Thermodynamic and Kinetics of Crystallization

The thermal transition of the 5 form was also studied by de Candia et al. [77] by using different techniques such as thermal analysis, thermogravimetry X-ray diffraction, and infrared spectroscopy. Experimental evidence showed that the solvent included in the crystal lattice was partially released on heating the sample within the range of stability of the 5 form. The solvent release depends on the time and temperature of annealing. Furthermore, the transition 5 to y occurs through an intermediate form characterized by conformational order, without crystalline order. This mesomorphic form was found to be impermeable to the vapor of dichloromethane at low activity, and it was possible to calculate its fraction. 

In the transition from 5 to y form, the value of crystallinity, as derived from the X-ray diffractograms, remains very similar (35% in the 8 and 38% in the y form), but there is a significant increase in the fraction of mesophase (from 20% in the 8 form to 37% in the y form). 

Several authors have addressed crystallization measurements and kinetics of SPS [23-26,78-82]. The experiments were carried out in both isothermal and non-isothermal mode by means of differential calorimetry techniques (DSC) [24-26,78-82]. 

The effect of the processing parameters, in particular of the melt temperature, the cooling rate, the crystallization temperature and pressure, the annealing time and the crystallization time have been extensively studied [23,25,78-80]. 

The melt crystallization toward the a form is favored by fast cooling or by low isothermal temperatures. Crystallization at high temperatures (close to 

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The thickness of the lamellae which form by secondary growth on the primary lattice sites may be understood by invoking the thermodynamics and kinetics of crystallization (Painter and Coleman, 1994). This analysis shows that... 

Liquid crystal forming polymers with flexible spacers in the side-chain were developed as a logical consequence of the analysis of side-chain crystallization. With sufficiently long side-chains, starting with about 10 chain atoms, the crystallization behavior becomes increasingly similar to low molecular mass molecules, i.e. the macromolecule backbone becomes only a connecting backbone with little consequence for the thermodynamics and kinetics of crystallization Detailed reviews of... 

Phase Transformations discusses the thermodynamics and kinetics of crystallization and phase separation. 

Elyashevich, G. K. Thermodynamics and Kinetics of Orientational Crystallization of Flexible-Chain Polymers. Vol. 43, pp. 207 — 246. 

Thermodynamics and Kinetics of Orientational Crystallization of Flexible-Chain Polymers... 

It should be noted that the fraction of ECC in samples obtained by other methods described in Sect. 2 is approximately as small as that of the framework in the orientation-ally crystallized samples. These methods differ in details but depend on the mechanical treatment of the crystallizing system and are therefore given the common name stress-induced crystallization . Although the structure of the samples obtained by these methods has some features in common with that of orientationally crystallized samples, the thermodynamics and kinetics of orientational crystallization are fundamentally different from the mechanism of stress-induced crystallization. 

Swathirajan and Bruckenstein [113] have recently discussed the thermodynamics and kinetics of underpotential deposition phenomena on polycrystalline electrodes. Since work functions and surface structural features vary in different crystal faces, upd phenomena on single crystals have shown distinctive differences [109]. 

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