ASTM D465-15(2020)

Standard Test Methods for Acid Number of Pine Chemical Products Including Tall Oil and Other Related Products

SIGNIFICANCE AND USE
3.1 These test methods are designed to broaden the scope of the earlier editions of the test method by the inclusion of tall oil and tall oil derived products as test materials and will be referenced in Test Methods D803.  
3.2 The acid number is an important property of pine chemical products, such as tall oil, and the products obtained by the fractionation of tall oil. It is the test method widely used to determine the total free acid content of these products.  
3.3 The potentiometric test method should be used when the most reproducible results are required.
SCOPE
1.1 These test methods are intended for determining the acid number of pine chemical products as defined in Terminology D804 including tall oil products, wood and gum rosin, and other related materials. These test methods may not be applicable to all modified rosin products. Two test methods are covered, as follows:  
1.1.1 Potentiometric method (referee), and  
1.1.2 Internal indicator method (alternate).  
1.2 The potentiometric method is suitable for use with both light- and dark-colored products. It should be considered the referee method. The internal indicator method is suitable for use only with light- and medium-colored products with a Gardner color of less than 12. It should be considered the alternate method.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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.  
1.5 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-May-2020
• ICS: 87.060.20 - Binders
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.34 - Pine Chemicals and Hydrocarbon Resins

Relations

• Replaces: ASTM D465-15 - Standard Test Methods for Acid Number of Pine Chemical Products Including Tall Oil and Other Related Products
• Effective Date: 01-Jun-2020
• Refers: ASTM E70-24 - Standard Test Method for pH of Aqueous Solutions With the Glass Electrode
• Effective Date: 01-Jan-2024
• Refers: ASTM E70-07(2015) - Standard Test Method for pH of Aqueous Solutions With the Glass Electrode
• Effective Date: 01-Jun-2015
• Refers: ASTM E177-14 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2014
• 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 E177-13 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2013
• Refers: ASTM D803-12 - Standard Test Methods for Testing Tall Oil
• Effective Date: 01-Nov-2012
• Refers: ASTM D804-12 - Standard Terminology Relating to Pine Chemicals, Including Tall Oil and Related Products
• Effective Date: 01-Jun-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 E177-10 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Oct-2010
• Refers: ASTM E691-08 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Oct-2008
• Refers: ASTM E177-08 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Oct-2008
• Refers: ASTM D804-07 - Standard Terminology Relating to Naval Stores, Including Tall Oil and Related Products
• Effective Date: 01-Jun-2007
• Refers: ASTM E177-06b - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 15-Nov-2006
• Refers: ASTM E177-06a - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Nov-2006

Overview

ASTM D465-15(2020) is the internationally recognized standard for determining the acid number of pine chemical products, including tall oil, wood and gum rosin, and other related materials. Developed by ASTM International, this standard provides test methods essential for quality control and specification compliance in industries utilizing pine chemicals. The acid number is a key property reflecting the content of free acids, crucial for both raw materials assessment and finished product quality.

Key Topics

• Scope and Materials
  The standard is applicable to pine chemical products as defined in ASTM D804, such as:

  • Tall oil and tall oil-derived products
  • Wood and gum rosin
  • Related pine chemical materials
  • Not suitable for all modified rosin products

• Test Methods Provided

  • Potentiometric Method (Referee): Suitable for both light- and dark-colored products, offering the most reproducible and accurate results. Recommended as the primary method for official testing.
  • Internal Indicator Method (Alternate): Appropriate for light and medium-colored products (Gardner color <12). Provides a practical alternative when potentiometric equipment is not available.

• Units of Measurement

  • Results are reported in SI units only (mg KOH/g sample).

• Analytical Preparation

  • Requires careful sample preparation and handling to avoid oxidation.
  • Specific solvents and standard solutions must be used as outlined in the standard.

• Precision and Reproducibility

  • Repeatability and reproducibility limits are clearly defined, supporting consistent results across laboratories.

