Electrospinning Mechanism And Experimental Study Of Natural Rubber Latex

With the development of electrospinning technology,electrospun fiber has been widely used in biomedical,energy electronics,environmental protection,chemistry,functional textile and other fields.Electrospinning was divided into two major categories,solution and melt.Among them,solution electrospinning had a wide range of applications due to its simple equipment and fine fiber diameter.In electrospinning,thermoplastic materials were currently used.For thermosetting or elastic materials,spinning was more difficult.Natural rubber is a thermosetting material with unique properties such as high elasticity,high elongation,flexibility,tear resistance,etc.Natural rubber has a low glass transition temperature and strong entanglement and retraction ability between molecular chains at room temperature,which prevents spinning alone.How to mix it or mix it with a certain material to achieve the unique properties of rubber spinning was currently an urgent research topic.In this paper,based on the study of natural rubber forming mechanism and electrostatic spinning mechanism,natural rubber latex/polyvinyl alcohol(NRL/PVA)composite fiber and natural rubber(dissolution)fiber were prepared by solution electrostatic spinning technology,respectively.We had completed the simulation analysis of the variation law of the electric field strength,voltage,receiving distance and spinning needle size of natural rubber latex electrostatic spinning.Through experimental research,the process parameters of natural rubber latex electrostatic spinning were determined and optimized.The optimal ratio of NRL/PVA composite fiber and natural rubber fiber spinning solution was explored.The main work was as follows:1.Two methods of preparing NRL/PVA composite fiber by using polyvinyl alcohol as spinning aid and natural rubber fiber by dissolving in organic solvent were presented.2.The variation law of electric field intensity and voltage,receiving distance and spinning needle size was simulated.It was concluded that the electric field intensity increases linearly with the increase of the spinning voltage.The electric field intensity increased with the decrease of receiving distance,the decrease of needle diameter and the decrease of needle length.3.The effects of different spinning parameters and different NR solid contents on the morphology and properties of NRL/PVA composite fibers were studied.The effect of graphene dispersion(GR)with different volume fraction on the conductivity of NRL/PVA composite fiber was investigated.Within the range of technological parameters set in the experiment,continuous composite fiber could be prepared when the spinning voltage was 20 kV,the receiving distance 20 cm and the feeding speed 0.05 mL ? min-1.The internal crystallization of the fiber was good.The NRL/PVA composite fiber had the best overall morphology,the highest fiber crystallinity,the best molecular chain arrangement regularity and the highest melting temperature of 194.1?,when the solid content of NR in the blended solution was 8%.Through infrared spectroscopy,it was found that NR had no effect on the molecular structure of PVA.The excellent molecular structure performance of PVA was well preserved.The elongation at break of the composite fiber reached the maximum value,and the elongation at break of the fiber reached the maximum value of 100%,when the solid content of NR was 20%.The conductivity of NRL/PVA composite fiber increased by 7 orders of magnitude compared with that without addition,when GR with 10% volume fraction was added.The experimental results showed that the NRL/PVA composite fiber was successfully prepared by using PVA as spinning aid,and the conductivity of NRL/PVA composite fiber was significantly improved by adding GR.4.The effects of different spinning parameters,solvent N,N-dimethylformamide(DMF)on the morphology and properties of natural rubber fiber were investigated.Through the adjustment and optimization of solution concentration and DMF dosage,the optimal experimental parameters of natural rubber fiber spinning were obtained: solution concentration of 3%,voltage of 18 kV,receiving distance of 15 cm.The experimental results showed that continuous fibers could not be formed in the spinning solution without adding the solvent DMF.The homogeneity of the natural rubber fiber morphology and diameter was the best,when the volume fraction of DMF in the mixed solvent was 15%.In summary,when the spinning voltage was 20 kV,the receiving distance was 20 cm,the liquid supply speed was 0.05 mL ? min-1,and the solid content of NR was 8%,the NRL/PVA composite fiber had the best morphology,crystallinity,molecular chain arrangement regularity and the highest melting temperature.The uniformity of natural rubber fiber morphology and diameter was the best,when the solution concentration was 3%,the voltage 18 kV,the receiving distance 15 cm,and the ?DMF 15%.It provides important technological parameters and data analysis for the research and development of natural rubber latex and natural rubber in electrostatic spinning,which has important practical significance.