Hardness Studies on Biochar Filled Polyester Matrix Composites

Introduction: In the 21st century the search for new innovative materials is still in hunt as the researchers are moving towards development of innovative materials by means of utilizing the available resources in an efficient manner. One such thing is the evolution of biochar which attracts multidisciplinary research because of its special characteristics, good performance, and flexibility, possess carbon rich content. The development of biochar is not new to the environment since it was obtained by the typical ancient slash and burn method (1,2). From the literature it has been noted that the search for new biochar extracted from various agricultural wastes is still needed based on this research attempt for deriving a biochar from sugarcane and cashew nut shell taken and its hardness studies be reported. Methods: The materials used for this work are cashew nut shell waste and sugarcane waste that procured from the local markets in Virudhunagar District, Tamilnadu. The biochar extracted from these wastes are used for making the composites. Unsaturated polyester resin used as a matrix procured from Vasavibala resins pvt., ltd., Chennai. Biochar extracted from both the two wastes by means of pyrolysis process at a temperature of 5000C and varying time of 1 hour and 3 hours respectively. The extracted biochar is then subjected to ball milling process to obtain in fine powder form. The specimens are prepared by means of solution dispersion method in which the castings are prepared using a glass mould. Initially resin is taken and biochar of different weight percentages 5%,10% and 15% wt are taken and mixed thoroughly with the resin manually. Then the mixer is poured into the glass mold and allowed to cure for 24 hours without any disturbance. Results & Discussions: The various combinations of biochar reinforced polyester composite specimens prepared were subjected to shore D hardness studies to know the improvement in surface hardness and the change in structure behaviors by the addition of biochar. For each combination from the prepared composite casting ten specimens are cut as per the ASTM standard to perform the harness study and the average of those ten values are reported for further discussion. in the case of biochar extracted from the sugarcane wastes along with the polyester matrix possess an increase in the hardness from 20 to 32. In general, the addition of filler increases the hardness by making the surface rougher and strong in such a way provides better bonding. Among all combinations when compared to pure polyester the addition of 15% wt biochar possess high hardness value especially in 3 hours heating condition. Also in this case, the hardness value increases gradually with the increase in weight percentages. On the other hand, the in 1 hour heating case there is a sudden drop in harness for 10%wt weight addition which may be due to the discontinuity flow of the biochar with matrix. In the case of the next type biochar extracted from the cashew nut shell waste possess an excellent progress in the hardness results. Conclusions: Biochar extracted successfully by the pyrolysis process from various agricultural wastes such as cashew nut shell and sugarcane. The hardness value increased to 11% and 22% by the addition of sugarcane waste and cashew nut shell waste extracted biochar. Among all, cashew nut shell waste extracted biochar of 15 % wt has the highest hardness value. From this study clearly evident because of the good hardness values this biochar has the potential to be used as effective filler along with natural fiber reinforced polymer composites preparation in terms possess some interesting change in the mechanical properties. Keywords: Biochar, Hardness, Polymer matrix References 1. Wenfu Chen, Jun Meng, Xiaori Han, Yu Lan, Weiming Zhang, Past, present, and future of biochar, Biochar.2019; 1:75–87. https://doi.org/10.1007/s42773-019-00008-3 2. Anil Kumar Sakhiya, Abhijeet Anand, Priyanka Kaushal, Production, activation, and applications of biochar in recent times, Biochar. 2020; 2: 253–285 https://doi.org/10.1007/s42773-020-00047-