Synthesis and characterization of novel aromatic polyimides from 4,4-bis(p-aminophenoxymethyl)-1-cyclohexene

A novel diamine, 4,4-bis(p-aminophenoxymethyl)-1-cyclohex (CHEDA), was synt hesized from 4,4-bis(hydroxymethyl)-1-cyclohexene and p-chloronitrobenzene by nucleophilic aromatic substitution and subsequent catalytic reduction of the intermediate dinitro compound. A series of aromatic polyimides were pr epared from CHEDA and commercial dianhydrides with varying flexibility and electronic character in two-step direct polycondensation reactions. High mo lecular weight polyimides with intrinsic viscosities between 0.57 and 10.2 dL/g were obtained. Most of these polyimides, excluding those from PMDA and BPDA, were soluble in polar aprotic solvents such as NMP and DMAc, and man y were also soluble in CHCl3 and THF. DSC analysis revealed glass transitio ns in the range of 190 to 250 degrees C. No significant weight losses occur red below 450 degrees C in nitrogen and 350 degrees C in air. Bromination a nd epoxidation of cyclohexene double bond in CHDEA-6FDA (3e) were investiga ted as examples of possible polymer modifications. Qualitative epoxidation and selective bromination of the double bond were demonstated. (C) 1999 Joh n Wiley C Sons, Inc.