Preparation And Characterization Of Ionic Liquid Plasticized Nylon 6

The high performance of PA6 fiber has been a hot topic in the research of PA6 fiber performance improvement.Because the hydrogen bonding force between PA6 macromolecules is too strong,HSHMPA6 can not be prepared by super drawing.At present,most researchers use Lewis acid,rare earth and iodine to modify PA6 in order to shield the hydrogen bond between PA6 macromolecules,weaken the hydrogen bond force between the PA6 chains,improve the activity of the PA6 molecular chain and the mechanical properties of the PA6 fibers.Part of the current research mainly aims at the issue that whether the plasticizer added in PA6 can destroy the hydrogen bonding between PA6 chains.Ionic liquids are used as plasticizers of PA6 in the paper.(1)The interaction between different contents of ionic liquids([BMIM]BF4(1-butyl-3-methyl imidazole tetrafluorate)and [BMIM]PF6(1-butyl-3-methyl imidazole))with PA6 were studied.The PA6 plasticized films with different contents of ionic liquid(0.5 wt %,1.5 wt % and 2.5 wt %)were prepared by ionic liquid [BMIM]BF4 and [BMIM]PF6 with PA6 respectively by the method of cosolvent.The differences in hydrophillic nature,thermal stability,crystallization ability,surface morphology,functional group absorption peak and the the crystal position between PA6/BF4 and PA6/PF6 were compared.The results indicated that the interaction force between PA6 chains and molecules was weaken and the ordering of PA6 molecular chains was destroyed by ionic liquid [BMIM]BF4 or ionic liquid [BMIM]BF6.(2)The effect of ionic liquid [BMIM]PF6 on the structure and properties of plasticized PA6 fibers was studied.Ionic liquid([BMIM]PF6)was preferred to plasticize PA6 and then melt granulate and spin by comparing the effects of ionic liquid [BMIM]BF4 and ionic liquid [BMIM]PF6 on PA6.Three plasticized PA6 fibers containing ionic liquids of 0.5 wt %,1.5 wt % and 2.5 wt % were prepared.The differences in thermal stability,degree of orientation,crystallization ability,mechanical properties and other structure and performance between plasticized PA6 fibers and PA6 fibers were compared.The results indicated that the breaking strength of 2.5 wt % plasticized PA6 fibers increased by 25.45 % compared with PA6 fibers.The Tm of the plasticized PA6 fibers decreased by 6 oC.The Tg of the plasticized PA6 fibers decreased by 10 oC.The plasticized effect was the best.(3)The changes of the structure and performance of plasticized PA6 fibers after washing and plasticized PA6 fibers were studied.The differences in structure,thermal stability,mechanical properties and other performance between plasticized PA6 fibers which were washed in water and plasticized PA6 fibers were compared.The results indicated that hydrogen bonds may be reformed between molecular chains after plasticized PA6 fibers which were washed in water.The breaking strength of PA6/PF6-1.5 % fibers which were washed in water were higher than un-plasticized PA6 fibers.In the end,the paper summarizes the whole work and analyzes the main problems.