In order to inhibit and remove the thin ice and extend the lifetime of the damaged bridge, the self-healing mechanism and hydrophobic performance of asphalt modified by siloxane and polyurethane (ASP) were studied by ...In order to inhibit and remove the thin ice and extend the lifetime of the damaged bridge, the self-healing mechanism and hydrophobic performance of asphalt modified by siloxane and polyurethane (ASP) were studied by dynamic shear rheology (DSR), fluorescence microscope (FM), atomic force microscope (AFM), the fracture-healing-re-fracture test and molecular simulations. The experimental results indicated that the selfhealing capability of ASP increased with increasing heating time and temperature. Furthermore, the addition of siloxane could improve the reaction energy barrier and complex modulus, and it is believed that the self-healing is a viscosity driven process, consisting of two parts namely crack closure and properties recovery. Contact angle of ASP increased with the increasing siloxane content and it deduced that the siloxane could improve the hydrophobic performance of ASP and the ASP molecule model could simulate well the self-healing mechanism and hydrophobic performance of ASP.展开更多
Two series of polyurethanes based on mixed polychloromethyl methyl siloxane and poly-tetramethylene oxide in different weight fractions were synthesized. The phase separation ofsamples was studied using DSC and dynami...Two series of polyurethanes based on mixed polychloromethyl methyl siloxane and poly-tetramethylene oxide in different weight fractions were synthesized. The phase separation ofsamples was studied using DSC and dynamic mechanical property analysis. The results showedthat the introduction of chloromethyl group into polysiloxane increased its polarity and henceimproved the miscibilities with polytetramethylene oxide and polyurethane hard segment.Particularly, in the case of N-methyldiethanolamine extended materials, the surface and tensileproperties of these samples can be adjusted by various ratios of two soft segments.展开更多
Siliconated polyurethane （Si-PU） was synthesized using isophorone diisocyanate （IPDI）, hydroxybutyl-terminated polydimethylsiloxane （PDMS）, polytetramethylene ether glycol （PTMG）, polypropylene glycol （PPG）,...Siliconated polyurethane （Si-PU） was synthesized using isophorone diisocyanate （IPDI）, hydroxybutyl-terminated polydimethylsiloxane （PDMS）, polytetramethylene ether glycol （PTMG）, polypropylene glycol （PPG）, 1,6-hexanediol （HDO）, dimethylol propionic acid （DMPA） and triethylamine （TEA）. Based on butyl acrylate （BA）, 2, 2, 2-trifluoroethylmethacrylate （TFEMA） and Si-PU as a seed emulsion, a novel core-shell type acrylic-polyurethane hybrid emulsion, containing siloxane and fluorine （F-Si-PU）, was prepared by seeded emulsion polymerization. The contents of siloxane and fluorine were determined according to the feed ratio. Fourier transform infrared spectroscopy （FTIR） was used to identify the chain structures of Si-PU and F-Si-PU. Investigation of transmission electron microscopy （TEM） confirmed the core-shell structure of F-Si-PU emulsion. Measurement results of water contact angle and the swelling ratio in water and n-octane for cured film showed that the water and the oil resistances for F-Si-PU had been significantly improved at a suitable content of fluorine and siloxane.展开更多
基金Funded by the National Natural Science Foundation of China(No.51808329)Science and Technology Department of Shanxi Province International Cooperation(No.201603D421027)the Special Project of Commercialization of Shanxi Province Research Foundation(No.201804D131034)
文摘In order to inhibit and remove the thin ice and extend the lifetime of the damaged bridge, the self-healing mechanism and hydrophobic performance of asphalt modified by siloxane and polyurethane (ASP) were studied by dynamic shear rheology (DSR), fluorescence microscope (FM), atomic force microscope (AFM), the fracture-healing-re-fracture test and molecular simulations. The experimental results indicated that the selfhealing capability of ASP increased with increasing heating time and temperature. Furthermore, the addition of siloxane could improve the reaction energy barrier and complex modulus, and it is believed that the self-healing is a viscosity driven process, consisting of two parts namely crack closure and properties recovery. Contact angle of ASP increased with the increasing siloxane content and it deduced that the siloxane could improve the hydrophobic performance of ASP and the ASP molecule model could simulate well the self-healing mechanism and hydrophobic performance of ASP.
文摘Two series of polyurethanes based on mixed polychloromethyl methyl siloxane and poly-tetramethylene oxide in different weight fractions were synthesized. The phase separation ofsamples was studied using DSC and dynamic mechanical property analysis. The results showedthat the introduction of chloromethyl group into polysiloxane increased its polarity and henceimproved the miscibilities with polytetramethylene oxide and polyurethane hard segment.Particularly, in the case of N-methyldiethanolamine extended materials, the surface and tensileproperties of these samples can be adjusted by various ratios of two soft segments.
基金Financial supports from the National Natural Science Foundation of China(No.50273035)Hangzhou Zhijiang Silicone Chemical Industry Co.,Ltd.are acknowledged.
文摘Siliconated polyurethane （Si-PU） was synthesized using isophorone diisocyanate （IPDI）, hydroxybutyl-terminated polydimethylsiloxane （PDMS）, polytetramethylene ether glycol （PTMG）, polypropylene glycol （PPG）, 1,6-hexanediol （HDO）, dimethylol propionic acid （DMPA） and triethylamine （TEA）. Based on butyl acrylate （BA）, 2, 2, 2-trifluoroethylmethacrylate （TFEMA） and Si-PU as a seed emulsion, a novel core-shell type acrylic-polyurethane hybrid emulsion, containing siloxane and fluorine （F-Si-PU）, was prepared by seeded emulsion polymerization. The contents of siloxane and fluorine were determined according to the feed ratio. Fourier transform infrared spectroscopy （FTIR） was used to identify the chain structures of Si-PU and F-Si-PU. Investigation of transmission electron microscopy （TEM） confirmed the core-shell structure of F-Si-PU emulsion. Measurement results of water contact angle and the swelling ratio in water and n-octane for cured film showed that the water and the oil resistances for F-Si-PU had been significantly improved at a suitable content of fluorine and siloxane.
