Study on preparation and properties of novel reactive phenolic hydroxyl-containing polyimides

Abstract

Novel reactive polyimides (PIs) containing phenolic hydroxyl functionalities were prepared from 4-(4-hydroxyphenyl)-2,6-bis[3-(4-aminophenoxy)phenyl]pyridine (m,p-HAPP) with various aromatic dianhydrides via one-step polycondensation procedure. The inherent viscosities of the PIs were 0.54-0.63 dL/g in DMF solution and most of them were readily soluble in common organic solvents such as DMF, DMAc, NMP, and m-Cresol, etc. Meanwhile, the PIs also had good thermal stability, with the glass transition temperature (T g ) of 221.7-310.5°C, the temperature at 10 % weight loss of 524.1-579.3°C in nitrogen atmosphere. Then commercial epoxy resin was cured in the presence of different ratios of the reactive polyimide, giving a series of polyimide modified epoxy films. Thermogravimetric analysis showed the increase of the temperature at 5 % weight loss of the films with the increase of the polyimide content; 296°C for 0 %, 309°C for 1.95 %, 337°C for 3.85 % and 350°C for 5.63 %.

Synthesis and properties of hyperbranched polyimides derived from novel triamine with prolonged chain segments

“…It has been proved that introduction of flexible linkages into the polymer backbone could improve the solubility of polyimides . Solubility of polyimides can also be improved by incorporation of less symmetric meta ‐linked aromatic units in the main chain . The incorporation of meta ‐linked units into the polymer backbone may have interrupted the chain packing, thus leading to improved solubility.…”

Thermal properties of diacetylene–containing polymer prepared from propargyl-terminated monomer with pyridine

“…16,18 Recently, relevant extensive research studies have been carried out on polyimides (PIs) by various teams with the purpose of improving their comprehensive properties via introducing pyridine or substituted pyridine derivatives into the backbone. Yi and coworkers [19][20][21][22][23] and Liaw and coworkers [24][25][26] have successively prepared various PIs with the symmetrical-substituted pyridine structure in the backbone, which exhibited excellent heat resistance, good processability, and considerable mechanical properties. Moreover, many other polymers containing pyridine ring in the backbone, namely, polyamide, 27,28 polyester, 29,30 polybenzimidazole, 31,32 also have been extensively investigated, and all presented excellent comprehensive properties.…”

Fabrication and characterization of novel hyperbranched polyimides with excellent organosolubility, thermal and mechanical properties

“…Furthermore, the pyridine ring, with a localized lone pair of electrons in the sp 2 orbital, can be easily protonized by acids or coordinated with various metal ions; this augments the solubility of the heterocycle or heterochain polymers containing pyridine moieties in the backbone and offers the possibility of further functional modifications . Recently, Liaw and coworkers, Wang and coworkers, Shang et al, and our team have successively introduced the symmetrical triaryl‐substituted pyridine structure into PI backbones. The resulting PIs have been found to exhibit excellent thermal stabilities, good organosolubilities, and considerable mechanical properties.…”