ASTM D6474-20

Standard Test Method for Determining Molecular Weight Distribution and Molecular Weight Averages of Polyolefins by High Temperature Gel Permeation Chromatography

SIGNIFICANCE AND USE
5.1 This test method measures the molecular weight distribution and molecular weight averages of polyethylene (except LDPE and UHMWPE) and polypropylene resins. Differences in molecular weight and molecular weight distribution significantly affect physical properties, such as morphology, strength, melt flow etc., and as a result, the final properties of products made from these resins.
SCOPE
1.1 This test method covers the determination of molecular weight distributions and molecular weight averages of polyolefins by high temperature gel permeation chromatography (GPC). This test method uses commercially available polystyrene standards and equipment and is applicable to polyethylenes (excluding high pressure low density polyethylene (LDPE) and ultra-high molecular weight polyethylene (UHMWPE)) and polypropylenes soluble in 1,2,4-trichlorobenzene (TCB) at 140°C. This test method is not absolute and requires calibration.
Note 1: Size exclusion chromatography (SEC) often is used as an alternative name for gel permeation chromatography (GPC).
Note 2: Specific methods and capabilities of users may vary with differences in columns, instrumentation, applications software, and practices between laboratories.
Note 3: One general method is outlined herein; alternative analytical practices can be followed and are attached in notes where appropriate.
Note 4: There is no known ISO equivalent to this standard.  
1.2 The values stated in SI units, based on IEEE/ASTM S1-10, are to be regarded as the standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2020
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.70 - Analytical Methods

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D6474 −20
Standard Test Method for
Determining Molecular Weight Distribution and Molecular
Weight Averages of Polyolefins by High Temperature Gel
1
Permeation Chromatography
This standard is issued under the fixed designation D6474; 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.
1. Scope* 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method covers the determination of molecular
D883 Terminology Relating to Plastics
weight distributions and molecular weight averages of poly-
D3016 Practice for Use of Liquid Exclusion Chromatogra-
olefins by high temperature gel permeation chromatography
phy Terms and Relationships
(GPC). This test method uses commercially available polysty-
D5296 Test Method for Molecular Weight Averages and
rene standards and equipment and is applicable to polyethyl-
Molecular Weight Distribution of Polystyrene by High
enes (excluding high pressure low density polyethylene
Performance Size-Exclusion Chromatography
(LDPE) and ultra-high molecular weight polyethylene (UHM-
E685 Practice for Testing Fixed-Wavelength Photometric
WPE)) and polypropylenes soluble in 1,2,4-trichlorobenzene
Detectors Used in Liquid Chromatography
(TCB) at 140°C. This test method is not absolute and requires
E691 Practice for Conducting an Interlaboratory Study to
calibration.
Determine the Precision of a Test Method
IEEE/ASTM S1-10 Standard for Use of the International
NOTE 1—Size exclusion chromatography (SEC) often is used as an
System of Units (SI): The Modern System (replaces
alternative name for gel permeation chromatography (GPC).
ASTM E 380 and ANSI/IEEE Standard 268-1992)
NOTE 2—Specific methods and capabilities of users may vary with
differences in columns, instrumentation, applications software, and prac-
3. Terminology
tices between laboratories.
3.1 Definitions—Definitions of terms applying to plastics
NOTE 3—One general method is outlined herein; alternative analytical
appear in Terminology D883.
practices can be followed and are attached in notes where appropriate.
NOTE 4—There is no known ISO equivalent to this standard.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 polyolefin, n—used in this context,referstoPE(except
1.2 The values stated in SI units, based on IEEE/ASTM
LDPE) and PP thermoplastics.
S1-10, are to be regarded as the standard.
4. Summary of Test Method
1.3 This standard does not purport to address all of the
4.1 In this test method, a polyolefin sample is dissolved in a
safety concerns, if any, associated with its use. It is the
solvent and injected onto a chromatographic column(s) packed
responsibility of the user of this standard to establish appro-
with a substrate, which separates the molecules according to
priate safety, health, and environmental practices and deter-
their size in solution.The separated molecules are detected and
mine the applicability of regulatory limitations prior to use.
recorded as they elute from the column according to size by a
1.4 This international standard was developed in accor-
concentration sensitive detector. Through calibration, retention
dance with internationally recognized principles on standard-
times are converted to molecular weights. Molecular weight
ization established in the Decision on Principles for the
averages and molecular weight distributions are determined
Development of International Standards, Guides and Recom-
from the calibration curve and detector response.
mendations issued by the World Trade Organization Technical
5. Significance and Use
Barriers to Trade (TBT) Committee.
5.1 This test method measures the molecular weight distri-
bution and molecular weight averages of polyethylene (except
1
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
2
and is the direct responsibility of Subcommitttee D20.70 on Analytical Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2020. Published April 2020. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1999. Last previous edition approved in 2019 as D6474–19. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D6474-20. the ASTM website.
*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
1

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...

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.
Designation: D6474 − 19 D6474 − 20
Standard Test Method for
Determining Molecular Weight Distribution and Molecular
Weight Averages of Polyolefins by High Temperature Gel
1
Permeation Chromatography
This standard is issued under the fixed designation D6474; 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.
1. Scope*
1.1 This test method covers the determination of molecular weight distributions and molecular weight averages of linear
polyolefins by high temperature gel permeation chromatography (GPC). This test method uses commercially available polystyrene
standards and equipment and is applicable to polyethylenes (excluding high pressure low density polyethylene–LDPE) and
polyethylene (LDPE) and ultra-high molecular weight polyethylene (UHMWPE)) and polypropylenes soluble in 1,2,4-
trichlorobenzene (TCB) at 140°C. This test method is not absolute and requires calibration.
NOTE 1—Size exclusion chromatography (SEC) often is used as an alternative name for gel permeation chromatography (GPC).
NOTE 2—Specific methods and capabilities of users may vary with differences in columns, instrumentation, applications software, and practices
between laboratories.
NOTE 3—One general method is outlined herein; alternative analytical practices can be followed and are attached in notes where appropriate.
NOTE 4—There is no known ISO equivalent to this standard.
1.2 The values stated in SI units, based on IEEE/ASTM S1-10, are to be regarded as the standard.
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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
D3016 Practice for Use of Liquid Exclusion Chromatography Terms and Relationships
D5296 Test Method for Molecular Weight Averages and Molecular Weight Distribution of Polystyrene by High Performance
Size-Exclusion Chromatography
E685 Practice for Testing Fixed-Wavelength Photometric Detectors Used in Liquid Chromatography
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
IEEE/ASTM S1-10 Standard for Use of the International System of Units (SI): The Modern System (replaces ASTM E 380 and
ANSI/IEEE Standard 268-1992)
3. Terminology
3.1 Definitions—Definitions of terms applying to plastics appear in Terminology D883.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 polyolefin, n—used in this context, refers to PE (except LDPE) and PP thermoplastics.
1
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommitttee D20.70 on Analytical Methods.
Current edition approved Nov. 1, 2019April 1, 2020. Published December 2019April 2020. Originally approved in 1999. Last previous edition approved in 20122019 as
D6474–12.–19. DOI: 10.1520/D6474-19.10.1520/D6474-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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
1

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D6474 − 20
4. Summary of Test Method
4.1 In this test method, a polyolefin sample is dissolved in a solvent and injected onto a chromatographic column(s) packed with
a substrate, which separates the molecules according to their size in solution. The separated molecules are detected and recorded
as they elute from the column according to size by a concentration sensitive detector. Through calibration, retention times are
converted to molecular weights. Molec
...