It is well known that addition of a small amount nanoparticles to liquid crystals may enhance their nonlinear optical properties. To date, in most reports, semiconductor- or metallic-core LCs have been described. Here, we report on the synthesis two types novel based cubic siloxane cage (RSiO3/2)8, as polyhedral oligosilsesquioxane (POSS) with Si–O skeleton surrounded by covalently attached eight groups (R) azo-benzene mesogenes differing length aliphatic chains. These dielectric-core...

Spent coffee grounds (SCG) have potential as a sustainable bio-filler in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) composites, offering an environmentally friendly approach to waste utilization. This study investigated the effect of SCG content on mechanical, thermal, and morphological properties PHBV biocomposites compared them with those composites containing wood flour hemp fibers. The were fabricated via extrusion injection molding, followed by characterization their mechanical...

In this paper we investigate the dielectric response of cured epoxy resins based on biphenyl group. We chose two monomers, which were earlier synthesised, containing same mesogen but with long and short symmetric tails. They standard amines (DDM, DMAP). Firstly optimised conditions curing process by optical observation in situ. Small differences dynamics observed different mixtures. For four selected products made measurements a wide range frequency temperature. Although, generally, is...

Modern science and technology demand a low glass transition temperature, yet one tailored to specific thermoset needs individual hardener applications. Two novel, nonterminal liquid crystalline epoxy resins (LCER) were synthesised, with their structures characterized via nuclear magnetic resonance (NMR), mass spectrometry (MS), elemental analysis. Their nature thermal properties determined using polarized optical microscopy (POM), thermogravimetric analysis (TGA), differential scanning...

Abstract A new liquid‐crystalline epoxy monomer (LCEM) containing central triaromatic mesogen and aliphatic spacers consisting of eight methylene units terminated with groups was synthesized characterized by means IR NMR spectrometry, differential scanning calorimetry (DSC), polarized optical microscopy, wide‐angle X‐ray scattering. The cure reaction LCEM primary aromatic diamines in a stoichiometric ratio tertiary amine catalyst polymerization the properties cured products were investigated...

The curing behaviour of the composition a liquid-crystalline diepoxy monomer (LCEM) with central triaromatic mesogenic group was studied using differential scanning calorimetry, conventional DSC and temperature-modulated TMDSC nuclear magnetic resonance 1H-NMR spectroscopy. stoichiometric amount primary aromatic diamine, 4,4′-diaminodiphenylmethane (DDM), used as agent. TOPEM® allowed separation thermal effects related to reversible processes (e.g. phase transitions) from irreversible...

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 used as filler the with matrix obtained by crosslinking diepoxy monomer LCEM containing triaromatic mesogenic group. curing agent 4,4′‐diaminodiphenylmethane. morphology and thermomechanical properties final products were characterized differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA),...

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 the synthesis curing of a series composites based monomers. authors experimented with several factors which influence crosslinking reaction determined conditions are most favorable developing crystalline‐like molecular order in final products. New results selected mixtures addition anisotropic fillers also presented. process...

Abstract Two types of liquid crystal epoxy precursors and corresponding epoxy‐amine networks are investigated in this paper. The groups non‐terminal one the monomers (NTEM) terminal other (MU22). Both contain same mesogen exhibit properties. Structural differences between carbon chains affect physical properties products curing, which involves a typical diamine—DDM (4,4′‐diaminodiphenylmethane). Phase transition temperatures, conditions curing reaction glass temperatures cured determined...

A simple and efficient method for the synthesis of biodegradable, highly branched polycaprolactone (PCL) is presented. The solvent-free (bulk) reaction was carried out via ring opening polymerization (ROP), catalyzed by tin octanoate Sn(Oct)2, it employed hyperbranched polyamide (HPPA) as a macro-initiator. core–shell structure obtained products (PCL-HPPA), with HPPA core linear PCL chains shell, in focus product characterization. 1H nuclear magnetic resonance (1H NMR) elemental analysis...

Novel nonterminal liquid crystalline epoxy resin has been synthesized, and its structure nature have determined via nuclear magnetic resonance (NMR) polarized optical microscopy (POM).Then, it was cured with the use of 4,4′-diaminodiphenylmethane (4,4′-DDM).The curing process investigated differential scanning calorimetry (DSC) infrared spectroscopy (FTIR) methods.Polymerization conducted (1.2 T) without presence a strong field.The properties obtained polymers described using DSC,...

A nonterminal liquid crystal epoxy monomer is used to create an epoxy–amine network with a typical diamine 4,4′diaminodiphenylmethane. The plain matrix compared matrices modified inorganic fillers: TiO2 or SiO2. Conditions of the curing reaction and glass transition temperatures in cured products are determined through differential scanning calorimetry broadband dielectric spectroscopy. process also followed optical electrical observations. response all investigated networks reveals...

The properties of two pairs recently synthesised compounds with mesogenic unit were compared. four consist a central segment (based on biphenyl or phenylbenzoate) symmetric carbon chains ended vinyl epoxy groups. Typical measurement techniques (including microscopic observations, differential scanning calorimetry and wide-angle X-ray scattering dielectric studies) used to examine phase transitions in the studied materials. transition sequences determined for all A liquid crystalline appeared...

This work focused on obtaining a low-temperature powder coating characterized by self-healing properties. To achieve this, acrylic resin, blocked polyisocyanates (bPICs) with 1,2,4-triazole, and unsaturated commercial resin were used. The synthesis of bPICs triazole enabled the curing reversible Diels–Alder (DA) reaction at 160 °C. chemical structure was confirmed using 1H-NMR. occurrence DA retro-DA (rDA) reactions in crosslinked polymer, temperatures 60–85 °C 90–130 °C, respectively,...

A method of quantitative analysis polypropylene/linear low density polyethylene blends was determined by using differential scanning calorimetry. The samples were prepared means extrusion process. based on the principle that melting enthalpies components in mixture are proportional to their amount, but it has been found presence two polymers blend influence crystallization its components. Previous studies seemed neglect this phenomenon, so a linear correlation allowing eliminate...

Theoretical studies of molecular structure and electric charge distribution were carried out for three epoxy compounds with different mesogenic cores. The exhibit a nematic phase form polymer networks that are potential bases various composites. Results compared to analogous materials non-polar chains. A customized process involving geometry optimization series conformations was employed greatly increase likelihood reaching global energy minimum each molecule. All computations used Density...

Two recently synthesised diepoxy compounds based on the same rigid central segment with carbon chains of different lengths were compared. Microscopic observations, differential scanning calorimetry (DSC) and dielectric measurements confirmed existence a mesophase in both enabled determination temperatures phase transitions. Wide-angle X-ray scattering (WAXS) optical observations identification types. Nematic appeared compounds; material longer smectic A was also detected. Lengths molecules...