Preparation of cellulose nanofibers and their improvement on ultradrawing properties of ultrahigh molecular weight polyethylene nanocomposite fibers

Novel ultrahigh molecular weight polyethylene (UHMWPE)/cellulose nanofiber (CNF) (F₁₀₀CNF_y) and UHMWPE/modified cellulose nanofiber (MCNF^x) (F₁₀₀MCNF^x_y) as‐prepared nanocomposite fibers were successfully prepared by gel‐spinning F₁₀₀CNF_y and F₁₀₀MCNF^x_y gel solutions, respectively. CNF nanofillers with a specific surface area at 120 m²/g and a nanofiber diameter of 20 nm were successfully prepared by proper acid hydrolysis of cotton fibers using sulfuric acid solution. MCNF^x nanofillers were prepared by grafting various contents of maleic anhydride grafted polyethylene (PE_g‐MAH) onto CNF nanofillers. The ultimate σ_f value of the best‐prepared F₁₀₀MCNF^x_y drawn fiber reached 4.5 GPa, which is about 67% higher than that of the UHMWPE drawn fiber prepared without the addition of any nanofiller. To understand the interesting ultradrawing, orientation, and tensile properties of F₁₀₀CNF_y and F₁₀₀MCNF^x_y fibers, Fourier transform infrared, transmission electron microscopic analyses of the CNF and MCNF^x nanofillers, and scanning electron microscopic analyses of profile surfaces of the etched drawn fibers were performed. This is the first work in this area of research wherein very small amounts of MCNF^x nanofillers prepared from cotton fibers were efficiently used as nucleating agents to enhance the ultradrawing and ultimate tensile properties of F₁₀₀MCNF^x_y fibers. Copyright © 2016 John Wiley & Sons, Ltd.