Esterification Reaction for Novel Synthesis Castor-Based Polyester and Formulation as Base Oil in Synthetic Drilling Fluid

Ricinoleic acid [hydroxyl fatty acid] is the meager constituent fatty acid in castor oil (85 95 %). Castor oil is inedible oil which is one of the crops available, reachable oil in Egypt. Novel polyesters produced form esterification of different ratios of hydroxyl fatty acid (35, 55, and 75 %) with glycerol and phthalic anhydride, at temperatures between 120 and 240C. Three different novel polyesters were collected and designated as HD35, HD55 and HD75 respectively. The average degree of polymerization is monitoring by determining the acid number of the aliquot of the reaction mixture and by measuring the volume of water evolved. The chemical structure of the new prepared polyesters were elucidated using Faurier transform infrared (FTIR) spectrophotometer, and the molecular weight determinations were conducted by Mass spectrophotometer. The average molecular weight of the novel polyesters compound ranged from 980 to 1500. The biodegradability of the new prepared polyesters gives us good indications the ability to be environmentally friendly. The new prepared polyesters were formulated and evaluated as a synthetic based mud (esterbased mud) for oilwell drilling fluids. The evaluation includes study of the rheological properties, filtration and thermal stability of both reference commercial esterbased mud and ester basedmuds formulated with the new prepared polyesters according to AIP specifications.