ASTM D4419-90(2005)
(Test Method)Standard Test Method for Measurement of Transition Temperatures of Petroleum Waxes by Differential Scanning Calorimetry (DSC)
Standard Test Method for Measurement of Transition Temperatures of Petroleum Waxes by Differential Scanning Calorimetry (DSC)
SIGNIFICANCE AND USE
DSC in a convenient and rapid method for determining the temperature limits within which a wax undergoes during transitions. The highest temperature transition is a solid-liquid transition associated with complete melting; it can guide the choice of wax storage and application temperatures. The solid-solid temperature transition is related to the properties of the solid, that is, hardness and blocking temperature.
Note 2—For a relatively narrow cut petroleum wax, the lowest transition will be a solid-solid transition. A narrow cut wax is one obtained by deoiling a single petroleum distillate with a maximum range of 120°F between its 5 % and 95 % vol in accordance with Test Method D 1160 boiling points (converted to 760 torr). The DSC method cannot differentiate between solid-liquid and solid-solid transitions. Such information must be predetermined by other techniques. In the case of blends, the lower temperature transition may be envelopes of both solid-liquid and solid-solid transitions.
Since petroleum wax is a mixture of hydrocarbons with different molecular weights, its transitions occur over a temperature range. This range is one factor that influences the width, expressed in °C, of the DSC peaks. The highest temperature transition is a first-order transition. If, for a series of waxes, there is supporting evidence that the highest temperature transition of each wax is the major first-order transition, its relative width should correlate with the relative width of the wax’molecular weight distribution.
SCOPE
1.1 This test method covers the transition temperatures of petroleum waxes, including microcrystalline waxes, by differential scanning calorimetry (DSC). These transitions may occur as a solid-solid transition or as a solid-liquid transition.
1.2 The normal operating temperature range extends from 15C to 150C (Note 1).
1.3 The values stated in SI units are to be regarded as the standard.
1.4This 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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:D4419–90(Reapproved 2005)
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 3.1.1 Differential Scanning Calorimetry (DSC)—A tech-
nique in which the difference in energy inputs into a substance
1.1 This test method covers the transition temperatures of
and a reference material is measured as a function of tempera-
petroleum waxes, including microcrystalline waxes, by differ-
ture, while the substance and a reference material are subjected
ential scanning calorimetry (DSC). These transitions may
to a controlled temperature program. The record is the DSC
occur as a solid-solid transition or as a solid-liquid transition.
curve. Two modes, power-compensation DSC and heat-flux
1.2 The normal operating temperature range extends from
DSC, can be distinguished depending on the method of
15°C to 150°C (Note 1).
measurement used. For additional background information
1.3 The values stated in SI units are to be regarded as the
refer to Practice
E472, Terminology E473, and Test Method
standard.
E474.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
4.1 Separate samples of petroleum wax and a reference
priate safety and health practices and determine the applica-
material or blank (empty sample container) are heated at a
bility of regulatory limitations prior to use.
controlled rate in an inert atmosphere. A sensor continuously
2. Referenced Documents monitors the difference in heat flow to the two samples. The
DSC curve is a record of this difference versus temperature.A
2.1 ASTM Standards:
transition in the wax involves the absorption of energy relative
D87 Test Method for Melting Point of Petroleum Wax
to the reference, resulting in an endothermic peak in the DSC
(Cooling Curve)
curve. While the transition occurs over the temperature range
D1160 Test Method for Distillation of Petroleum Products
spanned by the base of the peak, the temperature associated
at Reduced Pressure
with the peak apex is designated the nominal transition
D3418 Test Method for Transition Temperatures and En-
temperature (Note 1).
thalpies of Fusion and Crystallization of Polymers by
Differential Scanning Calorimetry
NOTE 1—Test Method D87 also monitors energy transfer between wax
E472 Practice for Reporting Thermoanalytical Data and a standard environment. The highest temperature DSC transition may
differ from the melting point because the two methods approach the
E473 Terminology Relating to Thermal Analysis and Rhe-
solid/liquid phase transition from different directions.
