ASTM D3168-85(2022)

Standard Practice for Qualitative Identification of Polymers in Emulsion Paints

SIGNIFICANCE AND USE
5.1 Identification of specific acrylic polymers in emulsion paints is often difficult or impossible by infrared alone. This is particularly true when the acrylic is present in a small amount as a comonomer with vinyl acetate, or when blended with alkyds or other ester systems. If identification of an acrylic component is required in such a system, it may often be accomplished by gas-liquid chromatographic analysis of the pyrolyzed paint film. The presence of a number of other polymers may often also be confirmed by pyrolysis since they produce characteristic and reproducible pyrograms.  
5.2 The pyrograms obtained from unknown samples vary in complexity according to the sample composition. It is necessary to establish the presence or absence of as many components as possible from a study of the infrared spectra obtained in the first part of this practice. The gas-liquid chromatography results may then be used to help identify any unknown components present and to confirm identifications made by infrared.
SCOPE
1.1 This practice describes a procedure for the qualitative identification in emulsion paints of most types of polymers present as major components of the paint vehicle. Limitations are discussed in Sections 5 and 10.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
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: 30-Nov-2022
• ICS: 87.040 - Paints and varnishes
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.21 - Chemical Analysis of Paints and Paint Materials

Relations

• Refers: ASTM D16-24 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Jan-2024
• Refers: ASTM D2621-87(2016) - Standard Test Method for Infrared Identification of Vehicle Solids From Solvent-Reducible Paints
• Effective Date: 01-Dec-2016
• Refers: ASTM D16-16 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Jul-2016
• Refers: ASTM D16-14 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Dec-2014
• Refers: ASTM D16-12 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Aug-2012
• Refers: ASTM D16-11a - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Jun-2011
• Refers: ASTM D2621-87(2011) - Standard Test Method for Infrared Identification of Vehicle Solids From Solvent-Reducible Paints
• Effective Date: 01-Jun-2011
• Refers: ASTM D16-11 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Jan-2011
• Refers: ASTM D16-10 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Feb-2010
• Refers: ASTM E275-08 - Describing and Measuring Performance of Ultraviolet and Visible Spectrophotometers
• Effective Date: 15-Oct-2008
• Refers: ASTM D16-08 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Jul-2008
• Refers: ASTM D16-07 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 01-Jul-2007
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D2621-87(2005) - Standard Test Method for Infrared Identification of Vehicle Solids From Solvent-Reducible Paints
• Effective Date: 01-Jul-2005
• Refers: ASTM D16-03 - Standard Terminology for Paint, Related Coatings, Materials, and Applications
• Effective Date: 10-Jul-2003

Overview

ASTM D3168-85(2022), titled Standard Practice for Qualitative Identification of Polymers in Emulsion Paints, is an internationally recognized standard developed by ASTM for the qualitative identification of polymers used as major components in emulsion paint vehicles. This standard outlines a practical, reliable methodology combining infrared (IR) spectroscopy and pyrolysis-gas liquid chromatography (pyrolysis-GLC) for identifying a wide range of polymer types in paint formulations.

The standard is essential for manufacturers, quality control laboratories, and researchers who require accurate identification of polymers, particularly acrylics, vinyl acetates, alkyds, and their blends, in emulsion paints. ASTM D3168-85(2022) helps ensure paint performance, regulatory compliance, and supports the investigation of product composition in both industrial and commercial applications.

Key Topics

• Polymer Identification in Emulsion Paints: Focuses on the qualitative identification of most polymer types present in significant quantities in paint vehicles.
• IR Spectroscopy and Limitations: IR analysis is a primary method for initial identification, but can be limited when acrylics are present in minor amounts or are part of complex blends.
• Pyrolysis-Gas Liquid Chromatography: When IR alone does not suffice, pyrolysis followed by gas-liquid chromatographic analysis of the paint film provides characteristic and reproducible pyrograms, helping confirm the presence of specific acrylic and other polymers.
• Sample Preparation: Details on extracting paint vehicles, removing impurities, and preparing samples for accurate analysis.
• Safety and Regulatory Considerations: Emphasizes the user’s responsibility for adhering to safety, health, environmental, and regulatory guidelines.

Applications

ASTM D3168-85(2022) finds practical application across various sectors of the paint and coatings industry:

• Quality Control: Ensures that paint products meet formulated ingredient specifications by confirming the presence of required polymer types.
• Research and Development: Assists in evaluating new emulsion paint formulations and identifying the impact of different polymers on paint performance.
• Regulatory Compliance: Supports meeting regulatory requirements regarding the composition of emulsion paints by providing a standardized identification process.
• Forensic and Failure Analysis: Used in investigating product failures, disputes, or deviations in performance by verifying the paint’s polymer composition.
• Raw Material Verification: Assesses incoming raw materials, ensuring that the supplied emulsions contain the correct polymer blend for the intended application.

