Effects of polysiloxanes with different molecular weights on in vitro cytotoxicity and properties of polyurethane/cotton–cellulose nanofiber nanocomposite films

Abstract

A series of polyurethane/cotton–cellulose nanofiber nanocomposite films are manufactured using amino-terminated polydimethylsiloxane (H₂N-PDMS-NH₂), polycarbonate diol (PCDL), isophorone diisocyanate (IPDI), and dispersed cotton–cellulose nanofibers (c-CNF). The heat resistance, hydrophobicity, mechanical properties, surface morphology and effect on cells of the film are studied. The results show that as the molecular weight of H₂N-PDMS-NH₂ increases, the heat resistance and hydrophobicity of the material improve, and when the molecular weight is 4000, its surface free energy reaches 14.9 mJ m⁻². This is mainly because an increase in the molecular weight of H₂N-PDMS-NH₂ changes the chemical structure of the polymer and increases the possibility of low surface energy Si enrichment on the surface. In addition, the cell viability reaches 78.31% in the MTT experiment, which may be related to the biocompatibility of H₂N-PDMS-NH₂. The relative hemolysis rate of the polymer material to red blood cells is less than 2%, and also shows lower adhesion to platelet cells, which may be related to the hydrophobicity of the surface.