Preparation of Nanolignocellulose/Chitin Composites with Superior Mechanical Property and Thermal Stability

Abstract

To resolve the issues of special processing equipment, cumbersome process flow and high cost of the composite material. The poplar wood fiber was used as the raw material, which were effectively crosslinked with chitin by the simple mechanical thermal rubber milling method, then the high performance nanolignocellulose/chitin composite were obtained by the binderless hot-press method. The nanostructure, chemical structure, surface composition, and thermal stability of nanolignocellulose/chitin composites were investigated by the scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and thermogravimetric/ differential thermogravimetric (TG-DTG), respectively. Results turned out that the nanolignocellulose was laminated by the grinding and the composite material appeared layered structure after the binderless hot-pressing. Chitin/chitosan from crab shell powder can be effectively crosslinked with nanofibrillarized lignocellulose to increase the contact area of surface hydroxyl groups. The static bending strength (MOR), modulus of elasticity (MOE) and internal bonding strength of the nanolignocellulose/chitin composite were 34.13 MPa, 7072 MPa and 0.97 MPa, respectively. Meanwhile, the swelling value of thickness after water absorption was only 9.27%, demonstrating the dimensional stability. According to the profile density distribution, the density of nano-lignocellulose/chitin composites was relatively uniform, which indicates that the preparation process is reasonable. The nanolignocellulose/chitin composite has excellent thermal stability, since the mass loss of pyrolysis process is lower than the untreated binderless fiberboard. In this study, a new and effective methods for preparing composite materials was proposed, which provides some research ideas and theoretical guidance for the efficient development of new nanolignocellulose composite and waste marine arthropod materials.