The Synthesis Of TLCPEI And Its Modify For Polyetherimide

Polyetherimide(PEI) is one kind of thermoplastic polyimide. PEI is one kind of polymer materials having unusual thermal and oxidative stability, good insulation properties, outstanding solvent resistance, high mechanical strength etc. PEI can be considered as advanced materials used in electronic devices, aerospace fields and medical equipment etc. However, for its molecular chain is too rigidity, PEI has high melting point. So the cost in PEI forming and machining processesis too high. It’s hard to form and machining processes for PEI. And the thermotropic liquid crystal polymer(TLCP) is the material having good melt-processability, dimensional stabilities and self-reinforced etc. When TLCP blends with thermoplastics(TPI), TLCP can be as reinforcing modifier to reinforce TPI. In-situ microfiber reinforced composite based on TPI and TLCP become research focus.In this paper, four series of TLCPEI which have thermotropic liquid crystalline behavior were synthesized by Higashi direct polycondensation method. The structure of synthesized monomer and polymer were tested by FTIR and H1-NMR. The TLCPEI related to structures was synthesized by Higashi method According to the IR and NMR results. The thermotropic liquid crystalline behavior of the polymer were tested by DSC、WAXD and PLM. According to the DSC、WAXD and PLM results, the synthesized TLCPEI were the material having good thermotropic liquid crystalline behavior. Then In-situ microfiber reinforced composite based on PEI and TLCP were prepared by injection molding. The mechanical properties of blends were studied by changing the contents of PESI. In order to further study the mechanical properties of blends, the fractured surface of blends were observed by SEM. Based on the mechanical properties tests and the SEM images, it was concluded that the mechanical properties of blends were improved with little TLCPEI without other modifier.