Modification of poly(D,L-lactic acid)-co-poly(ethylene glycol) copolymer by low energy electron beam (EB) radiation

摘要

Poly(D,L-lactic acid)-co-poly(ethylene glycol) copolymer (D,L-PLEG) synthesized by melt polycondensation was irradiated using low energy electron beam (EB) in the presence of triallyl cyanurate (TAC) and tetraallyl pentaerythritol (TAPE) as crosslinking agents. The tensile strength of D,L-PLEG/TAC and D,L-PLEG/TAPE samples increases up to 48 MPa and 28 MPa at dose of 80 kGy and 60 kGy, respectively, and decreases with further increase of dose, whereas the elongation at break decreases continuously with increasing dose. The glass transition temperature (Tg) is improved to some extent due to the formation of molecular chain network. Degradation of D,L-PLEG is retarded with introduction of cross-linked network. The results suggest that the physical properties of crosslinked D,L-PLEG can be adjusted easily by varying irradiation dose.