低热膨胀系数共聚型聚酰亚胺薄膜的制备与表征

Preparation and Characterization of Copolymerized Polyimide Films with Low Coefficient of Thermal Expansion

采用均苯四甲酸二酐(PMDA),4,4′-氧双邻苯二甲酸酐(ODPA)和对苯二胺(PDA)共聚制备了聚酰胺酸(PAA),经热亚胺化得到聚酰亚胺(PI)薄膜。利用红外光谱(FTIR)、力学性能测试、静态热力学分析仪(TMA)、热失重分析仪(TGA)等研究了PI薄膜的性能。结果表明:制备的PI薄膜热膨胀系数较低,当PMDA与ODPA物质的量比为6∶4时,热膨胀系数为1.3×10-5 K-1,小于铜箔的热膨胀系数,说明具有良好的尺寸稳定性;热失重5%的温度(T5%)为582.5℃,热稳定性好。同时薄膜具有较好的力学性能和优异的介电性能。

1,2,4, 5-Benzenetetracarboxylic anhydride （PMDA）, 4,4＇-oxydiphthalic anhydride （ODPA） and P-phenylenediamine （PDA） were selected to synthesize polyamide acid （PAA） by copolymerization, and polyimide （PI） films were obtained by the subsequent thermal imidization. The properties of PI films were studied by FTIR, mechanical property test, TMA, TGA, etc. The results indicate that the coefficient of thermal expansion （CTE） of PI films is relatively low. When the molar ratio of PMDA： ODPA is 6：4, the CTE value reaches 1.3×10^-5K-1, and is lower than the CTE value of copper foil with good dimensional stability; and the temperature of T5% is 582.5℃ with good thermal stability. Besides, it possesses favorable mechanical property and excellent dielectric property.