7. Future of antioxidants

Competent and creative research is still needed in the study of oil antioxidants. Some important questions as why one type of antioxidant is efficient in one kind of oil and inefficient in another is often puzzling. Lubricants can affect the environment to various extents; thus, the development of new environmentally friendly lubricant formulations is required. Moreover, new types of antioxidants are still being developed and further improvement in the design of high temperature antioxidants is required. Furthermore, several key issues in the field of lubrication and their relation to recent improvements are revealed as follows: corrosive properties of oily additives, shear strength and durability of high pressure agents, internal cohesion and viscosity of organic liquids, improvements in the viscosity index scale, and synthetic oils and their improvement [14].

In the future, along with improvement in lubricants performance, the service change lifetime also is intended to be extended. Polybutenes play a key role for control the viscosity in an extensive range of automotive and industrial lubricants. The disadvantages of using lowviscosity polybutenes are due to restrictions in volatility and oxidation resistance limit for base oil applications. ZnDTPs, hindered phenols, alkylated diphenylamines, organomolybdenum compounds and dithiocarbamates are antioxidants that are used for the protection of lubricants against oxidation. On the other hand, future antioxidants should be developed with consideration related the to environmental and emissions concerns, improved fuel/energy efficiency, higher performance standards, and new base stocks [1].
