Polylactide: Ring Opening Polymerization of Lactide using Zinc (II) octoate as Catalyst and Optimization of Reaction Parameters

Polylactides with molecular weights ranging from 2245 to 4798 g mol(-1) were synthesized by ring opening polymerization of L-lactide using zinc octoate catalyst and ethanol as an initiator. Effects ofreaction parameters i.e. reaction temperature, monomer to catalyst molar ratio (M/C) and initiator to catalyst molar ratio (M/C) were studied on number average molecular weight (M-n), %yield and %crystallinity (%chi(c)) of polylactides. Prepared polymers were analyzed using various techniques techniques. FTIR and H-1 NMR analysis confirmed the formation of polylactides. %chi(c) of polylactides was determined by XRD while number average molecular weight by H-1 NMR and end group analysis. Thermal degradation temperatures of polylactides were determined by TGA. I/C and M/C molar ratios were varied from 1 to 10 and 10 to 100, respectively. Reaction temperature was varied from 120 to 180 degrees C. Polylactide with maximum m(n)% yield, %chi(c) and thermal stability was observed at I/C = 5 and M/C 100 at 130 degrees C.