Flame Retardant Finishing Of Silk And Nylon Fabric Based On Dopamine Surface Modification

In this paper,dopamine modified silk/nylon fabric and its effect on flame retardant finishing were studied.The purpose of dopamine modification is to improve the reactivity between silk/nylon fabric and flame retardants,which can endow the fabric with more durable flame retardancy.Dopamine was applied to modify silk/nylon fabric by exhaustion method.The effect of modification temperature,solution pH,dopamine concentration and time on the fabric modification was investigated to optimize the modification process by testing the color depth of fabric.The optimum modification process was as follows:silk was treated with2g/L dopamine hydrochloride solution at the pH value of 8.5,vibrating at 45^oC for 24 h.And nylon fabric was treated with 1g/L dopamine hydrochloride solution at pH of 8.5,vibrating at 45^oC for 18 h.The color of modified fabric was yellowish brown;it has good laundering ability and light fastness,and has certain anti UV and antistatic properties.Different metal compounds were deposited to silk and nylon fabrics before and after dopamine modification by evaluating the limit oxygen index?LOI?.It was found that dopamine modified silk could complex metal ions,while there was only physical adsorption between pure silk and metal ions with poor washability.The LOI value of dopamine modified fabric treated by MgCl₂ or FeCl₃ could reach more than 29%and 27%after K₂TiF₆ and FeSO₄ treatment.The modified silk fabric treated with FeCl₃ or FeSO₄still has a certain flame retardancy after 15 times washing.However,the effect of nylon fabric treated with different metal compounds was not good.After metal compound treatment,dopamine modified silk fabrics showed reduced heat release rate and total heat release amount and increased thermal stability the char forming ability.Fe³⁺and Fe²⁺could change the color of the fabric and give it a certain resistance to UV.In addition,the surface of the fabric treated with different metal compounds becomes rough and the hydrophobicity was improved.The modification of dopamine could improve the reactivity of nylon fabric,after modification,the fabric was treated with ammonium sulfamate,the effects of ammonium sulfamate concentration,curing temperature and time on fabric burning performance were investigated.The results showed that the charring properties and thermal stability have increased,LOI value reached 37.6%,and the melting drop decreased.