59 Oleo-Furan Sulfonates
assessment (cradle-to-gate) for OFS surfactants and estimated a 45% reduction in carbon
emissions compared to ether sulfate surfactants currently in consumer products.*
A common misconception for renewably sourced consumer product ingredients is that
plant-based ingredients are inherently sustainable, without considering competing uses
or the environmental impact of their feedstocks. This is increasingly a cause for concern
when considering imported natural oils such as palm oil, which can be unsustainably
farmed due to overcultivation and deforestation. This concept also extends to agricultural
resources that could serve as food for an ever-increasing population or agricultural waste
that could be recycled to improve crop yields. To improve sustainability and versatility
in feedstock selection, we have initiated multiple research projects that use domestic and,
where possible, non-food renewable resources.
With the assistance of funding from the United Soybean Board and the Indiana
Soybean Alliance, we prepared new surfactant variants from soybean oil, including both
hydrogenated soybean oil (primarily stearic acid) and lower carbon content fatty acids
sourced from industrial processing of high oleic soybean oil. Figure 3 provides an overview
of the broad range of OFS surfactant structures Sironix has achieved with versatility in
natural oil and cellulosic furan selection. In addition to feedstock selection, the process
chemistries implemented for surfactant production are critical to tuning the surfactant
design, including an optional hydrodeoxygenation process for acyl group removal and a
tunable sulfonation process to control sulfonate content.
Figure 3. Illustration of structural variations for the oleo-furan sulfonate surfactant platform.
*Confidential results from an internal study.

60 JOURNAL OF COSMETIC SCIENCE
MATERIALS AND METHODS
All materials were purchased and used as received unless otherwise noted. Sodium
hydroxide (≥97%, 221465), Zein (Z3625), SLS (≥98.5%), calcium chloride (≥97%,
C4901), sodium chloride (≥99%, S9888), citric acid, potassium sorbate, sodium benzoate,
and deuterated water (99.9 atom %D, 293040) were purchased from Sigma (Missouri,
USA). SLES (Steol CS-330) and Sodium alkylbenzene sulfonic acid (Bio-Soft 101) were
purchased from Stepan (Illinois, USA) the alkylbenzene sulfonic acid was neutralized to
pH 7 with sodium hydroxide prior to use. OFS surfactants were prepared as solid powders
by a combination of propriety methods and those previously described.18 Cotton skeins
were purchased from Testfabrics (1203007 Pennsylvania, USA). Cocoamidopropyl betaine
powder purchased from Eazy Colors (South Yorkshire, UK) contained approximately 10
wt% sodium chloride, which was accounted for in all formulation salt loadings. Sodium
lauroamphoacetate (ColaTeric L-32) was purchased from Colonial Chemical (Pennsylvania,
USA). Dimethyl lauramide (Ninol CAA) and glyceryl caprylate/caprate (Mild GCC) were
purchased from Stepan. Aloe vera (200x, HUM-ALVE-02), hydroxypropyl starch (TEX-
HPST-01), hydroxyethyl cellulose (THK-HYCEL-01), and xanthan gum (THK-XTGM-01)
powders were purchased from Making Cosmetics (Washington, USA). SIPERNAT® 500LS
hydrated silica was purchased from Evonik (Pennsylvania, USA).
SURFACTANT ANALYSIS AND PROPERTY TESTING
Structural confirmation of sodium dodecanoyl methylfuran sulfonate surfactant purity was
provided by 1 H NMR analysis of a 0.05 M surfactant solution in deuterated water with
(trimethylsilyl) propionic acid internal standard on a Bruker AVance series spectrometer with
a 1 H frequency of 300 MHz. The SO
3 active content of the surfactant solid was determined by
potentiometric titration performed according to ASTM D4251 and found to contain 90–95%
SO
3 by mass, with the remainder of the composition primarily comprised of sodium sulfate.
Tensiometer measurements to determine surfactant critical micelle concentration were
performed with a Krüss Drop Shape Analyzer at ambient temperature. Ten aqueous
solutions of sodium dodecanoyl methylfuran sulfonate with concentrations ranging from
10–0.1 mmol had their surface tensions analyzed. The surface tension measurement
was taken when the drop volume was approximately 90% of detachment volume. A
minimum of three measurements per solution was used for reproducibility. Critical micelle
concentration (CMC) was calculated as the intersection between two lines of best fit to the
data of surface tension versus ln (surfactant concentration).
Ross-Miles foaming tests were conducted in an apparatus purchased from Wilmad
LabGlass (LG-3941-100), which consists of a temperature controlled glass receiver and a
200 mL glass pipet. A surfactant concentration of 0.25 wt.% aged at 49°C for 30 minutes
was used for testing. The receiver was kept at ambient temperature (∼23°C). 50 mL of the
test solution was rinsed along the walls of the receiver. Foam heights were measured to the
nearest millimeter at the time when 200 mL solution was emptied from the pipet into the
receiver followed by a subsequent measurement after 5 minutes had expired.
High shear foaming tests were performed in a Black and Decker 40 oz 10 speed blender at
the lowest setting with a measured blade rotation of 13,700 rpm. Each 0.1 wt% surfactant
solution was agitated for 30 seconds at this setting, after which time the initial foam height
was measured, followed by a subsequent measurement after 5 minutes had expired.