SORPTION AND DIFFUSION OF COMPRESSED CARBON DIOXIDE IN POLYCAPROLACTONE FOR THE DEVELOPMENT OF POROUS SCAFFOLDS

M. A. FANOVICH, P.T. JAEGER

MATERIALS SCIENCE & ENGINEERING. C, BIOMIMETIC MATERIALS, SENSORS AND SYSTEMS

ELSEVIER SCIENCE BV

Año: 2011

0928-4931

In this work different phenomena related to sorption of carbon dioxide in polycaprolactone(PCL) have been investigated systematically. The use of compressed carbon dioxide isdiscussed for obtaining porous scaffolds from this biocompatible polymer. In order todetermine the plasticization effect of carbon dioxide on the degree of foaming it is necessaryto discuss sorption data with respect to morphological features of the polymer at conditionsnearby the melting point. The amount of carbon dioxide dissolved and the kinetics of thesorption process are found to depend strongly on temperature and pressure. The solubilitytakes values of up to 25 wt% being favoured by a melting and glass transition temperaturedepression which can be observed along with an enhanced mass transfer rate. In general, CO2sorption in PCL increases linearly with pressure. When decompressing, microfoaming occurswhich enhances the rate of gas release. Changes in morphology and crystallinity occur as aconsequence of the pressure treatment. Compared to the melting temperature at atmosphericpressure there is a dramatic reduction observed under pressure where melting occurs alreadyat a temperature below 40°C. Even after pressure-treatment, there is a remaining change inmelting temperature and crystallinity observed. Optimum conditions for obtaining adecuateporous scaffolds of PCL are a relatively slow decompression after treatment at 17 MPa and35ºC.Keywords: polycaprolactone, porous scaffolds, supercritical carbon dioxide.