Y TYPED NOVEL POLYURETHANE WITH NONLINEAR OPTICAL PROPERTY AND PREPARING METHOD FOR THE SAME

摘要

A Y-typed polyurethane is provided to exhibit heat stability even in the temperature range higher than glass transition temperature thereof, to realize no collapse phenomenon of the second harmonic generator, and to be applicable to nonlinear optical devices. A Y-typed polyurethane contains 2,3-dioxy benzylidenemalononitrile groups as a nonlinear optical chromophore and is represented by the following formula 1. In the formula 1, Ar is a substituent selected from C1-6 alkyl groups and C1-6 alkoxy groups and is a substituted or unsubstituted phenylene group or bisphenyl group, and n represents the number of repeat units in the formula 1 and is 30-48. A method for preparing the Y-typed polyurethane includes a step of subjecting 2,3-di-(2'-hydroxyethoxy)benzylidenemalonitrile and diisocyanate to urethane polymerization.