A novel diamine monomer containing tert-butyl

ether linkages and bisphenol A unit

2

2-bis(3'-(tert-butyl)-4'-aniline-bisphenyl-4-ehter)propane (4)

was designed and synthesized from 2-tert-butylaniline and bisphenol A.Then it was polymerized with several commercial aromatic dianhydrides

including OPDA

PMDA

6FDA and BPDA

via one-pot method to afford a series of aromatic polyimides.Their chemical structures are confirmed by NMR

FTIR and EA measurements.The number-averaged molecular weights of the resulting PIs are in the range from 1.9104 to 3.9104 with PDI from 2.63 to 4.63 by GPC measurements.They exhibit excellent solubility in many organic solvents

such as NMP

DMF

m-cresol

DMAc

THF and CHCl3 etc

which can be attributed to the incorporation of tert-butyl groups and bisphenol A units into their rigid backbones.They can form transparent films by solution casting and the light transparency was equal to or higher than 90% in the visible light range from 400 to 760 nm.The XRD results demonstrate that they are amorphous glassy polymers.Furthermore

their inherent outstanding performance is still retained

including the high 5% weight loss temperature in nitrogen and Tg

good mechanical properties and low water absorption rates.