Preparation of Eco-friendly and Durable Hyperbranched Short-chain Fluorinated/Nano-SiO2 Composite Modifier and Superhydrophobic Modification of Cotton Fabric

To address the high bioaccumulation and serious environmental risks of conventional long-chain fluorine-containing textile modifiers, this study prepared perfluoro branched short-chain fluoroalcohol using perfluoroalkyl ethyl acetate as raw material, further synthesized hyperbranched fluorinated polyurethane, and compounded it with nano-SiO 2 to obtain an eco-friendly and durable superhydrophobic composite modifier for cotton fabrics. By regulating the degree of branching of hyperbranched polyurethane and the dosage of nano-SiO 2 , the synergistic optimization of micro/nano structures and low-surface-energy components on the fabric surface was realized. Characterization results showed that the polymer possessed a narrow molecular weight distribution and controllable degree of branching; a moderate degree of branching was more favorable for the full exposure of fluorocarbon segments and stable bonding with cotton fibers. Uniform micro-nano rough structures were formed on the surface of modified fabrics, with a maximum water contact angle of 153.5 ± 0.8° and a sliding angle of 5.0°. The fabric possessed an initial decomposition temperature of approximately 200 °C and favorable air permeability, which meets the requirements of daily applications. It retained excellent hydrophobicity after mechanical abrasion, repeated laundering, acid–alkali immersion, and UV irradiation. This short-chain fluorinated modifier exhibited lower bioaccumulation and toxicity, integrating superhydrophobicity, high durability, and environmental friendliness, and can be used as a green alternative to traditional long-chain fluorine finishing agents.