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A new liquid-crystalline epoxy monomer (LCEM) containing central triaromatic mesogen and aliphatic spacers consisting of eight methylene units terminated with epoxy groups was synthesized and characterized by means of IR and NMR spectrometry, differential scanning calorimetry (DSC), polarized optical microscopy, and wide-angle X-ray scattering. The cure reaction of LCEM with primary aromatic diamines in a stoichiometric ratio and with a tertiary amine catalyst of polymerization and the properties of the cured products were investigated with a DSC technique. The effects of the curing conditions (polyaddition vs anionic polymerization) and the structures of the amines on the formation of liquid-crystalline networks were studied. The monomer cured with selected amines yielded an anisotropic network.

Physically crosslinked low-temperature elastomers were prepared based on linear polydimethylsiloxane (PDMS) elastic chains terminated on both ends with mesogenic building blocks (LC) of azobenzene type. They are generally (and also structurally) highly different from the well-studied LC polymer networks (light-sensitive actuators). The LC units also make up only a small volume fraction in our materials and they do not generate elastic energy upon irradiation, but they act as physical crosslinkers with thermotropic properties. Our elastomers lack permanent chemical crosslinks—their structure is fully linear. The aggregation of the relatively rare, small, and spatially separated terminal LC units nevertheless proved to be a considerably strong crosslinking mechanism. The most attractive product displays a rubber plateau extending over 100 °C, melts near 8 °C, and is soluble in organic solvents. The self-assembly (via LC aggregation) of the copolymer molecules leads to a distinctly lamellar structure indicated by X-ray diffraction (XRD). This structure persists also in melt (polarized light microscopy, XRD), where 1–2 thermotropic transitions occur. The interesting effects of the properties of this lamellar structure on viscoelastic and rheological properties in the rubbery and in the melt state are discussed in a follow-up paper (“Part II”). The copolymers might be of interest as passive smart materials, especially as temperature-controlled elastic/viscoelastic mechanical coupling. Our study focuses on the comparison of physical properties and structure–property relationships in three systems with elastic PDMS segments of different length (8.6, 16.3, and 64.4 repeat units).

This work focuses on obtaining ordered liquid crystalline epoxy networks and applying them as matrices for nanofillers. The article summarizes research carried out by us on the synthesis and curing of a series of composites based on liquid crystalline epoxy monomers. The authors experimented with several factors which influence the crosslinking reaction and determined curing conditions which are the most favorable for developing liquid crystalline‐like molecular order in the final products. New results of curing selected mixtures with the addition of anisotropic fillers are also presented. The crosslinking process was followed by differential scanning calorimetry (DSC) measurements and the morphology of liquid crystalline epoxy resin (LCER) composites was investigated by wide‐angle X‐ray scattering technique (WAXS‐2D). The experiments demonstrated that nanorods only have a small impact on the thermal properties of the composite (e.g., the change of Tg is just about 2°C) as well as structural ones (diffraction images of the plain matrix and the nanocomposite only differ in a single additional reflection near 0.73 nm−1 which appears in all the studied matrices containing nanorods). In one case monodomain ordering could be achieved in both the matrix alone and that with the nanofiller, when curing was conducted in the presence of a magnetic field. POLYM. COMPOS., 38:277–286, 2017. © 2015 Society of Plastics Engineers

In the present paper we describe the curing process of a new liquid crystalline epoxy monomer with 4,4′‐diaminodiphenylenemethane (DDM). The characteristic of cured product is presented. Both the monomer and cured product have been characterized by IR and NMR spectroscopy, differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide‐angle X‐ray scattering (WAXS) and dielectric relaxation spectroscopy (DRS).The curing process was analysed with the use of DSC and real‐time DRS.