Ti(OBu)4/B(OBu)3: Deciphering the mechanism for the formation of high molecular weight poly(butylene succinate)

Abstract We report the use of titanium tetraalkoxide in combination with trialkyl borate as an efficient catalyst system For the synthesis of high molecular weight PBS. It is observed that, the addition of trialkyl borates during polycondensation reaction results in the formation of high molecular weight PBS. This might be due to the activation of free terminal carboxylic acids in PBS oligomer by trialkyl borates via the formation of highly reactive acyloxyboron intermediate. A plausible mechanism for the activation of free terminal carboxylic acids by trialkoxy borates has also been proposed.