Strong yet tough, excellent thermal resistant and UV-Protective Polydopamine/Poly(vinyl alcohol) composites via hydrogen-bonding interaction

Abstract

Strength and toughness are regarded to be mutually exclusive in polymeric materials. Herein, highly strong and tough polymeric materials, which simultaneously combined excellent heat resistance and UV-shielding function, were obtained by in-situ polymerization of dopamine in the presence of poly (vinyl alcohol) (PVA) solution based on hydrogen bonding interaction. Polydopamine (PDA)/PVA composites were prepared by a conventional solution-casting method. Strong hydrogen-bonding interaction between PDA and PVA was demonstrated by Fourier transform infrared (FT-IR) spectroscopy and rheological test. It is found that the addition of 2 wt% PDA has 42.6% and 104.9% increase in strength and toughness respectively compared with neat PVA. More importantly, the maximum thermal decomposition temperature of PDA-2 wt% composite was up to 389.0 °C with a remarkable increment of 79.4 °C. Accordingly, the decomposition activation energy of PDA-2 wt% composite was much larger than that of PVA. Additionally, unlike those fillers such as graphene and carbon nanotube, PDA-2 wt% composite was transparent in visible region but obviously blocked ultraviolet (UV) light. This work offers a simple and facile strategy to prepare strong, tough, thermal stable and UV-blocking polymeric materials, which will expand their applications in high-grade packaging and tissue engineering.