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.

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BEATA MOSSETY-LESZCZAK *)1) , HENRYK GALINA 1) , MAGDALENA W£ODARSKA 2) , MARCIN KOWALIK 3) , KRZYSZTOF £OKAJ 4) , ZBIGNIEW FLORJAÑCZYK 4) ywice i sieci epoksydowe o w³aoeciwooeciach anizotropowych Autorzy dedykuj¹ publikacjê Pani Profesor Marii Nowakowskiej (Uniwersytet Opolski) z okazji Jubileuszu 80-lecia Jej urodzin i 50-lecia pracy naukowej. Streszczenie-Na podstawie literatury podano ogóln¹ charakterystykê ciek³okrystalicznych uk³adów polimerowych ze szczególnym uwzglêdnieniem uk³adów epoksydowych. W ramach badañ w³asnych przedstawiono sposób syntezy ciek³okrystalicznego monomeru diepoksydowego (LCM, schemat A), w którym ugrupowanie mezogeniczne stanowi³ czteropieroecieniowy diester aromatyczny bifenylo-4,4'-diolu. Budowê chemiczn¹ tego monomeru potwierdzono metodami FT-IR i 1 H-NMR. LCM sieciowano 4,4'-diaminodifenylometanem (DDM), 4-(N,N-dimetyloamino)pirydyn¹ (DMAP) b¹dŸ kwasem pimelinowym (KP); w charakterze nanonape³niacza w procesie utwardzania zastosowano nanoprêty z difenylofosforanu glinu (NP). Proces sieciowania badanych uk³adów (zawieraj¹cych NP albo bez tego nanonape³niacza) zbadano metod¹ skaningowej kalorymetrii ró¿nicowej (DSC), a strukturê utwardzonych kompozycji oceniono za pomoc¹ mikroskopu polaryzacyjnego i me-tod¹ rentgenograficzn¹ (WAXS). Metod¹ DSC okreoelono te¿ w³aoeciwooeci cieplne tych kompozycji po utwardzeniu. Ustalono warunki temperaturowe procesu sieciowania prowadz¹ce do powstawania sieci polimerowych charakteryzuj¹cych siê w³aoeciwooeciami anizotropowymi. Stwierdzono, ¿e przyczynê ograniczaj¹c¹ mo¿liwooeci otrzymywania materia³ów jednorodnie uporz¹dkowanych ze struk-tur¹ monodomenow¹ stanowi znaczna lepkooeae LCM w fazie smektycznej, w której rozpoczyna siê proces sieciowania. S³owa kluczowe: polimery ciek³okrystaliczne, ¿ywice epoksydowe, nanokompozyty, sieciowanie, anizotropowe sieci polimerowe, w³aoeciwooeci cieplne. EPOXY RESINS AND NETWORKS WITH ANISOTROPIC PROPERTIES Summary-A general characteristics of liquid crystalline polymer systems, especially epoxy ones, is given on the basis of literature. Own research was focused on the synthesis of liquid crystalline diepoxy monomer (LCM, Scheme A) in which a tetracyclic aromatic diester of biphenyl-4,4'-diol was a mesogenic unit. The chemical structure of this monomer was confirmed by FT-IR and 1 H NMR methods. LCM was cured with 4,4'-diaminodiphenylmethane (DDM) or 4-(N,N-dimethylamino)pyridine (DMAP) or pimelic acid (KP). Diphenyl aluminum phosphate nanorods (NP) were used as a filler during a curing. The curing processes of the compositions, containing NP or not, were studied using differential scanning calorimetry (DSC, Fig. 1 and 2, Table 1) while their structures were evaluated with use of polarization microscope (Fig. 3) and by X-ray radiography (WAXS, Fig. 4). Thermal properties of cured compositions were determined by DSC method (Fig. 5). The temperature conditions of curing allowing formation of polymer networks showing anisotropic properties were found. It was stated that high viscosity of LCM in smectic phase, in ...

The synthesis of a novel ordered liquid crystalline epoxy carbon composite was presented in this article. Anthracite thermally modified at 2,000°C (SV2000) having graphitic structure was used as a filler in the composite with matrix obtained by crosslinking a liquid crystalline diepoxy monomer LCEM containing triaromatic mesogenic group. The curing agent was 4,4′‐diaminodiphenylmethane. The morphology and thermomechanical properties of the final products were characterized by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and wide angle X‐ray scattering (WAXS) analysis. It was found by WAXS measurements that alignment of LCEM was effectively induced in the matrix and in the composite filled with SV2000 by applying external magnetic field during cure. Thermosets with locked smectic C structure were obtained in all cases, with mesogenic fragments arranged along the applied field. The experimental results indicated that the presence of SV2000 as the filler of composite partially decreased the degree of order. The oriented composites exhibited anisotropy of the dynamic‐mechanical properties. POLYM. COMPOS., 39:E2573–E2583, 2018. © 2018 Society of Plastics Engineers

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