Related Standards

For comprehensive analysis and quality assurance in paint and coatings, the following related ASTM standards complement D3168-85(2022):

• ASTM D16: Terminology for Paint, Related Coatings, Materials, and Applications - provides definitions of key terms used in the industry.
• ASTM D1193: Specification for Reagent Water - ensures consistency in water quality for analytical procedures.
• ASTM D2621: Test Method for Infrared Identification of Vehicle Solids from Solvent-Reducible Paints - supports identification of vehicle solids using IR spectroscopy.
• ASTM E275: Practice for Describing and Measuring Performance of Ultraviolet and Visible Spectrophotometers - offers guidance on performance measurement for spectroscopy instruments.

Practical Value

Implementing ASTM D3168-85(2022) in laboratory and industrial settings ensures a reliable, efficient, and standardized process for identifying polymers in emulsion paints. This reduces the risk of product inconsistencies, enhances traceability, and underpins informed decision-making in product formulation, quality assurance, and regulatory compliance. By using a combination of infrared analysis and pyrolysis-GC, users benefit from high-confidence identification even in complex blends or low-concentration components, supporting the integrity and performance of emulsion paints in diverse applications.

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: D3168 −85 (Reapproved 2022)
Standard Practice for
Qualitative Identification of Polymers in Emulsion Paints
This standard is issued under the fixed designation D3168; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 4. Summary of Practice
1.1 This practice describes a procedure for the qualitative 4.1 The vehicle is extracted from the dried paint and after
identification in emulsion paints of most types of polymers filtering is cast on a salt plate. The infrared spectrum is
present as major components of the paint vehicle. Limitations obtainedandcomparedwithreferencespectraforidentification
are discussed in Sections 5 and 10. of major components.
1.2 The values stated in SI units are to be regarded as the 4.2 The paint is applied to a filament and pyrolyzed to
standard. The values given in parentheses are for information depolymerizethevehicle.Aninternalstandardisaddedandthe
only. pyrolyzate is separated into its components by gas-liquid
chromatography. Monomers are identified by comparison of
1.3 This standard does not purport to address all of the
relative retention times.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 5.1 Identification of specific acrylic polymers in emulsion
1.4 This international standard was developed in accor-
paints is often difficult or impossible by infrared alone. This is
dance with internationally recognized principles on standard- particularly true when the acrylic is present in a small amount
ization established in the Decision on Principles for the
as a comonomer with vinyl acetate, or when blended with
Development of International Standards, Guides and Recom- alkyds or other ester systems. If identification of an acrylic
mendations issued by the World Trade Organization Technical
component is required in such a system, it may often be
Barriers to Trade (TBT) Committee. accomplished by gas-liquid chromatographic analysis of the
pyrolyzed paint film. The presence of a number of other
2. Referenced Documents
polymers may often also be confirmed by pyrolysis since they
2.1 ASTM Standards:
produce characteristic and reproducible pyrograms.
D16TerminologyforPaint,RelatedCoatings,Materials,and
5.2 Thepyrogramsobtainedfromunknownsamplesvaryin
Applications
complexity according to the sample composition. It is neces-
D1193Specification for Reagent Water
sary to establish the presence or absence of as many compo-
D2621Test Method for Infrared Identification of Vehicle
nents as possible from a study of the infrared spectra obtained
Solids From Solvent-Reducible Paints
inthefirstpartofthispractice.Thegas-liquidchromatography
E275PracticeforDescribingandMeasuringPerformanceof
results may then be used to help identify any unknown
Ultraviolet and Visible Spectrophotometers
components present and to confirm identifications made by
infrared.
3. Terminology
3.1 Definitions—For definitions of terms, refer to Terminol-
6. Interferences
ogy D16.
6.1 Dibutylmaleateanddibutylfumaratemonomersarenot
successfully recovered by this procedure. If their presence is
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
suspected as comonomer in a vinyl acetate copolymer system,
Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
n-butyl alcohol should be found in the pyrolyzate. This
Current edition approved Dec. 1, 2022. Published December 2022. Originally
evidence, together with the absence of butyl acrylate or butyl
approved in 1973. Last previous edition approved in 2016 as D3168–85(2016).
methacrylate monomer peaks, is an indirect indication of the
DOI: 10.1520/D3168-85R22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or presence of one or both of these monomers.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.2 The presence of relatively low quantities of copolymer-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ized acids may not be successfully established by this
