Crystallization kinetics modeling, thermal properties and biodegradability of poly (ε-caprolactone)/niobium pentoxide and alumina compounds

Biocomposites based on poly (caprolactone) (PCL) incorporating different contents of niobium pentoxide (Nb2O5) and alumina (Al2O3) were prepared in a laboratory internal mixer. The thermal properties, biodegradability and non-isothermal crystallization kinetics modeling of the composites were investigated. Crystallization kinetics were analyzed using the methods of Pseudo-Avrami and Mo models with cooling rates of 2, 4, 8 and 16 °C/min, and the results indicated that the models described well the non-isothermal crystallization kinetics of the tested samples. The addition of oxides leads to a slight increase in the thermal stability of the polymeric matrix, either with alumina or niobium pentoxide and regardless of concentration, delaying the degradation process. The melting temperature tends to remain constant regardless of the increase in the heating rate or content of niobium pentoxide or alumina present, indicating that the melting temperature does not appear to be affected by these parameters. The presence of the fillers accelerates the biodegradation of the PCL matrix in the composites and this effect becomes more evident with the increase in the filler content, and more for alumina than niobium pentoxide.