Synthesis, Characterization and Application of Biobased Unsaturated Polyester Resin Reinforced with Unmodified/Modified Biosilica Nanoparticles

Abstract

This paper presents sustainable technology for environmentally friendly composite production. Biobased unsaturated polyester resin (b-UPR), synthesized from waste polyethylene terephthalate (PET) glycosylate and renewable origin maleic anhydride (MAnh) and propylene glycol(PG), was reinforced with unmodified and vinyl-modified biosilica nanoparticles obtained fromrice husk. The structural and morphological properties of the obtained particles, b-UPR, as well ascomposites, were characterized by Fourier-transform infrared spectroscopy (FTIR), nuclear magneticresonance spectroscopy (NMR), scanning electron microscopy (SEM), and transmission electronmicroscopy (TEM) techniques. The study of the influence of biosilica modification on the mechanicalproperties of composites was supported by hardness modeling. Improvement of the tensile strengthof the b-UPR-based composite at 2.5 wt.% addition of biosilica modified with vinyl silane, named“b-UPR/SiO2-V” composite, has been achieved with 88% increase. The thermal aging process appliedto the b-UPR/SiO2-V composite, which simulates use over the product’s lifetime, leads to the deterioration of composites that were used as fillers in commercial unsaturated polyester resin (c-UPR).The grinded artificially aged b-UPR composites were used as filler in c-UPR for the production of atable top layer with outstanding mechanical properties, i.e., impact resistance and microhardness, aswell as fire resistance rated in the V-0 category according to the UL-94 test. Developing sustainablecomposites that are chemically synthesized from renewable sources is important from the aspect ofpreserving the environment and existing resources as well as the extending their life cycle.