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

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