Poly(ether imide)s containing cyano substituents and thin films made from them

A series of poly(ether imide)s containing functional cyano groups has been prepared by polycondensation reaction of 2,6-bis(m-aminophenoxy)benzonitrile with different bis(ether dianhydride)s, such as 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]isopropane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)-phenyl]hexafluoroisopropane dianhydride, 1,1-bis[4-(3,4-dicarboxyphenoxy)phenyl]cyclohexane dianhydride, and 3,3-bis[4-(3,4-dicarboxyphenoxy) phenyl]phthalide dianhydride. The polymers were soluble in polar aprotic solvents and even in less polar solvents and were processed into thin films by casting their solutions. The properties of the polymers, particularly the crosslinking of macromolecular chains through cyano groups, were studied by using dynamic mechanical analysis (DMA), thermal stability, glass transition, and solubility measurements. Also, the molecular relaxations were evidenced by DMA and dielectric spectroscopy. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012