Cardo-type polyimide

To improve the thermal stability, a high-Eg cardo-type polyimide with a dendronized CLD-type chromophore has been developed [119]. A high poling efficiency was achieved to afford a very large EO coefficient (71 pm/V at 1.3 pm) more than 90% of this value can be retained at 85°C for more than 650h. 

M. Pourafshari Chenar, M. Soltanieh, T. Matsuura, A. Tabe-Mohammadi, and K. C. Khulbe. The effect of water vapor on the performance of commercial polyphenylene oxide and cardo-type polyimide hollow fiber membranes in CO2/CH4 separation applications. J. Membr. ScL, 285(l-2) 265-271, November 2006. 

The authors claim to have successfully appUed the site isolation principle to a rigid 3-F cardo-type polyimide wifli very high Tg. At the same time high poling efficiency is also claimed to yield very large electrooptic coefficient (71pmA at 1.3 pm) More than 90% of this value is claimed to be retained at 85 "C for more than 650 hours. 

Figure 22.7 Chemical structures of the cardo-type polyimide.

Karashima, S., Tokuda, Y., Tachiki, A., Takagi, K., Haraya, K., and Kamizawa, C. (1999). Development of Cardo-type polyimide hollow fiber membranes for CO2 separation. Fourth International Conference on Greenhouse Gas Control Technologies (GHGT-4), 1035. 

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