Preparation and Characterization of Highly Cross-linked Polyimide Aerogels Based on Polyimide Containing Trimethoxysilane Side Groups
In this study, highly cross-linked and completely imidized polyimide aerogels were prepared from polyimide containing trimethoxysilane side groups, which was obtained as the condensation product of polyimide containing acid chloride side groups and 3-aminopropyltrimethoxysilane.After adding water and acid catalyst, the trimethoxysilane side groups hydrolyzed and condensed one another, and a continuous increase in the complex viscosities of the polyimide solutions with time was observed.The formed polyimide gels were dried by freeze-drying from tert-butanol to obtain polyimide aerogels, which consisted of a three-dimensional network of polyimide fibers tangled together.By varying the solution concentration of the polyimide containing trimethoxysilane side groups, polyimide aerogels with different densities (ranging from0.19 to 0.42 g/cm3) were obtained.The resulting polyimide aerogels had small pore diameter (ranging from 20.7 to 58.3 nm), high surface area (ranging from 310 to 344m2/g), high 5% weight loss temperature in air (at about 440 ℃) and excellent mechanical property.In addition, the glass transition temperature (349 ℃) of the polyimide aerogels was much higher than that (210 ℃) of the corresponding linear polyimide.So, even after being heated at 300 ℃ for 30 min, the porous structure of the polyimide aerogels was not completely destroyed.
aerogel polyimide trimethoxysilane side groups
Xueliang Pei Wentao Zhai Wenge Zheng
Ningbo Institute of Materials Technologies and Engineering, Chinese Academy of Sciences, Ningbo,315201
国内会议
宁波
英文
370-395
2014-11-11（万方平台首次上网日期，不代表论文的发表时间）