ASTM D3826-18

Standard Practice for Determining Degradation End Point in Degradable Polyethylene and Polypropylene Using a Tensile Test

SIGNIFICANCE AND USE
4.1 The tensile elongation property determined by this practice is of value for the characterization of degradable materials. It is possible that the tensile elongation property will vary with specimen thickness, method of preparation, speed of testing, type of grips used, and manner of measuring test extension. Consequently, where precise comparative results are desired, these factors must be carefully controlled.  
4.2 It is acceptable to use the tensile elongation property to provide data for research and development and engineering design as well as quality control specifications. However, data from such tests cannot be considered significant for applications differing widely from the load-time scale of the test employed.  
4.3 Materials that fail by tearing give anomalous data that cannot be compared with those from normal failure.  
4.4 Before proceeding with this test method, reference needs to be made to the specifications of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters or a combination thereof, covered in the material specifications shall take precedence over those mentioned in this test method. If there are no material specifications, then the default conditions apply.
SCOPE
1.1 This practice covers the determination of a degradation-end point (a brittle point) for degradable polyethylene/polypropylene films and sheeting less than 1.0 mm (0.04 in.) thick. This practice is not intended for determination of the rate or degree of degradation of a polyethylene/polypropylene film or sheet, but rather, to assess when in the course of its degradation under some condition, a brittle point is reached. If one wishes to monitor tensile elongation during the degradation process (such as when the tensile elongation is significantly greater than 5 %), Test Method D882 is recommended. This practice is not to be considered the only way of determining a degradation-end point.  
1.2 Tensile properties of plastics 1.0 mm (0.04 in.) or greater in thickness shall be determined in accordance with Test Method D638.  
1.3 Use a static weighing-constant rate of grip separation test. This procedure employs a constant rate of separation of the grips holding the sample and a static load cell.  
Note 1: This procedure is based on the use of grip separation as a measure of extension; however, the desirability of using extension indicators accurate to ±1.0 % or better as specified in Test Method D638 is recognized, and a provision for the use of such instrumentation is incorporated in the procedure.  
1.4 This procedure has been successful for determining the degradation end point of ethylene-carbon-monoxide copolymers and has screened successfully two other additive-type polyethylenes in a round robin test.  
1.5 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.  
1.6 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.  
1.7 There is no equivalent ISO standard.  
1.8 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-Oct-2018
• ICS: 83.140.01 - Rubber and plastics products in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.96 - Environmentally Degradable Plastics and Biobased Products

Relations

• Replaces: ASTM D3826-98(2013) - Standard Practice for Determining Degradation End Point in Degradable Polyethylene and Polypropylene Using a Tensile Test
• Effective Date: 01-Nov-2018
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM D374/D374M-23 - Standard Test Methods for Thickness of Solid Electrical Insulation
• Effective Date: 01-Oct-2023
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2019
• Refers: ASTM D883-18a - Standard Terminology Relating to Plastics
• Effective Date: 01-Dec-2018
• Refers: ASTM D883-18 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2018
• Refers: ASTM D883-17 - Standard Terminology Relating to Plastics
• Effective Date: 15-Aug-2017
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM D883-12e1 - Standard Terminology Relating to Plastics
• Effective Date: 15-Nov-2012
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM D883-11 - Standard Terminology Relating to Plastics
• Effective Date: 15-May-2011

Overview

ASTM D3826-18: Standard Practice for Determining Degradation End Point in Degradable Polyethylene and Polypropylene Using a Tensile Test provides a recognized method for assessing when degradable polyethylene and polypropylene films and sheeting reach a brittle stage during their lifecycle. Developed by ASTM International, this standard applies to films and sheeting under 1.0 mm thick and is widely used to characterize the loss of ductility in these plastic materials as they break down under degradation processes. It forms a crucial tool for researchers, manufacturers, and quality control teams who need to determine when a plastic product loses its elongation properties and becomes brittle.

