Flame Retardant Treatment Of Dopamine Modified Polyester/Cotton Blended Fabric Via Electrostatic Layer-by-Layer Self-assembly Method

In this paper,sodium phytate and chitosan were deposited alternatively onto dopamine modified polyester/cotton blended fabric via electrostatic layer-by-layer self-assembly method.The aim of this reseach is to develop an eco-friendly flame retardant system for polyester/cotton blended fabric by suppressing its "candlewick effect"First,one-factor-at-a-time method was used to optimized the technological parameters of dopamine modification for polyester/cotton blended fabric by evaluating the color strength(K/S value)of modified fabrics.The optimum process is that the add on of dopamine hydrochloride was 1.5 g/L.Fabrics were immersed into above dopamine solution with liquor ratio 1:80 and pH value of 8.5 at 45? for 24 h.After modification,the fabrics were covered with a dark brown coating which is laundering durable.After 30 laundering cycles,the fabrics still had the rating of 4-5 for color fastness to washing.Second,sodium phytate and chitosan was alternatively deposited onto dopamine modified polyester/cotton blended fabric via electrostatic layer-by-layer self-assembly method.The optimized technological conditions was selected by evaluating the limiting oxygen index(LOI)of treated fabrics as follows: fabrics firstly were immersed into sodium phytate solution(1.5%,pH=2)for 15 min at room temperature followed by water rinsing,then immersed into chitosan solution(1%,pH=5)for 15 min followed by water rinsing.After finishing the first bilayer,fabrics were repeated the above treatment instead that immersing time changed to 5 min.After 15 bilayer deposition,fabric had good flame retardancy with LOI of 28.7%.The results showed that dopamine modified polyester/cotton blended fabric had higher weight gain than unmodified fabrics which showed that dopamine modification can improve the depositon of flame retardant.Finally three kinds of polyester/cotton blended fabric with different blended ratio were treated with aboved optimized treatment conditions.And it is still compared the flameretardant property and mechanical property of treated samples in this paper.The results showed that char length,heat release rate were significantly reduced which can reduce the burning risk during combustion..With the increase of cotton component,weight gain rate,breaking strength,the LOI value and char residue had increased accordingly.The mechanism of the flame retardant treatment acted as intumescent flame retardant system by more char forming in condensed phase.