Recent advances in functional nanocomposites have created new frontiers in research for radiation-curable organic coatings making use of nanocomposite technology. Such UV curable systems would enable the widespread use of nanocomposites in microfabrication. Little is understood on incorporating organomodified clays in UV curable polymers. UV curable films were reinforced with organically modified montmorillonite (MMT). The organically modified MMT were prepared by an ion exchange process in which sodium ions were replaced by alkyl ammonium ions. Acrylate films were reinforced with organoclays, which serve as reinforcements and barrier fillers in the polymer matrix. The microstructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Physical properties were examined by real time infrared spectroscopy (RTIR), differential scanning calorimetry (DSC), photo-DSC, dynamic mechanical thermal analysis (DMTA), Instron, and pendulum hardness. Preliminary results showed that aliphatic urethane acrylate nanocomposite coatings exhibited an intercalated structure and enhanced properties. 10 to 20 percent increase in tensile strength and a 25 to 50 percent increase in Young's modulus were observed. Decreased cure time to a tack free film and a slight increase in conversion as seen by RTIR were interestingly reported, suggesting the presence of nanoclays can improve the cure speed of acrylate coatings. Thermal stability was also enhanced. Potential applications of UV curable materials exist in the electronics industry where it is desirable to have coatings with good flexibility, dimensional stability, chemical resistance, thermal stability, transparency, and fast cure. This work demonstrated coatings with nanoscale reinforcements are ideal in such applications.
Available at: http://works.bepress.com/shing-chung_wong/87/