Research On Preparation Of Silver Plated Polyamide Fabric Modified By Dopamine After The Calcium Chloride/Methanol Pretreatment

Polyamide(PA6)fibers have such disadvantages as high crystallinity,smooth surface,and difficult to have good interfacial bonding with other polymer materials.Due to these properties,the silver plated fabric which prepared with PA6 have certain restrictions in the coating effect and plating fastness as well.Before the subsequent processing,there must be a modification treatment that conduct on the fiber internal structure and surface properties.The purpose is to decrease the crystallinity of PA6 fibers and to get more reactively active group.We also need catalytic activity on the surface and sediment layers in PA6 fibers.Traditional pretreatment method is using chromic acid to coarsen the surface,meanwhile,using colloidal palladium to get the surface activated.This method has been used for a long time and the process has been very mature.However,the chromic acid belongs to the dangerous goods with irritation and carcinogenicity that are harmful to the environment and to the human.Colloid palladium glue lose activity easily when in reaction.Alkaline ion palladium also has problems as precipitation,high price and high cost for production.In view of the above situation,this study used PA6 fabrics as base materials.First,carried on the pretreatment by using calcium chloride/methanol solution system.The fibers’ internal structure and surface morphology would change by this step.Then,put further modification with the special properties of dopamine as adhesion and reducibility.Meanwhile,get the silver layer that played a connection and catalytic role between the silver plating and the fabric.It had laid a solid foundation for the preparation of conductive fabric which had better performance and ideal combine fastness.The study also concluded the optimal experiment scheme selection.The main contains of this study are as follows:1.Explored the modification effect by calcium chloride/methanol solution system of the PA6 fiber structure.The study also delved into its influence factors.It concluded that the optimal parameters are calcium chloride concentration of 20 g/L,processing time for 60 min.Ultrasound can effectively improve the efficiency of processing.The modification effect would achieve best result when the ultrasonic time is 30 min.2.Using the special properties of the dopamine to improve the combine fastness between subsequent silver layer and the fabric.It concluded that the optimal parameters are dopamine concentrations of 2 g/L,polymerization time for 24 h.Proceeding in-situ reduction for silver particles with dopamine as a substrate.We got the middle layer for connection and catalysis.In terms of loading ways of the dopamine,the study put forward and explored three methods as the siphon method,the oxidant method and the one-step method.Thus the optimal modification plan would be concluded.3.Characterized of the plating silver fabric performance after the pre-treatment and the modification.On this basis,the study explored the effect factors in the silver plating process included both activation and plating.Got the optimal scheme of silver plating process that fits with the own characters of PA6 fibers or fabrics.4.Compared the performance of calcium chloride/methanol pretreated and dopamine modified PA6 silver plated fabric with the traditional silver plating fabric,which could lead to the result that the silver layer produced by former method is more uniform and complete.The tensile properties,conductive performance,coating thickness and coating fastness of the fabric had been improved.