Liquid crystalline epoxy resins

Har Harada, M., Aoyama, K., Ochi, M. Influence of the loading rate on liquid-crystalline epoxy resin systems. J. Polym. Sci. Part B - Polym. Phys. 43 (2005) 1296-1302. [Pg.548]

Liquid crystals exhibit a partially ordered state (anisotropic) which falls in-between the completely ordered solid state and completely disordered liquid state. It is sometimes referred to as the fourth state of matter . In recent years, interest in liquid crystalline thermosets (especially liquid crystalline epoxy) has increased tremendously [33-44]. If the liquid crystal epoxy is cured in the mesophase, the liquid crystalline superstructure is fixed permanently in the polymer network, even at higher temperature. Liquid crystal epoxies are prepared using a liquid crystal monomer [33-38] or by chemical modification of epoxy resin [43] which incorporates liquid crystal unit in the epoxy structure. Liquid crystalline epoxy resins with different types of mesogen such as benzaldehyde azine [33], binaphthyl ether [34, 35], phenyl ester [36, 37] and azomethine ethers [38, 39] have been reported. Depending on the chemical nature of the mesogen, the related epoxies display a wide range of thermomechanical properties. The resins can be cured chemically with an acid or amine [40, 41] or by photochemical curing in the presence of a photo-initiator [3]. Broer and co-workers [42] demonstrated the fabrication of uniaxially oriented nematic networks from a diepoxy monomer in the presence of a photo-initiator. [Pg.176]

This statement holds true especially in the case of liquid crystalline epoxy resins. In fact, the structural features and distribution of crosslinks along the molecular backbone strongly influences the liquid crystalline phase developed during the curing process and the performances and the applicability of the resulting material. [Pg.389]

Liquid Crystalline Epoxy Resins can be cured in different ordered states depending on the curing agent used. With aromatic amines the thermoset is crosslinked in a nematic structure. No isotropization temperature can be detected. The reaction can be monitored by means of DSC analysis. A double peak exotherm indicates that the crosslinking reaction forms a liquid crystalline resin. Kinetic models can be applied to separate the contributions of the different reactions. [Pg.401]

Keywords Liquid crystalline thermosets, liquid crystalline epoxy resins, curing reactions, mechanical properties, thermal properties... [Pg.387]

Figure 11.7 Chemical structures of liquid crystalline epoxy resins with deferent mesogenic length. Reproduced from reference 27.

Figure 11.8 Chemical structures of naphthalene (a) and biphenyl (b) containing liquid crystalline epoxy resins. Reproduced from reference 28, 29.

Figure 11.21 2,2 -Bis(4-cyanatophenyl) isopropylidene (CE) and Liquid crystalline epoxy resin (LCE).

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Liquid Crystalline Epoxy Resin Based Nanocomposite... [Pg.459]

Table 19.1 Chemical structures of conventional and liquid crystalline epoxy resins... [Pg.461]

Liquid Crystalline Epoxy Resin Based Nanocomposite Table 19.2 (continued)... [Pg.469]

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Harada M, Ochi M, Tobita M, Kimura T, Ishigaki T, Shimoyama N, Aoki H (2003) Thermal-conductivity properties of liquid-crystalline epoxy resin cured under a magnetic field. J Polym Sci Polym Phys 41 1739-1743... [Pg.484]

Harada M, Watanabe Y, Tanaka Y, Ochi M (2006) Thermal properties and fracture toughness of a liquid-crystalline epoxy resin cured with an aromatic diamine crosslinker having a mesogenic group. J Polym Sci Polym Phys 44 2486-2494... [Pg.484]

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Huo L, Gao J, Du Y, Chai Z (2008) Synthesis and characterization of the two novel liquid crystalline epoxy resins based on hisphenol-S mesogen. J Appl Polym Sci 110 3671-3677... [Pg.484]

Le Hoang S, Shin S, Lim D-G, Nguyen Ngoc T, Bui Thanh S, Bae J-Y (2013) A novel wholly aromatic liquid crystalline epoxy monomer based on 2,7-naphthalene mesogen Synthesis and curing with aromatic diamine. Macromol Res 21 1105-1109 Lee JY, Jang JS (1998) Effect of substituents on the curing of liquid crystalline epoxy resin. J Polym Sci Polym Chem 36 911-917... [Pg.485]

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