摘要 |
<p>A polyimide having a high heat-resistance, good processability and recurring structural units of the formula (I); <CHEM> wherein R is a tetravalent radical selected from the group consisting of an aliphatic radical having at least two carbon atoms, alicyclic radical, monocyclic aromatic radical, fused polycyclic aromatic radical and polycyclic aromatic radical bonded through a direct bond or a bridge member.</p> |