Modified Fatty Acids as Alternative Soap Thickeners for Lubricating Greases

Presentation to NLGI 2021 Annual Meeting

Devin Granger & Shadaab Maghrabi

09/30/2021

Renewable raw materials

Tall oil rosin

Tall oil fatty acid

Lignin

▪Pavement

▪Lubricants

▪Oilfield

▪Biodiesel (1)

▪Adhesives

▪Paper size

▪Rubber

▪Inks

▪Sterols

▪Renewable energy

▪Mining

▪Ag chem

▪Pavement

▪Batteries

▪Dyes

Biorefinery

Derivative end-uses

Biofractions

Pulp Mill

2

Intermediate products

We Add Value Throughout the Pine Chemicals Chain

▪ CTO contracts in place to cover ~90% of 2022 demand; 65% covered by long-term supply agreements

▪ Anticipated cost inflation over the next 4-5 years

Crude tall oil

1| Early stages of market exploration and/or participation

Agenda

Project

Development

Methodology

Testing

Results

Conclusions

Alternatives to 12-Hydroxystearic Acid

Why alternatives to 12-HSA?

12-Hydroxystearic acid for the grease industry is primarily produced in 1 region

COVID-19 Pandemic highlighted potential for disruption [1] from:

• Raw material shortages

• Port closures

• Supply chain disruptions

Challenges

• 12-HSA is a high performing material with decades of data and usage

• Stearic acid, chemically modified stearic acid and other isomers of hydroxystearicacid underperform compared to 12-HSA [2]

• More recent fatty acid derivatives show some promise as alternative materials, but mostly targeted at modifying 12-HSA thickener structures [3]

[1] https://www.ilma.org/ILMA/ILMA/ILMA-News/2020/Castor_oil_derivatives.aspx[2] Mould, W.R.; Silver, H.B. “An Investigation of the Thickening Properties of Substituted Lithium Stearates in Liquid Paraffin Base Oil” NLGI Spokesman, April 1976, 22.[3] Bertin, P.A.; Bessette, P.A. “Biorefinery-Derived Long Chain Dibasic Complexing Agents for Lithium Thickened Lubricating Greases” NLGI Spokesman, 79 (5), 2015, 24.

Methodology

Raw Material Selection

Sample Preparation

Sample Evaluation

Base Oil

Thickener

Counterion

Formulate

Cook

Mill

Dilute

Standard Testing

Sample Preparation

Base Oil - Initial 55.39% 304.27

12-Hydroxystearic acid 14.75% 81.00

LiOH Monohydrate 2.16% 11.88

DI Water 23.76

Base Oil - Let Down 27.70% 152.14

Base Oil - Finishing - As Needed

Typical Charge 100% 549.29

Treat Mass (g)Component Treat Rate (%)

Formulate Cook Mill

Dilute

Sample Evaluation

DIN 51810-2Rheology of Greases

Lg M

od

ulu

s (

Pa)

Lg Shear Stress (Pa)

τy τf

G’

G”

LVE Range

ASTM D217Worked Penetration

ASTM D1831Roll Stability & ASTM D1403 ¼ Scale Penetration

ASTM D6184Oil Separation

ASTM D566Dropping Point

Naphthenic Base Oil 1 (NBO1) – ISO VG 22

MFA: Modified fatty acids

12-HSA: 12-Hydroxystearic acid

12-HSA 12-HSA/AA MFA1 MFA2

191

12 253 2.5

MFA2 16 246 3 0.2

Oil Bleed (%)

2.5 0.7

MFA1 13 245 3 0.2

0.2

12-HSA +

Azelaic Acid13 (11 + 2) 251

Dropping Point

(°C)

196

224

184

ThickenerThickener

Conc. (%)

Pentration

(0.1 mm)NLGI Grade

12-HSA

Shear Stability of NBO1 Greases

Naphthenic Base Oil 2 (NBO2) – ISO VG 220

12-HSA 12-HSA/AA MFA1 MFA2

MFA: Modified fatty acids

12-HSA: 12-Hydroxystearic acid

NLGI GradeDropping Point

(°C)

MFA2 12 284 2 182 0.3

MFA1 8 249 2.5 183 0.0

12-HSA +

Azelaic Acid8 (7 + 1) 241 3 223 0.7

Oil Bleed (%)

12-HSA 7 239 3 198 0.1

ThickenerThickener

Conc. (%)

Pentration

(0.1 mm)

Shear Stability of NBO2 Greases

Group I & II Base Oils

12-HSA 12-HSA/AA MFA1

Group II – ISO VG 22

12-HSA MFA1

Group I – ISO VG 22

12-HSA +

Azelaic Acid12 (10 +2) 255 2.5 220 3.4

MFA1 13 298 1.5 177 0.7

ThickenerThickener

Conc. (%)

Pentration

(0.1 mm)NLGI Grade

Dropping Point

(°C)Oil Bleed (%)

12-HSA 12 273 2 201 1.1

MFA1 16 332 1 183 2.2

ThickenerThickener

Conc. (%)

Pentration

(0.1 mm)NLGI Grade

Dropping Point

(°C)Oil Bleed (%)

12-HSA 12 273 2 205 1.3

Diacid Grease – VP100 Base Oil (paraffinic group I)

Group I Group II Group I Group II

Rheology by DIN 51810-2 Method A (Strain) for NBO1

Method:• Load sample• Heat to 40°C

• Rate = 0.4 °C/min• Hold at test temp

for 30 min• Strain sweep

• 0.01 – 100%• Angular frequency

(ω) = 10 1/s

G’ = Storage modulus❖ Solid component of VES❖ Related to film

strength/penetrationτy = yield point❖ Force needed to soften

the VESτf = yield point❖ Force needed to liquify

the VES

G' τy τf

12-HSA 5.20E+04 188 1210

12-HSA/AA 8.10E+04 183 1480

MFA1 4.50E+04 325 1020

MFA2 5.10E+04 230 936

Thixotropy of NBO1 Lithium Greases

Method:• Temperature equilibrated as in

DIN 51810-2• Strain set within the LVE (0.1%),

and baseline measured• Strain set above τf (100%), and

response measured• Strain set within the LVE (0.1%),

and modulus recovery observed

Gives a sense of physical state changes during deformation and relaxation

Summary

• Appearance and texture of all MFA greases are like Lithium 12-hydroxystearate and

Li 12-HSA/Azelaic acid greases

• Smooth, semi-transparent, easily spread with a pallet knife, sticks to surfaces

• Physical properties of MFA greases are base oil dependent

• Shear stability

• Water resistance

• Dropping points

• Oil separation

• Rheology of MFAs is comparable to Li 12-HSA and Li 12-HSA/AA