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Effect of Molecular Weight on Mesomorphic Behavior of Side-Chain Liquid-Crystalline Azopolymers

Published online by Cambridge University Press:  01 October 2015

Flores V. Daniela  and
Larios L. Leticia
Flores V. Daniela
Affiliation:
Departamento de Materiales Avanzados, Centro de Investigación en Química Aplicada, Saltillo, Coahuila, México.
Larios L. Leticia
Affiliation:
Departamento de Materiales Avanzados, Centro de Investigación en Química Aplicada, Saltillo, Coahuila, México.
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Abstract

Three methacrylic polymers bearing (phenylene)azobenzene moieties in the side-chain were synthesized via free-radical polymerization of monomer (E)-6-(4-((3’-cyano-4’-(hexyloxy) -[1,1’- biphenyl]-4-yl) diazenyl) phenoxy) hexyl methacrylate using 1, 5 and 10 mol% of 1,1’-azobis(cyclohexanecarbonitrile) (ABCN) as initiator. The chemical structures of monomer and polymers were confirmed by 1H NMR and FT-IR spectroscopies. Analysis by gel permeation chromatography (GPC) showed average molecular weights (Mw) of 1.0x105, 7.3x104, and 4.5x104 g/mol for polymers P1%, P5%, and P10%, respectively. These results indicate a clear dependence of the Mw on the amount of initiator used; the higher the amount of ABCN, the lowest the molecular mass. Thermotropic liquid-crystalline properties were analyzed by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). All polymers showed a liquid-crystalline behavior over a wide range of temperatures (>100°C) displaying smectic type mesophases. A small shift (around 8°C) upwards in the clearing temperature was observed on increasing the molecular masses from P10% to P1%. The trans-cis photo-isomerization of polymers was studied in solution and in thin films by UV-Vis spectroscopy. High cis-isomer contents in solution (>90%) were reached in relative short irradiation times.

Keywords

phase transformationliquidcrystal
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1765: Symposium 4A – Advanced Structural Materials—2014 , 2015 , pp. 133 - 138
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Ikeda, T., Yoneyama, S., Yamamoto, T. and Hasegawa, M., Mol. Cryst. Liq. Cryst. 401, 35–45 (2003).CrossRefGoogle Scholar
Xie, S., Natansohn, A. and Rochon, P., Chem. Mater. 5, 403–411 (1993).CrossRefGoogle Scholar
Zhang, H., Yu, Z., Wan, X., Zhou, Q.F. and Woo, E.M., Polymer 43, 2357–2361 (2002).CrossRefGoogle Scholar
Pugh, C., and Schrock, R.R., Macromolecules 25, 6593–6604 (1992).CrossRefGoogle Scholar
Craig, A.A. and Imrie, C.T., Mater. Chem. 4, 1705–1714 (1994).CrossRefGoogle Scholar
Gutiérrez, K.G., Larios, L., Rodríguez, R.J., Donnio, B. and Navarro, D., Liq. Cryst. 40, 534–545 (2013).CrossRefGoogle Scholar
Okano, K., Shishido, A. and Ikeda, T., Macromolecules 39, 145–152 (2006).CrossRefGoogle Scholar
García, T., Larios, L., Rodríguez, R.J., Martínez, G., Solano, C. and Navarro, D., Polymer 53, 2049–2061 (2012).CrossRefGoogle Scholar
Rodríguez, R.J., Larios, L. and Navarro, D., Liq. Cryst. 38, 831–839 (2011).CrossRefGoogle Scholar
Mijangos, I., Navarro, V.F., Guerreiro, A., Piletska, E., Chianella, I., Karim, K., Turner, A. and Piletsky, S., Biosensors and Bioelectronics 22, 381–387 (2006).CrossRefGoogle Scholar
Piletska, E., Guerreiro, A., Whitcombe, M. and Piletsky, S., Macromolecules 42, 4921–4928 (2009).CrossRefGoogle Scholar
Prajapati, A.K. and Pandya, H.M., Liq. Cryst. 31, 889–894 (2004).CrossRefGoogle Scholar
Yang, C., Wang, Q., Xie, H.L., Zhong, G.Q. and Zhang, H.L., Liq. Cryst. 37, 1339–1346 (2010).CrossRefGoogle Scholar
Komiya, Z., Pugh, C. and Schrock, R., Macromolecules 25, 3609–3616 (1992).CrossRefGoogle Scholar
Sekkat, Z. and Knoll, W., Photoreactive Organic Thin Films (Elsevier Science, 2002).Google Scholar