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Abstract  

There is considerable interest in performing volatilisation and evaporation measurements by thermogravimetry. A quick and simple method for determining vapour pressure using a conventional thermobalance and standard sample holders has been developed. These yield meaningful thermodynamic parameters such as the enthalpies of sublimation and vaporisation. Under favourable conditions the melting temperature and enthalpy of fusion of such compounds can be obtained. This technique has been used for the study of dyes, UV absorbers and plasticisers. The use of modulated- temperature programs for such work is also described.

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Abstract  

The fission track registration efficiency of diethylene glycol bis allyl carbonate (dioctyl phthalate doped) [CR-39 (DOP)] solid state nuclear track detector (SSNTD) in solution medium (K wet) has been experimentally determined and is found to be (9.7 ± 0.5) × 10−4 cm. This is in good agreement with the values of other SSNTDs. The gamma irradiation effects in the dose range of 50.0–220.0 kGy on the bulk etch rate, V b and the activation energy for bulk etching, E of this solid state nuclear track detector (SSNTD) have also been studied. It is observed that the bulk etch rates increase and the activation energies for bulk etching decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation.

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Abstract  

Non-isothermal crystallization kinetics of the ethylene–acrylic acid copolymer (EAA) in diluents during thermally induced phase separation (TIPS) process was investigated via differential scanning calorimetry (DSC). Dioctyl phthalate (DOP), diphenyl ester (DPE), and peanut oil were used as diluents. Kinetic models, such as Jeziorny theory, Ozawa theory, and Mo’s approach, were utilized for description. The effective activation energy of EAA component in mixture was calculated by Friedman’s method. In the results, the Jeziorny theory and Mo’s approach could obtain good linear fitting relationship with the primary crystallization behavior of EAA, but the Ozawa theory failed to get a suitable result. The homogeneous nucleation of EAA proceeded at the end of liquid–liquid phase separation, while the non-isothermal crystallization developed within a solid–liquid phase separation environment. In the mixtures, the molecular weight, polar groups, and conformation of the diluent molecules would affect the nucleation of EAA, and its growth rate. Comparing with the non-isothermal crystallization of neat EAA, EAA in diluents obtained a higher Avrami index n, and comparatively lower crystallization rate. Peanut oil facilitated the homogeneous nucleation of EAA, leading to a higher melting peak temperature of EAA in the subsequent melting endotherms. The largest EAA’s Avrami index obtained in peanut oil also indicated a higher crystal growth dimensional geometry. The crystallization rate and crystallinity of EAA during the non-isothermal process decreased in the sequence: EAA/DPE > EAA/DOP > EAA/peanut oil.

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Abstract  

Phthalic acid esters, and in particular bis-2-(ethylhexyl) phthalate, are common environmental contaminants with long-term toxic and carcinogenic effects that readily dissolve in lipid substances. DSC measurements of hydrated multilamellar dipalmitoyl phosphatidylcholine liposomes in the presence of different amounts of bis-2-(ethylhexyl) phthalate, dioctyl phthalate, dibutyl phthalate (DBP) and diethyl phthalate (DEP) were considered. The effects on the main transition temperature, ΔH, and the shape and width of the transition were studied. A decrease in Tm, without an accompanying decrease in ΔH,and increases in both the asymmetry and the width of the main transition peak were observed. In some cases, the calorimetric curve showed complex peak structures arising from the coexistence of various aggregates of different sizes. This was particularly evident in the liposomes with DEP and DBP contents ranging from 5.0 to 7.5% m/m. For all the considered model systems, the effects were noticeable even in the presence of small amounts of phthalates; in the presence of greater amounts, the overall structure of the bilayer was in some cases strongly modified, with the appearance of new different phases. Since the function of a membrane-associated protein is dependent on the lipid structure, phthalates could modify the function by modifying the membrane structure.

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Agro-Based Resources CRC Boca Raton . 23. Semsarzadeh , MA , Mehrabzadeh , M , Arabshahi , SS 2002 Dynamic mechanical behavior of the dioctyl phthalate plasticized polyvinyl chloride

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supplied by Harbin Huaer Chemical Ltd. Co., Harbin, China. Poplar wood flour (WF) (50–80 mesh size) used as filler and solid poplar wood as a control in combustion testing were purchased from a local timber market. Additives such as dioctyl phthalate

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