Multifunctional epoxidized natural rubber biocomposites reinforced with alginate-dispersed cellulose nanocrystals for green energy applications

Abstract

This research focuses on the fabrication of multifunctional biocomposites derived from epoxidized natural rubber (ENR), reinforced with 2 parts per hundred rubber (phr) cellulose nanocrystals (CNCs) and varying concentrations of sodium alginate (SA), aiming to enhance mechanical strength, self-healing, and triboelectric characteristics. The influence of SA content on the characteristics of ENR/CNC2/SAx biocomposites was thoroughly examined. Scanning electron microscopy demonstrated a uniform dispersion of CNC. The establishment of hydrogen-bonded supramolecular networks enhanced interfacial adhesion, leading to reduced swelling and enhanced mechanical properties. The tensile strength and elongation at break exhibited an increase with the addition of SA content, achieving a maximum tensile strength of 1.9 MPa at 5 phr SA. The efficiency of self-healing was observed to rise with elevated temperatures and prolonged healing durations, with ENR/CNC2/SA5 reaching a maximum healing efficiency of 43 % at 80 °C after 12 hs. Increasing SA content also improved biodegradability, thereby contributing to environmental sustainability. The triboelectric performance evaluated through a contact-separation TENG configuration demonstrated that ENR/CNC2/SA5 achieved optimal output, exhibiting an open-circuit voltage of 77.3 V, a short-circuit current of 8.1 μA, and a power density of 1.21 W/m² at a 1 MΩ load. The biocomposite maintained 96.7 % performance after repeated cycling, highlighting its durability and potential in eco-friendly flexible electronics, wearable sensors, and energy-harvesting systems. © 2025 The Authors