Synthesis and characterization of unsymmetrical benzonitrile-containing polyimides: Viscosity-lowering effect and dielectric properties
作者:David H. Wang、John K. Riley、Scott P. Fillery、Michael F. Durstock、Richard A. Vaia、Loon-Seng Tan
DOI:10.1002/pola.26927
日期:2013.12.1
5.33–9.81%, and tensile moduli of 2.11–2.97 GPa. Their film dielectric constants are 3.08–3.62 at 10 kHz, moderately higher than that (2.92) of analogous PI (CP2) without nitrile groups. Overall, we found that the reduction of structural symmetry in repeat units can improve the polymer processibility as well as increasing their dielectric constants. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part
通过两个连续的S N Ar反应以及氟化物在2中的温度依赖性反应性,合成了一种新的不对称二胺2-(3-氨基苯氧基)-6(4-氨基苯氧基)苄腈(3,4-APBN)。 6-二氟苄腈,其第一个S NAr反应在70°C时发生,其次在100°C时发生,从而可以控制反应顺序并避免跨醚化副反应。因此,由3,4-APBN与五种常见的二酐(6FDA,DSDA,ODPA,BTDA和PMDA)的聚合反应可制得一系列聚酰亚胺(PI)。为了进行比较,还用两个对称的二胺([2,6-双(3-氨基苯氧基)苄腈(3,3-APBN)和2,6-双(4-氨基苯氧基)苄腈(4,4- APBN)和6FDA或PMDA。由于其溶液粘度远低于基于对称二胺的PAA,因此第一个系列的聚酰胺酸(PAA)的可加工性得到了极大的改善。 249–332°C)和热稳定性[在505–542°C(空气)和512–546°C(氮气)范围内,重量损失了5%],这