ASTM D4875-2018 Standard Test Methods of Polyurethane Raw Materials Determination of the Polymerized Ethylene Oxide Content of Polyether Polyols.pdf

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1、Designation: D4875 11D4875 18Standard 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 adopt

2、ion 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. Scope*1.1 Test Method AProton Nuclear Magnetic Resonance Spectroscopy (1H NMR) mea

3、sures polymerized ethylene oxide (EO)in content of ethylene oxide-propylene oxide polyethers oxide (EO) propylene oxide (PO) polyether polyols used in flexibleurethanepolyurethane foams and nonfoams.non-foams. It is suitable for diols made from the commonly used initiators andinitiatedfrom glycols o

4、f EO or PO containing EO percentages above five. 5. For triols initiated with glycerin and trimethylol propane,glycerol (glycerin) and trimethylolpropane, an uncorrected EO value is obtained since both initiators have protons that contributeto the EO measurement.1.2 Test Method BCarbon-13 Nuclear Ma

5、gnetic Resonance Spectroscopy (13C NMR) measures the polymerized EO contentof ethylene oxide-propylene oxide polyethers EO-PO polyether polyols used in flexible urethanepolyurethane foams andnonfoams.non-foams. It is suitable for diols and triols made from the commonly used initiators and containing

6、 EO percentagesabove five.5.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of

7、this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this standard.1.5 This international standard was developed in accordance with international

8、ly recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D883 Terminolog

9、y Relating to PlasticsE386 Practice for Data Presentation Relating to High-Resolution Nuclear Magnetic Resonance (NMR) Spectroscopy(Withdrawn 2015)3E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE2977 Practice for Measuring and Reporting Performance

10、of Fourier-Transform Nuclear Magnetic Resonance (FT-NMR)Spectrometers for Liquid Samples3. Terminology3.1 DefinitionsDefinitionsForTerminology in these test methods follows the standard terminology defined in definitions ofterms that appear in this method refer to Terminology D883 and Practice E386E

11、2977.3.2 Definitions of Terms Specific to This Standard:3.2.1 heteric polyol, na polyether polyol in which ethylene oxide and propylene oxide units are randomly arranged.3.2.2 initiator, na substance with which ethylene oxide or propylene oxide reacts to form a polyether polyol.1 These test methods

12、are under the jurisdiction ofASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.22 on Cellular Materials - Plasticsand Elastomers.Current edition approved April 1, 2011April 1, 2018. Published April 2011April 2018. Originally approved in 1988. Last previous edition a

13、pproved in 20052011 asD4875 - 05.D4875 - 11. DOI: 10.1520/D4875-11.10.1520/D4875-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary pa

14、ge on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that

15、users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Con

16、shohocken, PA 19428-2959. United States13.2.2.1 DiscussionOne initiator unit is incorporated into each polymer or oligomer molecule.3.2.3 EO capped polyola polyol that contains a terminal block of ethylene oxide units4. Summary of Test Methods4.1 Test Method AThe 1H NMR spectra of polyether polyols

17、show two groups of resonance peaks corresponding peaks. Thefirst group corresponds to the methyl protons of propylene oxide (PO) and (PO). The second group corresponds to the methyleneand methine protons of EO and PO. PO and the methylene protons of EO. The EO peak area is obtained by subtracting th

18、e areaof the PO methyl peaks from the area of the methylene and methine peaks. Initiators other than glycols of EO and PO givesystematic errors (see Note 2).NOTE 2The initiator error can be estimated by calculating the theoretical contribution of initiator protons to the EO and PO peak areas. Thisca

19、lculation is outside the scope of this method.4.2 Test Method BThe 13C NMR spectra of polyether polyols contain multiple resonances arising from initiator, EO, PO,EO/PO,EO-PO sequencing, tacticity, and end-group distribution. The EO content can be determined relative to PO or and EO or,relative to P

20、O and triol initiator. the triol initiator if present. In the former, the area of the EO peaks methylene carbons is ratioedto the total area of PO methylene and methine carbons and EO methylene carbons. In the latter, the area of the EO peaks methylenecarbons is ratioed to the total area of PO methy

21、lene and methine carbons and two initiator carbons. This test method describes thedetermination of EO relative to PO and EO only.5. Significance and Use5.1 Measurements of EO content correlate withto polyol reactivity (as related to primary hydroxyl content), linearity of foamrise, and the hydrophil

