Preparation And Characterizations Of Flame-retardant Polyamide 6 And Fibers

Polycaprolactam(PA6)fiber is a kind of wide application and good performance synthetic fiber,such as good wear resistance,deformation resistance,resilience and low temperature resistance.However,with the poor flame retardancy and so many melting drops,the application of PA6 is limited.Therefore,the research of flame retardant PA6 has caused the attention of scientific researcher.In this paper,flame retardant MCA/PA6 was prepared via in-situ polymerization.On the basis of the introduction of flame retardant(MCA),silicon dioxide and montmorillonite were introduced in the polymerization system.Then flame retardant PA6 fibers*were obtained by melt spinning.Firstly,MCA was chosen for the flame retardant of PA6.The flame retardant PA6 was prepared via in-situ polymerization and characterized the structure and performance.Then in order to improve the molecular weight of MCA/PA6,the orthogonal experiment was designed.The results showed that the introduction of the flame retardant MCA had the effect of "nucleating agent" and enhanced the crystallization temperature of flame retardant PA6.TG showed the thermal degradation of PA6 was one-step,while flame retardant PA6 was two-step and the thermal decomposition temperature decreased.Flame retardant test showed that flame-retardant PA6 had good flame retardant.The limiting oxygen index was 31.8%and the vertical burned reached UL94-V0 when the flame retardant reached 8%.The results of orthogonal experiment showed that the affecting factors of MCA/caprolactam polymerization were followed by temperature,time,flame retardant dose,open loop dose.Secondly,in order to improve the efficiency of flame retardant and the molecular weight,on the basis of MCA/caprolactam polymerization,silicon dioxide and montmorillonite were introduced into the polymerization and the solid phase polycondensation of MCA/PA6 was to improve its molecular weight.The results showed that the introduction of the two association effect agents didn't affect the in-situ polymerization.TG results showed that the amount of carbon residue raised after the introduction of association effect agents.Vertical combustion showed that the introduction of the association effect agent didn't achieve the ideal effect for the first time,but it was difficult to ignite during the second combustion and the burning time shortened significantly.The results of solid phase polycondensation showed that with the increase of reaction temperature,the reaction rate and molecular weight increased significantly;at the same temperature,the early stage of the reaction the molecular weight improved obviously while the late stage of the reaction increased slowly.In conclusion,190? and 12h were suitable conditions of solid phase polycondensation.Finally,the flame retardant PA6 fibers were prepared by melt spinning process.The mechanical properties,orientation,flame retardant performance were investigated.The results showed that compared PA6 fibers,the orientation and mechanical properties of the flame retardant PA6 fibers were decreased significantly.It attributed to the introduction of the flame retardant which decreased the molecular weight and destroied the regularity of the macromolecular chain.The introduction of the flame retardant had slight impact on surface morphology.The simple burning test showed that flame retardant fabric(hose)had good flame retardancy.