Papers by Author: Li Huo

Abstract: The photocatalytic waterborne styrene-acrylic coating was prepared by adding different concentrations of homemade TiO₂ transparent emulsion and nanometer TiO₂ powders into styrene-acrylic emulsion. The adhesion, elastic, hardness, impact resistant properties of the film were measured and photocatalytic properties of the film were investigated through the degree of degradation of Rodamine B. The results showed that the photocatalytic properties of coating with homemade TiO₂ transparent emulsion were better than that of nanometer TiO₂ powders, and it does not affect the mechanical properties of the coating.

Abstract: UV-curable bi-component coating of glycidyl methacrylate (GMA)/polyurethane –acrylate (PUA) modified with the methylacryloylpropyl polyhedral oligomeric silsesquioxanes (MAP-POSS) were prepared. The dynamic mechanical properties and thermal behavior of nano-hybrid coating (GMA/PUA/MAP-POSS) were characterized with dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and the Fourier transform infrared spectrometer (FTIR). The results indicate the three components have very good compatibility and can co-cure in UV-radialization by a free radical polymerization. The addition of MAP-POSS enhanced the thermal properties, the mechanical loss peak temperature T_p is 85.5°C when the amount of MAP-POSS is 10wt%, which is increased by 12.6 °C than the pure system. When the content of MAP-POSS is 20wt%, thermal decomposition temperature in the initial stages was increased by 7 °C than that of the pure GMA/ PUA.

Abstract: A liquid crystalline epoxy resin of p-biphenylene di-4-(2,3-epoxypropyloxy)benzoate (p-BDEPB) was synthesized from allyl bromide, 4-hydroxy ethyl benzoate and 4,4-dihydroxybiphenyl. Its structure and liquid crystalline behavior were characterized by DSC, 1H-NMR, FTIR, POM and XRD. The results are shown that this compound is smectic liquid crystalline.The melting point of p-BDEPB is 210 oC and clearing point is over 300 oC, the epoxy value is 0.312 mol/100g. The average curing Ea of p-BDEPB/3-methyl-tetrahydrophthalic anhydride (MeTHPA) system is 97.2kJ/mol. The gel point of cured-system Tgel is 89.0 oC, curing temperature Tcu is 132.5 oC and finishing temperature Tf is 146.5 oC. The curing reaction can be described by the autocatalytic Šesták-Berggren (S-B) equation, the two reaction orders m and n is 0.23 and 0.74, respectively.