22、icity of the polyol and final product.5.2 Statistical data suggest that the 13C NMR test method is the preferred method for measuring low levels (less than 10 %) ofpolymerized EO in polyols.5.3 The 1H and 13C NMR test methods give different results which are highly correlated. The equation of the li

23、near regressionis:%EOproton 51.031 %EOcarbon213 !10.883 (1)The standard deviation of the regression is 0.49 and the multiple R-square is 0.9990.TEST METHOD AHYDROGEN-1APROTON NMR6. EquipmentApparatus6.1 NMR Continuous Wave (CW) or Fourier Transform (FT) NMR (FT-NMR) Spectrometer, with a 1Hproton res

24、onancefrequency of 60200 MHz or higher. The spectrometer is to have a minimum proton signal-to-noise ratio of 100:1 based on a 0.1 %ethylbenzene in deuterated chloroform (CDCl3) sample that has been pulsed once using a 90 pulse angle under the conditionsdescribed in Practice E2977.6.2 NMR Sample Tub

25、es,sample tubes, having an outside diameterdiameters of at least 5 mm.6.3 NMR spinners.7. Reagents and Materials7.1 All reagents are to be ACS-certified or spectroscopic grade unless otherwise specified.and free of magnetic materials.7.2 Trifluoroacetic Acid.acid.7.3 Chloroform-dDeuterated1, chlorof

26、orm, NMR-grade, containing tetramethylsilane (TMS) as an internal standard.8. Hazards8.1 Magnetic FieldsFollow the manufacturers recommendation for the safe operation of the instrument.8.1.1 Persons with implanted or attached medical devices such as pacemakers and prosthetic parts must remain outsid

27、e the5-gauss perimeter.8.1.2 Objects made of ferromagnetic material will be attracted to the magnet and are to be kept a safe distance away.9. Preparation of Apparatus9.1 Prepare a proton NMR experiment selecting appropriate parameters to obtain quantitative integration of the spectrum.D4875 1829.1.

28、1 Pulse Angle and Sequence Delay TimeSelect a 90 degree pulse angle with a delay of 10 T1 of the peak with the longestrelaxation time in the spectrum. It is acceptable to use a different pulse angle/sequence delay combination provided thatquantitative data acquisition is not compromised.9.1.2 Number

29、 of ScansSelect the appropriate number to yield a signal to noise of 100:1 between 2 and 0.5 ppm (usually 16to 64).9.1.3 Sweep Width14 ppm.9.1.4 Transmitter Frequency6 ppm.9.1.5 Acquisition Time2 to 4 s.10. Standard Calibration and Standardization10.1 This test method does not require standards. To

30、evaluate the test method, standards can be prepared from by blendingcommercially available poly(propylene oxide) and poly(ethylene oxide).oxide) diols. The molecular weights of the diols shouldideally be 300 or more since lower molecular weight polyols can contain structural configurations that are

31、not typical of polyetherpolyols used in flexible polyurethane foams and non-foams.9. Preparation of Sample9.1 Mix a few drops of polyol with deuterated chloroform to prepare 1 mL of an approximately 10 %4 polyol solution. Add adrop of trifluoroacetic acid, mix well, and transfer to an NMR tube.10. I

32、nstrument Preparation10.1 The instrument settings given here are for a Varian EM-390 CW spectrometer, a Varian XL-100 FT spectrometer, and aBruker AC 300 FT spectrometer. Instrument preparation can vary with the spectrometer. For a description of a particularspectrometer and suitable parameters, ref

33、er to the manufacturers 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

34、 90Pulse delay 0Spectral width 10 ppmAcquisition time 4 sData points 8KNumber of transients 12810.4 Typical Bruker 300 MHz console settings are as follows:Lock chloroform-d-1Pulse angle 90Pulse delay 5 sSpectral width 10 ppmAcquisition time 5.3 sData points 32KNumber of transients 6411. NMR Analysis

35、 Procedure11.1 Prepare a solution of the polyol in deuterated chloroform. A 0.5-5 % solution is recommended. Add one to two drops oftrifluoroacetic acid and mix well. More acid will be required if a higher than recommended concentration of polyol is used (seeNOTE 3).11.2 Transfer an appropriate amou

