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Abstract  

The concept of crystallization dynamics method evaluating the miscibility of binary blend system including crystalline component was proposed. Three characteristic rates, nucleation, crystal growth rates (N*, G*) and growth rate of conformation (G c*) were used to evaluate the miscibility of PVDF/at-PMMA and PVDF/iso-PMMA by the simultaneous DSC-FTIR. N*, G* and G c* depended remarkably on both temperature and blend fraction (ϕPMMA) for PVDF/at-PMMA system, which indicated the miscible system. PVDF/iso-PMMA showed small ϕPMMA dependency of N*, G* and G c*, was estimated the immiscible system. The ΔT/T m 0 values, corresponding to Gibbs energy required to attend the constant G* and G c*, evaluated from G* and G c* showed the good linear relationships with different slope. The experimental results suggested that the concentration fluctuation existed in PVDF/iso-PMMA system.

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Abstract  

The mixing state of poly(vinylidene fluoride) (PVDF) and two amorphous polymers,poly(methyl methacrylate) (PMMA) and poly(isopropyl methacrylate) (PiPMA) were investigated from the viewpoint of crystallization dynamics using simultaneous DSC-FTIR method. The crystallization rate (R *) and the growth rate of trans-gauche-trans-gauche’ (TGTG’) conformation (Rc *) depended on both the blend content (ϕ) and the crystallization temperature for PVDF/PMMA. The temperature and ϕ dependency of R * and Rc * were almost the same for PVDF/PMMA. However, R * and Rc * depended scarcely on f for PVDF/PiPMA, and the temperature dependency of R * differed from that of Rc * for PVDF/PiPMA. These results showed that PVDF and PMMA were miscible on molecular level, and that PVDF/PiPMA was immiscible and the concentration fluctuation existed in the PVDF-rich phase.

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) Recently, a combination of differential scanning calorimetry (DSC) and Fourier-transform infrared (simultaneous DSC-FTIR) microspectroscopy has been extensively applied to investigate the thermal-induced solid-state characterization of intramolecular

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Abstract  

Phase transitions of hexatriacontane (C36) and octacosane (C28), both as the solution grown single crystal (SGC) and polycrystalline aggregates (MCC) prepared by cooling at 1 K min–1 from the isotropic liquid state, were measured by the simultaneous DSC-FTIR method. MCC of C36 showed the freezing of the high temperature stable phase, which had a slight lower order of the lattice vibration mode comparing with the room temperature stable phase. MCC of C28 demonstrated thermo-reversible phase transition, however, had a binomial distribution of crystal stability of the monoclinic phase.

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Abstract  

The simultaneous DSC-FTIR was used for the observation of crystallization and melting of poly(vinylidene fluoride) (PVDF) and its blends with poly(methyl methacrylate) (PMMA) and poly(ethyl methacrylate) (PEMA). The isothermal crystallization was carried out under the condition of both α-form and γ-form crystallized competitively. The crystal growth rate of α -form and γ -form were evaluated from the absorbance changes at 795 cm-1 (α -form, CH2 rocking) and 810 cm-1 (γ -form, CH2 rocking) obtained by the DSC-FTIR. The crystal growth rate of γ -form decreased at the same crystallization temperature in the order of PVDF/syn-PMMA, PVDF/PEMA and PVDF/at-PMMA, which was corresponding to the order of interaction parameter. The mechanism of α -g transition of PVDF in the miscible blends with at-PMMA, syn-PMMA and PEMA was evaluated from the relationship between the decrease of α -form and the increase of γ -form. The critical crystallization temperature, at which the transformation from α -form to γ -form proceeded only in the solid state, shifted to higher temperature side in the order of interaction parameter.

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Abstract  

The thermally induced structural transformation of a hydrogen-bonded crystal formed from an amphoteric molecule of 6-[2-methoxy-4-(pyridylazo)phenoxy]hexanoic acid MeO was studied using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction measurement (XRD). Crystal form of the hydrogen-bonded crystal was measured by single crystal four circle diffractometer (Mo-Kα radiation). As a result, the crystal of MeO was stabilized by many C–H⋅⋅⋅O hydrogen bonds, and the C–H⋅⋅⋅O hydrogen bonds were broken by thermal energy reversibly. After transformation the supramolecular architecture was composed of supramolecular polymer including free-rotation pentamethylene main chains.

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conditions of isothermal and/or nonisothermal conditions [ 20 – 24 ]. To shed light on thermal properties of the widely used DPG, herein we characterized the thermal stability of DPG under nonisothermal conditions by a simultaneous TG/DSC-FTIR method

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selected instrumental techniques, DSC, FT-IR and Raman spectroscopy, can be useful for evaluation of the quality of substances and medicinal products. In practice, realization of this aim will be based on evaluation of potential use of the instrumental

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Abstract  

In this article, mechanochemical synthesis of barium titanate from different raw materials was studied. The prepared nanodispersed powders were investigated by means of XRD, DTA-TG, DSC, FTIR, Raman, UV–VIS, ESR spectroscopy, and low-temperature adsorption of nitrogen. Barium titanate possessing high specific surface area was produced directly during dry milling from the mixtures of barium oxides and titanium dioxide low-temperature forms (amorphous and anatase).

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Abstract

A new inorganically template metaphosphate of Ni(II) complex has been synthesized and characterized by different measurements such as DSC, FT-IR, C–H–N–S, X-RD and ICP-AES. Differential scanning calorimeter (DSC) elucidated negative specific heat of the system and has used to evaluate some thermodynamical constants like specific heat, enthalpy and entropy of that system. The specific heat capacity of the system is measured in atmospheric O2 at heating rate of 278 and 283 K min−1. The specific heat is found both positive and negative at 278 K min−1.

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