1、Designation:D427318Standard Test Method forPolyurethane Raw Materials:Determination of PrimaryHydroxyl Content of Polyether Polyols1This standard is issued under the fixed designation D4273;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revi
2、sion,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.Scope*1.1 Carbon-13 Nuclear Magnetic Resonance Spectroscopy(13C NMR)measures the primary hydroxyl content of ethyle
3、neoxide(EO)-propylene oxide(PO)polyether polyols used inpreparing flexible polyurethane foams.This method is bestsuited for polyether polyols with primary hydroxyl contents of10 to 90%.1.2 The values stated in SI units are to be regarded asstandard.1.3 This standard does not purport to address all o
4、f 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.NOTE1There is no known ISO equivalent to this standard.
5、1.4 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
6、Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2977 Practice for Measuring and Reporting Performance ofFourier-Transform Nuclear Magnetic Resonance(FT-
7、NMR)Spectrometers for Liquid Samples3.Terminology3.1 DefinitionsFor definitions of terms that appear in thismethod,refer to Terminology D883 and Practice E2977.4.Summary of Test Method4.1 Peaks of the primary and secondary hydroxyl carbons ofpolyether polyols used in flexible polyurethane foams arew
8、ell-resolved in high-resolution13C NMR spectra.The pri-mary hydroxyl content is determined from the ratio of theprimary hydroxyl area to the total hydroxyl(primary andsecondary)area.5.Significance and Use5.1 The primary hydroxyl content provides informationabout the relative reactivities of polyols.
9、6.Interferences6.1 Primary hydroxyl PO methylene carbons(where themethylene carbon is next to the hydroxyl group and themethine carbon is next to the ether oxygen)are integrated withthe secondary hydroxyl carbons and are therefore not includedin the primary hydroxyl content as measured by this metho
10、d.7.Apparatus7.1 Fourier-Transform NMR(FT-NMR)Spectrometer,withcarbon-13 capability and a carbon-13 resonance frequency of50 MHz(proton resonance frequency of 200 MHz)or higher.The spectrometer is to have a minimum carbon-13 signal-to-noise ratio of 70:1 based on the benzene carbon signal in a60%ben
11、zene-d6,40%p-dioxane(v/v)sample(ASTM NMRstandard)that has been pulsed once using a 90 pulse angleunder the conditions specified in Practice E2977.7.2 NMR sample tubes having outside diameters of 5 mm ormore.7.3 NMR spinners.8.Reagents and Materials8.1 All reagents are to be spectroscopic-grade and f
12、ree ofmagnetic materials.8.1.1 Deuterated chloroform or deuterated acetone,con-taining tetramethylsilane(TMS)as an internal standard.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.22 on Cellular Materials-Plastics and
13、 Elastomers.Current edition approved April 1,2018.Published April 2018.Originallyapproved in 1983.Last previous edition approved in 2011 as D4273-11.DOI:10.1520/D4273-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual B
14、ook of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international stan
15、dard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 9.Hazar
16、ds9.1 Magnetic FieldsFollow the manufacturers recom-mendation for the safe operation of the instrument.9.1.1 Persons with implanted or attached medical devicessuch as pacemakers and prosthetic parts must remain outsidethe 5-gauss perimeter.9.1.2 Objects made of ferromagnetic material will be at-tracted to the magnet and are to be kept a safe distance away.10.Preparation of Apparatus10.1 Prepareaprotondecoupledcarbon-13NMRexperiment,selecting appropriate parameters to obtain quanti-tative integra
