共缩聚聚酰胺酸和聚酰亚胺的合成与表征

Synthesis and characterization of polyamic acid and polyimide

以4,4′-二氨基二苯甲烷(MDA)为二胺单体,均苯四甲酸酐(PMDA)和3,3′,4,4′-二苯酮四羧酸二酐(BTDA)为二酐单体,低温溶液聚合生成一种共缩聚聚酰胺酸(PAA).然后亚胺化脱水环化生成共缩聚聚酰亚胺.通过特性粘度([η])、红外光谱(FT—IR)、热重分析(TG)和X衍射分析(XRD)等对聚合物进行了一系列的结构表征和性能测试.FT-IR表明,在1777 cm^(-1)和1723 cm^(-1)处观察到聚酰亚胺特征峰;TG表明.PI的10%热失重温度为568℃;XRD表明,PI的结晶度较低且分子链间距d为0.5069 nm.

The co-polycondensation type polyamic acid （PAA） was synthesized using 4, 4＇- diaminodiphenylmethane （MDA） as diamine monomer, 3, 3＇, 4, 4＇-benzoph-enonetetracarboxylic dianhydride （BDTA） and pyromellitic acid dianhydride （PMDA） as dianhydride monomers under conventional heating solution polycondensation. Then PAA came into being polyimide （PI） by an imidization at low-temperature. It was characterized by inherent viscosity （[η]）, fourier transform infrared （FT-IR）, thermogravimetric curve （TG） analyses and X-ray diffraction （XRD）. The FT-IR results were shown that, there were Pl＇s characteristic peaks around 1 777 cmI and 1 723 cm^-1, Thermogravimetric curve indicated that, PI＇s 10% thermal decomposition temperature under N2 was 568℃. XRD spectrum demonstrates that obtained polyimide has low-order aggregation structure with a d-spacing of 0. 506 9 nm.