10.1021/la5026735.s001
Xueliang Pei
Xueliang
Pei
Wentao Zhai
Wentao
Zhai
Wenge Zheng
Wenge
Zheng
Preparation and Characterization of Highly Cross-Linked
Polyimide Aerogels Based on Polyimide Containing Trimethoxysilane
Side Groups
American Chemical Society
2014
imidized polyimide aerogels
trimethoxysilane side groups
polyimide aerogels
Polyimide Containing Trimethoxysilane Side GroupsIn
acid chloride side groups
2014-11-11 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Preparation_and_Characterization_of_Highly_Cross_Linked_Polyimide_Aerogels_Based_on_Polyimide_Containing_Trimethoxysilane_Side_Groups/2236708
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 <i>tert</i>-butyl alcohol 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 from 0.19 to 0.42 g/cm<sup>3</sup>) 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 344 m<sup>2</sup>/g),
high 5% weight loss temperature in air (at about 440 °C), and
an excellent mechanical property. In addition, the glass transition
temperature (349 °C) of the polyimide aerogels was much higher
than that (210 °C) of the corresponding linear polyimide. So,
even after being heated at 300 °C for 30 min, the porous structure
of the polyimide aerogels was not completely destroyed.