melting

Thermodynamic Properties of 2-Methyl-5-arylfuran-3 Carboxylic Acids Chlorine Derivatives in Organic Solvents

The temperature dependences of the solubility of 2-methyl-5-(2-chloro-5-trifluoromethylphenyl)-furan-3-carboxylic acid and 2-methyl-5-(2,5-dichlorophenyl)-furan-3-carboxylic acid in acetonitrile, dimethyl ketone, isopropanol and ethyl acetate have been experimentally determined. The enthalpies of fusion of the investigated substances, as well as their enthalpies and entropies of mixing at 298 K have been calculated. The dependence of the saturated solution concentration on the values of enthalpy and entropy of solubility at 298 K has been determined.

The Effect of Cooling Rate during Crystallization on the Melting Behavior of Polypropylenes of Different Chemical Structure

The melting behavior of polypropylenes of different chemical structure (isotactic homopolypropylene, propylene-based block and random copolymers and maleic anhydride grafted polypropylene) was studied by differential scanning calorimeter (DSC) and optical microscopy. Melting behavior and the crystal structure of polypropylene and its copolymers were observed depending on the crystallization rate, chemical nature of co-monomer unites and regularity of co-monomer units arrangement in the polypropylene main chain.