Polyurethanes optical functionality

Figure 3.5 Structures of (a) [LaL3(HL)(phen)2(H20)] and (b) [EuL3(phen)(H20)] (HL = 4-aminobenzonic acid) [RE, black (large balls) O, grey N, black (small balls) C, white H, omitted]. (Redrawn from the GIF files of T. Fiedler et al, Synthesis, structural and spectroscopic studies on the lanthanoid p-aminobenzoates and derived optically functional polyurethane composites, European Journal of Inorganic Chemistry, 2007, 291-301, 2006 [40].)...

In this chapter we investigate the morphology of a series of polyurethanes based on polycaprolactone polyol (PCP), diphenylmethane diisocyanate (MDI), and butanediol (BDO). Samples of as-batch-reacted and solution-cast polymers were examined by optical microscopy, transmission electron microscopy, electron and x-ray diffraction, and differential scanning calorimetry. Our interest is to provide a mapping of the size and shape of the domains (and any superstructure such as spherulites) and the degree of order as a function of the fraction of each phase present. 

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. 

The use of TPEs in films and tapes is discussed in numerous reports. However, the latter provide essentially recipes of mixtures. They concern many technical fields pressure-sensitive adhesives, medical applications, barrier properties, porous films, etc., and some of them describe well defined electic properties, such as an electrostrictive system formed of a conductive polymer (polypyrrole, polyaniline, polythiophene) deposited onto opposing surfaces of a TPE film, e.g., a polyurethane [168]. The same comments hold for coating and painting where TPE are mainly used in the protection of metal or alloy substrates, such as electric wires some others impart additional functions to the protection, as is the case of optical fibers or textile fibers and different fabrics. Some few patents claim that a new TPE can be used as textile fiber with interesting properties, however these patents are almost never industrialized on the other hand, new TPE fiber processing techniques are proposed [169]. 

Wang et aL [31] used the solution intercalation of an organoclay to get pecuhar optical properties. In this case, the clay (saponite) was intercalated with a suitable compound bearing chromophore moieties. Ni et at [32] tried to use an amine-functionalized attapulgite as chain extender (instead of a diamine) in the polymerization reaction. The best mechanical performance was achieved by dispersing 2-5 wt% organophilic attapulgite in the polyurethane. 

Figure 33 (a) Five ink-jet-printed lines of /7s/fu-formed polyurethane, imaged using optical profilometry. From top to bottom, the parallel lines consist of an increased number of layers, where each layer consists of two print runs from both reactants. From top to bottom the number of layers decreases from 5 to 1. (b) Height and width measurements of the same five lines, displayed as a function of the number of layers. Reprinted with permission from Krbber, P. Delaney, J. T. Perelaer, J. etal. J. Mater. Chem. 2009, 19, 5234. Copyright 2010 the Royal Society of Chemistry. 

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