Natural Rubber Composites Filled with Cereals Straw Modified with Acetic and Maleic Anhydride: Preparation and Properties

摘要

This research paper aims to provide an examinations on biocomposites based on natural rubber (NR), natural straw fibers as well as their production techniques and properties. After pre-alkalization of the fillers, two main modification methods were carried out, with the usage of acetic or maleic anhydride to improve the adhesion of the fibers to the elastomeric matrix. Firstly, physicochemical characterization of straw particles, both pure and modified, using scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transmission infrared spectroscopy (FTIR) was performed. Moreover full characterization of the produced composites was also executed, which included: rheogical properties, static and dynamic mechanical properties, crosslinking density, damping properties, tear strength and resistance to simulated aging processes. Increased adhesion between modified straw fibers and the elastomeric matrix was observed for 10 phr filled composites, which was confirmed by dynamic mechanical thermal analysis (DMTA). In addition, the impact of the applied modifications was confirmed by higher values of the Payne effect, which resulted from the presence of developed secondary structure of the filler in vulcanizates. Furthermore, the crosslinking density of composites increased, which was reflected in the improvement of tensile properties, determined by tensile and tear strength and relative damping.