Radiation curable coatings are presently the standard in the wood flooring industry. Their great properties paired with their fast curing explain why they are now the most used coatings for prefinished wood flooring. Although important improvements can still be brought to these coatings. During the last years, nanoparticles have gained increasing interest in the paint and coatings industries. It could lead to similar results for the thermoset materials.
In this project, metal oxides (alumina, silica and zirconia) and clay nanoparticles were added in a typical UV acrylate formulation for wood flooring. This formulation was chosen mostly for its wear resistance, low yellowing and fast curing.
Nanoparticles were added in the acrylate formulation by different techniques (high speed mixing, ball milling, bead milling and three roll milling). Then, article size characterization was performed. Different techniques were employed according to the nanoparticles studied (metal oxides or clay). Microscopic experiments were also performed with an aim of supporting these results.
Then, nanoparticles and coupling agents addition effects on curing (speed and percentage of curing) were studied by photo-calorimetry (photo-DSC) and real-time infrared spectroscopy (RT-FTIR).
Mechanical properties (hardness, adhesion, scratch resistance, wear resistance, direct and reverse impact resistance) were evaluated. Optical properties (color, gloss, haze and optical clarity) and thermal properties were also assessed.
For clay-based coatings, an analysis of variance (ANOVA) was performed in order to determine if clay loading and clay dispersion affect the mechanical and optical properties.