric Alcohols in Alkyd Resins1This standard is issued under the fixed designation D 2998;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.
2、A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.e1NOTEEditorial changes were made throughout in November 1996.1.Scope1.1 This test method covers the qualitative and quantitativedetermination of t
3、he polyols in alkyl resins,including resin-and polymer-modified alkyds.Quantities as low as 0.5%maybe detected and measured.1.2 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.3 This standard does not purport to addres
4、s 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.For a specifichazard statement,see Section 7.2.Referenced Docu
5、ments2.1 ASTM Standards:D 1193 Specification for Reagent Water2E 260 Practice for Packed Column Gas Chromatography33.Summary of Test Method3.1 The resin sample is dried,subjected to aminolysis torelease the polyols,treated directly to form the trimethylsilyl(TMS)ether derivatives of the polyhydric a
6、lcohols which areseparated by gas-liquid chromatography.An internal standardis used for quantitative purposes.The description of apparatusand the recommended operating conditions are presented as aguide to a satisfactory analysis as all suitable variations intemperatures,column lengths,substrates,li
7、quid phases,pro-gramming rates,etc.,have not been determined.4.Significance and Use4.1 This test method is designed to identify polyhydricalcohols and to quantify amounts of polyols contained in alkylresins.Polyols are significant ingredients in alkyl resins andimpact on such important physical para
8、meters of alkyd paintsas weatherability,flexibility,moisture resistance,and adhesion.Use of this test method will provide a means whereby therelative applicability of the alkyd resin to the particular end usemay be estimated by the buyer and the seller.5.Apparatus5.1 LinearProgrammedTemperatureGasCh
9、romatographAny instrument with a thermal conductivitydetector and with programming features should be suitable ifadaptable to the following recommended operating conditions:Detector cell temperature,C300Detector cell current,mA160Injection port temperature,C300Helium flow at exit,cm3/min80Programmed
10、 temperature details:Approximate column heating rate,C/min6Starting column temperature,C100Finishing column temperature,C300NOTE1Flame ionization detectors are not recommended for this testas the reaction medium can contaminate the flame jet.5.2 ColumnA 16-ft(4.9-m)length of14-in.(6.4-mm)outside dia
11、meter copper tubing packed with 20 weight percentof silicone grease on 60 to 80-mesh white flux-calcineddiatomaceous earth,4and conditioned at 315C until“bleed-ing”reaches a minimum.5.3 Column and Instrument PerformanceNote the sepa-ration of closely adjacent polyol peaks and express as peakresoluti
12、on R as follows:R 5 2Y/A 1 B!(1)where:Y5 distance between maxima of closely adjacent peaks,A5 base width of first peak A,andB5 base width of peak B.NOTE2If the peak resolution is equal to or greater than 1.0,thecolumn and instrument are in satisfactory condition.5.4 Syringe,having a fixed needle,50-
13、L capacity.5.5 Erlenmeyer Flask,125-mL,with standard joint andwater-cooled condenser to fit.5.6 Micro Test Tube or screw cap vial.1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee
14、D01.33 on Polymers and Resins.Current edition approved April 28,1989.Published June 1989.Originallypublished as D2998 71.Last previous edition D2998 71(1981)e1.2Annual Book of ASTM Standards,Vol 11.01.3Annual Book of ASTM Standards,Vol 14.02.4The sole source of supply of the flux-calcined diatomaceo
15、us earth,ChromosorbW known to the committee at this time is Celite Corp.,P.O.Box 5108,Denver,CO80217-5108.If you are aware of alternative suppliers,please provide this informa-tion to ASTM Headquarters.Your comments will receive careful consideration at ameeting of the responsible technical committe
16、e,1which you may attend.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTM6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.5Other grades may beused,provided