Itaconic acid based epoxy resin and application of olive pomace on the production of composite materials

Abstract

The synthesis of eco-friendly and renewable epoxy resins, capable of substituting conventional epoxy resins derived from petroleum and possibly hazardous materials, holds significant importance. In this study, it was aimed to develop biobased itaconic acid (IA) based epoxy resin (EIA). In addition, to reduce the costs and improve the mechanical and other properties of the synthesized EIA, olive pomace waste (OP), a natural reinforcement material, was used both in its raw form and chemically treated with NaOH (NaOH-OP) and then added to the biobased matrix phase. The EIA was modified with bisphenol-A type epoxy resin (ER) and used as a matrix. The chemical structure of EIA was confirmed by using analytical techniques such as ¹H NMR, FT-IR, mass spectrometry, and epoxy group determination. The reinforcements and composites were analyzed using FT-IR, FE-SEM/EDX, TGA, water sorption, contact angle measurement (C.A.), mechanical tests, and particle size distribution analysis. The morphological analysis revealed an augmentation in the adhesion between NaOH-OP fillers and the ER-EIA matrix. In comparison to both neat ER-EIA and raw OP composites, the NaOH-OP composites exhibited higher tensile strength. The investigation revealed that the composite material, which included 20 wt% NaOH-OP in a weight ratio of 7:3, had outstanding performance in terms of tensile strength (94.2 MPa) and elastic modulus (e-modulus) (7.1 GPa). The TGA results demonstrated that the inclusion of OPs greatly enhanced the thermal stability of neat ER-EIA. The composites reinforced with NaOH-OP had hydrophobic surfaces. The DMA results indicate that the glass transition temperature (T_g) of the composites is higher than that of the neat ER-EIA mixture. The identical outcomes apply to the curing degrees derived from FT-IR spectra.