| abstract |
An aromatic polyimide containing a benzonorbornene structure in the main chain and a preparation method thereof, starting from p-benzoquinone and cyclopentadiene, and efficiently synthesized through D-A reaction, nucleophilic substitution, reduction and a two-step method A diamine monomer containing a benzonorbornene structure and an aromatic polyimide containing a benzonorbornene structure in the main chain. It not only ensures the flexibility of the molecular chain but also does not significantly reduce the thermal performance. With norbornene bicyclic ring as the side group, the free volume between segments is increased, the solubility of the polymer is preserved, and the dielectric constant of the material is reduced; the bicyclic ring has a cis double bond of sp 2 configuration with greater polarity , which ensures the stacking between macromolecules and increases the glass transition temperature of the polymer. At the same time, the double bond of bornene can be cross-linked by high heat to improve the thermal and mechanical properties of the material. Modification by copolymerization will further broaden the properties of the material and reduce the cost. Low cost, simple synthesis process, low dielectric constant, excellent thermal and mechanical properties. |