Preparation Mechanism And Experimental Study Of Natural Rubber Composite Fibers Based On Gas Spinning

Large aspect ratio fibers have high specific surface area and high porosity,which show great research and application prospects in filtration,electronics,optics,biomedicine and sensing.Solution air flow spinning is developed on the basis of melt blown technology,which has the characteristics of short duration,convenience,high efficiency,and low cost.On the basis of studying the properties of natural rubber and the mechanism of air flow spinning,this article proposes for the first time a solution air flow spinning method for natural rubber and its composite materials.Through this method,natural rubber elastic fibers,natural rubber/synthetic trans 1,4-polyisoprene blended elastic fibers,cellulose nanocrystals/natural rubber/synthetic trans1,4-polyisoprene composite fiber elastic materials are prepared;We have developed a spinning nozzle and simulated and analyzed the airflow field;Analyzed various factors that affect the process of natural rubber solution air spinning,and studied the influence and correlation of each factor on fiber spinning through variable experiments.Explored the preparation mechanism and optimal process for preparing high-strength elastic fibers,providing theoretical support for the research of micro nano high-strength elastic fibers.The main work of this paper is as follows :(1)The solution airflow spinning method of natural rubber and its composites was proposed for the first time,and the preparation mechanism of natural rubber fiber by airflow spinning was established.The problem of preparing thermosetting elastomer fibers such as rubber was solved.(2)A special spinning nozzle and experimental platform were developed,which solved the backflow phenomenon at the melt blown dual channel nozzle,and realized the goal of spinning natural rubber fibers by rotor spinning.(3)Using a larger liquid supply speed for spinning,the needle diameter limits the increase of fiber diameter when the needle diameter is small;when the needle diameter is large,the liquid supply speed limits the increase of fiber diameter.1)The effect of air flow rate on the properties of natural rubber fibers was studied.The experimental results show that the diameter of the spun fibers decreases with the increase of air flow rate,and the fiber morphology is poor when the flow rate is too large.2)The effect of the rotation speed of the collecting roller on the properties of the prepared natural rubber fiber was studied.The experimental results show that when the’ tension speed ’ is not reached,the spun fiber is in a relaxed state during the collection process and is not stretched.When the rotation speed of the collecting roller reaches the ’ tension speed ’,the faster the rotation speed,the smaller the diameter of the spun fiber,but the network structure of the fiber membrane is reduced.3)The effect of liquid supply rate on the properties of natural rubber fibers was studied.The experimental results showed that the smaller the liquid supply rate,the smaller the fiber diameter,but the lower the fiber continuity and the worse the morphology.4)The effect of needle diameter on the properties of natural rubber fibers was studied.The experimental results showed that the fiber diameter decreased with the decrease of needle diameter when the liquid supply speed was constant.5)The effect of roller pretreatment on the properties of natural rubber fibers was studied.The experimental results showed that the fibers could not be successfully spun when the number of rollers was too much or too little,and the fiber morphology was the best when the number of rollers was 35.6)The effect of spinning solution concentration on the properties of natural rubber fibers was studied.The experimental results showed that the fiber diameter decreased with the decrease of concentration.When the concentration is 4 %,the fiber morphology is the best.(4)The effects of different proportions of natural rubber and synthetic trans-poly-1,4-isoprene(NR / TPI)solution airflow blended fibers and different cellulose nanocrystals(CNCs)additions on NR / TPI solution airflow blended fibers were studied.The experimental results show that:1)For different proportions of NR / TPI solution air-flow blended fibers: with the increase of TPI proportion,the diameter of blended fibers decreased,and the specific surface area and porosity increased;the contact angle of water interface increases gradually.The tensile strength of the blended fiber increased,and the elongation at break decreased.When NR : TPI = 1 : 1,the tensile effect was the best,reaching895.14;the addition of TPI slightly increased the glass transition temperature of the blended fiber,which solved the problem of natural rubber cold flow.2)For NR / TPI solution blended fibers with different cellulose nanocrystals(CNCs)additions: with the addition of CNCs,the hydrophobicity of the fiber membrane decreased,and the water interface contact angle decreased from 112° to104°,a decrease of 7%;the tensile strength increased first and then decreased,and the tensile product reached the best of 1192.36 when the addition amount of CNCs was 1.2phr.The addition of CNCs effectively improved the hydrophilicity and related properties of the fibers.This paper provides a useful exploration for the preparation of elastomer fibers,and also provides more technical solutions and experimental data for the preparation and research of micro-nano fibers in the future.