Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) modified with toughening agents and surface treated by atmospheric cold...

In this work, we report an eco-friendly strategy to add improved toughness and hydrophilicity to the valuable properties of biobased poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). To increase toughness and hydrophilicity, PHBV was modified with flexible polymers such as polyethylene glycol, poly(3-hydroxyoctanoate), and a biodegradable thermoplastic polyurethane through melt blending, and the obtained blends were surface treated with atmospheric cold plasma. The polymeric modifiers reduced the melt viscosity and storage modulus of PHBV, increasing its toughness. Argon plasma treatment of PHBV and blends' surface led to a strong decrease in the contact angle by 30-55 % and improved surface hydrophilicity due to the formation of polar groups like hydroxyl, amino, and carboxylate. X-ray photoelectron spectroscopy showed that the atomic percentage of nitrogen increased while that of carbon decreased after plasma treatments, indicating important changes in the surface chemistry. Plasma treatment of the PHBV blends led to better cell adhesion and good cell viability as demonstrated by in vitro biocompatibility tests. This facile strategy can be applied to obtain biobased materials for tissue engineering applications.