Polyimides containing perfluorocyclobutane rings were synthesized from a new diamine 1

2

3

3

4

4-hexafluoro-1

2-bis(4-aminophenoxy)cyclobutane with three dianhydrides

namely bicyclo［2.2.1］octane-2

3

5

6-tetracarboxylic 2

3

5

6-dianhydride (BHDA)

biphenyltetracarboxylic dianhydride (BPDA) and benzophenone-3

3′

4

4′-tetracarboxylic dianhydride (BTDA)

respectively.The new diamine was synthesized via fluoroalkylation of 4-acetamidophenol with BrCF2CF2Br followed by Zn-mediated elimination and exothermic cyclodimerization.The polymers were characterized by means of FT-IR

inherent viscosity

solubility determination

differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).TGA studies indicated that the polymers were all stable up to 480℃.DSC results show that two of the three polymers have a Tg below 150℃.The polymers were found to be soluble in the commonly used polar solvents.Thus the polymers containing perflurocyclobutane rings exhibited excellent solubility and processability.