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3168 − 85 (2022)
procedure, due to some unavoidable decomposition of acrylate where such specifications are available. Other grades may be
and methacrylate esters to acrylic or methacrylic acid and the used, provided it is first ascertained that the reagent is of
corresponding alcohols during the pyrolysis. The infrared sufficiently high purity to permit its use without lessening the
spectrum and an acid number determination, both run on the accuracy of the determination.
polymer solids, may usually be relied upon to establish the
8.2 Purity of Water—Unless otherwise indicated, reference
presence or absence of acid groups in the polymer.
towatershallbeunderstoodtomeanreagentwaterconforming
to Type II of Specification D1193.
6.3 In the case where the polymer being analyzed is simple
(such as a vinyl acetate-alkyl ester copolymer, or a single
8.3 Extraction Solvent Mixture—Equal volumes of o-
acrylate-methacrylate copolymer), it might be advantageous to
dichlorobenzene, dimethylformamide, and tetrahydrofuran.
examine the total pyrolyzate directly by infrared (as a solution
8.4 Liquid Nitrogen.
in carbon disulfide).
8.5 Petroleum Ether (30°C to 60°C boiling range) or
heptane.
7. Apparatus
9. Procedure—Infrared Analysis
7.1 Spectrophotometer, recording, double-beam, infrared,
with a range from at least 2.5 µm to 15 µm and a spectral
9.1 Transfer 1g to 2g of emulsion paint to a 100mL
resolutionofatleast0.04µmoverthatrange.Forcheckingthe
borosilicate glass beaker. Add approximately 2 mL of water
performance of the infrared spectrophotometer, see Practice
andswirloruseacleanglassrodtospreadthepaintuniformly
E275.
over the bottom of the beaker.
7.2 Cell Mount, demountable.
9.2 Place the beaker in an oven at 105°C to 6 2°C for at
least 2h, breaking up any skins that form so that complete
7.3 Halide Salt Crystals, for use with demountable cell
drying is ensured.
mount.
9.3 Add50mLofwater,coverwithawatchglass,andplace
7.4 Oven, gravity or forced-draft, maintained at 105°C 6
on a steam bath or low-temperature hotplate for 1h. This
2°C.
process removes emulsifiers, protective colloids, and other
7.5 Linear Programmed Temperature Gas Chromatograph, water-soluble components that might interfere with interpreta-
equipped with a thermal conductivity detector. tion of the infrared spectrum. Decant off the clear water layer
and discard. If the addition of the distilled water to the dried
7.6 PyrolysisAccessory—Anysuitableapparatusforachiev-
paint film produces a milky dispersion, the drying step in 9.2
ing pyrolysis external to the chromatograph, that results in the
was not complete and should be repeated.
recovery of sufficient pyrolyzate for identification purposes.
NOTE 1—If there is an interest in characterization of the emulsifier
The apparatus described in theAnnex has been found to meet
systemused,thewatershouldbefilteredthroughafine-texturefilterpaper
these requirements.
and taken to dryness. The solids may then be examined by infrared.
7.7 GasChromatographicColumn,3m(10ft)inlength,6.4
9.4 Dry for 15min to 20 min in an oven at 105°C to 6
mm ( ⁄4 in.) in outside diameter copper tubing packed with
2°C. Add 50 mL of petroleum ether or heptane, cover with a
10%siliconeresin on80to100-meshacid-washed,dimethyl-
watchglass, and bring to a slow boil for approximately 5 min.
dichlorosilane treated calcined diatomaceous earth.
This process removes most emulsified plasticizers, oils, and
other water insoluble, nonpolymeric organic materials, which
7.8 Steam Bath or Low-Temperature Hot Plate.
might also interfere with the interpretation of the infrared
7.9 Flask, small Dewar.
spectrum. Decant off the solvent and discard.
NOTE 2—If there is an interest in characterizing the water-insoluble
8. Reagents
petroleum ether-soluble fraction, it should also be filtered through
fine-texture paper, taken to dryness, and examined by infrared.
8.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
9.5 Add 10 mL of the extraction solvent mixture (8.3) and
all reagents shall conform to the specifications of the Commit-
place on a steam bath or low-temperature hotplate for approxi-
tee onAnalytical Reagents of theAmerican Chemical Society,
mately 1h. Filter, while still hot, through a fine-texture filter
paper. If the polymer solution is viscous, it may be diluted
further with extraction solvent mixture and warmed prior to
filtration.Alternatively, the pigment may be removed from the
The sole source of supply of silicone resin SE-30, known to the committee at
this time is General Electric Co. If you are aware of alternative suppliers, please polymersolutionbycentrifuging.Evaporatethesolutiononthe
provide this information toASTM International Headquarters.Your comments will
steam bath or hotplate to a volume of 1 mL or less.
receive careful consideration at a meeting of the responsible technical committee,
which you may attend.
The sole source of supply of Chromosorb W, known to the committee at this Reagent Ch
...