Thermoplastic polyimides(PIs)with shape memory potential have received growing attention in recent years.In this work,highperformance thermoplastic PIs were fabricated by introducing PIs with chain rigidity(r-PI)into ...Thermoplastic polyimides(PIs)with shape memory potential have received growing attention in recent years.In this work,highperformance thermoplastic PIs were fabricated by introducing PIs with chain rigidity(r-PI)into PI with chain flexibility(f-PI).The influences of molecular chain entanglement andπ-πinteractions on their thermomechanical and shape memory properties were investigated.The degree of molecular chain entanglement was quantitively characterized based on dynamic mechanical analysis(DMA).Theπ-πinteractions were investigated in detail by X-ray diffraction(XRD)and UV-Vis spectroscopy.It was found that the entanglement density increased andπ-πinteractions became stronger with the introduction of r-PI into f-PI,leading to the improvement of shape recovery.Moreover,a broad and increased glass transition temperature(T_(g))was achieved,endowing the PIs with multiple shape memory properties.The synergistic effects of increased entanglement density and enhancedπ-πinteractions were beneficial to regulating interchain interactions and thereby achieving high shape memory performance of the PIs.展开更多
基金financially supported by the Engineering Research Center for Clean Production of Textile Printing and Dyeing,Ministry of Education(No.FZYR2021001)Shanghai Pujiang Program(No.19PJ1400400)Shanghai Key Laboratory of Lightweight Composite(No.2232019A4-04)。
文摘Thermoplastic polyimides(PIs)with shape memory potential have received growing attention in recent years.In this work,highperformance thermoplastic PIs were fabricated by introducing PIs with chain rigidity(r-PI)into PI with chain flexibility(f-PI).The influences of molecular chain entanglement andπ-πinteractions on their thermomechanical and shape memory properties were investigated.The degree of molecular chain entanglement was quantitively characterized based on dynamic mechanical analysis(DMA).Theπ-πinteractions were investigated in detail by X-ray diffraction(XRD)and UV-Vis spectroscopy.It was found that the entanglement density increased andπ-πinteractions became stronger with the introduction of r-PI into f-PI,leading to the improvement of shape recovery.Moreover,a broad and increased glass transition temperature(T_(g))was achieved,endowing the PIs with multiple shape memory properties.The synergistic effects of increased entanglement density and enhancedπ-πinteractions were beneficial to regulating interchain interactions and thereby achieving high shape memory performance of the PIs.
