Cross-Linked Epoxidized Natural Rubber (ENR) from Reused Palm Oil

Conventional crosslinking agents for Epoxidized Natural Rubber (ENR) are typically synthesized chemicals that pose toxic threats to living organisms and the environment. Glycerol, a major byproduct from waste palm oil biodiesel production, remains largely underutilized. This study aims to identify a novel, environmental-friendly crosslinking agent for Epoxidized Natural Rubber (ENR). While waste palm oil is commonly utilized for biodiesel production, its major byproduct, glycerol, remains largely underutilized. Consequently, this research investigates the potential of glycerol to serve as a crosslinking agent for ENR. Experimental results confirm that a crosslinking reaction successfully occurs between ENR and glycerol. This is substantiated by Fourier Transform Infrared Spectroscopy (FTIR) analysis, which reveals crosslinking via the opening of the ENR oxirane rings. Significant peaks observed at 1032 cm⁻¹, 3340 cm⁻¹, and 2900 cm⁻¹ correspond to C-O-C, O-H, and C-H bonds, respectively. Furthermore, results from gel fraction analysis and Moving Die Rheometer (MDR) testing corroborate the crosslinking interaction between ENR and glycerol, indicating that crosslinking density increases with higher glycerol loading. Mechanical property testing further demonstrates that the tensile strength of glycerol-crosslinked ENR improves in correlation with the increased degree of crosslinking.