Studies of Novel Chain Linked Biodegradable Polymers

The synthesis of high-molecular-weight lactic acid based polymers by chain linked polymerization was investigated. Lactic acid based hydroxyl terminated telechelic prepolymer was synthesized and then the molecular weight was increased by chain linked polymerization using methylene diphenyldiisocyanate. All polymerizations were carried out in the melt, using tin octoate as catalyst. The products were characterized by Differential scanning calorimetry, nuclear magnetic resonance spectroscopy and size exclusion chromatography. With the increase in diisocyanate concentration, an increase in the glass transition temperature, molecular weight and molecular weight distribution was observed.