In this paper we focus on the elastic and thermodynamic properties of the B1 phase of CaO by using the modified TBP model, including the role of temperature. We have successfully obtained the phase transition pressure and volume change at different temperatures. In addition elastic constants and bulk modulus of B1 phase of CaO at different temperatures are discussed. Our results are comparable with the previous ones at high temperatures and pressures. The thermodynamical properties of the B1 phase of CaO are also predicted. [...]
The 45S5 Bioglassr and its sintered bioactive glass-ceramic (BGC) have been widely investigated as bone implants, mainly for its ability to bond to hard tissues. However, high temperature treatment is not enough to improve its poor mechanical properties, but compromise its biologically relevant performances. The innovative BGC compositions based on the thermally treated 45S5 Bioglassr were developed by decreasing the P2O5 quantity and adding B2O3 (0-6%) into the Na2O–2CaO–3SiO2- based bioactive glasses (BG). The thermally treated BGCs were fully characterized from the microstructural and mechanical points of view and compared to each other. Their bioactivity and bio-dissolutionwere established by means of in vitro soaking tests. The new B2O3-added 45S5 BG analogues, named NCS-xB, can be transformed to crystalline phase (Na2Ca2Si3O9)-based BGCs of high compactness and bioactivity at a relatively low temperature heat treatment (≤ 900ºC), since their bioactivity is preserved. Our experimental results suggest that the new 45S5 BGC analogues with optimized composition exhibit improved micro- structural and mechanical properties, and are beneficial for making specific products such as porous scaffolds or composites for bone defect repair.
Ingeo® PLA (polylactic acid) knitted fabric was scoured through an exhaust technique. The scouring was carried out with sodium carbonate in the presence of a detergent at various concentrations and temperatures. The scoured fabric was bleached with various oxidative bleaching agents. Bleaching was carried out with hydrogen peroxide, sodium chlorite and sodium hypochlorite. Hydrogen peroxide was applied by exhaust and cold pad batch (CPB) techniques. It was observed that during scouring PLA fabric was degraded at high alkali concentrations and processing temperatures. The scouring temperature above 60ºC proved to be deleterious due to the scouring solution penetrating into the polymer structure and damaged the fiber. Sodium chlorite and sodium hypochlorite caused little damage to the mechanical properties of PLA. Hydrogen peroxide when applied by the CPB technique did not reduce strength appreciably but when applied by the exhaust technique decreased the strength significantly. SEM analysis revealed that hydrogen peroxide caused holes and slit formation in the fiber structure.
New organic/inorganic hybrid fillers were obtained by mechanical modification of magnesium silicate with selected polyhedral oligomeric silsesquioxane and characterized afterwards. MgO ∙ SiO2 was precipitated in a water system. The effect of chemical modification of magnesium silicate surface on their physicochemical properties was determined. Functionalization was carried out with the use of different amount of (1-(3-hydroxypropyl)dimethylsiloxy- 3,5,7,9,11,13,15-hepta(isobutyl)pentacyclo-[9.5.1.13, 9.15, 15.17, 13]octasiloxane). The polypropylene composites of 0.5, 1.0 and 1.5 wt.% modified by 10 weight parts by the mass of the filler were also produced. For the obtained polypropylene composites measurements of the tensile strength, Young’s modulus and elongation at break were performed