异氰酸酯交联环氧树脂非线性光学性质的计算化学研究

摘要

The nonlinear optical property and the excited state characteristics of a series of isocyanate crosslinked epoxy resin monomer molecule(refer to as monomer molecule) were studied by means of computational chemistry method and density functional theory. The results indicate that the introduction of substituent can improve the nonlinear optical property but which has little effect on the electronic spectra of the monomer molecule,so there will be no influence on the transparency of the monomer molecule. Introducing fluoro alkyl leads to the augment of the dipole moment and the decline of the charge transition density of the monomer molecule. The gain effect of the nonlinear optical property converges quickly with the increase of the carbon chain length in the fluoro alkyl. Introducing the alkoxy has less effect on the charge transition characteristics but increases the dipole moment, so the nonlinear optical property of the monomer molecule is enhanced.%利用计算化学方法,采用密度泛函理论研究了一系列异氰酸酯交联环氧树脂单体分子(简称单体分子)的非线性光学性质及激发态性质.结果表明:引入取代基可以提高单体分子的非线性光学性质,但取代基的引入对单体分子的电子光谱几乎没有影响,因此对其透明性也不会有影响;引入氟代烷基使单体分子的偶极矩增大,但电荷的跃迁密度下降,随着氟代烷基碳链的增长,单体分子的非线性光学性质的增益效果很快收敛;引入烷氧基则对电荷跃迁性质影响较小,但增加了分子的偶极矩,从而增强了非线性光学性质.