CONICET | Buscador de Institutos y Recursos Humanos

Biodegradable polymers have important applications in the biomedical field particularly in the development of drug delivery. In these systems, residual solvents are undesirable since they may contaminate the device and cause toxicity problems. In order to avoid those negative effects, alternative approaches are being developed, namely supercritical fluid processing, of which the most commonly used is carbon dioxide [1]. Carbon dioxide (CO2) solubility and diffusivity in polymers are influenced by both the molecular structure (the interaction between CO2 and molecular chains) and the morphology (crystalline or amorphous, related with free volume) of polymers. In fact, the gas sorption is not a merely physical phenomenon, but it implies also specific chemical interactions between CO2 and polymers. In this way, the behaviour of the polymer in the presence of CO2 (swelling, foaming, melting point, etc.) are the most important issues that should be studied. This work is focused on determining diffusivity and solubility of carbon dioxide in commercial poly-caprolactone (PCL) at elevated pressure, in order to properly design and develop SC-CO2-based processes such as the production of drug loaded microparticles or monolithic matrices. Moreover, the influence of gas sorption on different material properties like melting behaviour, cristallinity and foam structure was investigated.