Influence of additives on the imidization of poly(amide acid)

Abstract

Polyimides (PIs) are obtained by the ring-closing reaction of poly(amide acid) (PAA) by thermal treatment at over 300 °C. In order to lower the cure temperature, we investigated the influence of plasticizer, such as phthalates, phosphates, and polyethers, on the cyclization of PAA. Among them, polyethylene glycol (PEG) was found to be the most effective additive to lower the cyclization temperature. Though the cyclization of PAA without the plasticizer required high temperature up to 350 °C, in the presence of 5 wt% of PEG, the ring-closing reaction almost completed at 200 °C. © 2012CPST.