The Process Study On Suspension Polymerization Of Polyglycolide And Its Copolymers

Polyglycolide(PGA) and its copolymers are new-type biodegradable polymers, which have been widely used in medicine and surgical operation because of their biodegradability, biocompatibility and high mechanical behavious. At present these polymers are prepared only at the laboratory in China. Suspension polymerization of glycolide and glycolide-co-lactide less reported are a new search with good industrial outlook. The main contributions made by this paper are as follows: 1. The polyglycolide with high inherent viscosity have been prepared by suspension polymerization.The influences of quantity of catalyst, temperature and time of polymerization on the inherent viscosity of the polyglycolide were studied and the optimum conditions of the suspension polymerization for preparing PGA were concluded as follows : time of polymerization is 40min~1.5h,temperature of polymerization is about 180 C, quantity of catalyst is 0.25 %0~0.35%o. Under this condition, polyglycolide with inherent viscosity 0.90 can be got using suspension polymerization, while the inherent viscosity of polyglycolide, which can be used to spinning, prepared by bulk polymerization was only 0.82.The products were characterized by infrared spectroscopy(IR), nuclear magnetic resonance ('H-NMR) and the conversion of reaction was studied.2. The degradable regularity of polyglycolide was studied.At first the rate of degradation was slower, and the loss of weight was 10 percent after ten days; then the degradation began to accelerate, and the loss of weight reached 40 percent after twenty days, 80 percent after forty days. The surface of degradable products was observed using SEM to study deeply on its degradable regularity.3. The thermostability was analysed of PGA using differential scanning calorimetry (DSC) and thermogravimetry(TG).4. The glycolide-lactide coplymer (PGLA) was prepared with different proportion by suspension polymerization. Their polymerization regularity discussed simply. These copolymers characterized by infrared spectroscopy(IR), nuclear magnetic resonance ('H-NMR).5. The thermostability of coplymers was analysed using differential scanning calorimetry(DSC) and thermogravimetry(TG).