Synthesis of a cationic, waterborne organosilicone/castor oil-modified polyurethane and its application in dust-repellent and color-deepening fabric coatings

Current fabric coatings struggle with limited functionality, poor synergistic performance, insufficient durability, and inadequate environmental sustainability. This study developed a cationic waterborne polyurethane (SiWPU) fabric coating using polydimethylsiloxane (PDMS) as the functional modification unit and castor oil as the branching unit. The coating was systematically characterized for its chemical structure, stain resistance, color-deepening effect, antibacterial properties, mechanical properties, and abrasion resistance. The prepared SiWPU emulsion exhibits excellent stability, and increasing PDMS content enhances the film's thermal stability and hydrophobicity, achieving a maximum water contact angle of 102.1°. The coated fabric exhibits outstanding stain- and dust-repellent properties, with a notable enhancement in surface color strength (K/S) of up to 20.7%. It also demonstrates strong resistance to friction and washing, along with good resistance to acids and alkalis. Moreover, the coating delivers robust antimicrobial activity, with inhibition rates exceeding 90% against both Staphylococcus aureus and Escherichia coli , meeting antimicrobial standards.