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Poly(ethylene terephthalate) (PET), as one of the most used engineering thermoplastic, has wide application in automobile industry, electrics, food packaging, bottle containers and textile industry, causing the increase of the world consumption of PET twice in a period of ten years [1]. The widespread use of PET imposes solution of the plastic waste problem through recycling and reprocessing method classified as primary, secondary, tertiary and quaternary recycling [2]. The products of tertiary PET recycling, especially glycolytic PET depolymerization

The glycolytic recycling of waste PET presents a challenge for the production of secondary value-added products, such as alkyd resins. A way to overcome unsatisfactory mechanical, drying and chemical resistance properties met with alkyds obtained from difunctional glycolyzates, was proposed. Waste PET was glycolyzed using multifunctional alcohols: glycerol (G), trimethylolethane (TME), trimethylolpropane (TMP) and pentaerythritol (PE), giving tetra-and hexa-functional glycolyzates and, for comparison, using diethylene glycol (DEG), propylene glycol (PG) and dipropylene glycol (DPG) giving di-functional glycolyzates. The obtained glycolyzates were examined by 1 H and 13 C NMR, FTIR spectroscopy and elemental analysis and further used in the synthesis of alkyd resins. The properties of the prepared alkyd resins (acid, hydroxyl and iodine values, color, average molar masses and molar mass distributions, viscosity, drying time, hardness, flexibility, gloss, adhesion and chemical resistance) were investigated with respect to the functionality and the structure of the used glycolyzates. Alkyd resins derived from multifunctional glycolyzates (TME and TMP) showed considerably enhanced properties compared to those produced from difunctional glycolyzates and also to conventional general purpose resins.Please do not adjust margins Please do not adjust margins decreased the branching degree. Future work on this matter will involve the preparation, analysis and application of lacquers, paints and anticorrosive coatings based on the presented alkyd resins.

Unsaturated polyester resin (UPe)-based nanocomposites and fumed silica Aerosil R812S, R805 and R816, and R200 modified with phenyl terminal group, R200NPh, were prepared. UPe resins were synthesized from maleic anhydride and products of glycolysis, obtained by polyethylene terephthalate depolymerization with dipropylene glycol in the presence of tetrabutyl titanate catalyst. The obtained unsaturated polyesters were characterized by acid, hydroxyl, and iodine values and by FTIR and NMR analysis. The microstructural analysis of the prepared nanocomposites, performed by using transmission electron microscopy, confirmed that silica nanoparticles formed chain-like aggregates in the polymer matrix. The presence of modified silica nanoparticles had no influence on the glass transition temperature and thermal stability of polyester matrix.

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