36、nt of the sample solution to an NMR tube.11.3 Place the NMR tube containing the polyol solution into a spinner, adjust it to the appropriate depth and insert it into thespectrometer probe and optimize the field homogeneity. For CW NMR, scan the spectrum from 5 to 0 ppm. Integrate the spectrumfive ti

37、mes at a power level below that which causes saturation. See probe.Figs. 1 and 2 for examples of polyol spectra with highand low EO concentrations, respectively.11.4 Obtain a stable lock on the solvent.11.5 Tune and match the probe.11.6 Shim the sample to optimize field-homogeneity.D4875 18311.7 Acq

38、uire the NMR data.11.8 Zero fill the data. The recommended value is 1 or 2 x number of points.11.9 Apply a spectral weighting function (apodization) and Fourier Transform the Free Induction Decay (FID). Therecommended apodization is an exponential window multiplication and a typical line broadening

39、value is 1/acquisition time.11.10 Phase and baseline correct the spectrum.11.11 Set the internal TMS reference to 0 ppm.11.12 For FT NMR, acquire the desired number of transients and transform the free induction decay signal to the frequencydomain spectrum. Integrate the peaks as Expand and integrat

40、e the peaks of interest. The methyl protons of PO typically resonatein the 0.5-1.7 ppm region (AreaA). The methylene and methine protons of PO and the methylene protons of EO typically resonatein the 2.8-4.8 ppm region (Area B). An example is shown in Figs. 1 and 2Fig. 1. (see Note 4).NOTE 3Trifluor

41、oacetic acid is added to move hydroxyl (OH) protons to a higher chemical shift and away from the regions of interest. The sampleshould be run as soon as practical after preparation to minimize the formation of esters of trifluoroacetic acid.NOTE 4Allyl unsaturation, if present, will contribute to th

42、e integral value of Area B. This contribution is expected to be minor for typical EO-POpolyether polyols and can be corrected by subtracting the integral value of two ally protons that have chemical shifts outside the regions of interest. Thiscorrection is not included in the scope of this method.11

43、.3 Chemical shifts for the PO methyl proton resonances (area A) range from about 0.6-1.6 ppm and chemical shifts for theEO and PO methylene and methine proton resonances (area B) range from about 2.8-4.0 ppmFIG. 2 113HC NMR Spectrum of a Polyol Containing 8 % EO Uncorrected for Glycerin InitiatorGly

44、cerol Initiated Polyol (BB23794)D4875 18412. Calculation12.1 Determine the areas of the PO methyl protons (area A) and the EO and PO methylene and methine protons (area B) fromthe integrals. Calculate the weight percent EO from content using the following equation:EO5 333Z333Z1583100 (1)EO,wt%5 C*44

45、.05*100C *44.05!1D *58.08!3100 (1)where:Z = (B/A) 133 = g EO/mole after weighting for the number of EO protons vs. PO protons, and58 = g PO/mole.A = area of methyl PO protons,B = area of methylene and methine PO protons and area of methylene EO protons,C = (BA)/4 integral per EO proton,D = A/3 integ

46、ral per PO proton,44.05 = g EO/mole, and58.08 = g PO/mole.13. Report13.1 Report results to the nearest tenth percent EO.the % EO content to two decimal places. For polyether polyols with initiatorsother than glycols of EO and PO, report that the value is uncorrected for the initiator.14. Precision a

47、nd Bias14.1 Table 1 is based on a round robin conducted in 19812016 in accordance with Practice E691, involving six polyol sampleswith EO content ranging from 6 to 45 weight % (see five materials Table 2) tested by eightsix laboratories. For eachpolyol,material, all of the samplesssamples were prepa

48、red at one source, but the individual specimens were prepared at thelaboratories thatwhich tested them. Each test result was obtained from one individual NMR run. Each laba single determination.Each laboratory obtained two test results for each material on two separate days.material.14.2 CautionThe

49、explanation of “r” and “R” is only intended to present a meaningful way of considering the approximateprecision of this test method. Do not apply the data in Table 1 to accept or reject materials, as these data apply only to the materialstested in the round robin and are unlikely to be rigorously representative of other lots, formulations, conditions, materials, orlaboratories. Users of this test method need to apply the principles outlined in Practice E691 to generate data specific to theirmaterials and laboratory (or between specific labor