不同密度聚酰亚胺泡沫的制备与性能

Properties of Polyimide Foams with Different Densities

制备了基于3,3’-4,4’-二苯甲酮四酸二酐(BTDA)、多苯基多亚甲基多异氰酸酯(PAPI)及二苯甲烷二异氰酸酯(MDI)的聚酰亚胺泡沫,通过改变发泡时的环境压力,制备了不同密度的泡沫;利用红外光谱和扫描电镜对所制备的聚酰亚胺泡沫进行了结构与形貌表征,并对泡沫热性能和压缩强度行了表征。结果表明,所制备的泡沫密度随着制备压力的增大而增加,泡沫密度为7.3~160kg/m^3,红外光谱确认了目标聚合物的合成,泡沫T_g不低于250℃,且具有良好的热稳定性,经过250℃处理的泡沫的T_g达到270℃,T_(d5%)达到404℃,均高于230℃处理得到的泡沫的性能。压缩性能测试表明所制备泡沫压缩强度随着密度增加而增加,当密度为160kg/m^3时,压缩强度达到1.88 MPa。

Polyimide foams with different densities were prepared by changing the environmental pressure, using 3,3’,4,4’-benzophenonetetracarboxylic dianhydride （BTDA）, polymethylene polyphenyl isocyanate（PAPI）, methylene biphenyl diisocynante （MDI） as raw materials. The structure and morphology of the foam were characterized by FT-IR and SEM, and the thermal properties of the foam and compression strength were investigated. The results show that the densities, which is ranged from 7.3 kg/m3 to 160 kg/m3, increase while the pressure increases. The FT-IR confirms the synthesis of polyimide foams. The polyimide foams also have good thermal stability and high Tg no less than 250 ℃. It is observed that the polyimide foam which imidized at 250 ℃ has Tg up to 270 ℃ and Td5% about 404 ℃, superior to the polyimide which ia imdized at 230 ℃.The compression strength of the polyimide foam increases with the density increasing, it could be 1.88 MPa while the density is 160 kg/m3.