1、Designation: D4875 11Standard Test Methods ofPolyurethane Raw Materials: Determination of thePolymerized Ethylene Oxide Content of Polyether Polyols1This standard is issued under the fixed designation D4875; the number immediately following the designation indicates the year oforiginal adoption or,
2、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. Scope*1.1 Test Method AProton Nuclear Magnetic ResonanceSpectroscopy (1H NMR) measures pol
3、ymerized ethylene oxide(EO) in ethylene oxide-propylene oxide polyethers used inflexible urethane foams and nonfoams. It is suitable for diolsmade from the commonly used initiators and containing EOpercentages above five. For triols initiated with glycerin andtrimethylol propane, an uncorrected EO v
4、alue is obtained sinceboth initiators have protons that contribute to the EO measure-ment.1.2 Test Method BCarbon-13 Nuclear Magnetic Reso-nance Spectroscopy (13C NMR) measures the polymerized EOcontent of ethylene oxide-propylene oxide polyethers used inflexible urethane foams and nonfoams. It is s
5、uitable for diolsand triols made from the commonly used initiators andcontaining EO percentages above five.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concer
6、ns, 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.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 A
7、STM Standards:2D883 Terminology Relating to PlasticsE386 Practice for Data Presentation Relating to High-Resolution Nuclear Magnetic Resonance (NMR) Spectros-copyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 DefinitionsTerminology i
8、n these test methods followsthe standard terminology defined in Terminology D883 andPractice E386.3.2 Definitions of Terms Specific to This Standard:3.2.1 heteric polyol, na polyether polyol in which ethyl-ene oxide and propylene oxide units are randomly arranged.3.2.2 initiator, na substance with w
9、hich ethylene oxide orpropylene oxide reacts to form a polyether polyol.3.2.2.1 DiscussionOne initiator unit is incorporated intoeach polymer or oligomer molecule.3.2.3 EO capped polyola polyol that contains a terminalblock of ethylene oxide units4. Summary of Test Methods4.1 Test Method AThe1H NMR
10、spectra of polyetherpolyols show two groups of resonance peaks corresponding tothe methyl protons of propylene oxide (PO) and to themethylene and methine protons of EO and PO. The EO peakarea is obtained by subtracting the area of the PO methyl peaksfrom the area of the methylene and methine peaks.
11、Initiatorsother than glycols of EO and PO give systematic errors (seeNote 2).NOTE 2The initiator error can be estimated by calculating thetheoretical contribution of initiator protons to the EO and PO peak areas.4.2 Test Method BThe13C NMR spectra of polyetherpolyols contain multiple resonances aris
12、ing from initiator, EO,PO, EO/PO, sequencing, and end-group distribution. EO con-tent can be determined relative to PO or relative to PO and triolinitiator. In the former, the area of the EO peaks is ratioed to thetotal area of PO methylene and methine carbons. In the latter,the area of the EO peaks
13、 is ratioed to the total area of POmethylene and methine carbons and two initiator carbons. Thistest method describes the determination of EO relative to POonly.1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.22 on
14、CellularMaterials - Plastics and Elastomers.Current edition approved April 1, 2011. Published April 2011. Originallyapproved in 1988. Last previous edition approved in 2005 as D4875 - 05. DOI:10.1520/D4875-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custom
15、er Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
16、PA 19428-2959, United States.5. Significance and Use5.1 Measurements of EO content correlate with polyolreactivity (as related to primary hydroxyl content), linearity offoam rise, and the hydrophilicity of the polyol and finalproduct.5.2 Statistical data suggest that the13C NMR test method isthe pre
17、ferred method for measuring low levels (less than 10 %)of polymerized EO in polyols.5.3 The1H and13C NMR test methods give different resultswhich are highly correlated. The equation of the linear regres-sion is:%EOproton5 1.031 %EOcarbon213! 1 0.883 (1)The standard deviation of the regression is 0.4
18、9 and themultiple R-square is 0.9990.TEST METHOD AHYDROGEN-1 NMR6. Equipment6.1 NMR Continuous Wave (CW) or Fourier Transform(FT) Spectrometer, with a1H resonance frequency of 60 MHzor higher.6.2 NMR Sample Tubes, having an outside diameter of atleast 5 mm.7. Reagents and Materials7.1 All reagents a
19、re to be ACS-certified or spectroscopicgrade unless otherwise specified.7.2 Trifluoroacetic Acid.7.3 Chloroform-d1, NMR-grade, containing tetramethylsi-lane as an internal standard.8. Standard8.1 This test method does not require standards. To evaluatethe test method, standards can be prepared from
