ESTERIFICATION OF CITRIC ACID WITH ALIPHATIC ALCOHOLS С₂-С₅

Abstract

There is an ever increasing interest in the production and use of bio-based chemical substances for the preparation of polymeric materials designed to obtain children's toys, medical equipment and materials that are in contact with food. Trifunctional esters of citric acid - trialkyl citrates - obtained by esterification of citric acid with aliphatic alcohols C2-C5 are of hazard class 4, good plasticizing ability, compatibility with the polymer, a high flash temperature. Citric acid (global production of 0.85-1 mtpa) is a readily available raw material obtained from the waste of sugar production. The purpose of the study is to develop a model of citric acid esterification with linear alcohols C2-C5 in the presence of homogeneous acidic catalysts for the creation of a domestic technology for the synthesis of plasticizing compositions based on renewable raw materials. The selected catalyst is sulfuric acid. The correlation of reactivity of the aliphatic alcohols C2-C5 with their structure in the esterification of citric acid was studied. Some kinetic parameters (lnk0, Ea) were estimated. Synthesis modes were proposed. The reaction time of the preparation of trialkyl citrates at 96% conversion of citric acid (t = 90 °C) was calculated. Laboratory samples were obtained and tested. Some operational characteristics were determined.

Keywords

• citric acid
• esterification
• aliphatic alcohols
• sulfuric acid