Chemistry and Technology of Lubricants

The use oflubricants began in ancient times and has developed into a major international business through the need to lubricate machines of increasing complexity. The impetus for lubricant development has arisen from need, so lubricatingpractice has precededan understandingofthescientificprinciples. This is not surprising as the scientific basis of the technology is, by nature, highly complex and interdisciplinary. However, we believe that the under­ standing of lubricant phenomena will continue to be developed at a mol­ ecular level to meet future challenges. These challenges will include the control of emissions from internal combustion engines, the reduction of friction and wear in machinery, and continuing improvements to lubricant performanceand life-time. More recently, there has been an increased understanding ofthe chemical aspects of lubrication, which has complemented the knowledge and under­ standing gained through studies dealing with physics and engineering. This book aims to bring together this chemical information and present it in a practical way. It is written by chemists who are authorities in the various specialisations within the lubricating industry, and is intended to be of interest to chemists who may already be working in the lubricating industry or in academia, and who are seeking a chemist's view of lubrication. It will also be of benefit to engineers and technologists familiar with the industry who requirea more fundamental understanding oflubricants.

1 Base oils from petroleum.- 1.1 Introduction.- 1.2 Base oil composition.- 1.2.1 Components of crude oil.- 1.2.2 Characteristics of the hydrocarbons for lubricant performance.- 1.2.3 Crude oil selection for base oil manufacture.- 1.3 Products and specifications.- 1.3.1 Physical properties.- 1.3.2 Chemical properties.- 1.3.3 Base oil categories.- 1.4 Conventional base oil manufacturing methods.- 1.4.1 Historic methods.- 1.4.2 Base oil manufacture in a modern refinery.- 1.4.3 Base oil production economics.- 1.4.4 Distillation.- 1.4.5 De-asphalting.- 1.4.6 Solvent extraction.- 1.4.7 Solvent de-waxing.- 1.4.8 Finishing.- 1.5 Modern catalytic processes.- 1.5.1 Severe hydro treatment.- 1.5.2 Special base oils from hydrocracking.- 1.5.3 Special base oils by wax isomerisation.- 1.5.4 Catalytic de-waxing.- 1.6 Future developments.- References.- 2 Synthetic base fluids.- 2.1 Introduction.- 2.2 Polyalphaolefins.- 2.2.1 Free radical oligomerisation.- 2.2.2 Ziegler catalysed oligomerisation.- 2.2.3 Friedel-Crafts catalysed oligomerisation.- 2.3 Alkylated aromatics.- 2.3.1 Introduction.- 2.3.2 Production and general properties.- 2.3.3 Applications.- 2.4 Polybutenes.- 2.4.1 Introduction.- 2.4.2 Production and general chemical properties.- 2.4.3 Application of PIB fluids.- 2.5 Synthetic esters.- 2.5.1 Introduction.- 2.5.2 Ester types.- 2.5.3 Manufacture of esters.- 2.5.4 Physicochemical properties of ester lubricants.- 2.5.5 Application areas.- 2.5.6 Future trends.- 2.6 Polyalkylene glycols.- 2.6.1 Introduction.- 2.6.2 Production.- 2.6.3 Chemistry.- 2.6.4 Key properties.- 2.6.5 Applications.- 2.7 Phosphate esters.- 2.7.1 Introduction.- 2.7.2 Manufacture.- 2.7.3 Physical and chemical properties.- 2.7.4 Applications.- References.- 3 Detergents/dispersants.- 3.1 Introduction.- 3.2 Detergents.- 3.2.1 Sulfonates.