ASTM D5017-1996(2003)e1 Standard Test Method for Determination of Linear Low Density Polyethylene (LLDPE) Composition by Carbon-13 Nuclear Magnetic Resonance《用碳-13核磁共振法测定线性低密度聚乙烯成分.pdf

1、Designation: D 5017 96 (Reapproved 2003)e1Standard Test Method forDetermination of Linear Low Density Polyethylene (LLDPE)Composition by Carbon-13 Nuclear Magnetic Resonance1This standard is issued under the fixed designation D 5017; the number immediately following the designation indicates the yea

2、r 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 (e) indicates an editorial change since the last revision or reapproval.e1NOTEEditorially changed content in Sections 2 and 3 in June 2003

3、.1. Scope1.1 This test method determines the molar composition ofcopolymers prepared from ethylene (ethene) and a secondalkene-1 monomer. This second monomer can include propene,butene-1, hexene-1, octene-1, and 4-methylpentene-1.1.2 Calculations of this test method are valid for productscontaining

4、units EEXEE, EXEXE, EXXE, EXXXE, and ofcourse EEE where E equals ethene and X equals alkene-1.Copolymers containing a considerable number of alkene-1blocks (such as, longer blocks than XXX) are outside the scopeof this test method.1.3 This standard does not purport to address all of thesafety concer

5、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. See Section 8 for aspecific hazard statement.NOTE 1There is no equivalent ISO stand

6、ard.2. Referenced Documents2.1 ASTM Standards:E 177 Practice for Use of the Terms Precision and Bias inASTM Test Methods2E 386 Practice for Data Presentation Relating to High-Resolution Nuclear Magnetic Resonance (NMR) Spectros-copy3E 691 Practice for Conducting an Interlaboratory Study toDetermine

7、the Precision of a Test Method3IEEE/ASTM SI-10 Standard for Use of the InternationalSystem of Units (SI): The Modern System43. Terminology3.1 Some units, symbols, and abbreviations used in this testmethod are summarized in IEEE/ASTM SI-10 and PracticeE 386. Other abbreviations are listed as follows:

8、3.2 Abbreviations:Abbreviations:3.2.113Ccarbon 13,3.2.2 LLDPElinear low-density polyethylene,3.2.3 T1relaxation time, and3.2.4 TRpulse repetition time.3.3 Definitions of Terms Specific to This Standard:3.3.1 With a few modifications, terms used to designatedifferent carbon types were suggested by Ca

9、rman.5Methinecarbons are identified by CH and branch carbons are labeledaccording to branch type as summarized in Table 1. Branchcarbons are numbered starting with the methyl as number one.3.3.2 Backbone methylene carbons are designated by a pairof Greek letters that specify the location of the near

10、est methinecarbon in each direction. For example, a,a-methylene carbonis between two methine carbons or an a,d+methylene carbonhas one immediate methine neighbor and the second methinecarbon is located at least four carbons away.4. Summary of Test Method4.1 Polymer samples are dispersed in hot solve

11、nt andanalyzed at high temperatures using Carbon-13 nuclear mag-netic resonance (NMR) spectroscopy.4.2 Spectra are recorded under conditions such that theresponse of each chemically different carbon is identical.Integrated responses for carbons originated from the differentcomonomers are used for ca

12、lculation of the copolymer com-position.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved June 10, 2003. Published August 2003. Originallyapproved in 1991. Last previous

13、edition approved in 1996 as D 5017 96.This revision includes the addition of an ISO equivalency statement and anupdate of model numbers of referenced NMR instruments.2Annual Book of ASTM Standards, Vol 14.02.3Annual Book of ASTM Standards, Vol 14.01.4Available from ASTM International Headquarters, 1

14、00 Barr Harbor Drive,C700, West Conshohocken, PA 19428.5Carman, C. J., Harrington, R. A., and Wilkes, C. E., Macromolecules 1977, Vol10, p. 536.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Significance and Use5.1 Performance pr

15、operties are dependent on the numberand type of short chain branches. This test method permitsmeasurement of these branches for ethylene copolymers withpropylene, butene-1, hexene-1, octene-1, and4-methylpentene-1.6. Apparatus6.1 NMR Spectrometer,13C pulse-Fourier transform withfield strength of at

