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  • Author or Editor: G Siracusa x
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Abstract  

The polycondensation reactions between 4,4′-[sulphonyl bis(p-benzoyl)(p-phenyleneoxy)]dibenzoic acid (I) andp-phenylenediamine (II), 1,5-diaminonaphthalene (III), 4,4′-sulphonyldianiline (IV), 4,4′-diaminodiphenylsulphide (V) 4,4′-methylenedianiline (VI) and 4,4′-oxydianiline (VII) to form aromatic polyamides containing sulphone, ether and ketone linkages were attempted by a solid-solid interaction route. A stoichiometric 1∶1 molar ratio of solid reactants was dynamically heated directly in a TG/DSC apparatus, and simultaneous TG/FT-IR was performed to interpret the mechanism of reaction. The results suggest that the polycondensation is dependent on the diamine used. The formation of polyamide was successful when I interacted with II, III, VI and VII. The interaction with IV and V was in part successful because partial decarboxylation of the diacid, made unstable by the diamine, occurred before the condensation reaction.

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Thermal behaviour of solid complexes of phenoxyalkanoic acids and divalent metals

III. Study on cobalt(II) and nickel(II) phenoxyacetates

Journal of Thermal Analysis and Calorimetry
Authors: L. Abate, C. Gandolfo and G. Siracusa

Solid Co(II) and Ni(II) phenoxyacetates were studied by DSC and TG techniques. The results showed that they were dihydrate and tetrahydrate respectively in the solid state. No evidence of the location of water molecules in different coordination shells was obtained. Both compounds decomposed with the formation of oxide as final product; the corresponding activation energies suggested a stronger metal-carboxylate bond in the nickel salt.

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Thermal behaviour of uranium(VI) complexes

Uranyl acetate dihydrate-N-phenylthiourea system: synthesis and decomposition

Journal of Thermal Analysis and Calorimetry
Authors: L. Abate, A. Chisari, G. Romeo, R. Maggiore and G. Siracusa

The solid-state syntheses of complexes of uranyl acetate dihydrate andN-phenylthiourea have been attempted by heating various stoichiometric mixtures of the reactants directly in a DSC and in a TA apparatus. Both the DSC and the TG results indicate that only the 1∶1 adduct is formed, independently of the molar ratios of the reactants. It appears that the reaction is complete only with a large excess ofN-phenylthiourea, in agreement with IR data.

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The thermal behaviour of solid zinc phenoxyacetate was investigated by DSC and TG techniques. The results obtained showed that this compound is a dihydrate and that the water molecules are differently bonded. The compound melts and then decomposes in two steps, with the formation of ZnCO3 and ZnO, respectively. The thermodynamic parameters associated with the thermal processes were evaluated.

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