- 3.2.2 Phenates/salicylates/phosphonates.- 3.2.3 Detergent classification.- 3.3 Dispersants.- 3.4 Other lubricants.- 3.4.1 Automatic transmission fluids (ATFs).- 3.4.2 Gear lubricants.- 3.4.3 Tractor hydraulic oils.- 3.5 Performance evaluation.- References.- Further reading.- 4 Oxidative degradation and stabilisation of mineral oil based lubricants.- 4.1 Introduction.- 4.2 Autoxidation of hydrocarbons.- 4.2.1 Oxidation of hydrocarbons at low temperature (30–120°C).- 4.2.2 Oxidation of hydrocarbons at high temperature (> 120°C).- 4.2.3 Metal catalysed autoxidation of hydrocarbons.- 4.3 Oxidation stability of base oils.- 4.4 Inhibition of oxidative degradation of lubricants.- 4.4.1 Radical scavengers.- 4.4.2 Hydroperoxide decomposers.- 4.4.3 Multifunctional additives.- 4.4.4 Synergism between antioxidants.- 4.5 Application of antioxidants.- 4.5.1 Industrial lubricants.- 4.5.2 Engine oil.- 4.6 Future antioxidant technology.- 4.6.1 Antioxidants for industrial lubricants.- 4.6.2 Antioxidants for engine oils.- Acknowledgements.- References.- 5 Viscosity index improvers and thickeners.- 5.1 Introduction.- 5.2 Overview of VI improver chemistry.- 5.3 Chemistry and manufacture of commercial VI improvers.- 5.3.1 Polymethacrylates.- 5.3.2 Olefin copolymers.- 5.3.3 Hydrogenated styrene—diene copolymers.- 5.3.4 Styrene polyester.- 5.3.5 Concentrate-compatible PMA/OCP blends.- 5.4 Function and properties.- 5.4.1 Solution properties.- 5.4.2 Mechanism offunction.- 5.4.3 Shear stability.- 5.4.4 Thermal-oxidative stability.- 5.5 Performance.- 5.5.1 Low temperature viscosity.- 5.5.2 High temperature viscosity.- 5.5.3 Deposits.- 5.6 Prognosis for future developments.- References.- 6 Miscellaneous additives.- 6.1 Friction modifiers.- 6.1.1 Introduction.- 6.1.2 Friction and lubricating regimes.- 6.1.3 Friction modifier mechanisms.- 6.1.4 Chemical aspects of friction modifiers.- 6.2 Pour point depressants.- 6.2.1 Low temperature operations.- 6.2.2 Mechanism of pour point depressants.- 6.2.3 Pour point depressant additives.- 6.3 Demulsifiers and antifoams.- 6.3.1 Introduction.- 6.3.2 Emulsion stabilisation.- 6.3.3 Demulsification.- 6.3.4 Demulsifiers.- 6.3.5 Foam stability.- 6.3.6 Antifoams.- 6.3.7 Foam studies.- 6.4 Corrosion inhibitors.- 6.4.1 The process of corrosion.- 6.4.2 Corrosion inhibitors.- 6.4.3 Corrosion testing.- Reference.- 7 The formulation of automotive lubricants.- 7.1 Introduction.- 7.2 What type of lubricant is wanted?.- 7.3 Why there are so many types oflubricant.- 7.4 Multifunctional lubricants.- 7.5 Definition oflubricant performance.- 7.5.1 Broad performance definition—lubricant classifications.- 7.5.2 Detailed performance definition—special applications.- 7.6 Lubricant formulation—the physical phase.- 7.6.1 Basestocks.- 7.6.2 Viscosity index improvers.- 7.6.3 Additive package.- 7.6.4 Small scale (and analytical) tests.- 7.6.5 Screening tests.- 7.6.6 Engine tests.- 7.6.7 Other aspects of performance.- 8 Industrial lubricants.- 8.1 Introduction.- 8.1.1 General aspects of industrial lubricants.- 8.1.2 Classification of industrial lubricants.- 8.2 Bearing lubricants.- 8.2.1 Bearings.- 8.2.2 Gaseous lubricants.- 8.2.3 Liquid lubricants.- 8.2.4 Greases.- 8.2.5 Solid lubricants.- 8.3 Compressor lubricants.- 8.3.1 General description.- 8.3.2 Lubricants for gas compressors.- 8.3.3 Lubricants for refrigerators.- 8.3.4 Vacuum pump lubricants.