20、commerciallyavailable poly(propylene oxide) and poly(ethylene oxide).9. Preparation of Sample9.1 Mix a few drops of polyol with deuterated chloroform toprepare 1 mL of an approximately 10 %3polyol solution. Adda drop of trifluoroacetic acid, mix well, and transfer to an NMRtube.10. Instrument Prepar
21、ation10.1 The instrument settings given here are for a VarianEM-390 CW spectrometer, a Varian XL-100 FT spectrometer,and a Bruker AC 300 FT spectrometer. Instrument preparationcan vary with the spectrometer. For a description of a particularspectrometer and suitable parameters, refer to the manufact
22、ur-ers operating manual.10.2 Typical Varian EM-390 console settings are as follows:Lock optional, TMSOffset 0Sweep width 5 ppmSweep time 2 minIntegration time 2 minRf Filter openRF power 0.05 mG10.3 Typical Varian XL-100 console settings are as follows:Lock chloroform-d-1Pulse angle 90Pulse delay 0S
23、pectral width 10 ppmAcquisition time 4 sData points 8KNumber of transients 12810.4 Typical Bruker 300 MHz console settings are asfollows:Lock chloroform-d-1Pulse angle 90Pulse delay 5 sSpectral width 10 ppmAcquisition time 5.3 sData points 32KNumber of transients 6411. NMR Analysis11.1 Place the NMR
24、 tube containing the polyol solution intothe spectrometer probe and optimize the field homogeneity. ForCW NMR, scan the spectrum from 5 to 0 ppm. Integrate thespectrum five times at a power level below that which causessaturation. See Figs. 1 and 2 for examples of polyol spectrawith high and low EO
25、concentrations, respectively.11.2 For FT NMR, acquire the desired number of transientsand transform the free induction decay signal to the frequencydomain spectrum. Integrate the peaks as shown in Figs. 1 and2.11.3 Chemical shifts for the PO methyl proton resonances(area A) range from about 0.6-1.6
26、ppm and chemical shifts forthe EO and PO methylene and methine proton resonances (areaB) range from about 2.8-4.0 ppm12. Calculation12.1 Determine the areas of the PO methyl protons (area A)and the EO and PO methylene and methine protons (area B)from the integrals. Calculate the weight percent EO fr
27、om thefollowing equation:EO 533 3 Z33 3 Z 1 583 100 (2)where:Z =(B/A)133 = g EO/mole after weighting for the number of EOprotons vs. PO protons, and58 = g PO/mole.13. Report13.1 Report results to the nearest tenth percent EO.14. Precision and Bias14.1 Table 1 is based on a round robin conducted in 1
28、981 inaccordance with Practice E691, involving six polyol sampleswith EO content ranging from 6 to 45 weight % (see Table 2)tested by eight laboratories. For each polyol, all of the samplesswere prepared at one source, but the individual specimens wereprepared at the laboratories that tested them. E
29、ach test resultwas obtained from one individual NMR run. Each lab obtainedtwo test results for each material on two separate days.3Highfield, FT spectrometers require less concentrated solutions.A1 % solutionis more appropriate for such spectrometers.D4875 11214.2 In Table 1, for the polyols indicat
30、ed and for test resultsthat are derived from testing two specimens of each polyol oneach of two separate days:14.2.1 Sris the within-laboratory standard deviation of theaverage: Ir= 2.83 Sr(see 14.2.3 for application of Ir).14.2.2 SRis the between-laboratory standard deviation ofthe average; IR= 2.8
31、3 SR(see 14.2.4 for application of IR).14.2.3 RepeatabilityIn comparing two test results for thesame polyol, obtained by the same operator using the sameequipment on the same day, those test results are to be judgednot equivalent if they differ by more than the Irvalue for thatpolyol and condition.1
32、4.2.4 ReproducibilityIn comparing two test results forthe same polyol, obtained by different operators using differentequipment on different days, those test results are to be judgednot equivalent if they differ by more than the IRvalue for thatpolyol and condition. (This applies between different l
33、abora-tories or between equipment within the same laboratory.)14.2.5 Any judgment in accordance with 14.2.3 and 14.2.4will have an approximate 95 % (0.95) probability of beingcorrect.14.2.6 Other polyols can give somewhat different results.14.3 For further information on the methodology used inthis
34、section see Practice E691.14.4 There are no recognized standards on which to base anestimate of bias for this test method.FIG. 11H NMR Spectrum of a Polyol Containing 45 % EOFIG. 21H NMR Spectrum of a Polyol Containing 8 % EOUncorrected for Glycerin InitiatorTABLE 11H Method, % EO Content, for Eight
