Due to the intensive search for new types of advanced polymer materials for targeted applications, this work offers insight into the properties of low-density polyethylene/hematite composites. The specific feature of this study lies in the use of elongated hematite particles of different shapes. Uniform ellipsoid-, peanut- and rod-shaped hematite particles were hydrothermally synthesized and incorporated into the polymer matrix of low-density polyethylene (LDPE). LDPE/hematite composites are prepared by melt mixing. Hematite particles are characterized by scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD). The pure LDPE polymer and LDPE/hematite composites were studied by FT-IR and UV-Vis-NIR spectroscopy and by thermogravimetric analysis (TGA). The determination of the mechanical and barrier properties was also carried out. The obtained results indicate the influence of the elongated particles on the improvement of LDPE properties. An increase in thermal stability and UV-absorption was observed as well as the improvement of mechanical and barrier properties. The improvement of the composites’ properties in comparison to the pure LDPE is especially visible in the composites prepared with low content of hematite (0.25%). LDPE/hematite composites have promising characteristics for application as packaging materials with enhanced mechanical, thermal and barrier properties as well as UV-protective materials.

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.