Synthesis and Characterization of Poly(D,L-Lactide-co-Glycolide) Copolymer

Cynthia D’Avila Carvalho Erbetta, Ricardo José Alves, Jarbas Magalhães Resende, Roberto Fernando de Souza Freitas, Ricardo Geraldo de Sousa

Chemical Department, Exact Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, Brazil..
Pharmaceutical Products Department, Pharmacy School, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Polymer Science and Technology Laboratory, Chemical Engineering Department, School of Engineering.
Polymer Science and Technology Laboratory, Chemical Engineering Department, School of Engineering, Federal University of Minas Gerais, Belo Horizonte, Brazil.

DOI: 10.4236/jbnb.2012.32027                

Abstract

The copolymer poly(D,L-lactide-co-glycolide) is one of the most interesting polymers for medical applications. This interest is justified by the fact that it is bioreabsorbable, biocompatible and non-toxic, while its degradation kinetics can be modified by the copolymerization ratio of the monomers. In this study, copolymers were synthesised at 175?C by opening the rings of the cyclic dimers of the D,L-lactide and glycolide monomers in the presence of stannous octoate initiator and lauryl alcohol co-initiator. The application of vacuum to the reaction medium, coupled with adequate stirring, is essential for obtaining good results. The following analytical techniques were used to characterise the synthesised copolymers: Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Nuclear Magnetic Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Both the input monomers and the reaction products were analysed. Important characteristics, such as melting temperature, glass transition temperature, thermal stability, chemical composition and the ratio of the monomers in the synthesised copolymer, were obtained from these analyses. These results helped to infer the absence of residual monomers in the synthesised copolymers.

Keywords

PLGA; Synthesis; Characterization; DSC; TG; NMR; FTIR

Conflicts of Interest

The authors declare no conflicts of interest.

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