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Thermal properties of 4,4′(2,2′-propylidene)-diphenol, referred to as bisphenol A, or BPA, are discussed. Parameters of thermal transitions were measured by DSC. The commercial product crystallizes in α-form crystals which melt at 157°C (onset) and 161°C (peak) with a heat of fusion 134.37 J g−1. Supercooled BPA shows a glass transition at about 40°C. Almost identical results were obtained for samples recovered by different methods: flakes, pastilles and prills. Two new polymorphs, the β and γ-forms were identified. The β-form melts at 131°C with a heat of fusion of 104.9 J g−1. The melting point of the γ-form was measured to be 138°C and its heat of fusion is 118.3 J g−1. Thermal conductivity of crystalline BPA was measured.
Abstract
The copolyamides consisting of ε-caprolactam and 6.1–24.5 wt.% of nylon salt prepared from adipic acid and 1-(2-aminoethyl) piperazine were synthesized. Physical and thermal characteristics of polyamide 6 and the copolyamides were compared. Nylon salt does not influence the polyreaction equilibrium so it is possible to prepare the copolyamides with high molecular weight and with the content of low-molecular compounds comparable with that of pure PA 6. Melting temperatures of the copolyamides are lower in comparison with PA 6 and decrease proportionally to the amount of the nylon salt. The thermal stability of the copolyamides is good and equal to that of PA 6. The melting enthalpies indicate that the process of crystallization of the copolyamides is influenced by the time of crystallization and the amount of comonomer present. Longer time of the crystallization assures higher degree of crystallization. The kinetics and the level of crystallization are positively influenced by the mobility of copolyamide segments mainly up to 10 wt.% of comonomer.
temperatures, pressures etc.) that allow to obtain various metal, oxide, and composite layers. Besides for choice of deposition conditions the information about thermal properties of used precursor is necessary first of all. For this purpose the series of
, L , Simon , C , Elkamel , A . 2009 Renewable agricultural fibers as reinforcing fillers in plastics prediction of thermal properties . J Therm Anal Calorim. 96 : 85 – 90 . 10.1007/s10973-008-9855-8 . 2
Study of thermal properties of intumescent additive
Pentaerythritol phosphate alcohol
important factor since its applicability can be assessed only on these grounds. In the present investigation, PEPA was synthesized and its structure was confirmed using FT-IR, 1 H and 13 C NMR spectral data. Its thermal properties were studied using TGA
Abstract
Poly(lactic acid)/organo-montmorillonite nanocomposites were prepared by melt intercalation technique. Maleic anhydride-grafted ethylene propylene rubber (EPMgMA) was added into the PLA/OMMT in order to improve the compatibility and toughness of the nanocomposites. The samples were prepared by single screw extrusion followed by compression molding. The effect of OMMT and EPMgMA on the thermal properties of PLA was studied. The thermal properties of the PLA/OMMT nanocomposites have been investigated by using differential scanning calorimeter (DSC) and thermo-gravimetry analyzer (TG). The melting temperature (T m), glass transition temperature (T g), crystallization temperature (T c), degree of crystallinity (χc), and thermal stability of the PLA/OMMT nanocomposites have been studied. It was found that the thermal properties of PLA were greatly influenced by the addition of OMMT and EPMgMA.
Thermal properties of a molecule in a constrained state
Dye-amylose inclusion complex
The thermal properties of a dye molecule (guest) inside the cavity of a host amylose helix were studied by TGA, DSC, and Thermal Desorption MS. The results show that the degradation temperature of dye shifts to a higher temperature by approximately 20°C.
Abstract
This work aims in studying the temperature dependence of the thermal properties (thermal diffusivity, k, specific heat, C
p and thermal conductivity, 
) of some basalt group samples, collected from different regions in the eastern desert of Egypt. The thermal properties of these samples were measured in the temperature range from r.t. to 900 K. The average values of the thermal conductivity of these investigated samples lie in the range from 0.4·10–3 to 2.01·10–3 cal cm–1 s–1 K–1. This means that these samples are considered as thermal insulating materials. The thermogravimetric analysis (TG) confirmed that these investigated samples are dry rocks. X-ray fluorescence (XRF) and X-ray diffraction (XRD) confirmed that these rock samples have a crystalline phase, the peaks of XRD have a small change in their location as a result of heat treatment. This behaviour was attributed to the oxidation and firing of some minerals after the heat treatment.
Abstract
The thermal properties are presented for a precious opal sourced from Coober Pedy, South Australia and a moldavite from Bohemia, Czech Republic whose origins differ significantly as opal is derived from the slow isothermal diagenesis of silica, while the tektites are specimens of vitreous silica formed from the terrestrial impact of asteroids. The differences between the two glassy silicates are presented through measurement of the TG–DSC, TMA and high-vacuum-hot-extraction DEGAS analysis.
Abstract
The thermal properties of KTN crystal were investigated at low temperatures by DSC and TM. The phase transition enthalpies and the average specific heats of the crystal were measured. Results are analyzed and discussed.
