Recycling of Bagasse as an Agricultural Waste and its Effect as Filler on Some Mechanical and Physical Properties of SBR Composites

In the present study, a series of mixes based on different concentrations of carbon black (CB) as a reinforcing filler and sugarcane bagasse as supplementary filler, were investigated to examine their effects on the mechanical properties of styrene butadiene rubber (SBR) composites. To this end, the first group of mixes deals with the effect of different concentrations of CB ranging from 0 to 80 phr at fixed bagasse concentration of 25 phr. The second group of mixes involves the addition of bagasse with concentrations varying from 10 to 50 phr at 10 intervals with fixed CB concentration of 40 phr. The sizes of the employed ground bagasse powder (GBP) in all prepared formulations ranged from 20 to 180 μm. In addition, 2.5 phr of maleic anhydride (MA) was added to enhance the interfacial adhesion between SBR and agricultural waste fillers (i. e. bagasse). Tensile strength, elongation at break, modulus at 100% elongation, resilience, hardness (Shore A), abrasion and degree of swelling of the rubber vulcanizates were studied. The prepared samples were also analyzed by scanning electron microscopy (SEM) to show the distribution of fiber and the occurrence of fiber-matrix adhesion. The optimum concentration of bagasse to be used simultaneously with CB in SBR composites was found to be 30 phr. Overall, it was found from the obtained results that the addition of GBP up to 50 phr is feasible without impairing the mechanical properties of SBR vulcanizates.

Economic and sustainable management of wastes from rice industry: combating the potential threats

Rice is one of the imperative staple foods, particularly in the developing countries. The exponential boom in human population has resulted in the continuous expansion in the rice industry in order to meet the food demands. The various stages of paddy processing release huge quantity of solid wastes, mainly rice husk, rice husk ash and liquid wastes in the form of rice industry wastewater. The discharge of the rice industry wastewater imparts a substantial threat to the aquatic bodies and the nearby surrounding and, thus, consequently demands eco-benign treatment plan. As a result, different strategies are needed to enhance the effluent quality and minimize the operational cost of the treatment process. Therefore, efficient technological approach targeting the minimization of pollution as well as assuring the economic prosperity should be implemented. In this review article, several aspects related to the rice industry discussing the significant challenges involved in the generation of both solid and liquid wastes, mitigation experiments and future prospects have been meticulously elaborated. Furthermore, the article also focuses on the various processes utilized for reducing the pollution load and promoting the practice of reuse and recycle of waste rather than the discharge action for the sake of sustainability and the emergence of novel techniques for the generation of energy and value-added products.

Influence of Filler from a Renewable Resource and Silane Coupling Agent on the Properties of Epoxidized Natural Rubber Vulcanizates

Rice husk ash (RHA) was used as a reinforcing filler in epoxidized natural rubber (ENR) with various loading levels (0, 10, 20, and 30 phr), and silica filled ENR was also studied for comparison. The effects of RHA content on cure characteristics, mechanical properties, dynamic mechanical properties, and thermoelastic behavior of the filled ENR composites were investigated. It was found that the incorporation of RHA significantly affected the cure characteristics and mechanical properties. That is, the incorporation of RHA caused faster curing reactions and increased Young’s modulus and tensile strength relative to the unfilled compound. This might be attributed to the metal oxide impurities in RHA that enhance the crosslinking reactions, thus increasing the crosslink density. Further improvements in the curing behavior and the mechanical properties of the filled composites were achieved byin situsilanization with bis(triethoxysilylpropyl) tetrasulfide (Si69). It was found that the rubber-filler interactions reinforced the composites. This was indicated by the decreased damping characteristic(tan ⁡δ)and the other changes in the mechanical properties. Furthermore, the ENR composites with Si69 had improved filler dispersion. Temperature scanning stress relaxation (TSSR) results suggest that the metal oxide impurities in RHA promote degradation of the polymer network at elevated temperatures.