Authors:J. Haponiuk, M. Strankowski, and T. Łazarewicz
The melting and crystallization of a series of polyurethanes derived from poly(1,6-hexylene adipate)diol (PHA), 4,4'-dicyclohexylomethane
diisocyanate (HMDI) and 4,4'-bis(10-hydroxydecaoxy)biphenyl (BHDBP) as a chain extender were investigated by using DSC. Thermal
properties of the polyurethanes were found to be strongly influenced by the hard segment content.
The energy of combustion of crystalline 3,4,5-trimethoxybenzoic acid in oxygen at T=298.15 K was determined to be -4795.91.3 kJ mol-1 using combustion calorimetry. The derived standard molar enthalpies of formation of 3,4,5-trimethoxybenzoic acid in crystalline
and gaseous states at T=298.15 K, ΔfHmΘ (cr) and ΔfHmΘ (g), were -852.91.9 and -721.72.0 kJ mol-1, respectively. The reliability of the results obtained was commented upon and compared with literature values.
Authors:D. Czakis-Sulikowska, J. Radwańska-Doczekalska, A. Czylkowska, and J. Gołuchowska
The new mixed ligand complexes with formulae M(4-bpy)(C2H5COO)22H2O (where M(II)=Mn, Co, Ni; 4,4'-bpy or 4-bpy=4,4'-bipyridine) and Cu(4-bpy)0.5(C2H5COO)2H2O were prepared and characterized by VIS (for solid compounds of Co(II), Ni(II), Cu(II) in Nujol), IR spectroscopy, X-ray
powder diffraction and molar conductance in MeOH, DMF or DMSO. Thermal behaviour of complexes was studied under static conditions
in air atmosphere. Corresponding metal oxides were identified as final products of pyrolysis. A coupled TG-MS system was used
to analysis of principal volatile thermal decomposition and fragmentation products of isolated complexes under dynamic air
and argon atmosphere. The principal species correspond to: C+, OH+, H2O+, NO+, CO2+ and other; additionally CO+ in argon atmosphere.
Authors:Margit Bán, J. Madarász, Petra Bombicz, G. Pokol, and S. Gál
Composition and structure of crystals of unknown origin, crystallizing spontaneously from ethylenediamine on standing, has
been determined by elemental analysis, FTIR, 1H and 13C NMR spectroscopy and X-ray diffraction. The crystal with molecular formula C6H14N4 has been found to be a highly symmetric
saturated imino compound with double-ring structure, and unambiguously identified as trans-1,4,5,8-tetraazodecalin by 1H NMR and powder X-ray diffraction based on both its specific AA'BB' spin coupling system and simulated XRD pattern calculated
from available data of previous single crystal structure determination, respectively. Simultaneous TG/DTA measurement shows
one-step degradation of this compound. The volatile decomposition products have been followed by both TG/DTA-MS and TG-FTIR.
Group of the largest fragments (m/z=80, 81 and 82) observed by TG/DTA-MS corresponds to an aromatic 1,4-diazine (pyrazine). In the EGA-FTIR spectrum of released
gaseous species measured at the highest evolution rate by TG-FTIR, ethylenediamine can be identified as another decomposition
Authors:D. Czakis-Sulikowska, A. Malinowska, and A. Łuczak
Two lactates and four new mixed ligand complexes with formulae Co(lact)22H2O, Ni(lact)23H2O, Co(4-bpy)(lact)2, Co(2,4'-bpy)2(lact)2, Ni(4-bpy)(lact)22H2O and Ni(2,4'-bpy)2(lact)2 (where 4-bpy=4,4'-bipyridine, 2,4'-bpy=2,4'-bipyridine, lact=CH3CH(OH)COO-) were isolated and investigated. The thermal behaviour of compounds was studied by thermal analysis (TG, DTG, DTA). In the
case of hydrated complexes thermal decomposition starts with the release of water molecules. The compounds decompose at high
temperature to metal(II) oxides in air. A coupled TG-MS system was used to analyse the principal volatile products of thermolysis
and fragmentation processes of obtained complexes.
Authors:Anca Moanţă, Cătălina Ionescu, P. Rotaru, Margareta Socaciu, and Ana Hărăbor
class of dyes.
We have reported the synthesis, spectral characterization [ 18 – 20 ], and thermal stability [ 21 – 29 ] of some synthetic azoic dyes, which have a 4-[(4-chlorobenzyl)oxy]azobenzene derived structure. These compounds were
The mineral stercorite originated from the Petrogale Cave, Madura, Eucla, Western Australia. Many minerals may form in these caves, some of which include archerite (K, NH 4 )(H 2 PO 4 ) [ 1 ], and mundrabillaite
Authors:Yifeng Zhou, Liling Wang, Tiebing Liu, Zedong Mao, Qing Ge, and Jianwei Mao
thousands of years [ 1 – 3 ]. Moreover, O. japonicus is also considered a functional food in China, Japan, and some south-eastern Asian countries [ 4 ]. Homoisoflavonoids, steroidal saponins, and polysaccharides are the main active constituents of O