Straightforward Route To Design Biorenewable Networks Based on Terpenes and Sunflower Oil

Abstract

By using a combination of bio-based monomers, sunflower oil (S) and monoterperne, the β-myrcene (M), or a sesquiterpene, the β-farnesene (F), a series of novel networks S x M 100– x and S x F 100– x with different compositions were prepared by a green chemistry route, without any solvent or catalyst, using the Diels–Alder reaction at 100 °C to obtain branched materials. The presence of oxygen during this process is responsible of the formation of oxidation products that are characterized by Fourier transform infrared (FTIR) and Raman spectroscopies, a swell as X-ray photoelectron spectroscopy (XPS) analysis. Materials prepared with 100% terpenes (PM 100 and PF 100 ) are very hard and brittle, whereas materials prepared from vegetable oil (PS 100 ) are tearable. The properties of S x M 100– x and S x F 100– x are closely linked to the composition and, in particular, to the content of terpenes. It is observed that, by increasing the proportion of terpenes from 0 to 80 wt %, there was a marked increase in the glass-transition temperature ( T g ) values, from 13.8 °C to 58.2 °C for S 20 F 80 networks and up to 92.3 °C for S 20 M 80 networks. Although the S 20 M 80 network presents higher tensile modulus (97 MPa) and tensile strength (8.8 MPa), the S 50 M 50 network is the more promising material, combining high resistance and good flexibility. These resulting materials exhibited remarkable swelling capacity when they were immersed in eugenol, which is an interesting antibacterial compound. The release profile indicated a Fickian diffusion model with the release of 90% of eugenol in 30 days, providing interesting antibacterial properties to the materials.