摘要 |
<p>A method is provided for making polyetheramide acid having an intrinsic viscosity in N,N-dimethylacetamide of about 0.05 dl/g to 0.4 dl/g at 25.degree.C. A mixture of aromatic bis (ether dicarboxylic acid) or dianhydride is heated with a substantially equal molar amount of organic diamine in the presence of water and in the substantial absence of an organic solvent. The resulting polyetheramide acid is recovered as a finely divided powder and can be used to make high molecular weight polyetherimide by malt extrusion.</p> |