Influência de parâmetros experimentais na Síntese de Poli (l-ácido lático)

Abstract

The productivity of industrial polymerization plants is highly dependent on the conversion rates. In the polymerization of L lactide the presence of water traces must be avoided due to their negative influence on the reaction kinetics. The use of liquid nitrogen has been reported but it greatly increases process complexity and costs. The objective of this work was to obtain poly(L lactic acid) and evaluate the influence of temperature, catalyst concentration and the injection of gaseous nitrogen on the polymer final molar masses and conversion. Results demonstrated that gaseous nitrogen (injection 40 minutes) can be used to avoid the negative influence of water traces and also that the increase in reaction temperature (1400C) and catalyst concentration (11.000 molL-lactídeo/molcat) led to an increase in the conversion efficiency. In most experimental conditions was observed depolymerization reaction times up to 20 hours.