Síntese e caracterização de copolímeros P(MMA-coBCA) via polimerização em massa

Abstract

The development of new polymeric materials for application as biomaterials has been constantly pursued, especially for preparation of polymeric nanoparticles for targeted drug delivery. One common strategy used to manufacture polymers with specific desirable properties is to perform copolymerization reactions, which involve different monomers. In this context, the present work studied the production of poly(methyl methacrylate-co-butyl cyanoacrylate), P(MMA-co-BCA), via bulk copolymerization reactions conducted through the usual free radical polymerization mechanism, varying the contents of the BCA comonomer at 0%, 10%, 25%, 50%, 75% and 100% m/m in relation to the monomer charge and the content of the initiator AIBN, between 0.1% and 1% m/m in respect to the total organic load. The obtained materials were characterized in terms of conversion, molar mass distribution, chemical structure, thermal behavior and behavior in degradation tests. Reactions conducted with 0.1% of AIBN resulted in lower conversions, higher average molar masses, and higher rates of incorporation of the BCA, when compared to reactions conducted with 1% of AIBN. In both cases, however, the copolymerization reactions were carried out effectively. The degradation tests were carried out in neutral, basic, acidic and enzymatic aqueous media, and evaluated with the aid of a gravimetric technique and through the analysis of the molar mass distributions. There was a slow increase of degradation rates with the incorporation of BCA, although the molar masses values have increased, indicating the occurrence of possible cross-linking reactions.