Papers by Keyword: Metallomesogen

Abstract: The combination of the concept of metallopolymers with urethane chemistry offers a versatile approach for the synthesis of new polyurethane materials. Polyurethanes are a distinct class of materials with tremendous industrial importance, and it is of interest to develop these materials with modified thermal and liquid crystalline behavior for advanced applications. Generally, polyurethanes suffer a major disadvantage of poor thermal stability. This can be improved upon by chemical modification of their structures by the incorporation of thermally stable heterocyclic ring structures along with transition metals. Metal-containing polyurethanes prepared from a polymeric diol, diisocyanate and a metal containing diol (metallodiol and metallomesogenic diol) as a chain extender are attracting contemporary research interest. The addition of a polymeric diol (polyol) induces flexibility to the polyurethane by reducing the glass transition temperature, increases its solubility and imparts elastomeric properties. Multifunctional polymers are materials poised for applications in different avenues with preference for plastic electronics. An introduction-cum-overview of synthesis and applications of metal-containing polyurethanes is presented in this chapter.

Abstract: To investigate the influence of alkyl chain on thermotropic and mesomorphic properties of 1,1’-disubstitued ferrocene derivatives, two series of ferrocene derivatives containing Schiff's base, 1,1’-C8H17FcC6H4COOC6H4CH=NC6H4OOCC6H4R1 (R1 = H, OCnH2n+1, n = 2, 4, 6, 8 ) and 1,1’-C8H17FcC6H4COOC6H4CH=NC6H4N=NC6H4R2 (R2 = Br, Cl, CH3 ) have been synthesized and characterized by IR and 1H NMR. Polarized optical microscopy (POM) and differential scanning calorimetry (DSC) results showed that all compounds exhibit nematic mesophase. The results show that the flexible alkyl chain connecting with ferrocene moiety could lower the melting points and clearing points, favor the formation of nematic mesophase.