Influence of the chemical modification of hemp fibers on selected mechanical properties of polypropylene composite materials

The synthesis of composites based on polypropylene (PP) (Table 1), hemp fibers (Table 2) and a compatibilizer (polypropylene grafted with maleic anhydride -MAH-PP) has been presented. The components were initially homogenized on heated roll mills, and the shapes of the test specimens obtained by injection molding. The hemp fibers were subjected to chemical modification namely: acetylation, alkylation or treatment with maleic anhydride. The influence of such modification on selected mechanical properties of the composites (static tensile strength, elongation at break, Young's modulus, and Charpy impact strength) was studied. In the case of composites containing the chemically modified fibers and compatibilizer, an increase in tensile strength and Young's modulus while a decrease in elongation at break and impact strength in comparison with the virgin PP (Figs. 1-4).