The heterogeneous selective reduction of PHB as a useful method for preparation of oligodiols and surface modification

Abstract

A selective heterogeneous reduction of natural PHB with lithium borohydride as a reducing agent has been described. Despite the method proceeding in a heterogeneous way, it allows obtaining hydroxyl terminated oligomers with low polydispersity, controlled average molecular weight, and defined end groups. The structure of resulting oligomers has been proven by ¹H NMR and mass spectrometry. This method would constitute a source of PHB oligodiols useful in the synthesis of new tailor-made biomaterials. It has also been demonstrated that this simple method may be used to modify the surface chemistry of the polyester by generating free hydroxyl groups on the outermost face. The presence of hydroxyl groups on the polymer surface was confirmed by ATR-FTIR studies as well as contact angle measurement. As expected, the change in surface chemistry improved the hydrophilicity of the polymer surface. Since surface properties are critically important for cell–material interactions, this kind of modification may be a very useful tool in tissue engineering.