Y. Chern, Jeng-Tay Twu, Jyh‐Chien Chen
Apr 1, 2009
Citations
1
Influential Citations
24
Citations
Journal
European Polymer Journal
Abstract
Abstract A series of new polyimides (PIs) containing di-tert-butyl side groups were synthesized via the polycondensation of 4-(4-amino-2-chlorophenyl)-1-(4-aminophenoxy)-2,6-di-tert-butylbenzene ( 3 ) with various aromatic tetracarboxylic dianhydrides. The introduction of the asymmetric di-tert-butyl groups and twisted-biphenyl structures is an effective way to increase the inter chain distance and decrease the intermolecular interaction and packing ability of the resulted polymers. Thus, these novel PIs exhibited low dielectric constants (2.83–3.10), low moisture absorption (0.95–1.69%), excellent solubility, and high glass transition temperatures (307–456 °C). The PIs derived from the new diamine and the rigid pyromellitic dianhydride (PMDA) were soluble in N -methyl-2-pyrrolidinone, N , N -dimethylacetamide, tetrahydrofuran, m -cresol, and cyclohexanone. The polymers also show good retention of storage modulus at high temperature (325 °C). In addition, 1 H NMR spectrum of the diamine 3 revealed that the protons of 4-aminophenoxy moiety are not chemical shift equivalent.