Synthesis of high molecular weight L-Polylactic acid (PLA) by reactive extrusion at a pilot plant scale: Influence of 1,12-dodecanediol and di(trimethylol propane) as initiators

Abstract The present work describes the synthesis of polylactic acid (PLA) of isotactic high molecular weights via reactive extrusion ring-opening polymerization of L-lactide in presence of 1,12-dodecanediol (DDD) or di(trimethylol propane) (DTMP) as initiators. Weight-average molecular weights between 183 and 217 kDa were deduced by both diffusion NMR and SEC measurements. The functionality of each initiator allowed the obtention of PLA of linear multiarm branching with superior mechanical and rheological properties than those described in commercial references. PLA_DTMP demonstrated good performance in cast filming and PLA_DDD in injection molding. The reactive extrusion process presented herein has been validated in a relevant industrial environment and represents an interesting alternative to traditional synthesis methods with consequent cost savings.