Polyester isosorbide succinates are biobased terpolyesters from succinic acid, isosorbide and either 2,3-butanediol or 1,3-propanediol, containing at least 60 - 70 % of isosorbide, having molecular weights and glass transition temperatures suitable for thermosetting powder coating applications.
Provided that isosorbide of high purity is used, these coatings are transparent and colorless. This, in combination with their excellent mechanical properties, makes polyester isosorbide succinate very promising material for coating applications. Due to the high attainable Tg values, these renewable polyesters can be used in powder coating formulations. Accelerated weathering experiments have shown that isosorbide-based coating systems appear to have similar weathering resistance as commercially available terephthalic acid-based formulations.