Sustainable polyesters for powder coating applications from recycled PET, isosorbide and succinic acid

Abstract

A new method for the synthesis of polyesters that combines the chemical recycling of poly(ethylene terephthalate) (PET) with the use of monomers derived from renewable resources, such as isosorbide and succinic acid, has been developed. A kinetic study has been performed in order to determine the best catalyst for PET depolymerisation with isosorbide and for the subsequent polycondensation of PET oligomers with succinic acid. Using the correct amounts of isosorbide and succinic acid it is possible to obtain polymers which well fit the properties (glass transition temperature and end-group composition) necessary for powder coating applications. The coating produced using this new environmentally friendly approach presents applicative properties similar, and in some cases superior, to those of a commercial coating obtained from non-renewable resources.

Powder coatings for indoor applications from renewable resources and recycled polymers

“…20 However, it is well known 10 that the chemical nature of the polyester and the characteristics of its end-groups are responsible for the final coating performances in terms of UV stability, gloss, hardness, and adhesion to the substrate. Moreover, powder coatings for indoor applications must face demanding conditions such as the exposure to solvents, to moisture, and to scratches while maintaining good aesthetic characteristics (gloss, color, etc.)…”

“…For this reason, a moredetailed study on the effects of all these variables on the final performances of the coating is necessary along with the analysis of more properties that are of fundamental importance for indoor application (e.g., adhesion, solvent resistance, boiling water resistance, surface hardness, scratch resistance, etc.). For these reasons, the aim of the present article is the preparation of a new set of polymers, prepared following the synthetic method previously described, 20 based on the use of recycled PET with isosorbide, and the evaluation of their performances in indoor applications.…”

Degradation of Poly(ethyleneterephtalate) Waste to Obtain Oligomers Using a Zinc Complex as Catalyst

“…The PET bottles are discarded in huge quantities, originating a serious ecologic problem because they accumulate in the environment, such as, sewer system obstruction and its accumulation in green areas prevents the natural growth of plants. Therefore, there is a growing interest in recycling PET by degradation as a partial solution to the solid waste problem, PET waste degradation consists of the decomposition by chemical agents to obtain monomers and oligomers as raw materials for the syntheses of polyesters or employed as precursors for high molecular weight polyurethanes 1 , polyester 2 and other specific uses 3 . PET can be recycled by chemical depolymerization using diols, alcohols, water and even ethanolamine 4,5 and diethanolamine as depolymerizing agents 6 .…”

Green antimicrobial coating based on quaternised chitosan/organic montmorillonite/Ag NPs nanocomposites

“…In comparison with liquid coating, powder coating with no emission of volatile organic compounds and energy saving merits is a green coating technique, aiming to meet the market demands [2,3]. And the utilisation of environmental-friendly resources in powder coating technology would offer a 'green C green' solution to the current coating industry [4][5][6]. Powder coatings employed in medical and consumer products including medical devices, food packages, household appliances, building materials and so forth require sterile, therefore the addition of innoxious antimicrobial agent with excellent antibacterial activity is much in demand [7][8][9].…”