A method of making dianhydride includes contacting a N-Substituted diimide with a carboxylic acid and substituted or unsubstituted dimethyl sulfoxide in an aqueous medium to provide a reaction mixture including tetra acid, triacid, imide diacid and diimide along with substituted or unsubstituted acetic acid, dimethyl sulfoxide and their derivatives. The method includes the isolation of tetra acid by precipitation in water followed by centrifuge or filtration. The tetra acid is converted into the corresponding dianhydride. The dianhydride prepared by the method are also described as precursor to make polyetherimide.
一种制备二酐的方法包括将N-取代二
酰亚胺与
羧酸和取代或未取代的
二甲基亚砜在
水介质中接触,以提供包括
四酸、三酸、亚酰基二酸和二
酰亚胺以及取代或未取代的
乙酸、
二甲基亚砜及其衍
生物的反应混合物。该方法包括通过在
水中沉淀后进行离心或过滤来分离
四酸。
四酸被转化为相应的二酐。该方法制备的二酐也被描述为制备聚醚
酰亚胺的前体。