Simple synthetic route to soluble polyimides via nitro‐displacement reaction and their second‐order nonlinear optical properties
作者:Yeong‐Beom Lee、Han Young Woo、Chong‐Bok Yoon、Hong‐Ku Shim
DOI:10.1039/a902230i
日期:——
Nonlinear optical (NLO) functionalized polyimides were directly synthesized using the nitro-displacement reaction between an alkanediol monomer and a diimide monomer without a thermal curing step. The polyimides were soluble in aprotic polar solvents such as DMSO, DMAc, DMF and NMP, and showed glass transitions at temperatures between 172 and 198 °C. We observed good thermal stability up to around 300 °C (at 5% weight loss) for the polymers. The weight average molecular weights of the resulting polymers were determined to be 10 400–15 100 (M
w
/M
n
= 1.84–2.00). The poled polymer films showed good nonlinearity (d
33
= 76 pm V
–1
) in the Maker fringe method for the second harmonic generation (SHG).
通过硝基取代反应,直接合成了非线性光学(NLO)功能化的聚酰亚胺,该反应在无热固化步骤的情况下,利用烷二醇单体与二酰亚胺单体之间的反应进行。这些聚酰亚胺可溶于DMSO、DMAc、DMF和NMP等非质子极性溶剂,玻璃化转变温度介于172至198°C之间。我们观察到这些聚合物具有良好的热稳定性,直至约300°C(5%重量损失)。所得聚合物的重均分子量确定为10400至15100(Mw/Mn = 1.84至2.00)。在用于二次谐波生成(SHG)的Maker条纹法中,极化后的聚合物薄膜显示出良好的非线性(d33 = 76 pm V-1)。