Thermosetting polyimides and composites based on highly soluble phenylethynyl-terminated isoimide oligomers

Abstract

Highly soluble phenylethynyl-terminated isoimide oligomers were investigated as matrix resins which can produce high performance thermosetting polyimides and composites.

HighTgand Thermo‐Oxidatively Stable Thermosetting Polyimides Derived from a Carborane‐Containing Diamine

“…In the field of advanced polymers, thermosetting polyimides (PIs) occupy a preponderant position due to their excellent chemical stability, thermal and mechanical properties . Thermosetting PIs are being designed for aerospace applications to meet the expectation of performance and durability in high temperature oxidative environments . It is well known that, the glass transition temperature ( T g ) is a fundamental characteristic of any thermoset, and polymers with higher T g are actively sought for a variety of high‐performance applications .…”

“…[1][2][3][4][5][6] Thermosetting PIs are being designed for aerospace applications to meet the expectation of performance and durability in high temperature oxidative environments. [7][8][9][10][11][12][13] It is well known that, the glass transition temperature (T g ) is a fundamental characteristic of any thermoset, and polymers with higher T g are actively sought for a variety of high-performance applications. [14] However, the conventional PIs, due to the influence of bond energy of C, H, O, and N, are susceptible to decomposition at elevated temperatures in oxidative environments, and have T g which are usually lower than 450 °C.…”

1,4‐Bis(2,3‐dicarboxyl‐phenoxy)benzene dianhydride‐based phenylethynyl terminated thermoset oligoimides for resin transfer molding applications

“…Characteristic absorptions of the imide ring at 1370 cm −1 were also observed, which demonstrated the successful synthesis of imide oligomers. The characteristic peak at 2210 cm −1 was attributed to the stretching vibration of C≡C groups, which confirmed the existence of the end group …”

Highly soluble phenylethynyl‐terminated imides derived from mellophanic dianhydride (MPDA)

“…From a processing point of view, lowboiling point solvents are definitely preferred for high-quality composites since they are much easier to be removed. 30 The solubility of oligoimides in different solvents was determined by dissolving 0.33 g of oligoimide powder in 0.67 g of organic solvent (achieving about 33 wt% of solid content), and the solution was stirred at room temperature. As shown in Table 2, the oligoimides were all soluble in NMP, DMAc, N,N-dimethylformamide, DMSO, and m-cresol.…”