Łukasz Byczyński

Synthesis, spectral and thermal study of La(III), Nd(III), Sm(III), Eu(III), Gd(III) and Tb(III) complexes with mefenamic acid

New binuclear complexes of La(III), Nd(III), Sm(III), Eu(III), Gd(III) and Tb(III) ions with mefenamic acid were obtained in solid phase. For all compounds considered, complexation occurs at pH 6–6.5. The analyzed complexes were characterized on the basis of chemical and elemental analyses, molar conductance, UV–Vis, IR and 1H NMR spectroscopies as well as thermoanalytical techniques. According to the research results, the molecular formula of the complexes is Ln2(C15H14NO2)3(OH)3×nH2O, with the exception of the La(III) complex which has the formula La2(C15H14NO2)5(OH). The results show that only the carboxyl group is involved in the coordination of the rare earth ions in the bidentate mode. Coordination does not occur through the nitrogen atom. All the complexes are soluble in DMSO, and they are nonelectrolytes. The TG-FTIR technique was employed in order to study a decomposition pathway of the obtained compounds. The received results provide information on the composition, thermal stability, thermal decomposition, as well as the gaseous products that evolved during the thermal decomposition of the considered compounds.

Poly(urethane-siloxane) Copolymers as New Coating Materials

The chapter deals with the structure and chemistry of poly(urethane-siloxane) copolymer waterborne poly(urethane-siloxane). The chapter also discusses the network formation and significance of urethane-siloxane copolymers. This detailed study reveals that copolymers can be used as coatings giving superior adhesion and other chemical properties.

Methods of increasing hydrophobicity of polyurethane materials: important applications of coatings with low surface free energy

The synthesis of polyurethane coatings by polyaddition in bulk using polyesterols and polyetherols with variable polarity was successfully carried out. IR and NMR spectra confirmed the structure of obtained polyurethanes and the incorporation of a polydimethylsiloxane(PDMS) modifier into the polyurethane structure. The differential scanning calorimetry and IR spectroscopy were employed for the microstructural assessment of the obtained materials. It was noted that crucial effect on free surface energy of the coatings has polyol structure as well as ratio of hard to soft segments. The contact angle measurements indicated that with increasing content of the polysiloxane in the flexible PTMO segments, the hydrophobicity significantly increased. It was demonstrated that hydrophobicity and mechanical strength, which are important for applications as biomaterials, are adversative in significant extent. The resulting coatings were characterized in terms of the heat resistance and changes during incubation in a Baxter saline solution.