ASTM D5017-17

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. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D5017 − 96 (Reapproved 2009) D5017 − 17
Standard Test Method for
Determination of Linear Low Density Polyethylene (LLDPE)
Composition by Carbon-13 Nuclear Magnetic Resonance
This standard is issued under the fixed designation D5017; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Reapproved with editorial changes in April 2009.
1. Scope Scope*
1.1 This test method determines the molar composition of copolymers prepared from ethylene (ethene) and a second alkene-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 products containing units EEXEE, EXEXE, EXXE, EXXXE, and of course
EEE where E equals ethene and X equals alkene-1. Copolymers containing a considerable number of alkene-1 blocks (such as,
longer blocks than XXX) are outside the scope of this test method.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use. See Section 8 for a specific hazard statement.
NOTE 1—There is no equivalent ISO known ISO equivalent to this standard.
2. Referenced Documents
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E386 Practice for Data Presentation Relating to High-Resolution Nuclear Magnetic Resonance (NMR) Spectroscopy
(Withdrawn 2015)
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E2977 Practice for Measuring and Reporting Performance of Fourier-Transform Nuclear Magnetic Resonance (FT-NMR)
Spectrometers for Liquid Samples
IEEE/ASTM SI-10 Standard for Use of the International System of Units (SI): The Modern System
3. Terminology
3.1 Some units, symbols, and abbreviations used in this test method are summarized in IEEE/ASTM SI-10 and Practice E386.
Other abbreviations are listed as follows:
3.2 Abbreviations:
3.2.1 C—carbon 13,
3.2.2 LLDPE—linear low-density polyethylene,
3.2.3 T1—relaxation time, and
3.2.4 TR—pulse repetition time.
3.3 Definitions of Terms Specific to This Standard:
3.3.1 With a few modifications, terms used to designate different carbon types were suggested by Carman. Methine carbons
are identified by CH and branch carbons are labeled according to branch type as summarized in Table 1. Branch carbons are
numbered starting with the methyl as number one.
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
Current edition approved April 1, 2009March 1, 2017. Published June 2009March 2017. Originally approved in 1991. Last previous edition approved in 20032009 as
ε1
D5017 – 96(2003)(2009) . DOI: 10.1520/D5017-96R09E01.10.1520/D5017-17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from ASTM International Headquarters, 100 Barr Harbor Drive, C700, West Conshohocken, PA 19428.
Carman, C. J., Harrington, R. A., and Wilkes, C. E., Macromolecules 1977, Vol 10, p. 536.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5017 − 17
TABLE 1 Designations for Different Carbon Types
Monomer Branch Type Label
Propene (P) methyl M1
Butene-1 (B) ethyl E1–E2
Hexene-1 (H) butyl B1–B4
4-Methylpentene-1 (MP) isobutyl IB1–IB3
Octene-1 (O) hexyl H1–H6
3.3.2 Backbone methylene carbons are designated by a pair of Greek letters that specify the location of the nearest methine
+
carbon in each direction. For example, α,α-methylene carbon is between two methine carbons or an α,δ methylene carbon has one
immediate methine neighbor and the second methine carbon is located at least four carbons away.
4. Summary of Test Method
4.1 Polymer samples are dispersed in hot solvent and analyzed at high temperatures using Carbon-13 nuclear magnetic
resonance (NMR) spectroscopy.
4.2 Spectra are recorded under conditions such that the response of each chemically different carbon is identical. Integrated
responses for carbons originated from the different comonomers are used for calculation of the copolymer composition.
5. Significance and Use
5.1 Performance properties are dependent on the number and type of short chain branches. This test method permits
measurement of these branches for ethylene copolymers with propylene, butene-1, hexene-1, octene-1, and 4-methylpentene-1.
6. Apparatus
6.1 NMR Spectrometer, C pulse-Fourier transform spectrometer with a field strength of at least 2.35 T.
NOTE 2—The system should have a computer size of at least 32 K for 50-MHz carbon frequency with digital resolution of at least 0.5 Hz/point in the
final spectrum.
6.2 Sample Tubes, 10-mm outside diameter.
NOTE 3—Sample tube size can be varied; however, the sample preparation procedure described in 10.1 may need to be altered to maintain the minimum
signal-to-noise requirement of 9.4.
7. Reagents and Materials
7.1 Ortho-dichlorobenzene or 1,2,4-trichlorobenzene, reagent grade
7.2 Deuterated o-dichlorobenzene or p-dichlorobenzene. This material is used at a concentration up to 20 % with the reagent
specified in 7.1 as an internal lock.
