PREPARATION AND PROPERTIES OF THERMOSETTING ACRYLIC COATINGS USING TITANIUM-OXO-CLUSTER AS A CURING AGENT

Thermosetting acrylic coatings were prepared by using carboxyl acid group-containing acrylic oligomer and curing with titanium-oxo-clusters which were first pre-hydrolyzed from titanium n-butoxide. The curing ability of the titanium-oxo-cluster was examined using a microdielectric analytical (DEA) curing monitor, Fourier transformed infrared spectroscopy (FTIR), and Soxhlet extraction experiments, and the properties of the resulted coatings were investigated with pendulum hardness tester, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and ultraviolet-visible spectrometer. The effect of titania-oxo-cluster in leading acrylic oligomers to form thermosetting acrylic coatings was confirmed. An increasing pendulum hardness and modulus of acrylic coatings with increasing titania content was observed, which resulted from the increment of crosslinking degree rather than of the titania content. The thermosetting acrylic/titania coatings also showed better thermal stability and higher UV-blocking properties than those coatings using organic curing agent.