Preparation, characterization and gas separation properties of nanocomposite materials based on novel silane functionalizing polyimide bearing pendent naphthyl units and ZnO nanoparticles

Abstract

A novel diamine with a naphthyl pendent group was prepared by the nucleophilic substitution reaction of 5-methylnaphthalen-1-amine and 4-fluoronitrobenzene followed by reduction with hydrazine monohydrate and Pd/C. An aromatic polyimide (PI) with a silane end group was synthesized and the hybrid nanocomposite films of the PI with silane end groups and different amounts of zinc oxide were successfully fabricated and characterized by different techniques. Thermogravimetry analysis indicated that the hybrid films had high thermal stability. The transmission electron microscopy of nanohybrid films showed that the ZnO phase is well dispersed in the polymer matrix. The mechanical properties of PI/ZnO nanocomposite films improved with increasing ZnO content. The gas separation properties of the hybrid membranes were studied, and the results show that the permeation of N₂, O₂, CH₄ and CO₂ increased in comparison with the pristine PI membrane.