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The rheological properties of shear thickening fluids based on silica powder of particles size in range 0.10 – 2.80 μm and poly(propylene glycol) of 425, 1000, 2000 g/mol molar mass were investigated. The effect of particle size and the length of the polymeric chain was considered. The objective of this study was to understand basic trends of physicochemical properties of used materials on the onset and the maximum of shear thickening and dilatant effect. Outcome of the research suggested that an increase in the particle size caused a decrease in dilatant effect and shift towards higher shear rate values. Application of carrier fluid of higher molar mass allowed to increase dilatant effect but it resulted in the increase of the initial viscosity of the fluid.

The paper concerns the synthesis and the characterization of new water-thinnable binder such as poly(acrylic-styrene) with the addition of a new amphiphilic macromonomer and it application in shaping of unmodified and modified (by silanization) Al 2 O 3 by die pressing. The organic additives decomposed thermally to non-toxic gases which is beneficial from ecological point of view. Thus, the careful thermal analysis of synthesized binder was done. To characterize the synthesized binder, the glass transition temperature, wetting angle and diameter of polymer particles size in water were also measured. In the next step of the work, the density, porosity, tensile and bending strength, and microstructure observations have been done for modified and unmodified Al 2 O 3 samples obtained by die pressing. The results confirmed that the synthesized binder is eco-friendly, because it decomposed to non-toxic gases such as carbon dioxide and water vapor during heating up to ca. 527°C. The synthesized binders are characterized by low glass transition temperatures 5.6°C and -0.5°C which are much lower than that of PVA (42°C). It provided the high tensile strength (0.22 ± 0.01 MPa) of green bodies, 57% higher than strength of bodies with commercially available PVA and bending strength around 192 MPa. Density of sintered samples was around 95% of TD. Nevertheless, the best results were obtain for bodies based on modified Al 2 O 3 where tensile strength of green bodies and bending strength of sintered samples were 0.30 ± 0.04 MPa and 237 ± 19 MPa, respectively.

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Composites based on polylactide (PLA) and hydroxyapatite (HA) were prepared using a thermally induced phase separation method. In the experimental design, the PLA with low weight-average molar mass (Mw) and high Mw were tested with the inclusion of HA synthesized as whiskers or hexagonal rods. In addition, the structure of HA whiskers was doped with Zn, whereas hexagonal rods were mixed with Sr salt. The composites were sterilized and then incubated in phosphate-buffered saline for 12 weeks at 37 °C, followed by characterization of pore size distribution, molecular properties, density and mechanical strength. Results showed a substantial reduction of PLA Mw for both polymers due to the preparation of composites, their sterilization and incubation. The distribution of pore size effectively increased after the degradation process, whereas the sterilization, furthermore, had an impact on pore size distribution depending on HA added. The inclusion of HA reduced to some extent the degradation of PLA quantitatively in the weight loss in vitro compared to the control without HA. All produced materials showed no cytotoxicity when validated against L929 mouse skin fibroblasts and hFOB 1.19 human osteoblasts. The lack of cytotoxicity was accompanied by the immunocompatibility with human monocytic cells that were able to detect pyrogenic contaminants.