Strength properties and ability to dissipate mechanical energy of biopolypropylene basalt/cellulose composites with the addition of antibacterial turmeric.

The aim of this study was to evaluate the possibility of producing novel reinforced biocomposites based on polypropylene produced from biomass with the addition of antibacterial turmeric as a natural antibacterial agent for the manufacturing of orthoses and other small external medical equipment. Six hybrid composites containing 5-15% basalt fibers, 5-15% microcellulose fibers, 2% turmeric powder and 2% anhydride maleic compatibilizer were produced on a biobased polypropylene matrix by injection molding. The basic strength properties were determined in a static tensile, bending and impact test. The low-cycle dynamic test was carried out to determine changes in dissipation energy and the development of relaxation processes. In order to assess the microstructure of the composites, SEM micrographs were taken after the tensile test. The obtained results confirm that it was possible to produce functional biocomposites based on biopolypropylene with the addition of basalt and lignocellulosic fibers modified with natural antibacterial turmeric. Based on the results of strength properties tests, it can be seen that the addition of basalt fibers increases strength and stiffness, while microcellulose particles reduce the ability to dissipate mechanical energy, and in both cases water has a plasticizing effect on the produced composites. The addition of fibers increases the flexural modulus by 39-196% and is higher the higher the fiber content. The most promising seem to be hybrid composites with a balanced proportion of 10:10 and 15:15 basalt and EFC fibers, which are characterized by 20% higher strength and almost two and a half times higher stiffness than neat polypropylene.