流延法制备聚酰亚胺薄膜的热膨胀系数表征

Characterization on the Coefficient of Thermal Expansion of Polyimide Film Produced by Casting Method

采用静态热机械分析仪(TMA)测量流延法生产的聚酰亚胺薄膜的热膨胀系数,考察了各种实验条件(循环升降温扫描、不同升温速率、不同负荷、不同恒温温度)对流延法生产的聚酰亚胺薄膜在MD(机械方向)、TD(垂直机械方向)方向上热膨胀系数的影响。结果表明,测试过程中热处理能消除制膜过程中的热应力;聚酰亚胺薄膜在MD方向交联作用要明显强于TD方向,导致其在不同的测试条件下MD方向的热形变和膨胀系数与TD方向有较大的差异。

The thermal expansion coefficient(CTE)of polyimide film produced by casting method was analyzed by thermo-mechanical analyzer(TMA),and the effects of experimental conditions(multiple process of heating and cooling,heating rate,load and constant temperature)on CTE of polyimide film in the direction of MD(machine direction)and TD(transverse direction)were discussed.The results show that polyimide films could release residual stress based on TMA measurement.The cross linking effect of polyimide films on MD is more obvious than TD.The thermal deformation and expansion coefficient of MD and TD are quite different under different test conditions.