ASTM D4419-90(2021)

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: D4419 − 90 (Reapproved 2021)
Standard Test Method for
Measurement of Transition Temperatures of Petroleum
Waxes by Differential Scanning Calorimetry (DSC)
This standard is issued under the fixed designation D4419; 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 E472 Practice for Reporting Thermoanalytical Data (With-
drawn 1995)
1.1 This test method covers the transition temperatures of
E473 Terminology Relating to Thermal Analysis and Rhe-
petroleum waxes, including microcrystalline waxes, by differ-
ology
ential scanning calorimetry (DSC). These transitions may
E474 Method for Evaluation of Temperature Scale for Dif-
occur as a solid-solid transition or as a solid-liquid transition.
ferential Thermal Analysis (Withdrawn 1986)
1.2 The normal operating temperature range extends from
15 °C to 150 °C (Note 1). 3. Terminology
1.3 The values stated in SI units are to be regarded as the 3.1 Definitions of Terms Specific to This Standard:
3.1.1 Differential Scanning Calorimetry (DSC), n—A tech-
standard.
nique in which the difference in energy inputs into a substance
1.4 This standard does not purport to address all of the
and a reference material is measured as a function of
safety concerns, if any, associated with its use. It is the
temperature, while the substance and a reference material are
responsibility of the user of this standard to establish appro-
subjected to a controlled temperature program. The record is
priate safety, health, and environmental practices and deter-
the DSC curve. Two modes, power-compensation DSC and
mine the applicability of regulatory limitations prior to use.
heat-flux DSC, can be distinguished depending on the method
1.5 This international standard was developed in accor-
of measurement used. For additional background information
dance with internationally recognized principles on standard-
refer to Practice E472, Terminology E473, and Test Method
ization established in the Decision on Principles for the
E474.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
4. Summary of Test Method
Barriers to Trade (TBT) Committee.
4.1 Separate samples of petroleum wax and a reference
material or blank (empty sample container) are heated at a
2. Referenced Documents
controlled rate in an inert atmosphere. A sensor continuously
2.1 ASTM Standards:
monitors the difference in heat flow to the two samples. The
D87 Test Method for Melting Point of Petroleum Wax
DSC curve is a record of this difference versus temperature. A
(Cooling Curve)
transition in the wax involves the absorption of energy relative
D1160 Test Method for Distillation of Petroleum Products at
to the reference, resulting in an endothermic peak in the DSC
Reduced Pressure
curve. While the transition occurs over the temperature range
D3418 Test Method for Transition Temperatures and Enthal-
spanned by the base of the peak, the temperature associated
pies of Fusion and Crystallization of Polymers by Differ-
with the peak apex is designated the nominal transition
ential Scanning Calorimetry
temperature (Note 1).
NOTE 1—Test Method D87 also monitors energy transfer between wax
and a standard environment. The highest temperature DSC transition may
This test method is under the jurisdiction of ASTM Committee D02 on
differ from the melting point because the two methods approach the
Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of
solid/liquid phase transition from different directions.
Subcommittee D02.10 on Properties of Petroleum Waxes and Alternative Wax-like
Materials.
5. Significance and Use
Current edition approved Jan. 1, 2021. Published February 2021. Originally
5.1 DSC in a convenient and rapid method for determining
approved in 1984. Last previous edition approved in 2015 as D4419 – 90 (2015).
DOI: 10.1520/D4419-90R21.
the temperature limits within which a wax undergoes during
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4419 − 90 (2021)
transitions. The highest temperature transition is a solid-liquid 9. Calibration
transition associated with complete melting; it can guide the
9.1 Using the instrument manufacturer’s recommended
choice of wax storage and application temperatures. The
procedure, calibrate the instrument’s temperature scale over
solid-solid temperature transition is related to the properties of
the temperature range of interest with appropriate standards.
the solid, that is, hardness and blocking temperature.
These include, but are not limited to:
NOTE 2—For a relatively narrow cut petroleum wax, the lowest
Melting Point
transition will be a solid-solid transition. A narrow cut wax is one obtained
Standard 99 % Purity Min. °C K
by deoiling a single petroleum distillate with a maximum range of 120 °F
Phenoxybenzene (1) 26.9 300.0
between its 5 % and 95 % vol in accordance with Test Method D1160
p-Nitrotoluene (2) 51.5 324.8
boiling points (converted to 760 torr). The DSC method cannot differen- Naphthalene (3) 80.3 353.6
A
Benzoic Acid 122.4 395.7
tiate between solid-liquid and solid-solid transitions. Such information
Adipic Acid (4) 153.0 426.3
must be predetermined by other techniques. In the case of blends, the
Indium Metal (1) 156.6 429.9
lower temperature transition may be envelopes of both solid-liquid and
solid-solid transitions.
A
See Test Method D3418. 99.98 % purity available from U.S. Bureau of Standards
5.2 Since petroleum wax is a mixture of hydrocarbons with
as SRM 350.
different molecular weights, its transitions occur over a tem-
9.2 The specimen weight and test procedure should be those
perature range. This range is one factor that influences the
specified in Section 10, except that the precycle (11.3) is
width, expressed in °C, of the DSC peaks. The highest
omitted.
temperature transition is a first-order transition. If, for a series
of waxes, there is supporting evidence that the highest tem-
10. Specimen Preparation
perature transition of each wax is the major first-order
10.1 To ensure homogeneity, completely melt the entire
transition, its relative width should correlate with the relative
sample by heating it to 10 °C above the temperature at which
width of the wax’s molecular weight distribution.
the wax is completely molten. Using a clean eyedropper,
transfer a few drops to the surface of a clean sheet of aluminum
6. Interferences
foil to form a thin wax film. Separate the wax from the foil, and
6.1 The test specimen must be homogeneous and represen-
break it into pieces.
tative. The small sample size (10 mg) makes these require-
ments particularly important. 11. Procedure
11.1 Weigh 10 mg 6 1 mg of the wax pieces into a sample
6.2 Intimate thermal contact, sample-to-pan and pan-to-
sensor, is essential to obtain accurate and reproducible results. pan, and insert the pan in the calorimeter sample compartment.
6.3 The heating rate must be the specified 10 °C ⁄min 6 NOTE 3—Intimate thermal contact, sample-to-pan and pan-to-sensor, is
essential. Ensure that pan bottoms are flat and also that sensor surfaces
1 °C ⁄min. Faster or slower rates will produce a different
where pans rest are clean. If the equip
...