Key Topics

• Tensile Elongation Property: The standard focuses on measuring the reduction in tensile elongation as an indicator of the material’s degradation. When a plastic sample’s elongation at break falls below 5% for 75% of the specimens, the material is considered to have reached the brittle point.
• Controlled Testing Conditions: To achieve reliable and reproducible results, factors such as specimen thickness, preparation methods, testing speed, grip type, and extension measurement technique must be closely managed.
• Scope and Limitations: ASTM D3826-18 is specifically not for determining the overall rate or degree of degradation, but to identify the endpoint where the material loses flexibility. For monitoring tensile elongation above 5%, Test Method D882 is recommended.
• Applicability: The method applies to degradable polyolefin films and sheeting, including polyethylene (PE), polypropylene (PP), as well as certain copolymers and additive-modified materials.

Applications

ASTM D3826-18 holds significant practical value across several areas:

• Material Characterization: Enables clear identification of the brittle point, supporting the development of environmentally degradable plastics.
• Quality Control: Assists manufacturers in ensuring that products meet performance specifications throughout their intended service life and degrade appropriately after disposal.
• Research and Development: Provides essential data for the design and improvement of degradable polymer products, particularly in the packaging and agricultural industries.
• Regulatory Compliance: Offers an accepted means to demonstrate compliance with guidelines or product claims concerning degradability.
• Engineering Design: Supplies crucial material property data for engineers designing products using degradable polyethylene and polypropylene.

Related Standards

For a comprehensive approach to plastics testing and degradation, the following ASTM standards are commonly referenced alongside ASTM D3826-18:

• ASTM D638: Standard Test Method for Tensile Properties of Plastics, recommended for materials 1.0 mm or thicker.
• ASTM D882: Standard Test Method for Tensile Properties of Thin Plastic Sheeting, suitable for monitoring tensile elongation above 5%.
• ASTM D618: Practice for Conditioning Plastics for Testing, establishing standard environmental conditions before testing.
• ASTM D5208: Practice for Fluorescent Ultraviolet (UV) Exposure of Photodegradable Plastics, to simulate environmental exposure conditions.
• ASTM D883: Terminology Relating to Plastics, for standard definitions.
• ASTM D374: Test Methods for Thickness of Solid Electrical Insulation, for precise measurement of specimen thickness.
• ASTM D5947: Test Methods for Physical Dimensions of Solid Plastics Specimens.

By using ASTM D3826-18 in conjunction with these related standards, users can ensure robust evaluation and documentation of degradable polyolefin materials’ performance and end-of-life characteristics.

Keywords: ASTM D3826-18, degradation end point, brittle point, polyethylene, polypropylene, degradable plastics, tensile elongation, plastic sheeting, plastics testing, quality control.

