Carboxylic acids and derivatives having a general formula X-O-Ar-O-Y in which X and Y are aromatic mono or di-basic carboxylic acid groups of derivatives which may be the same or different. Ar is a divalent aromatic group having at least one tertiary alkyl substituent and not more than one such substituent ortho to each of its bonds to the ether groups. A polyetherimide is prepared by reacting an anhydride derivative of the above formula with a diamine. Gas separation membranes can be fabricated from the resultant polyetherimides.
具有一般公式X-O-Ar-O-Y的
羧酸及其衍
生物,其中X和Y是芳香族单基或二基
羧酸衍
生物,可以相同也可以不同。Ar是一个双价芳香族基团,具有至少一个三级烷基取代基,并且不超过一个这样的取代基正交于其对
乙醚基团的每个键。通过将上述公式的酐衍
生物与二胺反应制备聚醚
酰亚胺。可以从所得的聚醚
酰亚胺制备气体分离膜。