Applications

The acid number determination is critical in various sectors, particularly for manufacturers, processors, and users of pine chemicals. Practical applications include:

• Quality Control: Ensures that raw materials and finished pine chemical products meet desired acid content specifications, directly impacting product performance.
• Product Classification: Enables reliable classification of tall oil fractions and related derivatives based on their acid content.
• Regulatory Compliance: Supports conformance with customer and regulatory acid value requirements in multiple industries, including adhesives, inks, resins, and coatings.
• Research and Development: Provides standardized data for the development of new pine chemical products and formulations.
• Inter-laboratory Consistency: Offers validated precision and accuracy for acid number testing required in contract laboratories or multi-site organizations.

Related Standards

For comprehensive assessment and reference, the following ASTM standards are commonly used alongside ASTM D465-15(2020):

• ASTM D803: Test Methods for Testing Tall Oil
• ASTM D804: Terminology Relating to Pine Chemicals, Including Tall Oil and Related Products
• ASTM E70: Test Method for pH of Aqueous Solutions With the Glass Electrode
• ASTM E177: Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• ASTM E691: Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

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By providing standardized procedures for acid number measurement, ASTM D465-15(2020) ensures consistency, reliability, and comparability of results, greatly benefiting stakeholders in the pine chemicals industry. Proper application of this standard supports quality assurance, regulatory compliance, and industry best practices.

