Characterization of new natural fibres from various parts of plants have become increasingly popular not only in textile industries, automotive sector, electrical applications, and construction industries, but in various industrial applications because of their versatile characteristics, availability, biodegradability and providing sustainable solutions to support technical innovation. This study aimed to determine the characterization and physicochemical properties of Phaseolus vulgaris fibers (PVF) by Thermo gravimetric analysis (TGA)/DTG, X-Ray Diffraction analysis (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Eventually, fourier transform analysis and XRD analysis of PVFs demonstrated the presence of cellulose with a crystallinity index of 43.01%. The surface morphological analysis was observed and reveals that PVFs contain rougher surfaces, which would be favourable to develop good bonding with the matrix for making composites.

This investigation is aimed to analyze the effect of sodium hydroxide (NaOH) treatment on the physical, chemical, structural, thermal and surface topography of Phaseolus vulgaris fibers (PVFs). The surface of raw PVFs was modified by soaking with 5% NaOH solution for 15, 30, 45 and 60 min. The various functional groups of the alkali-treated PVFs (APVFs) were studied Fourier-transform infrared spectroscopy. The outcomes of thermogravimetric analysis evident that the optimum treatment time for 5% NaOH was 45 min. It was noticed that optimally treated PVFs have higher cellulose (69.48 wt.%), crystallinity index (52.27%) and lower hemicellulose (4.30 wt.%), lignin (7.02 wt.%) contents. The thermogravimetric analysis (TGA) of PVFs also revealing moderate thermal stability was observed; atomic force microscopy (AFM) investigation inveterates that the surface of the fiber is rough and it will be a potential reinforcement for polymer composites.

In this study, the electrical, thermal, and mechanical properties of hybrid natural fiber composite are taken under consideration. Fly ash waste is used as the filler material. Unsaturated polyester resin is used as the matrix material to bind the composite. Alkali-treated Phaseolus vulgaris fiber (PVF) (5% NaOH for 45 min) is taken as the primary filler. Nanosilica synthesized is added to the composite samples at a constant percentage (1%). Samples of various weight percentages are prepared (2%, 4%, 6%, 8%, and 10% of PVF) and studied. Dielectric strength test for electrical property, thermal conductivity test for the thermal property, mechanical tests like tensile strength, Brinell hardness, Izod impact tests, and water absorption test are also taken under consideration. The composite showed a regular increasing trend in mechanical and electrical properties with varying weight percentages until 6% PVF; afterward, a decreasing trend in the mechanical and electrical properties of the composite was found with greater weight percentages. Whereas for thermal conductivity and water absorption tests, the results showed a regular decreasing trend until 6% PVF; afterward an increasing trend was found. It is found that the composite of 6% PVF and 1% SiO₂ shows better electrical, thermal, and mechanical properties.