Study on Direct Grafting Maleic Anhydride onto Poly(D,L-lactide-co-glycolide) Chains

ABSTRACT

Direct graft copolymerization of maleic anhydride (MAH) onto poly(D,L-lactide-co-glycolide) (PLGA) was performed by use of benzoyl peroxide (BPO) as initiator. Fourier transform infrared spectra, nuclear magnetic resonance, titration analysis of maleation extent and water contact angle were employed to characterize the obtained MPLGA. The effects of monomer concentration, initiator concentration and reaction temperature on the degree of maleation were investigated. The MPLGA scaffold was obtained by using NaCl as the porogen. The results showed that maleic anhydride was successfully grafted onto the PLGA chains. The monomer and initiator concentrations played an important role in the graft copolymerization; the extent of maleation first increased with increasing content of MAH and BPO and then declined. The extent of maleation continuously increased with increasing temperature to 100°C, and then the rate of increase decreased. The extent of maleation could be controlled in the range from 0.15 to 0.71% by adjusting the graft copolymerization conditions. The introduction of anhydride enhanced the water contact angle of PLGA. The MPLGA scaffold showed a network of interconnected pores ranging from 50 to 300 μm.

KEYWORDS:

• Degree of maleation
• direct graft copolymerization
• maleic anhydride
• poly(D,L-lactide-co-glycolide)

Acknowledgements

This work was financially supported by the Scientific Research Fund of Hunan Provincial Education Department (No. 17C0018).