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: D3826 − 18
Standard Practice for
Determining Degradation End Point in Degradable
Polyethylene and Polypropylene Using a Tensile Test
This standard is issued under the fixed designation D3826; 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 1.7 There is no equivalent ISO standard.
1.8 This international standard was developed in accor-
1.1 This practice covers the determination of a degradation-
dance with internationally recognized principles on standard-
end point (a brittle point) for degradable polyethylene/
ization established in the Decision on Principles for the
polypropylene films and sheeting less than 1.0 mm (0.04 in.)
Development of International Standards, Guides and Recom-
thick.This practice is not intended for determination of the rate
mendations issued by the World Trade Organization Technical
or degree of degradation of a polyethylene/polypropylene film
Barriers to Trade (TBT) Committee.
or sheet, but rather, to assess when in the course of its
degradation under some condition, a brittle point is reached. If
2. Referenced Documents
one wishes to monitor tensile elongation during the degrada-
tion process (such as when the tensile elongation is signifi-
2.1 ASTM Standards:
cantly greater than 5 %), Test Method D882 is recommended.
D374/D374M Test Methods for Thickness of Solid Electri-
This practice is not to be considered the only way of deter-
cal Insulation
mining a degradation-end point.
D618 Practice for Conditioning Plastics for Testing
D638 Test Method for Tensile Properties of Plastics
1.2 Tensile properties of plastics 1.0 mm (0.04 in.) or
D882 Test Method for Tensile Properties of Thin Plastic
greater in thickness shall be determined in accordance with
Sheeting
Test Method D638.
D883 Terminology Relating to Plastics
1.3 Use a static weighing-constant rate of grip separation
D5208 Practice for Fluorescent Ultraviolet (UV) Exposure
test. This procedure employs a constant rate of separation of
of Photodegradable Plastics
the grips holding the sample and a static load cell.
D5947 Test Methods for Physical Dimensions of Solid
NOTE 1—This procedure is based on the use of grip separation as a
Plastics Specimens
measure of extension; however, the desirability of using extension
E691 Practice for Conducting an Interlaboratory Study to
indicators accurate to 61.0 % or better as specified in Test Method D638
Determine the Precision of a Test Method
is recognized, and a provision for the use of such instrumentation is
incorporated in the procedure.
3. Terminology
1.4 This procedure has been successful for determining the
3.1 Definitions of Terms—For definitions of terms used in
degradation end point of ethylene-carbon-monoxide copoly-
this specification associated with plastics issues refer to the
mers and has screened successfully two other additive-type
terminology contained in Terminology D883.
polyethylenes in a round robin test.
3.2 Definitions:
1.5 The values stated in SI units are to be regarded as the
3.2.1 Definitions of terms and symbols relating to tension
standard. The values in parentheses are for information only.
testing of plastics appear in the Annex to Test Method D638.
1.6 This standard does not purport to address all of the
3.2.2 line grips, n—in tensile testing machines, grips having
safety concerns, if any, associated with its use. It is the
faces designed to concentrate the entire gripping force along a
responsibility of the user of this standard to establish appro-
single line perpendicular to the direction of testing stress.
priate safety, health, and environmental practices and deter-
3.2.3 tear failure, n—in tensile testing of films, a failure
mine the applicability of regulatory limitations prior to use.
characterized by fracture initiating at one edge of the specimen
This practice is under the jurisdiction ofASTM Committee D20 on Plastics and
isthedirectresponsibilityofSubcommitteeD20.96onEnvironmentallyDegradable
