The Synthesis And Properties Characterization Of Polyimide Foams

The polyimide foams have excellent properties of low density, non-toxic, low smoke and flame retardant, heat insulation, sound insulation, appropriate strength, high toughness, dimensional stability and low water absorption, have become the research direction of domestic and foreign ships cabins insulation materials, our country has not formed the forming products can be applied. The successful development of this material has a very important significance to break foreign technology monopoly, and promote our military and civilian the grade of the products.The polyimide foams were prepared respectively by one-step process and two-step process ,and were characterized. The polyimide foams were observed by optical microscope and scanning electron microscopy (SEM), foams structure and properties were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) differential scanning calorimetry (DSC) respectively ,and the compression strength was tested. The analysis verifies that polyimide foams were both prepared by the two processes. Further studies the influence of the types and viscosity of A component and A, B component proportion to polyimide foams foaming in one-step process, and the influence of reaction system, foaming temperature, heating rate, powder particles size etc to foams foaming in two-step process.Experimental results show that the one-step process suitable for the preparation of low density and low intensity polyimide foam, the two-step process suitable for the preparation of high density, high strength polyimide foam; the cell structure of the polyimide foams that were prepared by one-step process is more uniform ,and the process is simple; the polyimide foams that were prepared by two-step process have excellent heat resistance and mechanical properties, but the process is more complex and the cost also is relatively higher.