35、 Laboratories, SixPolyolsSample Mean SrSRIrIR1 10.85 0.3207 1.045 0.898 2.9262 16.40 0.3951 1.086 1.106 3.0413 46.05 1.009 1.680 2.825 4.7044 7.97 0.6809 1.557 1.907 4.3605 13.61 0.5831 1.225 1.641 3.4306 24.64 0.4496 0.5573 1.259 1.560TABLE 2 Description of Samples AnalyzedSampleApproximateMolecula
36、rWeightNominalFunctionalityPolymerized EODistributionApproximateWeight, % EO1 4000 diol cap 102 2800 diol cap 153 4000 diol random/cap 454 3000 triol random 65 3200 triol random 106 6500 triol cap 24D4875 11314.5 Six CW spectrometers (60 and 90 MHz) were used inthis study and two FT instruments (100
37、 MHz). The participat-ing companies were Dow, Union Carbide, Mobay, Texaco,Olin, Arco, and Upjohn.TEST METHOD BCARBON-13 NMR15. Equipment15.1 Fourier-Transform NMR (FT-NMR) Spectrometer,with carbon-13 capability. The spectrometer is to have aminimum signal-to-noise ratio of 70:1.15.2 NMR Sample Tube
38、s, with diameters of 5 mm or more.16. Reagents16.1 All reagents are to be spectroscopic grade deuteratedsolvents.16.2 Deuterated acetone, NMR-grade, containing tetram-ethylsilane (TMS) as an internal standard.17. Standards17.1 This test method does not require standards. Standardsprepared from poly(
39、propylene oxide) and poly(ethylene oxide)can be used to approximate the spectrum of block copolymers.They are not suitable for heteric polyols.18. Preparation of Sample18.1 Mix 3 mL of polyol with 1 to 2 mL of deuteratedacetone. Transfer an appropriate amount to an NMR tube.19. Instrument Preparatio
40、n19.1 Prepare a decoupled carbon-13 experiment, selectingappropriate parameters to obtain quantitative intergration of thepeaks.19.2 The settings presented here apply to a Varian CFT-20spectrometer and a Bruker AC 300 spectrometer. Instrumentsettings for other spectrometers vary. Consult the manufac
41、tur-ers operating manual.19.3 Typical Varian CFT-20 spectrometer parameters are asfollows:Lock acetone d-6Pulse angle 60Acquisition time 2 sPulse delay 0 sSpectral width 2000 HzData points 8KFT transform 8KExponential weighting function 0.8H-1 decoupler on19.4 Typical BrukerAC 300 spectrometer param
42、eters are asfollows:Lock acetone d-6Pulse angle 90Acquisition time 2 sPulse delay 5 sSpectral width 100 ppmData points 32KH-1 decoupler on, or gated decoupling20. NMR Analysis20.1 Place the NMR tube containing the sample solutioninto the spectrometer probe. After a stable lock is obtained,optimize t
43、he field homogeneity. Acquire a sufficient number oftransients to obtain satisfactory signal to noise, usually 1000 to2000. Transform the weighted free induction decay signal tothe frequency domain spectrum. The PO methine and methyl-ene carbon resonances range from 76.6 to 72.8 and 67.0 to 65.2ppm
44、(TMS reference). Chemical shifts for the EO peaks rangefrom 72.6 to 68.3 and 62.0 to 61.0 ppm. See Figs. 3 and 4 forexamples of EO capped polyols.20.2 Integrate the PO methine and methylene carbons andthe EO carbons as shown in Fig. 4.21. Calculation21.1 Determine the areas of the PO peaks (B8 +C8 F
45、,Fig.4) and the areas of the EO peaks (B+C+F,Fig. 4). (See Note3.) Calculate the PO to EO ratio from the following equation:PO/EO 5B8 1 C8 2 FB 1 C 1 F(3)where:B8 = area of PO methylene and methine carbons,B = area of EO carbons,C8 = area of PO terminal methine carbon,C = total area of terminal EO c
46、arbons, andF = area of terminal EO carbon of an EO block.NOTE 3Areas C and F are only significant in EO-capped polyols.Area F corrects for the beta carbon of a terminal EO block which resonatesat 73.1 ppm and integrates as a PO carbon.21.2 Determine the weight percent EO using the PO/EOratio calcula
47、ted in 21.1:EO 54458PO/EO! 1 443 100 (4)where:44 = g EO/mole, and58 = g PO/mole.22. Report22.1 Report data to nearest tenth percent EO.23. Precision and Bias423.1 Table 3 is based on a round robin conducted in 1981 inaccordance with Practice E691, involving six polyol sampleswith EO content ranging
48、from 6 to 45 weight % (see Table 4)tested by eight laboratories. For each polyol, all of the sampleswere prepared at one source, but the individual specimens wereprepared at the laboratories that tested them. Each test resultwas obtained from one individual NMR run. Each lab obtainedtwo test results
49、 for each material on two separate days.23.2 In Table 3, for the polyols indicated and for test resultsthat are derived from testing two specimens of each polyol oneach of two separate days:23.2.1 Sris the within-laboratory standard deviation of theaverage: Ir= 2.83 Sr(see 23.2.3 for application of Ir).23.2.2 SRis the between-laboratory standard deviation ofthe average; IR= 2.83 SR(see 23.2.4 for application of IR).4Supporting data are available from ASTM Headquarters. Request RR:D20-1148.D4875 11423.2.3 RepeatabilityIn comparing two test results for t
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