8. Hazards
8.1 Warning—Solvents shouldshall be handled in a well-ventilated fume hood.
9. Instrument Parameters
9.1 Pulse angle, 90°
9.2 Pulse repetition, 10 s
9.3 Sample temperature, 130°C
NOTE 4—The precise temperature should be measured using the NMR thermometer (cyclooctane/methylene iodide).
9.4 Minimum signal-to-noise, 5000:1
NOTE 5—The signal-to-noise ratio is defined as 2.5 times the signal intensity of the 30.0-ppm peak (isolated methylenes) divided by the peak to peak
noise for the region from 50 to 70 ppm. Calculation of signal-to-noise is permitted using an equivalent software procedure.
9.5 Sweep width, 175 ppm
9.6 Transmitter frequency (F1), 50 to 55 ppm
9.7 Apodisation, 2 (exponential) Hz
−1
9.8 Pulse width, <[4 × sweep width Hz]
Available from Wilmad Scientific Glass Co.
Vidrime, D. W., and Peterson, P. E., Analytical Chemistry , Vol 48, 1976, p. 1301.
D5017 − 17
9.9 Decoupling, complete
4, 7, 8
NOTE 6—The nuclear Overhauser enhancement for the carbons used for quantitative analysis have been shown to be full.
10. Procedure
10.1 Weigh a 1.2-g sample into a 10-mm NMR tube. Add 1.5 mL of solvent (7.1) and 1.3 mL deuterated solvent (7.2) to the
tube. Cap the tube.
NOTE 7—Solution concentration can be varied with instruments of different field strength as long as one meets the minimum signal-to-noise
requirement of 9.4.
10.2 Homogenize the sample in an oven at 150°C for 3 to 4 h. Keep the tube in a vertical position during the heating step.
10.3 Set spectrometer parameters as detailed in Section 9.
10.4 Transfer the tube to the NMR spectrometer and equilibrate 10 to 15 min at 130°C.
10.5 Scan the sample with complete broadband decoupling using the parameters of Section 9.
10.6 Record the spectrum and the accurate full-scale integral from 10 to 50 ppm. Adjust partial integrals so that integral of the
second largest peak in the spectrum is at least 50 % of full-scale. This partial integral must be flat before and after the area to be
measured.
NOTE 8—The combination of sample preparation time and acquisition time necessary to obtain the signal-to-noise requirement of 9.4 can lead to
prohibitively long experiments if samples are run multiplicatively. It is acceptable to perform sample determinations using a single analysis. Duplicate
runs in accordance with 13.1 were performed for the round-robin exercise.
11. Calculation
11.1 Measure the area between the appropriate integration limits outlined in Annex A1.
11.2 Substitute the integrals into the appropriate equations from 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 accordance with
11.1 and 11.2.
NOTE 9—With the prescribed repetition time (10 s) and pulse angle (90°), the maximum allowable relaxation time (T ) for carbons used for quantitative
analysis is 2 s. To shorten the analysis time, a shorter pulse repetition time can be used if one accounts for the relaxation time differences. Relaxation
9, 10
times of carbons for the five copolymers were determined at a carbon frequency of 50 MHz using the inversion recovery method. Appendix X1
summarizes these relaxation times and correction factors (reciprocal of the relative intensities) for a 4-s repetition time (T ). With the shorter T , multiply
R R
integrals by these correction factors before using the equations in Annex A2. The T values would have to be remeasured for analyses performed at
spectrometer frequencies other than 50 MHz.
11.4 If desired, convert results from mole percent alkene-1 to branches per 1000 carbons (br/1000C) using the equations in
Annex A4.
12. Report
12.1 Report the mole percent alkene-1 from 11.2 or branches/1000C from 11.4, or both.
13. Precision and Bias
13.1 Table 2 is based on a round robin conducted in 1988 in accordance with Practice E691, involving nine materials tested by
six laboratories. For each material, all the samples were prepared at one source, but the individual specimens were prepared at the
laboratories that tested them. Each “test result” was the average of two individual determinations. Each laboratory obtained one
test result for each material. (Warning—The following explanations of r and R (13.2 – 13.2.3) are only intended to present a
meaningful way of considering the approximate precision of this test method. The data in Table 2 shouldare not to be rigorously
applied to acceptance or rejection of material, as those data are specific to the round robin and mayare not be representative of other
lots, conditions, materials, or laboratories. Users of this test method should need to apply the principles outlined in Practice E691
to generate data specific to their laboratory and materials, or between specific laboratories. The principles of 13.2 – 13.2.3 would
then be valid for such data.)
13.2 Concept of r and R—If S and S have been calculated from a large enough body of data, and for test results that were
r R
averages from testing two specimens:
13.2.1 Repeatability—Two test results obtained within one laboratory shall be judged not equivalent if they differ by more than
...