Regulating the mechanical properties of poly(1,8-octanediol citrate) bioelastomer via loading of chitin nanocrystals

Abstract

Chitin nanocrystal (ChiNC), a biocompatible and biodegradable nanofiller, was used to regulate the mechanical properties of poly(1,8-octanediol citrate) (POC) elastomer. The facile casting/evaporation method was utilized to prepare ChiNC/POC nanocomposite and its structure and properties were characterized by Fourier transform infrared spectroscopy, wide angle X-ray diffraction, scanning electron microscopy, dynamic mechanical analysis, uniaxial tensile test and static water-contact-angle analysis. The results showed the ChiNCs were uniformly distributed in the POC matrix at any test loading ratio and proved to be chemically bonded to the POC network, leading to a gradually increasing tensile modulus and strength, concomitantly without causing damage to elongation at break. Thus regulation of the strength and modulus of POC by loading with ChiNCs can be realized. Furthermore, the incorporation of ChiNCs into POC networks provided more hydrophilicity and the equilibrium swelling degree in PBS buffer was as low as 11%, which is in favour of in vivo usage.