Synthesis and Properties of Polyetherimides by Nucleophilic Displacement Reaction

A series of polyetherimides was prepared by nucleophilic displacement reaction of bisnitrophthalimides containing ether and sulfur linkages with aromatic diols in dimethyl sulfoxide. The two new bisnitrophthalimides, 4,4′-bis(N-phenoxy-4-nitrophthaliimide)-2,2′-diphenylisopropylidene and 4,4′-bis(N-phenoxy-4-nitrophthalimide)-diphenylsulfide were prepared from the corresponding diamines and 4-nitrophthalic anhydride. The nitro displacement polymerization yielded high molecular weight polyetherimides with inherent viscosities of 0.46-0.54 dL/g. The polyetherimides were soluble in dipolar aprotic solvents such as DMSO, DMF and NMP. These polymers had glass transition temperatures around 200 °C. Thermogravimetric analysis indicated that the 10% weight loss temperature for these polymers ranged from 430 to 490 °C with a high char yield at 800 °C.