Spracovanie a vlastnosti biodegradovatelnych polymerov a ich zmesi

Available from Slovak Centre of Scientific and Technical Information, under shelf-number: A591639 / Slovenska Technicka Univerzita v BratislaveSIGLESKSlovak Republi

Gel-type ion exchange resin stabilized Pd-Bi nanoparticles for the glycerol oxidation in liquid phase

Palladium-bismuth nanoparticles were supported into strongly basic anion-exchange resin of gel-type and tested as catalysts for the selective oxidation of glycerol with molecular oxygen at atmospheric pressure. Detailed study of the precursors preparation and reduction were undertaken. The catalyst 3%Pd-1%Bi where the bismuth was deposited on the palladium particles (3.4 nm) exhibited at 95% glycerol conversion more than 63% yield toward glyceric acid and tartronic acid after 3 h of reaction. The catalyst maintains practically similar catalytic performance as in fresh state for at least five consecutive catalytic cycles without extra catalyst treatment and reactivation. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved

Influence of various starch types on PCL/starch blends anaerobic biodegradation

Research concentrated on the biodegradable capability of PCL blends with various types of starch in an anaerobic aqueous environment of mesophilic sludge from a municipal wastewater treatment plant. For blend preparation, use was made of a native starch Meritena from maize, another from Waxy - a genetically modified type of maize, as well as Gel Instant, a gelatinized starch, and an amaranth starch. Additional PCL/starch blends were prepared from the same starch types, but these were initially plasticized with glycerol. The biodegradability tests were supplemented with thermo gravimetric analysis (TGA), and differential scanning calorimetry (DSC); morphology was identified using scanning electron microscopy (SEM), plus mechanical properties were also tested. While mixtures of PCL with starches plasticized with glycerol exhibited improved mechanical properties and a higher degree of biodegradation in the anaerobic environment, mixtures of PCL with pure forms of starch were ascertained as rather resistant to the anaerobic aqueous environment. TGA and DSC analysis confirmed the removal of starch and glycerol from the PCL matrix. SEM then proved these results through the absence of starch grains in the samples following anaerobic biodegradation. © 2013 Elsevier Ltd. All rights reserved

Changes of physical properties of PLA-based blends during early stage of biodegradation in compost

Three biodegradable plastics materials, namely pure poly(L-lactide) (PLA), PLA with plasticizer triacetine (TAC) and the mixture PLA/polyhydroxybutyrate (PHB) and TAC were investigated concerning changes of physical properties due to biodegradation in compost at 58 °C up to 16 days. With rising time of degradation in compost, both number and weight molecular masses were decreasing progressively, but only marginal change of the polydispersity index was observed which indicates that biodegradation is not random process. FTIR spectroscopy revealed that in spite of the extensive decrease of molecular weight, no substantial change in chemical composition was found. The most significant modification of the spectra consisted in an appearing of the broad band in region 3100–3300 cm−1, which was assigned to a formation of biofilm on the sample surfaces. This effect appeared for all three materials, however, it was much more pronounced for samples containing also triacetine. Measurement of changes in crystalline portion confirmed that amorphous phase degrades substantially faster compared to crystalline part. The plasticizer triacetine is disappearing also rather fast from the sample resulting besides other effect also in a temporary increase of Tg, which at the beginning grows almost to the value typical for PLA without plasticizer but later the Tg is decreasing due to substantial changes in molecular weight. Generally during composting, the samples keep shape for up to 8 days, after that time the material disintegrates to rough powder. © 2018 Elsevier B.V.1/0122/15, SAV, Slovenská Akadémia Vied; APVV 0301-14, APVV, Agentúra na Podporu Výskumu a Vývoja; APVV 0741-15, APVV, Agentúra na Podporu Výskumu a Vývoja; VEGA 2/0108/14, SAV, Slovenská Akadémia ViedSlovak Research and Development [APVV 0301-14, APVV 0741-15]; Slovak Republic Government Education Department; Slovak Academy of Sciences VEGA [2/0108/14, 1/0122/15