Application of sustainable treatments to fiber surface for performance improvement of elastomeric polyurethane reinforced with basalt fiber

In order to overcome compatibility leakage between composite phases, which is a significant challenge in multidimensional composite applications, it is crucial to optimize the chemical nature of additives. The surface of basalt fiber (BF) was chemically enriched via biobased epoxy resin sizing and functional silanization process to improve its interfacial adhesion to the ecograde elastomeric polyurethane (EPU) matrix. The surface properties of BF were examined with the help of scanning electron microscopy X-ray spectroscopy (SEM/EDX) and Fourier-transformed infrared spectroscopy (FTIR) analyses. Impacts of surface modifications were compared based on mechanical, morphological, thermomechanical, and melt-flow behaviors of composites involving pristine and modified BF. Findings revealed that surface-modified BF inclusions improved the tensile strength and Shore-hardness values of composites. Tensile strength of EPU raised from 27.1 to 37.1 MPa after compounding with epoxy-sized BF. Additionally, the resin-coated BF incorporation exhibited a two-fold increase in the tensile modulus of EPU. Thermomechanical response of EPU exhibited an increasing trend by BF inclusions regardless of treatment type. Glass transition temperature of EPU shifted to 5 units higher value with modified BF loadings. SEM investigations confirmed the increased interfacial interaction between the EPU matrix and surface-sized BF. The chemically enriched surface of BF improves composite performance by improving adhesion at the EPU-BF interface. The results of this study confirmed that enhanced interfacial adhesion led to performance improvements for BF-loaded EPU composites.