Suberin is a natural polyester with aromatic and aliphatic domains, and occurs naturally in cork. With this composition, cork has excellent barrier properties combined with elasticity and low thermal conductivity. It is also antimicrobial and resists rotting, yet it is ultimately degradable. Despite this rich property profile, the uses of cork are limited as it can only be processes by rather crude methods, and because of insufficient availability. Thus, block copolymers with suberin-like structure that can be easily molded or cast into films are attractive bio-inspired materials with a range of potential applications.
The target polymers were synthesized from poly(pentadecalactone) as the aliphatic block, and different aromatic blocksL poly(2,3-dihydro-5H-1,4-benzodioxepin-5-one), oligo(polyethylene furanoate), and poly(2-hydroxyl cinnamic acid). We here report the synthesis and characterization of these new block copolymers, as well as their processing into polymer coatings. The polymer structures were confirmed by 1D and 2D NMR, FTIR, GPC an DSC. Atomic force microscopy studies revealed that the morphology of these block copolymer materials was distinctly different than that of either parent homopolymer, yet only a weak tendency towards nanophase separation was observed. Nevertheless, the coatings had a pronounced antibacterial activity against Escherichia coli and Staphylococcus aureus, and could thus make interesting coating materials for medical devices.