SYNTHESIS AND CHARACTERIZATION OF INTERPENETRATING POLYMER NETWORKS WITH NONLINEAR-OPTICAL PROPERTIES

We report the synthesis and characterization of interpenetrating polym er networks (IPNs) exhibiting nonlinear optical (NLO) properties. The network consists of aliphatic polycarbonate urethane (PCU) and poly(me thyl methacrylate-co-N,N-disubstituted urea), with a nonlinear optical (NLO) chromophore incorporated into N,N-disubstituted urea. The full IPNs have only one T-g, as determined by differential scanning calorim etry (DSC), together with scanning electron microscopy (SEM) observati ons, suggest a single phase morphology. The thin films of IPNs are tra nsparent and the unpoled samples produced second harmonic generation ( SHG) signals at room temperature. This result indicates that the NLO c hromophore is oriented noncentrosymmetrically during the IPN formation process and is tightly held between the permanent entanglements of th e two component networks of the IPN. (C) 1996 John Wiley & Sons, Inc.