The Use of Structuring Waxes in Developing Stick Formulations
Cosmetic formulations which rely on structuring agents such as Paraffin, Synthetic and Polyethylene waxes can
benefit from a better knowledge of the chemical nature of these waxes and what attributes they bring to the
formulation. This article will provide the cosmetic chemist some information concerning the use of Paraffin,
Synthetic and Polyethylene waxes. It will show that with the introduction of the new Acculin™ line of
Polyethylene Waxes from The International Group there is now a product that will bridge the gap from Paraffin
Wax to Polyethylene. These new Acculin™ waxes will complete the continuum of molecular weights as will be
described. This will also show how the physical properties of these wax types can affect a standard formulation.
Paraffin Wax
Paraffin Wax is the structural backbone of much cosmetic formulation. It can add hardness to lip care
formulation and increase the viscosity of emulsion products. Paraffin wax is a by product of mineral oil
manufacturing. Molecular weight distribution ranges from C-18 to C-60 but the useable range for cosmetics is
about C-22 to C-45. Within that range there are a variety of melting point products. Since most paraffins
contain straight chain and some branched chain molecules the physical characteristics can vary depending on the
method of manufacture. Paraffin wax is a distilled product so the molecular species with the same boiling point
will distill at the same time. So it is possible to have straight chain and branched chain (isomers) distilling at the
same time. Figure 1 show the typical molecular weight distribution of a paraffin wax. It is this molecular weight
distribution which gives the different physical characteristics of each paraffin wax.
Fig.1 Typical Gas Chromatograph of a Paraffin Wax
Figure 2 shows the relationship between the melting point and the penetration (Hardness) of some paraffin
waxes. Many times the two characteristics are confused but it should be pointed out that they are two different
distinct characteristics and do not necessarily correlate.
Penetration @ 25 C vs Melting Point Paraffin Wax
16
14
Penetration dmm
12
10
8
6
4
2
0
54.4
58.9
61.4
66.1
69.4
Melting Point Degree C
Fig. 2 Correlation between Melting Point and Penetration Paraffin Waxes
In cosmetics the use of paraffin wax imparts structure to the formulation. That structure generally leads to a
rigid, brittle product which then needs to be modified with oils and other waxes. The single largest use of
paraffin wax in cosmetics is in Color Cosmetics Lip Sticks, Lip Balms, Mascara, Eye Shadow and Eye Liners.
Synthetic Wax
Synthetic Waxes are generally known as Gas to Liquid (GTL) or Fischer Tropsch (FT) waxes. These are
produced by the reaction of Carbon Monoxide and Hydrogen gases by use of a catalysis. The Carbon Monoxide
can be sourced from coal, natural gas or from biomass. Through the controlled polymerization of these
materials these waxes can have long carbon chains. Figure 3 shows a typical GC of an FT wax. Although there
are some isomers in the FT waxes they are generally straight chain alkanes with both odd and even carbon chain
numbers.
Fig. 3 Typical GC of a Fischer Tropsch Wax
Figure 4 shows the relationship between the penetration and melting point of synthetic waxes. These are
polymer products with both even and odd carbon chains with lower isomer content than paraffin wax so that the
relationship between these two characteristics becomes more linear.
Penetration @ 25 C vs Melting Point Synthetic Wax
Penetration dmm
20
18
16
14
12
10
8
6
4
2
0
60
70
74.7
87
Melting Point Degree C
Fig. 4 Correlation between Penetration and Melting Point Synthetic Waxes
Polyethylene
Polyethylene is derived from ethylene gas via a polymerization process. This process produces carbon chains
which can range up into the hundreds. These waxes have high melting points and have very limited use in
cosmetic formulations. IGI had developed a new line of Polyethylenes called Acculin™ which have carbon
numbers and molecular weights ranges which are more useful in cosmetics. A typical GC of an Acculin™
product is shown in Figure 5.
Fig. 5 Typical GC of an Acculin™ Wax
As can be seen from the GC, Acculin™ wax is generally even carbon numbers with very low isomers content.
This would lead to a very linear melting point vs. penetration curve Figure 6.
Penetration @ 25 C vs Melting Point Acculin™ Wax
12
Penetration dmm
10
8
6
4
2
0
81
88
94
99
104
107
113
126
129
Melting Point Degree C
Fig. 6 Melting Point vs. Penetration Curve for Acculin Waxes
Once we understand the differences between these three waxes, it is important to know how each will perform in
a standard cosmetic stick formulation. The typical specifications for each of the waxes are in Table 1. The test
procedure for the various waxes changes due to the limits of each test procedure.
