微波辐射四元共缩聚聚酰亚胺的合成与表征

Synthesis and Characterizaion of Aromic Polyimide via Microwave-Assisted Copolycondensation

以3,3′,4,4′-二苯甲酮二酐(BTDA)、均苯四甲酸二酐(PMDA)、4,4′-二氨基二苯砜(DDS)和4,4′-二氨基二苯醚(ODA)为单体,采用微波辐射溶液缩聚得到一种四元共缩聚聚酰胺酸(PAA),然后经亚胺化得到聚酰亚胺(PI)。通过对数比浓黏度(ηinh)、红外光谱(FT-IR)、核磁(1H-NMR)、溶解性测试和热重分析(TGA)对聚合物进行了结构表征和性能测试。结果表明,微波辐射能显著提高反应速度、PAA的相对分子质量和产率;FT-IR表明生成了预期的聚合物;1H-NMR表明PAA亚胺化度达95%以上;溶解性测试表明PAA具有较好的溶解性;TGA表明所合成的PI具有较高的热氧化稳定性和热稳定性。

A polyamic acid （PAA） was synthesized in N, N＇-dimethylformamide （DMF） via microwave-assisted copolycondensation by using 3, 3＇, 4, 4＇-benzophen-onetetracarboxylic dianhydride （BDTA） and pyromellitic dianhydride（PMDA） as the dianhydride monomers, 4,4＇-diaminodiphenyl sulfone （DDS） and 4,4＇-diaminodiphenyl ether（ODA） as the diamine monomers. Then by imidization of PAA, PI was synthesized. The obtained polymers＇ structure and performance were characterized by viscosity, Fourier transform infrared spectroscopy（FT-IR）, proton nuclear magnetic resonance（^1H-NMR）, solubility, and thermal gravimetric analysis（TGA）. The results show that the molecular weight and yield of PAA are raised, and the speed of reaction is enhanced by microwave irradiation. FT-IR result indicates the predicted PI is prepared. Solubility test shows PAA has good solubility. TGA exhibits the PI has wonderful thermal oxidation stability in air and thermal stability in nitrogen.