Durable Antibacterial Finishing on Kapok Fibrous Nonwovens with Polydopamine/PEI Assisted Immobilization of Silver

As a natural cellulose fiber, kapok fiber is much easier to degrade due to its thin wall structure of fiber in the process of storage and use. In this work, a finishing modification was designed and developed to prevent kapok fiber from degradation. Dopamine was polymerized in situ and deposited on the surface of kapok fiber, which was operated in the mixed solvents of ethanol:water (1:1 in volume) to overcome the strong buoyancy. Polyethyleneimine (PEI) was introduced to assist dopamine polymerization and improve the load rate. An optimum dosage, 1.0 g/l of PEI could afford the highest loading rate of 32.1% of polydopamine (PDA), and remarkably improve loading fastness. As a multi-amino polymer, PEI could reduce Ag+ and chelate with metal silver (Ag). The PDA/Ag covered kapok fiber and nonwovens showed good antibacterial activity and better mechanic strength, which would be more suitable for durable oil absorption and sound absorption materials than pure kapok fiber.