High Performance Biodegradable Ester Lubricants from Sustainable and Non-Sustainable Feedstocks Andrew P Swallow (Technical Service Manager) John Eastwood (Technical Service Manager) Steven J Randles (Global Applications Director) ã Croda 2007 PRIOLUBE, PERFAD, HYPERMER, EMKAROX AND EMKARATE are trademarks of Croda

Agenda European ECO Labels Renewability Performance parameters Natural esters Oleochemical esters Petrochemical esters

Existing Eco-labels in Europe The European Eco-label has been based largely on the existing eco-labels of individual European countries, specifically: Germany (Blue Angel) Sweden (Swedish Standard) Nordic Countries (White Swan) France (NF Environment) Holland (VAMIL Regulation) Austria

An Eco-label for Europe In December 2004 the European Commission voted in favour of adopting a European Eco-label for Lubricants. The document was published in the Official Journal in the summer of 2005. A copy of the document is available at: http://europa.eu.int/comm/environment/ecolabel/product/pg_lubricants_en.htm

Renewable Raw Materials The lubricant shall have a carbon content derived from renewable raw materials that shall be: => 50% for hydraulic oils => 45% for greases => 70% for chain saw oils, concrete release agents and other total loss lubricants => 50% for two-stroke oils Additive targets are difficult achieve Biodegradability, bio-accumulation and toxicity targets are difficult to achieve while meeting the correct performance Few formulations currently meet the criteria A review of the European Eco-label will take place in 2008 Many of the European Eco-labels will continue in parallel

Lubricant Overview % Biodegradability 28 days OECD 301B % Renewability content Vegetable Oil 70 – 100 100 Mineral oil 20 – 40 PAO 20 – 60 Alkyl Benzene 5 - 20 Diesters 40 - 75 0 to 80 Aromatic ester 5 - 60 Polyol ester 20 - 90 0 to 85 Complex ester Polyalkylene Glycol 10 - 70 Biodegradability tends to decrease with increasing chain length, branching, aromaticity and saturation, and will be influenced by the nature of the structure

Esters as Lubricant Base fluids Three general categories Natural oils and fats Plant and animal derived Oleochemical derived esters Fatty unsaturated esters (e.g. oleates, dimerates) Fatty saturated esters (e.g. stearates, isostearates) Petrochemical esters Diesters ( e.g. adipates, sebacates, azelates)

Oleochemical Derived Esters Broad technology platform enabling the preparation of biodegradable esters with viscosities ranging from approximately 10cSt up to 1000cSt at 40°C Not classified as dangerous for the environment, nor are they classified as harmful to aquatic organisms Generally do not bio-accumulate in the environment. Typical esters used in the formulation of environmentally acceptable lubricants (EALs) have Log Kow values ranging from 10 to 25

Petrochemical Esters Diester advantages are : Long-life lubricants High temperature operating conditions Very low temperature environments In addition, diesters have a low viscosity. Until recently they have been the only real option for low viscosity lubricating oils Diesters disadvantages are: Non renewable Under new Eco-label criteria, petrochemical esters will become useful only as co-base fluids and the amount that can be used in a formulation will be dictated by the application in which the lubricant will be used based on renewability

The Ester Reaction Alcohol + Acid Ester + Water Hydrolysis R - OH R1 - C - OH R - O - C - R1 = O H2O = O Alcohol + Acid Ester + Water Degree of Hydrolysis High levels of water Degree of Esterification Low levels of water - Catalyst - Pressure - Temperature - Structure Acid Alcohol Hydrolysis Esterification

Improving Hydrolytic Stability Esters are acid catalysed Higher initial acid value the faster the breakdown Tightly controlled manufacturing processes Careful additive selection Anti-wear additives (use stable and low acid value) Anti-corrosion additives (neutral ones) Acid catchers Epoxides or carbo-imides

Performance Trade-Offs Degree of branching or aromaticity 100 Biodegradability Hydrolytic Stability Performance O – C – C – = O H2O Steric Hinderance Polyol Ester

Performance Trade-Offs Pyrolysis Wax formation 100 Oxidative Stability Performance Low Temp Operability Oxidation Low High Hydrolysis Natural Triglyceride Iodine value

Optimizing Pour Point Low Temp Flow PE = Pentaerythritol Ester Pour Point, °C TMP oleate (unsaturated C18) -51 TMP stearate (saturated C18) +45 TMP isostearate -30 PE branched C9 +30 PE linear C9 +8 PE branched C8 Mixed branched PE -38 Mixed linear and branched PE -48 PE = Pentaerythritol Low Temp Flow - Molecular weight - Degree of unsaturation Structural diversity Degree of branching “Regular shaped structures” can flocculate and crystallize over time. Pour point is not always a particularly reliable measurement

Low Temperature Fluidity Viscosity vs Storage time at - 30 °C 18000 16000 14000 12000 10000 TMPO Viscosity (cSt) 8000 Modified 6000 4000 2000 50 100 150 200 Time (h)

Diester + Complex ester ISO 46 Ester Comparison Physical Property Diester + Complex ester Standard TMP Oleate Modified Saturated Polyol Ester Opt. Ester Ester A Ester B Ester C Ester D Ester E Raw material source Petro Oleo Viscosity at 40°C, cSt 46 48 44 45 Viscosity at 100°C, cSt 8.1 9.8 8.7 8 8.8 Viscosity Index 150 196 181 143 180 Viscosity at -30°C, cSt after 72hrs 9,500 5,500 to 16,000 3,800 4,400 Pour point, °C -42 -51 -54 -45 Iodine value <1 84 72 2 Dry TOST Test hours (+1.5% RC9321) >>4000 500 540 >>4,000 On test >1,000 Biodegradability 28 days OECD 301B, % 61 99 85 77 Renewability, % 17 86 78 *Northern Europe would aim for <5,000 cSt at -30°C after 72hrs

Other Viscosities Oleo. derived Petro. Oleo Ester F Ester G Ester H Ester I Ester J Ester K Ester L Viscosity 40°C, cSt 11 26 35 65 138 320 1040 Viscosity 100°C, cSt 3.0 5.3 7.5 13 17.6 90 Viscosity Index 136 139 193 208 140 150 167 Pour point, °C -33 -54 -42 -21 -40 -24 Iodine value 1 <1 75 3 4 Dry TOST test hours (+2% RC9308) >4,000 500 Biodegradability 28 days OECD 301B, % 78 74 81 64 70 63 Renewability, % 85 88 73 Commercial high performance renewable esters have been developed for: Chain oils, Greases, Transformer oils, MWFs, 2T, Fuel additives, Marine and Offshore applications

Conclusions A wide range of esters commercially available that allow you to achieve optimum balance of Biodegradability Renewability Stability Low temperature properties Cost Careful selection of additives are required to optimise hydrolytic stability

Contact Andrew.Swallow@Croda.com +44 1642 435356 Wilton Centre Redcar TS10 4RF England Nina.Seryogina@Croda.com + please add your details here

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