Synthesis and properties of polyimides derived from a new phthalonitrile-containing diamine with high polyaddition reactivity

Synthesis and characterization of novel polyimides derived from 4,4'-bis(5-amino-2-pyridinoxy)benzophenone: effect of pyridine and ketone units in the main

A diamine monomer, 4,4’-bis(5-amino-2-pyridinoxy)benzophenone, was designed and synthesized, and used to react with commercially different kinds of aromatic dianhydrides to prepare a series of polyimides containing pyridine and ketone units via the classical two-step procedure. Glass transition temperatures (T_g) of the resultant polyimides PI-(1–5) derived from 4,4’-bis(5-amino-2-pyridinoxy) benzophenone with various dianhydrides ranged from 201 to 310 °C measured by differential scanning calorimetry. The temperatures for 5%wt loss of the resultant polyimides in nitrogen atmosphere obtained from the thermogravimetric analysis curves fell in the range of 472–501 °C. The temperatures for 10%wt loss of the resultant polyimides in nitrogen atmosphere fell in the range of 491–537 °C. Meanwhile, the char yields at 800 °C were in the range of 55.3–60.8%. Moreover, the moisture absorption of polyimide films was measured in the range of 0.37–2.09%. The thin films showed outstanding mechanical properties with tensile strengths of 103–145 MPa, an elongation at break of 12.9–15.2%, and a tensile modulus of 1.20–1.88 Gpa, respectively. The coefficients of thermal expansion of the resultant polyimides were obtained among 26–62 ppm °C⁻¹. To sum up, this series of polyimides had a good combination of properties applied for high-performance materials and showed promising potential applications in the fields of optoelectronic devices.

Synthesis and crosslinking study of isomeric poly(thioether ether imide)s containing pendant nitrile and terminal phthalonitrile groups

Upon crosslinking, phthalonitrile-terminated polyimide PN-PI (a–d) films exhibited better solvent resistance, and greater thermal and mechanical properties than PI (a–d) films.

Thermally stable phthalonitrile resins based on multiple oligo (aryl ether)s with phenyl-s-triazine moieties in backbones

Phenyl-s-triazine segments in the polymer backbones endowed phthalonitrile networks with enhanced thermal stability, which could also be tuned by the main-chain lengths of the aromatic ether.