Thermomechanical behavior of a novel biobased poly(furfurylalcohol)/silica nanocomposite elaborated by smart functionalization of silica nanoparticles

The Polyfurfuryl Alcohol (PFA) is a biobased cross-linked polymer presenting high thermal performances. This work presents the processing of PFA/silica nanocomposite starting from pre-existing spherical silica nanoparticles obtained via the Stöber method. Prior to dispersion, silica nanoparticles were smartly decorated with furanic entities and such modification was analyzed by ThermoGravimetric Analysis (TGA), Fourier Transform InfraRed spectroscopy (FTIR) and solid state Nuclear Magnetic Resonance (NMR) spectroscopy. About 2/3 of surface Si-OH sites were grafted with furans and these modified silica nanoparticles were efficiently dispersed during polymerization of Furfuryl Alcohol (FA) as confirmed by Transmission Electronic Microscopy (TEM) observations. The thermo-mechanical performances of the PFA/silica nanocomposites were investigated by means of Dynamic Mechanical Analysis (DMA) and TGA. Unmodified nanoparticles do not change the final properties while the nanocomposite processed with functionalized nanoparticles presented improved properties. Strong interactions between cross-linked furanic matrix and the furfurylated nanoparticles resulted in a more rigid material whose thermal degradation processes were shifted to much higher temperature (+65 °C).