Optimization of Nile rose role as a bio‐filler for green natural rubber composites

Abstract

The valorization of plant wastes for developing environmentally friendly composites has garnered increasing attention over the past two decades. The management of a significant quantity of Nile rose plant waste presents a mounting challenge, particularly in light of escalating water demand. This study delves into the impact of Nile rose fiber (RF) loading and utilizing Vinyltrimethoxysilane (VTMS) as a coupling agent on the characteristics of a composite comprising RF and natural rubber (NR). The verification of the fiber structure treated with silane (TF) was accomplished via Fourier transform infrared (FTIR) spectroscopy. The crosslinking between the NR matrix and the fibers is promoted by the formation of siloxane (SiOSi) linkages in 1050–1100 cm−1. An extensive evaluation of the impact of RF on the characteristics of NR composite was conducted, encompassing morphological properties, mechanical characteristics, and water absorption resistance. The results of the morphological analysis revealed that the modification of RF with silane enhanced the interfacial adhesion between RF and NR. Furthermore, the tensile strength (TS) of NR increases to values of 7.31 and 8.5 MPa by an improvement of 61% and 88% when 10 and 15 phr of TF are added, respectively. Moreover, rubber composites with silane exhibited superior water resistance to those without it across various filler loadings. Specifically, the composite with 20 phr TF absorbed 7% water, whereas the counterpart with untreated fiber (RF) absorbed 12.5% water. The analysis of swelling validated that the interaction between the RF and NR is significantly impacted by the modification of fiber and its incorporation into the composite, as evidenced by the decreased swelling index values from 367% to 298% observing in composites incorporating TF as opposed to those containing RF.Highlights Silane treatment improves the interaction between RF and NR. The TF and NR matrix interacted more and developed an interfacial bonding. The rate of vulcanization is accelerated in the presence of treated RF. TF/NR composites have fewer voids and microcracks, inhibiting water diffusion. 15% TF content optimal for good physical and mechanical properties.