Novel Functional Polycaprolactone/Hematite Composites with Improved Mechanical, Thermal, UV-Protective and Barrier Properties

The need for materials with advanced properties finds the candidates among modified polymers—for instance, polymer composites. Furthermore, the stated environmental concerns dictate the use of biodegradable polymers. This work studies the properties of polycaprolactone/hematite composites prepared by the incorporation of laboratory-synthesized hematite (α-Fe2O3) particles of different sizes into the polycaprolactone (PCL) matrix. PCL is a biodegradable, biocompatible and non-toxic polymer, while hematite is a thermally stable, corrosion-resistant, non-toxic and low-cost iron oxide. To avoid harmful solvents, PCL/hematite composites were prepared by melt mixing. PCL and PCL/hematite composites were studied by thermogravimetric analysis (TGA), FTIR and UV–Vis–NIR spectroscopy. The mechanical and barrier properties were also studied. The results indicate the influence of hematite particles on the enhancement of PCL properties, especially using the smaller hematite particles (average diameter of about 100 or 170 nm). An improvement of thermal stability, UV absorption and mechanical properties was observed. The composites prepared with the larger hematite particles (average diameter of about 1 or 2 µm) act as a significantly better barrier to water loss than pure PCL. Therefore, PCL/hematite composites can be used as novel functional materials, with enhanced mechanical, thermal, barrier and UV-protective properties, for packaging or biomedical purposes.