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Polymer resins, such as polyester-, polyurethane- and alkyd resins are frequently applied as binder component in paints, printing inks, coatings or materials for additive manufacturing. Besides aliphatic building blocks with different chain lengths, cyclic monomers are used as starting materials, to increase the hardness of the resulting coatings materials. For this, mostly aromatic compounds derived from petrochemical sources, such as phthalic anhydride, isophthalic acid or terephthalic acid are being used. Monomers from renewable resources with similar chemical structures and chemical properties are scarce. In this study, (1R,3S)-(+)-camphoric acid is used as alternative building block for UV-curing polyester resins derived from itaconic acid and 1,6-hexanediol. The properties of both resins and final materials are compared to similar resins derived from isophthalic acid. In both cases, the incorporation of the cyclic monomer led to an increase in glass transition temperature, as well as viscosity of the resins. Thermal as well as mechanical properties of the cured materials were also improved in comparison to a resin without any cyclic building block incorporated.

Recently, itaconic acid has drawn considerable attention as a novel radical-curing building block for polyester resins. These bio-based materials have been used in thermal, as well as ultra violet (UV) curing applications, such as printing inks or coatings. Poly(ester amide)s from itaconic acid could be very interesting, as the amide group could alter the properties of the resins as well as cured materials. However, standard polycondensation reactions with diamines are not possible with itaconic acid as the amines preferably react via an aza-Michael addition at the &alpha, &beta, unsaturated double bond. Therefore, alternative and more elaborate synthetic strategies have to be developed. Herein, we present two different synthetic strategies to poly(ester amide)s from itaconic acid that circumvent the addition reaction of the amines. This is in both cases done by a pre-reaction to form stable amide building blocks that are then reacted with itaconic acid or polyesters derived thereof. The structural composition and the properties of the resin are characterized, and the UV-curing reactivity is examined. All properties are compared to corresponding polyesters from itaconic acid.