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: D465 − 15 (Reapproved 2020)
Standard Test Methods for
Acid Number of Pine Chemical Products Including Tall Oil
and Other Related Products
This standard is issued under the fixed designation D465; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 Thesetestmethodsareintendedfordeterminingtheacid
number of pine chemical products as defined in Terminology D803 Test Methods for Testing Tall Oil
D804 Terminology Relating to Pine Chemicals, Including
D804 including tall oil products, wood and gum rosin, and
other related materials. These test methods may not be appli- Tall Oil and Related Products
E70 Test Method for pH of Aqueous Solutions With the
cable to all modified rosin products. Two test methods are
covered, as follows: Glass Electrode
E177 Practice for Use of the Terms Precision and Bias in
1.1.1 Potentiometric method (referee), and
ASTM Test Methods
1.1.2 Internal indicator method (alternate).
E691 Practice for Conducting an Interlaboratory Study to
1.2 The potentiometric method is suitable for use with both
Determine the Precision of a Test Method
light- and dark-colored products. It should be considered the
referee method. The internal indicator method is suitable for
3. Significance and Use
use only with light- and medium-colored products with a
3.1 These test methods are designed to broaden the scope of
Gardner color of less than 12. It should be considered the
theearliereditionsofthetestmethodbytheinclusionoftalloil
alternate method.
and tall oil derived products as test materials and will be
1.3 The values stated in SI units are to be regarded as
referenced in Test Methods D803.
standard. No other units of measurement are included in this
3.2 The acid number is an important property of pine
standard.
chemical products, such as tall oil, and the products obtained
1.4 This standard does not purport to address all of the
by the fractionation of tall oil. It is the test method widely used
safety concerns, if any, associated with its use. It is the
to determine the total free acid content of these products.
responsibility of the user of this standard to establish appro-
3.3 Thepotentiometrictestmethodshouldbeusedwhenthe
priate safety, health, and environmental practices and deter-
most reproducible results are required.
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
4. Preparation of Sample
dance with internationally recognized principles on standard-
4.1 If the sample for analysis is rosin, it shall consist of
ization established in the Decision on Principles for the
small pieces of rosin chipped from a freshly exposed part of a
Development of International Standards, Guides and Recom-
lump or lumps, and thereafter crushed to facilitate weighing
mendations issued by the World Trade Organization Technical
and dissolution. Prepare the sample the same day on which the
Barriers to Trade (TBT) Committee.
test is begun, in order to avoid changes in properties due to
surface oxidation. This is very pronounced on ground rosin
having a large surface area exposed to the air. Existing rosin
These test methods are under the jurisdiction of ASTM Committee D01 on
dust and powdered rosin must not be used.
Paint and Related Coatings, Materials, and Applications and are the direct
responsibility of Subcommittee D01.34 on Pine Chemicals and Hydrocarbon
Resins. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved June 1, 2020. Published June 2020. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1937. Last previous edition approved in 2015 as D465 – 15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D0465-15R20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D465 − 15 (2020)
4.2 If the sample is a nonhomogenous liquid, heat the entire alcohol conforming to 5.1, and dilute to 1 L with the same
sample in a closed container fitted with a capillary vent or the solvent.Standardizeto 60.001Nbydissolvingpotassiumacid
equivalent. Some kind of agitation, even if done occasionally phthalate (KHP) in 60 mLof water followed by the addition of
byhand,savesmuchtime.Heatbyimmersioninopensteamor 40 mLof isopropyl alcohol once the KHPhas dissolved; 2.553
hot water bath to avoid overheating. When dealing with g of KHP will be neutralized by 25.0 mL of 0.5 N KOH
crystallized rosin a temperature of approximately 160°C may solution. Protect the standardized solution against evaporation
be needed. Sampling should take place only when the entire and absorption of carbon dioxide (CO ) from the air. The
sample is homogeneous and has been well stirred. solution should be standardized frequently, either potentio-
metrically or colorimetrically using either phenolphthalein or
4.3 For other products no special preparation is necessary
thymol blue as the indicator. The standardization should use
except storage in a closed container prior to testing.
the same equipment and techniques as used in the actual acid
4.4 Guideline for sample size, solvent, and titrant:
number determination.
Sample Size, Solvent I, Solvent II, Titrant,
7.2 Alkali, Standard Solution (0.1 N)—Dissolve 6.6 g of
Sample g mL mL KOH
potassium hydroxide (KOH) (pellets or sticks) in methyl
Fatty acids 4.0 ± 0.05 Isopropyl None 0.5N
alcohol conforming to 7.4, and dilute to 1 L with the same
A
DTO alcohol, or
solvent.Standardizeto 60.001Nbydissolvingpotassiumacid
Rosin soap
methanol
100 phthalate (KHP) in 60 mLof water followed by the addition of
40 mL of isopropyl alcohol once the KHP has dissolved;
FA esters 20 ± 0.1 Isopropyl None 0.1N
0.5106 g of KHPwill be neutralized by 25.0 mLof 0.1 N KOH
alcohol, or
methanol solution. Protect the standardized solution against evaporation
and absorption of carbon dioxide (CO ) from the air. The
solution should be standardized frequently, either potentio-
Rosin 4.0 ± 0.05 Toluene 25 Isopropyl 0.5N
A
CTO alcohol 75
metrically or colorimetrically using either phenolphthalein or
Pitch
thymol blue as the indicator. The standardization should use
Rosin esters 10 ± 0.1 Toluene 25 Isopropyl 0.1N the same equipment and techniques as used in the actual acid
10±0.1g alcohol 75
number determination.
A
7.3 Isopropyl Alcohol, as in 5.1.
DTO represents distilled tall oil, while CTO represents crude tall oil.
7.4 Methyl Alcohol, as in 5.1.
5. Purity of Reagents and Water
7.5 Toluene, as in 5.1.
5.1 Unless otherwise indicated, it is intended that all re-
7.6 Borax Buffer, Standard Solution (0.01 M, pH 9.18 at
agents shall conform to the specifications established by the
Committee on Analytical Reagents of the American Chemical 25°C)—Dissolve 3.81 6 0.01 g of disodium tetraborate
(Na B O 10H O) in water and dilute to 1 L in a volumetric
Society, where such specifications are available. References to
2 4 7 2
flask. Use the special grade of borax prepared specifically for
watershallbeunderstoodtomeandistilledordeionizedwater.
use as a pH standard. As an alternative, a commercially
POTENTIOMETRIC METHOD (REFEREE METHOD)
available buffer with a pH between 9 and 11 may be used
instead of self-prepared standard.
6. Apparatus
8. Standardization of Apparatus
6.1 Glass Elect
...