ASTM D7399-18

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: D7399 − 18
Standard Test Method for
Determination of the Amount of Polypropylene in
Polypropylene/Low Density Polyethylene Mixtures Using
Infrared Spectrophotometry
This standard is issued under the fixed designation D7399; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* E932PracticeforDescribingandMeasuringPerformanceof
Dispersive Infrared Spectrometers
1.1 This test method uses an infrared spectrometer for
E1421Practice for Describing and Measuring Performance
determining the amount of polypropylene (PP) physically
of Fourier Transform Mid-Infrared (FT-MIR) Spectrom-
mixedinwithlowdensitypolyethylene–usuallyforrecycling
eters: Level Zero and Level One Tests
purposes.
IEEE/ASTM SI-10Standard for Use of the International
NOTE1—Quantitativedeterminationsrequireseveralstandardmixtures
System of Units (SI): The Modern Metric System
in the concentration range of interest and well defined baseline anchoring
points. See Practice E168 for guidance.
3. Terminology
1.2 This standard does not purport to address all of the
3.1 Definitions—For definitions of plastics terms used in
safety concerns, if any, associated with its use. It is the
this test method, see Terminology standards D883 and D1600.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3.2 Terminology—Units,symbols,andabbreviationsusedin
mine the applicability of regulatory limitations prior to use.
this test method appear in Terminology E131 or IEEE/ASTM
NOTE 2—There is no known ISO equivalent to this standard. SI-10.
1.3 This international standard was developed in accor-
4. Summary of Test Method
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.1 Thin films representing a typical portion of the material
Development of International Standards, Guides and Recom-
are analyzed with an infrared spectrophotometer using two
mendations issued by the World Trade Organization Technical
absorbance bands—one characteristic for PP and one for
Barriers to Trade (TBT) Committee.
LDPE.Theratioofthesetwoabsorbenciesisusedtoassessthe
presence of polypropylene.
2. Referenced Documents
4.2 For quantitative determinations, several standards with
2.1 ASTM Standards:
known concentrations of PP in LDPE bracketing the range of
D883Terminology Relating to Plastics
interest are needed to develop a calibration curve. In addition,
D1600TerminologyforAbbreviatedTermsRelatingtoPlas-
baseline placement process is defined so as to produce repeat-
tics
able results.
D2238TestMethodsforAbsorbanceofPolyethyleneDueto
−1
Methyl Groups at 1378 cm
5. Significance and Use
E131Terminology Relating to Molecular Spectroscopy
E168Practices for General Techniques of Infrared Quanti-
5.1 In recycling PP and LDPE, it is important to the end
tative Analysis
product properties as well as to the processing conditions to
know what the composition of the mixture is.
ThistestmethodisunderthejurisdictionofASTMCommitteeD20onPlastics
6. Interferences
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
Current edition approved April 1, 2018. Published April 2018. Originally
6.1 PresenceofmaterialsotherthanPPorLDPEinasample
approved in 2008. Last previous edition approved in 2008 as D7399-08, which was
can cause error in measurement.
withdrawn February 2017 and reinstated in April 2018. DOI: 10.1520/D7399-18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.2 Inhomogeneity of sample is known to cause false
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
readings. It is recommended to verify the sample homogeneity
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. by measuring at least three different areas of the sample.
*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
D7399 − 18
7. Apparatus 9.2.2 Set the controls of the infrared spectrophotometer to
give a good signal to noise ratio. Increasing the number of
7.1 Infrared Spectrophotometer, either double beam or a
scans if a larger signal to noise ratio is required. User defined
Fourier transform.
quality objectives will define the minimum signal to noise
7.1.1 Double-Beam Infrared Spectrophotometer, capable of
-1
-1 ratio.Aspectralresolutionof4cm ,aBeer-Nortonmediumor
at least 4 cm spectral resolution as defined in Practice E932.
Happ-Genzel apodization function and 32 scans have been
The instrument shall be capable of scale expansion along the
found to be appropriate.
wavelength axis.
9.2.3 Record the infrared spectrum starting from at least
7.1.2 Fourier Transform Infrared Spectrometer (FTIR), ca-
-1 -1
-1
4000 cm to 700 cm or lower.
pable of at least 4 cm resolution. The instru
...