Effect of Chitin Nanocrystals on the Formation of Shish-Kebab Crystals in Bimodal Polyethylene Injection Bar

Bimodal polyethylene (BPE)/chitin nanocrystals (CNC) injection bars with various CNC content were prepared to explore the shish-kebab crystal structure of semi-crystalline polymer induced by bio-based nanofiller under flow field. The addition of CNC enhanced the ultimate tensile strength and Young’s modulus of the injection bars. Various characterization techniques were employed to investigate the mechanism of CNC reinforcing BPE injection bars. The wide-angle X-ray diffraction (WAXD) results showed that crystallinity and orientation were slightly increased with the 0.1–0.3 wt % CNC content but decreased in 0.5 wt %. The small-angle X-ray scattering (SAXS) results manifested that shish intensities were increased with the CNC content increasing, which suggests that more chains take part in the formation of shish-kebab crystals. The long period of shish-kebab with the CNC content was also increased firstly and then decreased with the CNC content increasing. The above results indicated that CNC plays a crucial role to promote shish-kebab formation. This research has an important theoretical significance in improving the mechanical properties of BPE industrial production.