Increasing plastic waste generation has become a pressing environmental problem. One of the most produced waste plastics originates from post-consumer packaging, of which PET constitutes a significant portion. Despite increasing recycling rates, its accumulation has created a need for the development of new recycling methods that can further expand the possibilities of recycling.
View Article and Find Full Text PDFThis paper presents an overview of the chemical recycling methods of polyethylene terephthalate (PET) described in the scientific literature in recent years. The review focused on methods of chemical recycling of PET including hydrolysis and broadly understood alcoholysis of polymer ester bonds including methanolysis, ethanolysis, glycolysis and reactions with higher alcohols. The depolymerization methods used in the literature are described, with particular emphasis on the use of homogeneous and heterogeneous catalysts and ionic liquids, as well as auxiliary substances such as solvents and cosolvents.
View Article and Find Full Text PDFThe synthesis of selected polyoxyethylene-polyoxypropylene block copolymer (poloxamer) fatty acid monoesters is presented. Organotin homogeneous catalyst Sn (2-ethylhexanoate) effectively catalyzed the esterification reaction of (EO)-(PO)-(EO) block copolymer (poloxamer) with fatty acids. The reaction proceeded in high yield and high selectivity to monoesters.
View Article and Find Full Text PDFStudies on the synthesis of esters of natural origin fatty acids (oleic acid) and a branched synthetic isostearic acid derived from oleic acid with commercially available selected higher polyols in the presence of homogeneous metallic catalysts have been carried out. The effects of the synthesis temperature, molar ratio and the catalysts amount have also been studied. It was shown that higher fatty acid conversion and selectivity to tri- and tetraesters were obtained for organotin catalyst Fascat 2003, which was used as the esterification catalyst.
View Article and Find Full Text PDFPerfluoroalkylglucosides comprise a very important class of fluorine-containing surfactants. These compounds can be synthesized by using the Fisher reaction, starting directly from glucose and the required perfluoroalcohols. We wish to report on the use of zeolite catalysts of different structure and composition for the synthesis of perfluoroalkylglucosides when using glucose and 1-octafluoropentanol as substrates.
View Article and Find Full Text PDFNew task-specific ionic liquids, hydroxy-functionalized 1-methyl-3-alkylimidazolium hydroxides, were used as catalysts in the transesterification of rapeseed oil with methanol. In comparison to the well-described 1-methyl-3-butylimidazolium hydroxide [bmim]OH, the new ionic liquids show unexpectedly high catalytic activity. In case of the ionic liquid [glymim]OH, which is structurally similar to glycerol, the conversion of rapeseed oil was nearly 100 %.
View Article and Find Full Text PDFThe synthesis of new 2-methylfuran-based alcohols is described. The odor and physicochemical characteristics of all new compounds are also presented.
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