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Nonlinear optical polyurethanes

Watanabe O, Tsuchimori M, Okada A. 1996. Two step refractive index changes by photoisomerization and photobleaching processes in the films of nonlinear optical polyurethanes and a urethane urea copolymer. J Mater Chem 6(9) 1487 1492. [Pg.44]

This chapter is organized as follows. Section 4.2 addresses the study of photoisomerization and photoinduced orientation of azobenzene molecules at the molecular level in SAMs of azo-silane molecules. Section 4.3 discusses photoinduced effects in supramolecular assemblies, i.e., LBK multilayer structures containing azobenzene molecules, and compares the photoinduced movement of azobenzenes in these structures to that observed in spin-cast films. Section 4.4 focuses on the isomerization and sub-Tg photoinduced orientation in a series of very high Tg (up to 350°C) nonlinear optical polyimide and thermoplastic donor-embedded polyurethane polymers containing azo dye, especially focusing on polymer structure-Tg-photoinduced molecular movement relationships. Section 4.5 describes pressure effects on photoisomerization and photo-orientation in films of a PMMA polymer containing azo dye. Finally, we make some concluding remarks in Section 4.6. [Pg.110]

I. Novel network polyurethane with azobenzene dye in the main frame, Macromolecules, 1995, 28, 6437 Nonlinear optical polymers. 2. Novel NLO linear polyurethane with dipole moments aligned transverse to the main backbone, Macromolecules, 1996, 29, 592. [Pg.211]

Ferrocene-containing polymers with long spacers have been prepared as new nonlinear optical (NLO) materials for second harmonic generation (SHG) applications (e. g. frequency doubling) [10], The use of ferrocene derivatives in this area is attractive as a result of their demonstrated large hyperpolarizability values combined with their thermal and photochemical stabilities [11], These factors make polyferrocenes desirable candidates for use as processable NLO materials. The polyurethane copolymer 4.4 was synthesized using a functional ferrocene monomer (Eq. 4.1) and has been well-characterized the molecular weight was estimated by GPC to be Mn=7600. The two possible orientations of the ferrocene NLO chromophore monomer unit, which correspond to opposite dipole orientations, were both present in the main chain. [Pg.131]

A novel class of nonlinear optical (NLO) urethane polymers for second harmonic generation is presented. These NLO polymers consist of NLO units which are embedded in the polymer backbone while the dipole moments are perpendicular to the main chain. The first is a linear polyurethane, T-polymer synthesized from 2,4-tolylene diisocyanate (TDI) and 4-[(2-hydroxy ethyl)amino]-2-(hy droxymethyl)-4 -... [Pg.151]

Because of the versatility of the polyurethane system it is possible to introduce comonomers which can affect the physical properties of the derived polymers. For example, photo cross-linkable polyurethanes are formulated using 2,5-dimethoxy-2,4 -diisocyanato stilbene as a monomer (76). Comonomers, having an azoaromatic chromophore, are used in optical bleaching applications (77), or in the formation of photorefractive polymers (78). The latter random poljnners have second-order nonlinear optical (NLO) properties. Linear poljnners are also obtained from HDI/PTMG and diacetylenic diols. These polymers can be cross-linked through the acetylenic linkages producing a network polymer with properties similar to poly(diacetylenes) (79). [Pg.6680]

Park, C.K., Zieba, J., Zhao, C.F., Swedek, B., Wljekoon, W.M.K.P., and Prasad, P.N. (1995) Highly cross-linked polyurethane with enhanced stability of 2 -order nonlinear-optical properties. Macromolecules, 28, i7 i- i7V7. [Pg.243]

These new polymers show high nonlinear responses and high glass transition temperatures. In comparison with the DRl azo-dye with a nitro group as electron donor, the optical properties of the boron-containing polyurethanes are slightly better. These polymers sean to be interesting new materials with potential application in NLO. [Pg.310]


See other pages where Nonlinear optical polyurethanes is mentioned: [Pg.1988]    [Pg.1988]    [Pg.7]    [Pg.19]    [Pg.140]    [Pg.169]    [Pg.250]    [Pg.62]    [Pg.62]    [Pg.368]    [Pg.185]    [Pg.151]    [Pg.327]    [Pg.330]    [Pg.266]   


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