ology
E474 Method for Evaluation of Temperature Scale for
5. Significance and Use
Differential Thermal Analysis
5.1 DSC in a convenient and rapid method for determining
3. Terminology the temperature limits within which a wax undergoes during
transitions. The highest temperature transition is a solid-liquid
3.1 Definitions of Terms Specific to This Standard:
transition associated with complete melting; it can guide the
choice of wax storage and application temperatures. The
This test method is under the jurisdiction of ASTM Committee D02 on
solid-solid temperature transition is related to the properties of
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
the solid, that is, hardness and blocking temperature.
D02.10 on Properties of Petroleum Wax.
Current edition approved May 1, 2005. Published May 2005. Originally
NOTE 2—For a relatively narrow cut petroleum wax, the lowest
approved in 1984. Last previous edition approved in 2000 as D4419 – 90 (2000).
transitionwillbeasolid-solidtransition.Anarrowcutwaxisoneobtained
DOI: 10.1520/D4419-90R05.
2 by deoiling a single petroleum distillate with a maximum range of 120°F
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
between its 5 % and 95 % vol in accordance with Test Method D1160
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
boiling points (converted to 760 torr). The DSC method cannot differen-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. tiate between solid-liquid and solid-solid transitions. Such information
Withdrawn. The last approved version of this historical standard is referenced
on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4419–90 (2005)
A
See Test Method D3418. 99.98 % purity available from U.S. Bureau of
must be predetermined by other techniques. In the case of blends, the
Standards as SRM 350.
lower temperature transition may be envelopes of both solid-liquid and
9.2 The specimen weight and test procedure should be those
solid-solid transitions.
specified in Section 10, except that the precycle (11.3)is
5.2 Since petroleum wax is a mixture of hydrocarbons with
omitted.
different molecular weights, its transitions occur over a tem-
perature range. This range is one factor that influences the
10. Specimen Preparation
width, expressed in °C, of the DSC peaks. The highest
10.1 To ensure homogeneity, completely melt the entire
temperature transition is a first-order transition. If, for a series
sample by heating it to 10°C above the temperature at which
of waxes, there is supporting evidence that the highest tem-
the wax is completely molten. Using a clean eyedropper,
perature transition of each wax is the major first-order transi-
transferafewdropstothesurfaceofacleansheetofaluminum
tion, its relative width should correlate with the relative width
foiltoformathinwaxfilm.Separatethewaxfromthefoil,and
of the wax’s molecular weight distribution.
break it into pieces.
6. Interferences
11. Procedure
6.1 The test specimen must be homogeneous and represen-
tative. The small sample size (10 mg) makes these require-
11.1 Weigh 10 6 1 mg of the wax pieces into a sample pan,
ments particularly important.
and insert the pan in the calorimeter sample compartment.
6.2 Intimate thermal contact, sample-to-pan and pan-to-
NOTE 3—Intimate thermal contact, sample-to-pan and pan-to-sensor, is
sensor, is essential to obtain accurate and reproducible results.
essential. Ensure that pan bottoms are flat and also that sensor surfaces
6.3 The heating rate must be the specified 10 6 1°C/min.
where pans rest are clean. If the equipment is available, it is advantageous
Faster or slower rates will produce a different transition
to ensure maximum sample-to-pan thermal contact by crimping a metal
temperature and transition peak width. cover against the pan with the sample sandwiched in between. A thermal
precycle (see section 10.3 ) improves pan contact and establishes the same
7. Apparatus
thermal history for every sample.
7.1 Differential Scanning Calorimeter, operating in either
11.2 Flushthesamplecompartmentofthetestcellwithinert
power compensation or heat flux mode, capable of heating at
gas throughout the test; a flow of 10 to 50 mL/min is typical.
10 6 1°C/min from 15°C to 150°C. Controlled cooling
11.3 Perform a thermal pr
...
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