Plastics and Biobased Products. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2018. Published November 2018. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1991. Last previous edition approved in 2013 as D3826 – 98 (2013). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D3826-18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3826 − 18
it is likely to be advantageous to increase slightly the radius of curvature
and progressing across the specimen at a rate slow enough to
of the edges where the grips come in contact with the test area of the
produce an anomalous load-deformation curve.
specimen.
3.3 Definitions of Terms Specific to This Standard:
5.3 Thickness Gage—A dead-weight dial micrometer as
3.3.1 film, n—for the purpose of this practice, a piece of
prescribed in Method C of Test Methods D374/D374M,
material not exceeding 0.250 mm (0.01 in.) in thickness.
reading to 0.0025 mm (0.0001 in.) or less.
3.3.2 brittle point, n—in degradable polyethylene/
5.4 Width-Measuring Devices—Suitable test scales or other
polypropylene film, that point in the history of a material when
width-measuringdevicescapableofreadingto0.25mm(0.010
75 % of the specimens tested have a tensile elongation at break
in.) or less.
of 5 % or less.
5.5 Specimen Cutter—Fixtures incorporating razor blades,
suitablepapercutters,orotherdevicescapableofsafelycutting
4. Significance and Use
the specimens to the proper width and producing straight,
4.1 The tensile elongation property determined by this
clean, parallel edges with no visible imperfections. A device
practice is of value for the characterization of degradable
consisting of two parallel knives mounted firmly against a
materials. It is possible that the tensile elongation property will
precision-ground base shear-block (similar to a paper cutter)
vary with specimen thickness, method of preparation, speed of
has proved satisfactory. The use of striking dies is not
testing, type of grips used, and manner of measuring test
recommended because poor and it is possible that inconsistent
extension.Consequently,whereprecisecomparativeresultsare
specimen edges will be produced. It is imperative that the
desired, these factors must be carefully controlled.
cutting edges be kept sharp and free from visible scratches or
4.2 It is acceptable to use the tensile elongation property to
nicks.
provide data for research and development and engineering
5.6 Extension Indicators—Ifemployed,extensionindicators
design as well as quality control specifications. However, data
shall conform to requirements specified in Test Method D638.
from such tests cannot be considered significant for applica-
In addition, such apparatus shall be so designed as to minimize
tions differing widely from the load-time scale of the test
stressonthespecimenatthecontactpointsofthespecimenand
employed.
the indicator.
4.3 Materials that fail by tearing give anomalous data that
NOTE 3—A high-response speed in the recording system is desirable,
cannot be compared with those from normal failure.
particularly when relatively high strain rates are employed for rigid
4.4 Before proceeding with this test method, reference materials. The speed of pen response for recorders is supplied by
manufacturers of this equipment. Take care to conduct tests at conditions
needs to be made to the specifications of the material being
suchthatresponsetime(abilityofrecordertofollowactualload)produces
tested. Any test specimen preparation, conditioning,
less than 2 % error.
dimensions, or testing parameters or a combination thereof,
6. Test Specimen
covered in the material specifications shall take precedence
over those mentioned in this test method. If there are no
6.1 Cut test specimens prior to exposure. Take utmost care
material specifications, then the default conditions apply.
in cutting specimens to prevent nicks and tears that are likely
to cause premature failures (see Note 4). The edges shall be
5. Apparatus
parallel to within 5 % of the width over the length of the
5.1 Testing Machines: specimen between the grips.
5.1.1 Use a testing machine of the constant rate-of-jaw-
NOTE 4—Amicroscopic examination of the specimen is a potential way
separation type. The machine shall be equipped with a weigh-
to detect flaws due to sample or specimen prep
...