- 8.4 Hydraulic lubricants (fluids).- 8.4.1 General description.- 8.4.2 Mineral oil based hydraulic lubricants.- 8.4.3 Synthetic hydraulic lubricants.- 8.4.4 Emulsions and water-based fluids.- 8.5 Industrial gear lubricants.- 8.5.1 General description.- 8.5.2 Lubricants.- 8.6 Turbine lubricants.- 8.6.1 General description.- 8.6.2 Industrial turbine lubricants.- 8.7 Metalworking lubricants.- 8.7.1 General description of metalworking processes.- 8.7.2 Lubricant types for metal forming processes.- 8.7.3 General lubricant types for metal cutting processes.- 8.8 Specialities.- 8.8.1 Process oils.- 8.8.2 Textile oils.- 8.8.3 Slideway oils.- 8.8.4 Cylinder oils.- 8.8.5 Other lubricants and related products.- References.- 9 Aviation lubricants.- 9.1 Introduction.- 9.2 Lubrication of rotary engines.- 9.3 Lubrication of conventional aircraft piston engines.- 9.4 Lubrication of aircraft turbine engines.- 9.5 Aircraft hydraulic fluids.- 9.6 Helicopter gearboxes.- 9.7 Undercarriage lubrication.- 9.8 Airframe lubrication.- 9.9 Safety aspects of aircraft lubrication.- 9.10 Space lubrication.- References.- 10 Marine lubricants.- 10.1 Introduction.- 10.2 Marine diesel engines.- 10.2.1 Slow speed engines.- 10.2.2 Medium speed engines.- 10.3 Fuel oil.- 10.4 Base oils.- 10.5 Additives.- 10.5.1 Alkaline detergents.- 10.5.2 Dispersants.- 10.5.3 Oxidation inhibitors.- 10.5.4 Corrosion inhibitors.- 10.5.5 Load carrying.- 10.5.6. Pour point depressants.- 10.6 Properties and formulation of marine lubricants.- 10.7 System oils.- 10.7.1 Demulsibility.- 10.7.2 Rust and corrosion protection.- 10.7.3 Oxidation and thermal stability.- 10.7.4 Load carrying.- 10.8 Cylinder oils.- 10.8.1 Colloidal stability.- 10.8.2 Acid neutralisation.- 10.8.3 Spreadability.- 10.8.4 Engine test.- 10.8.5 Field tests.- 10.9 Trunk piston engine oils.- 10.9.1 Filterability.- 10.9.2 Heavy fuel engine tests.- 10.10 Used oil analysis.- 10.10.1 Density.- 10.10.2 Viscosity.- 10.10.3 Flash point.- 10.10.4 Insolubles.- 10.10.5 Total base number.- 10.10.6 Water content.- 10.10.7 Wear metals.- References.- 11 Lubricating grease.- 11.1 Introduction.- 11.2 Structure and properties.- 11.3 Chemistry.- 11.4 Applications.- 11.5 Future developments.- 11.6 Conclusions.- References.- 12 Extreme-pressure and anti-wear additives.- 12.1 Introduction.- 12.2 Anti-wear additives.- 12.3 Extreme-pressure additives.- 12.4 Mechanisms of action of anti-wear and EP additives.- 12.5 Application of different classes of additive.- 12.6 Future developments.- References.- 13 Lubricants and their environmental impact.- 13.1 Introduction.- 13.2 Collection of waste lubricant.- 13.2.1 Used industrial lubricants.- 13.2.2 Used automotive lubricants.- 13.3 Treatment of collected lubricant.- 13.3.1 Production offuel oil blending component.- 13.3.2 Reclamation of lubricating oils.- 13.3.3 Production of re-refined lubricant base oils.- 13.4 Re-refined base oil quality.- 13.4.1 Possible contaminants in re-refined base oils.- 13.5 Health and safety aspects of re-refined oil.- 13.6 Environmental considerations of waste lubricant.- 13.7 Environmental impact of ‘consumed’ lubricant.- 13.8 Biodegradation tests for oils.- 13.8.1 Terminology.- 13.8.2 Current test method variations.- 13.8.3 Problems with lubricants.- 13.8.4 Current status and applicability.- 13.9 Future trends.- References.- Further reading.