Ecofriendly and biodegradable lubricant formulation and process for preparation thereof

A process for synthesizing the mineral oil free lubricant wherein the process comprises the steps of:

• (i) reacting a mixture of polyol of C3-C5 carbon, dicarboxylic acid of C6-C10 carbon in a ratio of 1:2 in presence of a heterogeneous catalyst and a solvent at refluxing temperature for a period ranging between 2 to 4 hours to obtain a reaction mixture;
• (ii) removing water from said reaction mixture and allowing the mixture to cool to obtain cooled mixture;
• (iii) reacting the cooled mixture obtained at step (ii) with at least 2 moles of mono alcohol under reflux condition until all remaining carboxylic groups are esterified, and completing the reaction in a period ranging from 8 to 12 hours, until water is removed to obtain Polyol complex esters as base oil;
• and
• (iv) blending the base oil obtained at step (iii), wherein the base oil is 94% to 100% with antioxidant 1-2% and an additive 1.5 to 4%, to obtain the mineral oil free lubricant.

A polyol complex ester selected from the group consisting of:

• (i) 2, 2-diethyl 1, 3-propane di adipic 2 ethyl 1 hexanoate (DEADEH),
• (ii) 2, 2-diethyl 1, 3-propane diazelaic 2 ethyl 1 hexanoate (DEAZEH),
• (iii) 2, 2-diethyl 1, 3-propane disebacic 2 ethyl 1 hexanoate (DESEH),
• (iv) 1, 1, 1-trishydroxymethyl propane triazilaic 2 ethyl 1 hexanoate (THAZEH),
• (v) 1,1, 1-trishydroxymethyl propane trisebacic 2 ethyl 1 hexanoate (THSEH), and
• (vi) 1, 1, 1-trishydroxymethyl propane triadipic 2 ethyl 1 hexanoate (THADEH).