Gallic acid—polyethyleneimine modified UHMWPE fibers with epoxy resin for investigating interfacial properties

In this paper, a safe, non-toxic, and low-cost method was adopted to modify ultra-high molecular weight polyethylene (UHMWPE) fibers. gallic acid (GA) and polyethyleneimine (PEI) were co-deposited on the surface of UHMWPE fibers by Michael addition and Schiff base reaction in an alkaline solution with pH 8.5. The structure and properties were analyzed and characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analyzer (TG), etc. The morphology of the UHMWPE fibers and the degree of firmness of the surface coatings were observed by Scanning Electron Microscope (SEM), and the effects of different mass ratios of GA-PEI on the UHMWPE fibers were investigated. The results showed that the surface active functional groups of the modified UHMWPE fibers increased, and the bending properties and interfacial shear strength of the composites with epoxy resin were significantly improved, with the bending strength and interfacial shear strength increased by 33.1