Malleable and recyclable imide-imine hybrid thermosets: influence of imide structure on material property

Although thermosetting polyimides have been widely used in many fields, it is still a challenging task to realize their repairability, reprocessibility, and recyclability, which are highly desired features given the...

High thermally stable thermosetting polyimides derived from a carborane-containing tetramine

In this study, we report the preparation of thermosetting polyimides (PIs) based on carborane-containing tetramine and their characterizations. The novel tetramine 1,2-bis(4-(3,5-diaminobenzoic acid phenyl ester))carborane (CBNH) was synthesized and characterized firstly. Then, it was used in the preparation of two kinds of branched imide oligomers via the method of thermal imidization. The cure behavior of the obtained phenylethynyl-terminated oligomers was investigated by differential scanning calorimetry. The effect of carborane substituent on the thermal properties of PIs was studied by comparing with a similar structure without the carborane group. The thermal properties of PIs and carbon fiber/PI composites were investigated by thermal gravimetric analysis and dynamic mechanical analysis, respectively. Because of the introduction of high steric hindrance of carborane structure, the resulting thermosets and carbon fiber/PI composites had excellent thermal property with a high char yield at 800°C (>66.5%) and a high glass transition temperature (up to 500°C), respectively.

Influence of monomer conformation on the mechanical and tribological properties of thermosetting polyimides

Thermosetting polyimides prepared by different oligomers with same calculated number-average molecular weights (Mn) and different conformation display different physical, chemical properties and tribological performance.

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

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

High performance crosslinked polyimide based on main-chain type polybenzoxazine

A novel approach has been developed to prepare thermosetting polyimides by incorporating benzoxazine structure as a repeating unit in the main chain. This method allows the crosslinked polyimide with excellent thermal and mechanical properties.

Thermosetting Polyimides with Improved Impact Toughness and Excellent Thermal and Thermo-Oxidative Stability

Thermoset polyimides were prepared by thermally curing B-staged endcapped polyimide resins that were obtained by thermally baking PMR polyimide matrix resins. The polyimide matrix resins were prepared by incorporating flexible ether-bridged aromatic segments [–Ar–O–Ar–] into PMR polyimide backbone to improve their processability and impact toughness. Experimental results indicated that the B-staged polyimide resins possessed adjustable and easily controllable thermal processability which ensure that thermoset polyimides are produced with improved impact strength and high glass transition temperature compared with PMR-15. Thermal and thermo-oxidative stability as well as hygrothermal resistance of the thermoset polyimides were also systemically investigated.