A theoretical method to calculate the mode of polyurethane（PU） prepolymers grafted to polyacrylic（PAC） was presented. Using hydroxyethyl acrylate（HEA） as coupling agent, polyurethane-acrylics（PU-AC） hybrid lat...A theoretical method to calculate the mode of polyurethane（PU） prepolymers grafted to polyacrylic（PAC） was presented. Using hydroxyethyl acrylate（HEA） as coupling agent, polyurethane-acrylics（PU-AC） hybrid latexes were prepared with varying HEA level and the reaction of HEA with PU prepolymers at different temperatures, and PU grafted to PAC was experimentally determined. The results show that PU grafted to PAC regularly increased, and the non-grafted and linear free PU regularly decreased with increase in HEA/NCO（isocyanate group）. The grafted PU on PAC was not proportional to HEA. More than half of linear PU prepolymers were grafted to PAC when HEA was at a low level with HEA/NCO at 0.33. While grafted PU increased to 84.80%（mass fraction）, when HEA/NCO increased to 1.0. The results were interpreted based on the theoretical calculation of PU grafted to PAC by the present method.展开更多
We report the preparation of amphiphilic Janus particles covered with fluorinated chains as well as the self-assembly and foam stabilization property of these particles over a limited range of concentrations.The struc...We report the preparation of amphiphilic Janus particles covered with fluorinated chains as well as the self-assembly and foam stabilization property of these particles over a limited range of concentrations.The structure and properties of these particles were characterized using scanning electron microscopy,Fourier transform infrared spectroscopy,fluorescence microscopy,pendant drop tensiometer,and foamscan.At a particle concentration of 0.6wt%,the adsorption of the Janus particles at the interface was saturated and an equilibrium surface tension of approximately 35mN/m was obtained. No further decreases in surface tension were observed with additional increases in the particle concentration.At a concentration of 0.4wt%,the Gibbs stability criterion was achieved and the foam volume was almost constant throughout the observation period.Additionally,the liquid fraction of the foam exhibited a static equilibrium at each concentration assessed,demonstrating that drainage was arrested effectively.These results confirm that the use of amphiphilic Janus particles is an efficient approach to stabilizing foams.展开更多
基金Supported by the National Natural Science Foundation of China(No20874040)the Research Fund from University of Jinan, China(NoXKY0721)
文摘A theoretical method to calculate the mode of polyurethane（PU） prepolymers grafted to polyacrylic（PAC） was presented. Using hydroxyethyl acrylate（HEA） as coupling agent, polyurethane-acrylics（PU-AC） hybrid latexes were prepared with varying HEA level and the reaction of HEA with PU prepolymers at different temperatures, and PU grafted to PAC was experimentally determined. The results show that PU grafted to PAC regularly increased, and the non-grafted and linear free PU regularly decreased with increase in HEA/NCO（isocyanate group）. The grafted PU on PAC was not proportional to HEA. More than half of linear PU prepolymers were grafted to PAC when HEA was at a low level with HEA/NCO at 0.33. While grafted PU increased to 84.80%（mass fraction）, when HEA/NCO increased to 1.0. The results were interpreted based on the theoretical calculation of PU grafted to PAC by the present method.
基金National Natural Science Foundation of China (NSFC No.51374073).
文摘We report the preparation of amphiphilic Janus particles covered with fluorinated chains as well as the self-assembly and foam stabilization property of these particles over a limited range of concentrations.The structure and properties of these particles were characterized using scanning electron microscopy,Fourier transform infrared spectroscopy,fluorescence microscopy,pendant drop tensiometer,and foamscan.At a particle concentration of 0.6wt%,the adsorption of the Janus particles at the interface was saturated and an equilibrium surface tension of approximately 35mN/m was obtained. No further decreases in surface tension were observed with additional increases in the particle concentration.At a concentration of 0.4wt%,the Gibbs stability criterion was achieved and the foam volume was almost constant throughout the observation period.Additionally,the liquid fraction of the foam exhibited a static equilibrium at each concentration assessed,demonstrating that drainage was arrested effectively.These results confirm that the use of amphiphilic Janus particles is an efficient approach to stabilizing foams.