16、least 2.35 T. Typical instruments include theJeol GSX-400, Bruker Avance DPX-300, and Varian 400 UnityPLUS spectrometers.NOTE 2The system should have a computer size of at least 32 K for50-MHz carbon frequency with digital resolution of at least 0.5 Hz/pointin the final spectrum.6.2 Sample Tubes,610

17、-mm outside diameter.NOTE 3Sample tube size can be varied; however, the sample prepa-ration procedure described in 10.1 may need to be altered to maintain theminimum signal-to-noise requirement of 9.4.7. Reagents and Materials7.1 Ortho-dichlorobenzene or 1,2,4-trichlorobenzene, re-agent grade7.2 Deu

18、terated o-dichlorobenzene or p-dichlorobenzene.This material is used at a concentration up to 20 % with thereagent specified in 7.1 as an internal lock.8. Hazards8.1 Precaution: Solvents should be handled in a wellven-tilated fume hood.9. Instrument Parameters9.1 Pulse angle, 909.2 Pulse repetition,

19、 10 s9.3 Sample temperature, 130CNOTE 4The precise temperature should be measured using the NMRthermometer (cyclooctane/methylene iodide).79.4 Minimum signal-to-noise, 5000:1NOTE 5The signal-to-noise ratio is defined as 2.5 times the signalintensity of the 30.0-ppm peak (isolated methylenes) divided

20、 by the peakto peak noise for the region from 50 to 70 ppm. Calculation ofsignal-to-noise is permitted using an equivalent software procedure.9.5 Sweep width, 175 ppm9.6 Transmitter frequency (F1), 50 to 55 ppm9.7 Apodisation, 2 (exponential) Hz9.8 Pulse width, 4 3 sweep width Hz19.9 Decoupling, com

21、pleteNOTE 6The nuclear overhauser enhancement for the carbons used forquantitative analysis have been shown to be full.4, 7 , 810. Procedure10.1 Weigh a 1.2-g sample into a 10-mm NMR tube. Add1.5 mL of solvent (7.1) and 1.3 mL deuterated solvent (7.2) tothe tube. Cap the tube.NOTE 7Solution concentr

22、ation can be varied with instruments ofdifferent field strength as long as one meets the minimum signal-to-noiserequirement of 9.4.10.2 Homogenize the sample in an oven at 150C for 3 to 4h. Keep the tube in a vertical position during the heating step.10.3 Set spectrometer parameters as detailed in S

23、ection 9.10.4 Transfer the tube to the NMR spectrometer and equili-brate 10 to 15 min at 130C.10.5 Scan the sample with complete broadband decouplingusing the parameters of Section 9.10.6 Record the spectrum and the accurate full-scale inte-gral from 10 to 50 ppm. Adjust partial integrals so that in

24、tegralof the second largest peak in the spectrum is at least 50 % offull-scale. This partial integral must be flat before and after thearea to be measured.NOTE 8The combination of sample preparation time and acquisitiontime necessary to obtain the signal-to-noise requirement of 9.4 can lead toprohib

25、itively long experiments if samples are run multiplicatively. It isacceptable to perform sample determinations using a single analysis.Duplicate runs in accordance with 13.1 were performed for the round-robin exercise.11. Calculation11.1 Measure the area between the appropriate integrationlimits out

26、lines in Annex A1.11.2 Substitute the integrals into the appropriate equationsfrom Annex A2 to calculate the mole percent alkene-1.11.3 Annex A3 gives a sample calculation for an ethylene-octene copolymer using integrals and equations in accordancewith 11.1 and 11.2.NOTE 9With the prescribed repetit

27、ion time (10 s) and pulse angle(90), the maximum allowable relaxation time (T1) for carbons used forquantitative analysis is 2 s. To shorten the analysis time, a shorter pulserepetition time can be used if one accounts for the relaxation timedifferences. Relaxation times of carbons for the five copo

28、lymers weredetermined at a carbon frequency of 50 MHz using the inversion recoverymethod.9, 10Annex A4 summarizes these relaxation times and correctionfactors (reciprocal of the relative intensities) for a 4-s repetition time (TR).With the shorter TR, multiply integrals by these correction factors b