Typical Melting Point °C
ASTM D-87
Typical Congealing
Point °C
ASTM D-938
Typical Mettler Drop
Melt Point °C
ASTM D-3954
Paraffins
IGI
IGI
IGI
IGI
1230A
1302A
1303A
1260A
54.4
58.9
67.8
Typical Needle
Penetration, dmm @
77°F (25°C)
ASTM D-1321
14
12
14
12
69.4
Synthetic
IGI
IGI
IGI
IGI
8718A
8719A
8722A
8755A
60
69
76.7
83
25
15
13
9
79.4
88.9
92.8
97.2
12
6
2.5
2
Polyethylene
Acculin
Acculin
Acculin
Acculin
400
500
600
655
2053A
2056A
2059A
2061A
Table 1 Typical Properties of Test Waxes
The following formulation was used to show how the chemical makeup of each of the wax types affects a stick
formulation. No color was added to the stick so that only the influence of the waxes could be tested.
Sebapet L
Cetylstearyl Alcohol
Test Wax
Synthetic Candelilla Wax R4770A
Microcrystalline Wax 5788A
Lanolin Alcohol
Synthetic Carnauba Wax R5159A
Isopropyl Palmitate
11%
15%
10%
8%
6%
6%
4%
40%
The following tests were performed on each test formulation. Table 2 shows the results of these tests.
Capillary Tube Melting Point USP 741 sometimes referred to as the slip point. This test consists of filling a
standard capillary tube with molten sample and allowing it to solidify. The capillary tube is then attached to a
thermometer and immersed in a water bath. The bath temperature is slowly raised and the point at which the
wax rises in the tube is the melting point. This test method is well suited for formulated products.
Needle Penetration ASTM D1321 is a standardize test procedure whereby a wax sample is poured into a defined
mold and held at a specific temperature for a given period of time. The hardness of the wax is then determined
by using a standard needle attached to a penetrometer. Readings are given in dmm which is the distance the
needle travels into the sample, hence the higher the readings the softer the wax.
Break Test is used to determine the strength of a stick formed using a typical lipstick bullet. Lipstick bullets
were made using a small polycarbonate mold. The wax sample was poured into the mold at 190°F and
immediately place in a freezer. The temperature was monitored until it was at or below 77°F; this usually took
between 5-7 minutes. The mold was then removed from the freezer and placed in a constant temperature bath at
77°F for thirty minutes before the test was performed. The bullet was suspended between two plates while a
weight was hung from the center of the bullet. The weight was increased until the bullet broke. (Drawing 1)
This same device was used in an Instron to confirm the measurement. In the case of the Instron the two plates
were pulled apart until the bullet broke and the force in grams was determined. The two methods had good
correlation.
Drawing 1
Samples
Cap Tube Melting Needle Penetration Breakage
Point °C
@ 25°C
Grams
Identification USP 741
ASTM D-1321
Paraffin Wax
IGI 1230A
IGI 1302A
IGI 1303A
IGI 1260A
51
52
59
62
114
112
116
116
778
944
1146
941
Synthetic Wax
IGI 8718A
IGI 8719A
IGI 8722A
IGI 8755A
58
62
68
71
122
129
111
103
1113
1347
1325
1443
Acculin™
400 2053A
500 2056A
600 2059A
66
71
74
97
100
86
1293
1572
1730
Table 2 Test Results
The results of this testing demonstrates the effect of the chemical structure of each wax on the final formulation.
Paraffin waxes while varying in melting points had little effect on the penetration and breakage of the sticks.
Synthetic waxes showed some relationship between the change in melting point, penetration and breakage.
While the Acculin™ polyethylene waxes showed and overall harder penetration and higher breaking strengths.
This data also shows that relying on the melting point only in the selection of a wax may not give the best
indication of the overall quality of the finished product.
THE INTERNATIONAL GROUP INC.
USA
1007 East Spring Street
Titusville, PA 16354
Canada
50 Salome Drive
Toronto
Ontario M1S 2A8
Visit our website at:
www.igiwax.com
www.igicares.com
Toll Free: 1-800-852-6537
Telephone: (814) 827-4900
Toll Free: 1-800-561-3509
Telephone: (416) 293-4151
WARRANTY DISCLAIMER STATEMENT
While the data and information contained herein are presented in good faith and believed to be accurate, it is provided for your guidance only. As actual conditions of use may vary and are beyond the
control of THE INTERNATIONAL GROUP, INC., the product’s specified characteristics cannot be guaranteed and are offered solely for the buyer’s evaluation and verification. SELLER (AND THE
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Accordingly, the buyer and each user assumes all risks and liability in connection with their use of such products. Nothing contained herein is to be construed as permission, recommendation or
inducement by THE INTERNATIONAL GROUP, INC. or its officers, employees, parents, subsidiaries or affiliates, to use any product or process so as to infringe or conflict with any patent. Further, it is the
user’s obligation to utilize this material in full compliance with health, safety and environmental regulations. THE INTERNATIONAL GROUP, INC. recommends that the Material Safety Data Sheet for this
product be consulted prior to handling.. 913