Preparation and performance study of a reactive polyurethane hot-melt adhesive/CS-Fe₃O₄ magnetic nanocomposite...

Magnetic nanoparticles are attracting significant attention for their wide application as biomaterials and magnetic storage materials. As an environmentally friendly adhesive, reactive polyurethane hot-melt adhesive (PUR) is a biocompatible polymer with a wide range of applications. In this paper, chitosan (CS)-surface-modified magnetic Fe₃O₄ nanoparticles were synthesized by the sol-gel method. Surface modification of the Fe₃O₄ nanoparticles with CS enhanced their mechanical properties in PUR. The nanoparticles were characterized by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses, while their surface morphology was elucidated using scanning electron microscopy (SEM) and projection electron microscopy (TEM) techniques. Subsequently, PUR/CS-Fe₃O₄ magnetic nanocomposite films were prepared using an in situ method, wherein different amounts of CS-surface-modified magnetic Fe₃O₄ nanoparticles were doped into the PUR and coated on the films. The thermal, UV resistance and mechanical properties of the PUR/CS-Fe₃O₄ magnetic nanocomposite films were investigated by TGA, UV spectrometer and tensile testing. CS-Fe₃O₄ nanoparticles were successfully prepared using the sol-gel method and CS to modify the surface of the Fe₃O₄ nanoparticles. The results show that the mechanical properties and UV resistance of PUR/CS-Fe₃O₄ magnetic nanocomposites are improved by almost 50%, so the constructed PUR/CS-Fe₃O₄ magnetic nanocomposites have good UV-resistant properties and mechanical properties. The as-synthesized CS-Fe₃O₄ magnetic nanocomposites show great potential for application to mechanical and textile development.