Nonlinear optical (NLO) polymers have attracted much attention in recent years. Epoxy based polymers with side hydroxyl groups have good film-forming properties and can be chemical cross-linked
which are good candidates for nonlinear optical polymers. In this paper
two kinds of iodinated aniline derivatives were synthesized by selective para-iodination between the reaction of 3-methyl aniline
3
5-dimethylaniline and iodine in a mixture of pyridine/dioxane under mild conditions. Three aniline derivatives with thiophene heterocycle substituent and different number of side methyl substituents were prepared by Suzuki coupling reaction between the iodinated aniline derivatives and 2-thiophenylboric acid. Three kinds of precursor epoxy based polymers were prepared by the polycondensation of diglycidyl ether of bisphenol-A and aniline derivatives prepared above. The precursor polymers were post-functionalized by tricyanovinylation reaction to prepare the final NLO polymers. The result polymers were characterized by
1
H-NMR
UV-Vis
DSC
TGA and GPC methods. The methyl substitutes have much effect on the degree of electrophilic substitution reaction of the precursor polymers. For BP-TA-TC and BP-3-TA-TC
the degree of functionalization can be reached about 80%. Anyway
the degree of functionalization of BP-3
5-TA-TC with two side methyl substitutes is less than 10%. With the increase of the number of methyl substitutes
the UV-visible maximum absorption of the final NLO polymers will decrease.