有机硅改性聚氨酯无氟疏水涂层的制备与性能OA

Polyethylene terephthalate(PET)fabrics find wide application in apparel,home textiles and industrial textiles for their high strength,high modulus and excellent wear resistance.PET fibers show strong surface chemical inertness and lack reactive groups.Commercial PET fabrics easily undergo wicking after alkali reduction treatment.Liquids penetrate and diffuse rapidly along fabric capillaries in this process,and this issue severely restricts their functional applications in waterproof and antifouling fields.Existing hydrophobic modification technologies(e.g.,fluorinated compound coating,and nanoparticle deposition)enjoy wide application.However,they have obvious drawbacks:environmental risks of fluorinated reagents,cumbersome preparation processes and insufficient coating durability.Thus,developing a fluorine-free,efficient and durable hydrophobic modification technology for PET fabrics becomes an urgent research demand. This study modifies polyether-based isocyanate-terminated polyurethane prepolymers with γ-aminopropyltriethoxysilane(KH550)and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane(KH792).It constructs modified polyurethane(SiPU)hydrophobic coatings on PET fabric surfaces via electric wire-wound bar coating technology.The study characterizes the chemical structure and surface morphology of SiPU coatings by Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS).It also systematically tests the core properties of modified fabrics in accordance with relevant standards,including hydrophobicity,antifouling performance,moisture permeability,air permeability,wear resistance and washing durability.The water contact angle of modified fabrics exceeds 130°.Their wicking height decreases significantly from 12.85 cm(pristine sample)to 1.00 cm and 0.30 cm,indicating a remarkable improvement in hydrophobic and anti-wicking properties.Modified fabrics exhibit excellent antifouling performance against liquid and solid contaminants.Their air permeability shows no significant difference from that of pristine fabrics,and their moisture permeability remains at a practical application level.EDS analysis verifies a sharp increase in N and Si contents on the surface of modified fabrics.The N and Si contents in SiPU2 samples reach 6.36%and 1.06%,respectively,proving a better coating adhesion effect of SiPU2 than SiPU1.SEM observation reveals that SiPU coatings uniformly cover fiber surfaces and do not block the weaving pores of fabrics.This structural feature provides stable support for the air permeability of modified fabrics.Durability tests show that the water contact angle of SiPU2 remains greater than 110° after 40 friction cycles and stays greater than 130° after 20 washing cycles.SiPU2 thus exhibits significantly better wear resistance and washing durability than SiPU1.This advantage stems from the dual amino functional groups of KH792.The groups form more reactive sites with polyurethane prepolymers,construct dense cross-linked networks and enhance the bonding force between coatings and fibers. This study confirms that the"polyurethane primer-silane coupling agent hydrophobic modification"composite strategy effectively improves the hydrophobicity,antifouling performance and coating durability of PET fabrics.The preparation process is simple and requires no complex equipment.It involves no fluorinated or toxic reagents,thus conforming to the development requirements of green manufacturing.This strategy provides a new technical route for the industrial preparation of functional fluorine-free hydrophobic PET fabrics.