Method of making polyetherimide

A method of making a polyetherimide includes forming an intermediate polyetherimide with an anhydride-amine stoichiometry of -2 to -40 mol% and melt mixing the intermediate polyetherimide with a bis(ether anhydride) for greater than 3 minutes at a temperature 50 to 225 degrees centigrade greater than the glass transition temperature of a final polyetherimide to produce the final polyetherimide. 一种制备聚醚酰亚胺的方法，包括形成具有-2至-40mol％的酸酐-胺化学计量的中间聚醚酰亚胺，和将该中间聚醚酰亚胺与双(醚酐)在比最终聚醚酰亚胺的玻璃化转变温度高50至225℃的温度下熔融混合大于3分钟以制备最终聚醚酰亚胺。