thank you MolaKule, if you can further provide detail explanation about esters in lubricants or maybe some links where I can learn from, I would appreciate your help
By T. G. Schaefer (Tom NJ) "In the simplest terms, esters can be defined as the reaction products of acids and alcohols. Thousands of different kinds of esters are commercially produced for a broad range of applications. Within the realm of synthetic lubrication, a relatively small but still..."