Development and characterization of novel photopolymerizable formulations for stereolithography

Novel photopolymerizable formulations, able to photopolymerize with a dual mechanism (cationic and radical), were developed and characterized as potential resins for stereolithography (SL) process. The influence of the presence of organically modified boehmite nanoparticles on the properties of the photopolymerizable mixtures was also analyzed. The main important properties required to a liquid SL resin are an high reactivity and a low viscosity. All the experimental formulations produced, even in presence of boehmite nanoparticles, are able to satisfy these significant requirements. Physical-mechanical and thermal properties of the photocured samples, obtained starting from the experimental formulations, were finally measured. The cured nanocomposite bars show an high transparency, confirming the good dispersion of the nanofiller in the polymeric matrix and posses improved glass transition temperature and mechanical performances, compared to the unfilled system and to a commercial stereolithographic resin. This result suggest the possibility to use the novel nanofilled photopolymerizable suspensions in the stereolithographic apparatus to build, not only esthetical, but also functional prototypes