Several innovative photopolymerizable siloxane-modified acrylic formulations were characterized, both in
presence or absence of organically Boehmite (OMB) nanoparticles, in order to assess their rheological and kinetic
behavior. The experimental formulations were mainly intended for the surface protection of porous stones or wood
elements. The importance of the experimental investigation lies in the specific requirements necessary for the proposed
applications, i.e. the innovative UV coatings developed should possess adequate viscosity, photopolymerization reaction
rate and time. The kinetics of the radical photopolymerization mechanism, induced by UV radiations, was studied by
calorimetric analysis and FTIR spectroscopy as function of the mixtures composition and test conditions (air or nitrogen
atmosphere). The addition of a silane coupling agent or a high molecular weight polysiloxane monomer to the acrylic
resin was found to reduce the heat of reaction. On the other hand, the presence of Boehmite nanoparticles in the UV
photopolymerizable formulations does not seem to modify the reactivity of the siloxane-modified acrylic formulations.
The effect of the presence of oxygen on the kinetic reaction was also investigated and correlated to the composition of the
systems. Finally, the viscosity of the formulations was studied at ambient temperature with a parallel plates rheomether as
a function of composition and shear rate. The viscosity curves were also fitted according to theoretical models as function
of shear rate and composition, obtaining a good agreement between experimental data and model predictions.