29、eforeusing the equations in Annex A2. The T1values would have to beremeasured for analyses performed at spectrometer frequencies other than50 MHz.6Available from Wilmad Scientific Glass Co.7Vidrime, D. W., and Peterson, P. E., Analytical Chemistry, Vol 48, 1976, p.1301.8Randall, J. C., “NMR and Macr

30、omolecules,” Chapter 9, American ChemicalSociety Symposium Series 247, 1984.9Farrar, T. C., and Becker, E. D., Pulse and Fourier Transform NMR, Chapter 2,Academic Press, New York, 1971.10Cheng, H. N., and Bennet, M. A., Macromolecule Chemistry, Vol 188, 1987,pp. 26652677.TABLE 1 Designations for Dif

31、ferent Carbon TypesMonomer Branch Type LabelPropane (P) methyl M1Butene-1 (B) ethyl E1E2Hexene-1 (H) butyl B1B44-Methylpentene-1 (MP) isobutyl IB1IB3Octene-1 (O) hexyl H1H6D 5017 96 (2003)e1211.4 If desired, convert results from mole percent alkene-1to branches per 1000 carbons (br/1000C) using the

32、equations inAnnex A5.12. Report12.1 Report the mole percent alkene from 11.2 or branches/1000C from 11.4, or both.13. Precision and Bias13.1 Table 2 is based on a round robin11conducted in 1988in accordance with Practice E 691, involving nine materialstested by six laboratories. For each material, a

33、ll the sampleswere prepared at one source, but the individual specimens wereprepared at the laboratories that tested them. Each “test result”was the average of two individual determinations. Each labo-ratory obtained one test result for each material.NOTE 10Caution: The following explanations of r a

34、nd R (13.2-13.2.3) are only intended to present a meaningful way of considering theapproximate precision of this test method. The data in Table 2 should notbe rigorously applied to acceptance or rejection of material, as those dataare specific to the round robin and may not be representative of othe

35、r lots,conditions, materials, or laboratories. Users of this test method shouldapply the principles outlined in Practice E 691 to generate data specific totheir laboratory and materials, or between specific laboratories. Theprinciples of 13.2-13.2.3 would then be valid for such data.13.2 Concept of

36、r and RIf Srand SRhave been calculatedfrom a large enough body of data, and for test results that wereaverages from testing two specimens:13.2.1 RepeatabilityTwo test results obtained within onelaboratory shall be judged not equivalent if they differ by morethan the “r” value for that material; “r”

37、is the intervalrepresenting the critical difference between two test results forthe same material, obtained by the same operator using thesame equipment on the same day in the same laboratory.13.2.2 Reproducibility Limit, R (Comparing Two Test Re-sults for the Same Material, Obtained by Different Op

38、eratorsUsing Different Equipment in Different Laboratories)Thetwo test results should be judged not equivalent if they differ bymore than the “ R” value for that material.13.2.3 Any judgment in accordance with 13.2.1 or 13.2.2would have an approximate 95 % (0.95) probability of beingcorrect.13.3 The

39、re are no recognized standards by which to esti-mate bias of this test method.14. Keywords14.1 carbon-13 NMR; composition; LLDPE; polyethyleneANNEXES(Mandatory Information)A1. AREA BETWEEN THE APPROPRIATE INTEGRATION LIMITS OUTLINESA2. EQUATIONS FOR CALCULATING MOLE % COMPOSITIONA2.1 Ethene-Propene

40、CopolymersA2.1.1 Moles Propene:P15a2carbons: 2A 1 B!/2 See Note A2.1! (A2.1)P25 CH carbons: 2A 1 C 2 H (A2.1)P8 5 average moles propylene: P11 P2!/2 (A2.1)A2.1.2 Moles Ethene:E8 5 C 1 D 1 E 1 F 2 A!/2 (A2.2)Mole % propene 5 100 % 3 P8 1 E8!See Note A2.2! (A2.2)A2.2 Ethene-Butene-1 CopolymersA2.2.1 M

41、oles Butene-1:B15a2carbons: 2A 1 B!/2 See Note A2.1!(A2.3)B25 CH carbons: A8 1 2C 1 2B!/4 (A2.3)11Supporting data are available from ASTM Headquarters. Request RR: D-20-1192.TABLE 2 Precision Statistics for Determination of Mole PercentBranching in LLDPE Copolymers by Carbon-13 NMRSpectroscopySample

