Preparation and research of GMA/ NMA-containing composite fluorine-free cross-linked water-repellent membrane materials modified by nanoparticles

In response to the growing global restrictions on fluorinated compounds, this study aims to develop an environmentally friendly and durable fluorine-free water-repellent finishing agent for textiles. A series of cross-linked acrylic emulsions were synthesized using MMA as the hard monomer, BA as the soft monomer, ODA as the hydrophobic functional monomer, and GMA and NMA as the crosslinking monomers. The effects of GMA content on the water repellency and emulsion properties were systematically investigated. To further enhance the hydrophobic performance, SiO₂ and TiO₂ nanoparticles were introduced through both composite emulsification and a step-by-step finishing method. The results showed that the optimal GMA content effectively improved the gelation rate, conversion rate, and contact angle of the treated fabric. Nanoparticle modification increased surface roughness, improved wash durability, and enhanced thermal stability, as confirmed by TG and DSC analyses. Among the modifiers tested, PTES achieved the best hydrophobic enhancement with a maximum contact angle of 146 °. Compared with untreated fabric, the spray grade increased from 0 to 4, and the abrasion resistance was markedly improved. This fluorine-free water-repellent system provides a promising alternative to traditional fluorinated agents, offering high water repellency, thermal stability, and fluorine-free and environmentally preferable.