Papers by Author: Joanna Ryszkowska

Abstract: Polymerisation of urea-nitryle-urethanes performed in electric heating devices. It was suggested to manufacture these materials using microwave radiation as the heat source. As a part of this research project urea urethanes were fabricated using various strength of microwave radiation. The structure and properties of manufactured materials were investigated.

Abstract: In the present study the distribution of nanofillers in the polyurethane matrix and the composite properties were investigated. As a nanofiller, zirconium oxide doped with 10% Eu3+ was used. The nanofiller was added at 0.1 wt%. Different ways of nanofiller incorporation were investigated. The microstructure of the obtained materials was examined by atomic force microscopy in force modulation. The size analysis of the nanofiller was investigated with HRSEM. The thermal (DSC, TGA) properties of polyurethane nanocomposites were also investigated in addition to the analysis of transmittance and luminescence of obtained materials. The results obtained indicate a possibility of fabrication of polymeric nanocomposites for optoelectronic applications via a relatively inexpensive processing route.

Abstract: Carboxyalumoxanes have been incorporated into a polyurethane matrix by in situ polymerization. The filler was dispersed in the polyurethane matrix by either both ultrasonic and mechanical mixing or by mechanical mixing alone. The physico-mechanical properties of the composites have been characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Using ultrasound improves the degree of dispersion of the fillers in the matrix, but it also causes changes in the structure of the polyurethane matrix.

Abstract: This paper presents the results of studies on ZrO2 containing 10% Eu3+ as a nanofiller in polyurethane nanocomposites with luminescent properties. The nanocomposites, which are potential materials for electro-optical-electronic applications, were prepared by in-situ polymerization. Emission spectra, thermodegradation, thermal analysis and mechanical properties of polyurethane ZrO2/10% Eu3+ were investigated and the structure examined using HRSEM. The aim was to investigate the influence of the distribution of nanofillers in the composite and the structure of hard domains of polyurethanes on the relevant properties for opto-electronic applications.

Abstract: This paper presents the application of stereology methods to the description of morphological properties of nanoboehmite and its nanocomposites. Images of boemithe, fracture and cut surface of composites were obtained using high-resolution electron microscopy technique and atomic force microscopy. Quantitative analysis of the fracture structure images obtained with HRSEM technique, allowed us to explain the mechanism of changes of mechanical and thermal properties of polyurethane nanocomposites, as well as allowed to determine relationships between structure characteristics and properties of examined materials. Quantitative image analysis was also found to be useful in comparative analysis of polyurethane nanocomposites structure and structure of boehmite and products of its modification.

Abstract: Segmented polyurethanes (PUR) based on poly(ε-caprolactone)diol (PCL) as soft segments and cycloaliphatic diisocyanate were obtained. Two different types of catalysts were used for synthesis: dibutyltin dilaurate (DBTDL) and iron (III) acetylacetonate Fe(acac)3. Structure, thermal analysis, water absorption of obtained polyurethanes were studied. Polyurethanes catalyzed by Fe(acac)3 have lower glass transition temperature (Tg2) and melting temperature (Tm2) of hard domains in comparison with polyurethanes synthesized with DBTDL. Amount of absorbed water is in the range of 1,0-2,0% and is higher for PUR catalyzed by DBTDL. SEM observations show that type of catalyst used in synthesis affect structure of polyurethanes. Biological test XTT was done in order to determine influence of various metallic compounds used as catalyst on viability of human bone cell culture. The XTT results indicate no influence on viability of human osteoblasts cultured on the obtained PUR.