| 摘要 |
<p>Aromatic polyimides have formula:- (where R is a tetravalent aromatic radical & R1 is a divalent hydrocarbon radical which is aromatic, aliphatic, cycloaliphatic, aliphatic-aromatic or heterocyclic, & which opt. contg. O,S,N, or P bridge). Prepd. by heating at 100-500 C a diamine deriv. of formula:- (where R2 is a monovalent aliphatic group) with an aromatictetra-acid (HO2C)2R(CO2H)2, the mol. ratio of diamine deriv: tetra-acid being pref. 0.95 - 1.05.</p> |