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: D3826 − 98 (Reapproved 2013) D3826 − 18
Standard Practice for
Determining Degradation End Point in Degradable
Polyethylene and Polypropylene Using a Tensile Test
This standard is issued under the fixed designation D3826; 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 practice covers the determination of a degradation-end point (a brittle point) for degradable polyethylene/
polypropylene films and sheeting less than 1.0 mm (0.04 in.) thick. This practice is not intended for determination of the rate ofor
degree of degradation of a polyethylene/polypropylene film or sheet, but rather, to assess when in the course of its degradation
under some condition, a brittle point is reached. If one wishes to monitor tensile elongation during the degradation process (such
as when the tensile elongation is significantly greater than 5 %), Test Method D882 is recommended. This practice shouldis not
to be considered the only way of determining a degradation-end point.
1.2 Tensile properties of plastics 1.0 mm (0.04 in.) or greater in thickness shall be determined in accordance with Test Method
D638.
1.3 Use a static weighing-constant rate of grip separation test. This procedure employs a constant rate of separation of the grips
holding the sample and a static load cell.
NOTE 1—This procedure is based on the use of grip separation as a measure of extension; however, the desirability of using extension indicators
accurate to 61.0 % or better as specified in Test Method D638 is recognized, and a provision for the use of such instrumentation is incorporated in the
procedure.
1.4 This procedure has been successful for determining the degradation end point of ethylene-carbon-monoxide copolymers and
has screened successfully two other additive-type polyethylenes in a round robin test.
1.5 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.7 There is no equivalent ISO standard.
1.8 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
2.1 ASTM Standards:
D374D374/D374M Test Methods for Thickness of Solid Electrical Insulation (Metric) D0374_D0374M
D618 Practice for Conditioning Plastics for Testing
D638 Test Method for Tensile Properties of Plastics
D882 Test Method for Tensile Properties of Thin Plastic Sheeting
D883 Terminology Relating to Plastics
D5208 Practice for Fluorescent Ultraviolet (UV) Exposure of Photodegradable Plastics
D5947 Test Methods for Physical Dimensions of Solid Plastics Specimens
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.96 on Environmentally Degradable
Plastics and Biobased Products.
Current edition approved Feb. 1, 2013Nov. 1, 2018. Published February 2013November 2018. Originally approved in 1991. Last previous edition approved in 20082013
as D3826 – 98 (2008).(2013). DOI: 10.1520/D3826-98R13.10.1520/D3826-18.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3826 − 18
3. Terminology
3.1 Definitions of Terms—For definitions of terms used in this specification associated with plastics issues refer to the
terminology contained in Terminology D883.
3.2 Definitions:
3.2.1 Definitions of terms and symbols relating to tension testing of plastics appear in the Annex to Test Method D638.
3.2.2 line grips, n—in tensile testing machines, grips having faces designed to concentrate the entire gripping force along a
single line perpendicular to the direction of testing stress.
3.2.3 tear failure, n—in tensile testing of films, a failure characterized by fracture initiating at one edge of the specimen and
progressing across the specimen at a rate slow enough to produce an anomalous load-deformation curve.
3.3 Definitions of Terms Specific to This Standard:
3.3.1 film, n—for the purpose of this practice, a piece of material not exceeding 0.250 mm (0.01 in.) in thickness.
3.3.2 brittle point, n—in degradable polyethylene/polypropylene film, that point in the history of a material when 75 % of the
specimens tested have a tensile elongation at break of 5 % or less.
4. Significance and Use
4.1 The tensile elongation property determined by this practice is of value for the characterization of degradable materials. The
It is possible that the tensile elongation property maywill vary with specimen thickness, method of preparation, speed of testing,
type of grips used, and manner of measuring test extension. Consequently, where precise comparative results are desired, these
factors must be carefully controlled.
4.2 The It is acceptable to use the tensile elongation property may be utilized to provide data for research and development and
engineering design as well as quality control specifications. However, data from such tests cannot be considered significant for
applications differing widely from the load-time scale of the test employed.
4.3 Materials that fail by tearing give anomalous data that cannot be compared with those from normal failure.
4.4 Before proceeding with this test method, reference should needs to be made to the specifications of the material being tested.
Any test specimen preparation, conditioning, dimensions, or testing parameters or a combination thereof, covered in the material
specifications shall take precedence over those mentioned in this test method. If there are no material specifications, then the
default conditions apply.
5. Apparatus
5.1 Testing Machines:
5.1.1 Use a testing machine of the constant rate-of-jaw-separation type. The machine shall be equipped with a weighing system
that moves a maximum distance of 2 % of the specimen extension within the range being measured. Also, there should needs to
be a device for recording the tensile load and the amount of separation of the grips; both of these measuring systems shall be
accurate to 62 %. The rate of separation of the grips shall be uniform and capable of adjustment from approximately 1.3 to 500
mm/min (0.05 to 20 in./min) in increments necessary to produce the strain rates specified in 9.2.
5.2 Grips—Use a gripping system that minimizes both slippage and uneven stress distribution with the test specimen.
NOTE 2—Grips lined with thin rubber, crocus-cloth, or pressure-sensitive tape as well as file-faced or serrated grips have been successfully used for
many materials. The choice of grip surface depends on the material tested and thickness. More recently, line grips padded on the round face with 1.0 mm
(40 mil) blotting paper have been found superior. Air-actuated grips have been found advantageous, particularly in the case of materials that tend to neck
into the grips, since pressure is maintained at all times. In cases where samples frequently fail at the edge of the grips, it may is likely to be advantageous
to increase slightly the radius of curvature of the edges where the grips come in contact with the test area of the specimen.
5.3 Thickness Gage—A dead-weight dial micrometer as prescribed in Method C of Test Methods D374D374/D374M, reading
to 0.0025 mm (0.0001 in.) or less.
5.4 Width-Measuring Devices—Suitable test scales or other width-measuring devices capable of reading to 0.25 mm (0.010 in.)
or less.
5.5 Specimen Cutter—Fixtures incorporating razor blades, suitable paper cutters, or other devices capable of safely cutting the
specimens to the proper width and producing straight, clean, parallel edges with no visible imperfections. A device consisting of
two parallel knives mounted firmly against a precision-ground base shear-block (similar
...