Impact of Silica Nanoclusters on Furfuryl Alcohol Polymerization and Molecular Mobility Nicolas Bosq, ‡ Nathanael Guigo,* ,‡ Guillaume Falco, ‡ Jacques Persello, † and Nicolas Sbirrazzuoli* ,‡ ‡ Institut de Chimie de Nice, UMR CNRS 7272, Universite ́ Cô te d’Azur, 06100 Nice, France † Institut de Physique de Nice, UMR CNRS 7010, Universite ́ Cô te d’Azur, 06100 Nice, France * S Supporting Information ABSTRACT: Nanocomposite materials present attractive properties and are widely employed in various applications. Most of the time, the insertion of nanoparticles in a polymer matrix induces an enhancement of its performances, yet the effect of the filler on the polymerization mechanisms and the glass transition is less often investigated. In the present study, the PFA/silica nanocomposite was studied to highlight the variation of its polymerization behavior, thermomechanical properties and glass transition induced by the presence of a clustered silica nanoparticles network. The structure of nanosilica clusters was studied by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR). The furfuryl alcohol (FA) polymerization was studied via its activation energy variation in the presence of nanosilica clusters and anhydride maleic (MA) that led to some modifications of the polymerization mechanism. An enhancement of thermal stability and an increase of glass transition temperature have been put in relief by dynamic mechanical analysis (DMA) and were correlated to the presence of silica. Finally, the activation energy associated with the glass transition highlighted a change of the polymer chain motion process in the presence of silica. 1. INTRODUCTION In order to reduce the environmental footprint, alternative resources to oil-based feedstocks must be considered. Biomass is the unique sustainable source of carbons for the preparation of organic polymers and materials. As an instance, large quantities of naturally existing polymers (cellulose, hemi- cellulose, lignin, tannins) or deconstructed building blocks such as sugars (glucose, xylose) can be obtained from the lignocellulosic biomass. 1 The furfural is a platform chemical obtained from the dehydration of C 5 sugars (xylose) which is mostly converted into furfuryl alcohol (FA). 2 The FA monomer can polymerize through cationic condensation reaction and finally leads to the polyfufuryl alcohol (PFA). 2 This thermosetting polymer can be used for many applications since it displays a good chemical inertness and thermal stability with high carbon content. The PFA is employed for the preparation of binders and fire resistant materials, 3,4 and as well for the foundry molds. 5,6 It is well-known that the elaboration of organic-inorganic hybrids is valuable since it allows the combination of organic polymer properties with those of inorganic fillers. The pioneering studies on PFA/SiO 2 hybrids was presented in the work of Spange et al. 7-9 and Kawashima et al. 10 via simultaneous polymerization. In these latter, the silica network was synthesized via a sol-gel process and the simultaneous polymerization with FA resulted in hybrid network. 11 Following an alternative strategy, the twin polymerization was introduced which allows preparing, in one single procedure, a nanometric combination of organic and inorganic polymeric systems. 12 The tetrafurfuryloxysilane (TFOS) which was synthesized from FA was the first example of twin monomer that has generated hybrid interpenetrated network of PFA and SiO 2 . 12,13 More recently, PFA/SiO 2 hybrid network was prepared neither from in situ sol-gel process nor twin polymerization but from polymerization of FA with pre-existing silica spherical nano- particles. These latter were decorated with furan entities onto surface which resulted in enhanced interactions with the furanic polymer as exemplified by the higher thermal performance of the nanocomposite. 14 Pre-existing silica particles can present different architectures. Colloidal aggregates can be formed through assembly of silica nanoparticles held together by surface-surface forces. 15 These aggregates can create some bridges with each other which can tune the mechanical or the flowing properties. For instance, they can have different resistance to compressive stress depending on the their dispersion in aqueous media. 16 The surface chemistry and the morphology appear to be the key step in the interplay between the matrix and the filler. Usually the silica surface is rather hydrophilic due to the presence of hydroxyl groups which thus limits the filler compatibility to hydrophilic matrices. The characteristic of the interphase between the filler and the matrix at molecular level governs Received: December 22, 2016 Revised: March 7, 2017 Published: March 17, 2017 Article pubs.acs.org/JPCC © XXXX American Chemical Society A DOI: 10.1021/acs.jpcc.6b12882 J. Phys. Chem. C XXXX, XXX, XXX-XXX