Ring opening polymerization of lactide by using zinc prolinate catalyst

Zinc salts of L-proline, D-proline were used in homopolymerization of L, L-lactide and D, L-lactide. Linear PLA oligomer with Mn 2900-3400 Da, can be prepared with zinc (L-prolinate)2 catalyst. Less racemization were occurred in presence of Zn (L-prolinate)2 than Zn (D-prolinate)2. The catalyst structure of Zn (L-prolinate)2 and Zn (D-prolinate)2 remains intact after polymerization. The zinc is bioactive molecule so these polymers prepared by using this catalyst are bioabsorbable. The resulting polymers were characterized by infrared spectroscopy (IR), size exclusion chromatography (SEC), differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), 13 C NMR, 13 C Cross Polarization /Magic Angle Spinning ( 13 C CP/MAS) and MALDI ToF-MS.