Three aromatic bismaleimide resins, 4, 4’-bismaleimidodiphenyl methane (BMIDDM), 4, 4’bismaleimidodiphenylether (BMIDDE) and 4, 4’-bismaleimidodiphenyl sulphone (BMIDDS) having various bridging groups from the corresponding amine monomers (4, 4’-diaminodiphenylmethane (DDM), 4, 4’-diaminodiphenylether (DDE) and 4, 4’-diaminodiphenylsulphone (DDS)) were prepared. These resins were characterized by FTIR and NMR spectroscopy techniques. BMIDDM/BMIDDE and BMIDDM/BMIDDS mixtures at various concentrations were prepared to study the bismaleimide resin eutectic mixtures. Differential scanning calorimetry analysis was used to demonstrate the phase diagrams, the melting and solubility of each constituent of these binary systems (BMIDDM/BMIDDE and BMIDDM/BMIDDS) in different liquid and solid phases. Furthermore, in the present work the relationship between binary systems and the concept of a eutectic mixture with its extraordinary thermal properties is investigated. The eutectic melting point of the BMIDDM/BMIDDS system is considerable because of the much lower melting point of the above system compared to that of the synthesized monomer having the lowest melting point. It shows also a very easy way of using these materials in the molten state. The same DSC study on other mixtures, i. e., BMIDDM/BMIDDE and BMIDDE/BMIDDS is performed and the results are reported. The end results illustrate that by increasing the quantity of one monomer in the mixture, two melting points appear until they acquire the melting temperature of the eutectic composition (Te, a single and homogeneous peak). Impurities have similar effects on To and Texo. The findings of this work can be applicable in the transportation industry, particularly in areas such as civil and military aircraft industry, aerospace, marine and automotive sectors.

To study the polarity scale of three deep eutectic solvents (DESs), i. e. choline chloride + glycerol (1: 2), choline chloride + ethylene glycol (1: 2) and choline chloride + lactic acid (1: 2), and their mixtures with water (in the whole mole fraction range), Kamlet-Taft solvent parameters (α, β, and π*), Dimroth-Reichardt’s ET(30) parameter were experimentally measured at constant temperature 298. 15±0. 1 K. These parameters were obtained based on UV–Vis absorbance of some solvatochromic probes. The spectral changes of these indicators were interpreted in terms of specifc and nonspecifc dye–solvent interactions. The parameter ET(30) was obtained from electronic absorbance of the betaine dye within the mixtures. It was found that the polarity, polarizability and acidity of the co-solvent mixtures decreases by increasing the mole fraction of DESs in the system, while basicity of the media increases with mole fraction of DESs.

Pure and eutectic mixtures of fatty acids are desirable Phase Change Materials (PCMs) for low/medium Thermal Energy Storage (TES) applications because of their high density of energy storage, biodegradability, sustainability, and compatibility with existing systems. In the current study, thermodynamics and the experimental standpoint of phase equilibrium for 10 ternary mixtures of fatty acids were considered. In this regard, an approach based on the Wilson model was developed to predict the melting temperature of fatty acids to predict the eutectic points of ternary mixtures including Capric acid, Undecanoic acid, pentadecanoic acid, Margaric and Stearic acid. It indicated that the eutectic points were close to the melting temperature of lower density compounds and for Capric+Undecanoic+Pentadecanoic the melting point has the minimum values among the other nine mixtures and equals 281.0 °C. A comparison of the derivate activity model with the experimental data represented deviations of less than 1% between experimental and predicted values.

Introduction In 2003 Abbott et al. reported a new generation of ionic liquid (IL) entitled deep eutectic solvents (DESs), a new class of solvents. DESs have two or three components with a large depression of melting points [1]. These ingredients involve a variety of ionic and neutral species and have the role of either hydrogen bond acceptors or hydrogen bond donors, which play the role of Lewis or Bronsted acids and bases [2]. Recyclability, low vapor pressure, and low toxicity are important properties of deep eutectic solvents. These Eco-friendly properties of deep eutectic solvents have attracted researchers' attention [2, 3]. Bio-oil and biofuel productions [4-7],...

In a recent paper published in Pharmaceutical Sciences Bala and coworkers1 characterized eutectic mixtures prepared from leflunomide and two monocarboxylic acids (adipic acid, picolinic acid), three dicarboxylic acids (maleic acid, malonic acid, sorbic acid), and two pyridine carboxamides (nicotinamide, isonicotinamide). The solid materials were subjected to infrared spectroscopic studies, powder X-ray diffraction analyses, and differential scanning calorimetric measurements to establish whether the materials were salts, cocrystals or eutectics. As part of the thermal studies the authors reported in Table 1 of their paper the endothermic melting point temperatures of the individual pure components and the respective eutectic mixtures. Table 2 of the paper1 gives the experimental enthalpy of fusion data.....

In the present research, different trends of temperature of eutectic ending and duration of eutectic transformation due to employment of different combinations of five types of inoculants and four types of modularizes, with different fading resistances, were studied. Cooling curves and image analysis were used to characterize the influence of holding time, for 0, 5, 10, 15 and 20 min, on the samples prepared from the melt processed by 2.5 wt% modularize and 0.4 wt% inoculants and kept at 1320ºC under nitrogen atmosphere. Chemical composition of 20 samples out of 100 attained by the means of emission spectrometry. While the dominant graphite morphology is spherical or flake, by succeeding of the fading phenomenon, temperature of eutectic ending and duration of eutectic transformation respectively decrease, increase and decrease again. When there is a combination of spherical, compacted and flake graphite, the above results are reverse. As long as the main graphite morphology is spherical, Mg, S and Al content decrease by advancement of fading, nevertheless after this stage, Mg and Al content reach a steady state whereas S content slightly increases.