Institute of Fundamental Technological Research

Novel polyurethanes based on synthetic, atactic poly[(R, S)-3-hydroxybutyrate] (a-PHB) and polycaprolactone (PCL) or polyoxytetramethylene (PTMG) diols were synthesized. It was shown that the presence of a-PHB within soft segments reduces crystallinity of PUR. Because of the low melting temperature for polyurethanes with PCL in soft segments, at this stage of work, electrospinning was limited to polyurethanes containing PTMG and a-PHB. Polyurethane containing 80% of PTMG and 20% of a-PHB was electrospun at various parameters from hexafluoro-2-propanole solution, resulting in formation of fibers with the average diameter ca. 2 μm. The fiber diameter decreased with decreasing polymer concentration in a solution and was practically insensitive to the needle-collector distance in the applied range of distances.

polyurethane, polyhydroxybutyrate, electrospinning, scaffolds

The estimation of compostability of different polyurethanes under natural weather depending conditions in compost with active sludge at waste treatment plant was the subject of this study. The incubation of polymer samples took place for a period up to 24 months. The characteristic parameters of compost: temperature, pH, moisture content and activity of dehydrogenases were monitored and their influence on degradation of polyurethanes was discussed. The proper compoststability of polyurethanes was investigated by changes of weight, tensile strength and morphology of polyurethane samples after incubation in environment. The degradation study revealed that the degree of degradation of polyurethanes in the natural environment, like compost, is dependent on their chemical and structural composition.

polyurethanes, degradation, compost