Curing and mechanical properties of UV-curable nano-composites

In this research, TiO2 pigmented and unpigmented epoxy acrylate/SiO2 nanocomposites were prepared and their curing behavior an d mechanical properties were evaluated. For this purpose, photo-DSC and DMA analysis were used. The extent of SiO2 co ntent in samples was chosen in the range of 0-3phr. The results showed that the ultimate conversionvalues increased by 14.1% and 17.6% when 1 and 3 phr silica nanoparticles was ad ded to unpigmented formulation, respectively. On the other hand, the final conversion ofTiO2 pigmented formulations in creased by 31.7% and 57.1%using 1 and 3phr silica nanoparticlesin the formulations, respectively. These results revealed that th e incorporation of silica nanoparicles into pigmented formulations had a more considerable effect comparing to the unpigmented one. T he elastic modulus of unpigmented cured films which had 1 and 3 phr silica nanoparticles increased by 21.4% and 23.8%, res pectively, in comparison to the neat sample. The effect of silica nanoparticles on the elastic modulus of pigmented cured film w as more considerable and it increased by 28% and 52% in comp arison to the neat sample when 1 and 3 phrnano-SiO2 was incorporat ed in the formulation. The Tg of nanocomposite samples w as found to be higher than that for the neat samples. Once again it was more significant for the pigmented formulations.

کلیدواژه ها:

UV cured coatings ، Pigmented coatings ، Nano-composites ، Curing behavior ، Mechanical properties