This present study is focused on exploring the possibility of using agricultural waste in the form of cereal straw as an active filler of biocomposites. The effect of lignocellulosic filler addition on the multifunctional properties of natural rubber composites was investigated. The results were compared with the properties of vulcanizates containing commonly used reinforcements in elastomer technology (carbon black, silica, chalk, talc). Rubber mixtures filled with straw showed the highest torque increase during rheometric measurements, which indirectly indicated a high degree of crosslinking and hardness of composites. It was found that the effect of straw addition on vulcanization time of elastomer blends was comparable with the results obtained for other conventional fillers. Moreover, the results confirmed that novel composites based on natural rubber filled with crop residues were attractive materials owing to their capacity for the formation of “structure” in combination with a good impact on reinforcement. Vulcanizates with the addition of straw showed the best barrier properties and resistance to thermo-oxidative aging from all tested samples. Furthermore, straw-based composites demonstrated that cereal straw waste could be used as an alternative, biodegradable and eco-friendly reinforcement of natural rubber composites.

This article concerns the functional properties of elastomeric composites reinforced with modified lignocellulosic material obtained from cereal straw. The aim of the research was to acquire new knowledge on the effectiveness of cereal straw modification methods in multifunctional properties, while reducing the flammability of newly designed elastomeric materials made of natural rubber. The article deals with investigating and explaining dependencies that affect the performance and processing properties of polymer biocomposites containing modified cereal straw. Three different silanes were used to modify the lignocellulosic filler: n-Propyltriethoxysilane, Vinyltriethoxysilane, and 3,3′-Tetrathiobis(propyl-triethoxysilane). The influence of the conducted modifications on the morphology and structure of straw particles was investigated using a scanning electron microscope, contact angle measurements, and thermogravimetric analysis technique. The increase in hydrophobicity and thermal stability of natural fibers was confirmed. In turn, the impact of silanization on the properties of filled composites was determined on the basis of rheometric characteristics and cross-linking density, static mechanical properties, tear resistance, thermal stability, and flammability tests. Noteworthy was the improvement of the mechanical strength of biocomposites and their resistance to burning. Correlations affecting the structure, morphology, dispersion, and properties of produced composites can facilitate the indication of a further research path in the field of development of new elastomeric biomaterials.

The aim of the presented research paper was to modify the biofiller in the form of milled cereal straw with 3-aminopropyl(diethoxy)methyl silane, and apply it to the natural rubber. To determine the material properties, an in-depth characterization of both the treated lignocellulosic material and the composites was studied. On the basis of thermogravimetric analysis, scanning electron microscopy, infrared spectroscopy and analysis of contact angle measurements, it was found that the silanization process significantly influenced thermal stability and hygroscopicity of the straw, its hydrophobicity as well as dispersion in polymeric matrix. Analyses of the new composites included static and dynamic mechanical properties, hardness, and barrier and damping properties, all of which showed improvement. This was because of improved interactions at the filler–elastomer, which resulted from better adhesion of the treated bio-additive to natural rubber. Biocomposites have also demonstrated greater resistance to flammability as well as thermo-oxidative aging processes. The research clearly indicates the application potential of these new multifunctional and biocompatible materials.

In this study, peppermint (Mentha piperita L.), German chamomile (Matricaria chamomilla L.) and yarrow (Achillea millefolium L.) were applied as natural fibrous fillers to create biocomposites containing substances of plant origin. The purpose of the work was to investigate the activity and effectiveness of selected plants as a material for the modification of natural rubber composites. This research was the first approach to examine the usefulness of peppermint, German chamomile and yarrow in the field of polymer technology. Dried and ground plant particles were subjected to Fourier transmission infrared spectroscopy (FTIR) and UV–Vis spectroscopy, thermogravimetric analysis (TGA), goniometric measurements (contact angle) and scanning electron microscopy (SEM). The characterization of natural rubber composites filled with bio-additives was performed including rheometric measurements, FTIR, TGA, cross-linking density, mechanical properties and colour change after simulated aging processes. Composites filled with natural fillers showed improved barrier properties and mechanical strength. Moreover, an increase in the cross-linking density of the materials before and after the simulated aging processes, compared to the reference sample, was observed.

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.