Biobased Nanocomposites Prepared by In Situ Polymerization of Furfuryl Alcohol with Cellulose Whiskers or Montmorillonite Clay

In this work, we employed an in situ polymerization approach to produce polyfurfuryl alcohol (PFA) nanocomposites without the use of solvents or surfactants. On the one hand, furfuryl alcohol (FA) has a dual function, serving both as an effective dispersant for the cellulose whisker (CW) and montmorillonite clay (MMT) nanoparticles and as the matrix precursor for the in situ polymerization. On the other hand, the CW and MMT nanoparticles also serve multiple functions, by first catalyzing the polymerization of FA, and then acting as an effective matrix modifier, increasing the thermal stability of the consolidated PFA nanocomposite. In the case of CW-PFA nanocomposites, the polymerization is catalyzed by sulfonic acid residues at the CW surface, left over from the whisker preparation. In the case of MMT-PFA nanocomposites, the polymerization is catalyzed by Lewis acid sites inherent to the MMT surface. Thermal analysis showed that both types of polymer nanocomposites (PNCs) were characterized by significantly higher temperature at the onset of degradation and higher residual weight after nonoxidative degradation compared to unmodified PFA. Most importantly, by choosing PFA as the matrix and nanoparticles of CW and MMT, we were able to produce nanocomposites that are not only marked by high thermal resistance, but which were produced entirely from biobased precursor materials.