As a coupling agent,(3-aminopropyl)triethoxysilane(APTES)was used to synthesize a series of silanized waterborne polyurethanes(Si-WPUs)through the acetone process.The Fourier transform infrared spectroscopy(FTIR)toget...As a coupling agent,(3-aminopropyl)triethoxysilane(APTES)was used to synthesize a series of silanized waterborne polyurethanes(Si-WPUs)through the acetone process.The Fourier transform infrared spectroscopy(FTIR)together with the X-ray photoelectron spectroscopy(XPS)was utilized to measure both elements and structures of these samples.The scanning electron microscope(SEM)results explained that APTES would be agglomerate on the surface of WPU films when the mass fraction of the agent concentration was more than 8%.Besides,the contact angle of water(CAW)can be improved from 56.5°to 90.0°by adjusting APTES concentration in Si-WPU.The decomposition temperature of films was also improved with the increase of APTES,and a significant increase could be seen in the glass temperature from 51.00℃to 85.74℃.展开更多
The conversion of perhydropolysilazane(PHPS)to silica at low temperature is beneficial for its application on thermally vulnerable substrates.In this work,it is demonstrated that(3-aminopropyl)triethoxysilane(APTES)ha...The conversion of perhydropolysilazane(PHPS)to silica at low temperature is beneficial for its application on thermally vulnerable substrates.In this work,it is demonstrated that(3-aminopropyl)triethoxysilane(APTES)has high catalytic efficiency for the low temperature conversion of PHPS and the catalytic mechanism of APTES was suggested.The influence of temperatu re and humidity on the catalytic conversion process was investigated,and it was found that PHPS can be rapidly converted to silica in 10 min at 80℃with relative humidity of 90%.The achieved silica is mainly composed of SiNO_(3)/SiO_(3)OH and SiO_(4)structure with O/Si of 1.74 and N content of 1%.As an approach to prepare inorganic coating,the low-temperature conversion method achieves a silica coating with low volume shrinkage of 0.86%,low roughness of R_(a)=0.293 nm,high nanoindentation hardness of 3.62 GPa and modulus of 30.06 GPa,which exhibits high potentials as protective coating for va rious materials even those vulnerable to high temperature.展开更多
基金Shanghai Undergraduate Training Program on Innovation and Entrepreneurship Grant,China(No.cs1904006)。
文摘As a coupling agent,(3-aminopropyl)triethoxysilane(APTES)was used to synthesize a series of silanized waterborne polyurethanes(Si-WPUs)through the acetone process.The Fourier transform infrared spectroscopy(FTIR)together with the X-ray photoelectron spectroscopy(XPS)was utilized to measure both elements and structures of these samples.The scanning electron microscope(SEM)results explained that APTES would be agglomerate on the surface of WPU films when the mass fraction of the agent concentration was more than 8%.Besides,the contact angle of water(CAW)can be improved from 56.5°to 90.0°by adjusting APTES concentration in Si-WPU.The decomposition temperature of films was also improved with the increase of APTES,and a significant increase could be seen in the glass temperature from 51.00℃to 85.74℃.
基金financially supported by the National Natural Science Foundation of China(No.21872152)Guangdong Natural Science Foundation(No.2019A1515111028)Xiejialin Foundation in the Institute of High Energy Physics(No.E15466U210)。
文摘The conversion of perhydropolysilazane(PHPS)to silica at low temperature is beneficial for its application on thermally vulnerable substrates.In this work,it is demonstrated that(3-aminopropyl)triethoxysilane(APTES)has high catalytic efficiency for the low temperature conversion of PHPS and the catalytic mechanism of APTES was suggested.The influence of temperatu re and humidity on the catalytic conversion process was investigated,and it was found that PHPS can be rapidly converted to silica in 10 min at 80℃with relative humidity of 90%.The achieved silica is mainly composed of SiNO_(3)/SiO_(3)OH and SiO_(4)structure with O/Si of 1.74 and N content of 1%.As an approach to prepare inorganic coating,the low-temperature conversion method achieves a silica coating with low volume shrinkage of 0.86%,low roughness of R_(a)=0.293 nm,high nanoindentation hardness of 3.62 GPa and modulus of 30.06 GPa,which exhibits high potentials as protective coating for va rious materials even those vulnerable to high temperature.