42、 ComonomerAverageMole,%Expressed as % of the AverageVrAVRBrCRDA butene 4.72 11.1 11.5 31.1 32.2B butene 4.22 11.9 11.9 33.3 33.3C hexene 3.64 17.1 18.2 47.9 51.0D hexene 4.03 14.3 14.3 40.0 40.0E octene 5.18 10.3 10.3 28.8 28.8F octene 0.76 27.5 40.6 77.0 113.7G 4-methyl-pentene 5.00 14.0 14.8 39.2

43、41.4H 4-methyl-pentene 1.26 37.4 38.2 104.7 107.0I propene 15.96 7.3 7.6 20.4 21.3AVr= within laboratory coefficient of variation for the indicated material. It isobtained by pooling the within laboratory standard deviations of the following testresults:Sr 5 (s1!21 s2!2.1 sn!2#/n#Vr 5 100 3Sr divide

44、d by the overall average for the material!.BVR= between laboratories reproducibility, expressed as coefficient of varia-tion, for the indicated material.Cr = within laboratory repeatability limit = 2.8 3 Vr.DR = between laboratories reproducibility limit = 2.8 3 VR.D 5017 96 (2003)e13B8 5 average mo

45、les butene21: B11 B2!/2 (A2.3)A2.2.2 Moles ethene:E8 5 2D 1 2E 1 2F 2 A8 2 B!/4 (A2.4)Mole % butene21 5 100 % 3 B8/B8 1 E8!See Note A2.2! (A2.4)A2.3 Ethene-Hexene-1 CopolymersA2.3.1 Moles Hexene-1:H15a2carbons: 1.5A 1 2B 1 D 1 E! 2 D#/3See Note A2.1! (A2.5)H25 CH carbons: A 1 2C 1 2D!/2 (A2.5)H8 5 a

46、verage moles Hexene21: H11 H2!/2 (A2.5)A2.3.2 Moles ethene:E8 5 F 1 G! 2 3A 2 3B 2 G 2 H#/2 1 H8 (A2.6)Mole % hexene21 5 100 % 3 H8/E8 1 H8!See Note A2.2! (A2.6)A2.4 Ethene-Octene-1 CopolymersA2.4.1 Moles Octene-1:O15a2carbons: A 1 2C 1 2D!/2 See Note A2.1!(A2.7)O25 CH carbons: 1.5A 1 2B 1 D 1 E! 2

47、D#/3 (A2.7)O8 5 average moles Octene21 5 O11 O2!/2 (A2.7)A2.4.2 Moles Ethene:E8 5 F 1 G 1 H! 2 3A 1 3B 1 H 1 P 1 I!#/2 1 O8(A2.8)Mole % octene21 5 100 % 3 O8/O8 1 E8!See Note A2.3! (A2.8)A2.5 Ethene-4-Methylpentene-1 CopolymersA2.5.1 Moles 4-Methylpentene-1:MP15a2carbons 1 CH2branch carbons: (A2.9)5

48、 2B 1 C 1 D 1 1.5E!/3 (A2.9)MP25 CH2branch carbon: A (A2.9)MP8 5 average moles 42Methylpentene21 5 MP11 MP2!/2(A2.9)A2.5.2 Moles Ethene:E8 5 F 1 G! 2 2B 1 1.5E 1 G 1 H!#/2 1 1.5MP8(A2.10)Mole 5 42methylpentene21 5 100 % 3 MP8/MP8 1 E8!(A2.10)NOTE A2.1“a-carbons” and “CH carbons” mean predominantlype

49、aks originating from a-carbons and CH-carbons, respectively.NOTE A2.2As their relaxation times are completely different, endgroups are not included in the area measurement. The formal correctionfor this omission is as follows:End group concentration in mole percent = (4 3 1400)/MnTABLE A1.1 Integration Limits for Ethylene CopolymersACopolymer Area Region, ppmEthene-propene A 47.5 to 44.5B 39.8 to 36.8C 35.5 to 32.5C+D+E 35.5 to 25.8F 25.8 to 23.8G 22.5 to 18.5H Peak at 21.6Ethene-butene-1 A 41.5 to 38.5A8 P