Preparation And Properties Of Nylon 46

Polyamide 46(PA 46)is a kind of polyamide with very excellent performance,which was widely used in cars and electronics industries.However,the study of PA46 is still at the early stage at domestic,and with the development of science and technology,the performance of pure Polyamide 46 is already difficult to meet the demands.Nanocomposite is one of hot topics in the current material science areas.Recently,as a new form of carbon,graphene sheets which possess excellent physical and chemical properties have become an important direction in the composite research.Based on these reasons,graphene oxide(GO)was prepared by oxidation of graphite using the Hummers method,and its morphology,dispersion situation and the degree of oxidation were characterized.Then,PA46 was synthesized in the presence of rare earth catalysts,the resulting polymers were characterized,and the polymer formation experimental conditions,such as pre-polymerazation temperature and time,post-polymerazation temperature and time,the kind and contents of catalysts.The optimum experimental conditions of PA46formation as follows:(1)2.75g 1,4-butanediamine and 4.5g adipic acid were added in 130ml NMP,kept the temperature in 70℃ for 20min,then kept the temperature in 100℃ for 1h,next,0.8%(wt)Lan(OTf)3 was added,and raised the reaction temperature to 150 oC for 2h,to 170℃ for 2h,after the reduced pressure distillation,the preploymer was prepared.(2)the prepolymer reacted in the round bottom flask in 255℃ at the pressure of 100 pa for 4h to get the polymer.At last,Using graphene oxide(GO)and PA46 as raw materials,PA46/graphene oxide nanocomposite were successfully prepared by a solution mixing technique.the combination properties of composite were investigated y transmission electron microscopy TEM,X-ray diffraction XRD,differential scanning calorimeter DSC,Dynamic thermo-mechanical analyzer DMA,thermo-gravimetric analyzer TGA,respectively.The research results were listed as following:Transmission electron microscopy showed nanoscale dispersion of GO within the PA 46 matrix.XRD and DSC analysis results indicate that the addition of graphene Oxide has a great influence on crystal morphology and increase crystallinity,crystallization temperature and crystallization rate,but has no influence on the crystal form.All of these may because that the addition of graphene enhances the crystallization of the matrix as nucleating agent.DMA analysis result shows that dynamic mechanical property of nanocomposites were improved.TGA analysis result shows that the thermal stability of nanocomposites were also improved.The increase of thermal stability of composite materials,may be because of dispersed GO with excellent thermal stability,forming a protective layer in the PA46 matrix.Not only GO content but also dispersed state in the matrix efect the thermal stability of composite materials.