Formation And Acoustic Simulation Of Polyimide Foams

In this article,a new kind of polyimide foam was successfully prepared via solution polymerization,taking 3,3',4,4'-benzophenone tetracarboxylic dianhydride(BTDA)and 4,4'-methylene dianiline(MDA)and methanol as main materials.Structures of polyimide foam were characterized by Fourier Transform Infrared Spectroscopy(FT-IR),The thermal Conductivity of polyimide foam was measured by thermal conductivity meter.And the thermal Properties of polyimide foam were tested by Thermogravimetic Analysis(TGA)and Differential Scanning Calorimetry(DSC),The Mechanical Properties of polyimide foam was measured by electronic universal testing machine.Moreover,ANSYS software was used for simulation of polyimide foam.The FT-IR results show that the optimal esterification time for BTDA was 1 h.The powder color changes from deep yellow to light yellow with increasing drying temperature and bubble size was 2mm-5mm evenly observed by appearance of polyamide resin precursor powder and the corresponding cell structure.And the TGA test results indicate that foaming temperature range of polyimide foam was 100?~250?.TGA,DSC and thermal conductivity coefficient results show that polyamide ester precursor powder was dried at 80??95? and 105?,corresponding to the Tg of polyimide foam were 286.8??289.6? and 300.3?.5% weight loss were 518??521? and 525?.And thermal conductivity coefficient ? were 5.903×10-2 W/(m·K),5.43×10-2 W/(m·K)respectively,showing that polyimide foam has high heat resistance insulation performance.Elongation at break of polyimide foam were 18.3%,19.7%,21.5%,23.7% corresponding density of 0.0223 g/cm3,0.0237g/cm3,0.0286g/cm3,0.0295g/cm3.In this paper,the acoustic performance of polyimide foam was simulated by ANSYS software.When the frequency are 500 Hz,1000Hz,1500 Hz and 1750 Hz,the sound absorption coefficient of polyimide foams are 0.1055,0.306,0.7445 and 0.251.