Investigation Mechanism Of Melt Differential Centrifugal Electro Spinning And The Preparation Of Polyphenylene Sulfide Ultrafine Fibers

Centrifugal electrospinning is a new method of preparing ultrafine fibers which combines centrifugal spinning with electrospinning.At present,the research on melt centrifugal electrospinning mainly focuses on equipment and technology,and the specific mechanism of fiber formation is still unclear.Polyphenylene sulfide(PPS)is a high-performance heat-resistant material.PPS fibers are always used in dust-proof filter bag At present,PPS fibers are mostly prepared by melt-blown method in industry,but the diameter of the fibers prepared by melt-blown method is thicker and the distribution is not uniform,which affects the performance of the fiber membranes.In this paper,the mechanism of centrifugal electrospinning is studied,and the preparation of PPS ultrafine fibers by electrospinning is explored,which provides a new way for the preparation of PPS ultrafine fibers.In order to obtain the best fibers,it is necessary to clarify the influence ofspinning parameters on fiber diameter in centrifugal electrospinning process.Therefore,the spinning mechanism of centrifugal electrospinning was studied firstly.Using Newton's law to analyze the force on the micro-element,thephysical model of the jet formation process in centrifugal electrospinning wasestablished,and the equation relationship between jet radius and spinning parameters was deduced by using the volume formula of jet,and the expression of the critical speed of centrifugal disk was obtained.It is found that the speed of centrifugal disk is the most important factor affecting the diameter of fibers prepared by centrifugal electrospinning,followed by material flow rate.On this basis,the orthogonal experiment of the influence of centrifugal electrospinning parameters on the fiber diameter of polypropylene(PP)was carried out.The influence weight of the spinning parameters on the fiber diameter was determined as follows:centrifugal differential disc speed,material flow rate,spinning voltage and spinning temperature,which was consistent with the deduced formula and verified the correctness of the explanation of the spinning mechanism.The centrifugal electrospinning device was improved and designed according to the study of fiber forming mechanism.Due to the high viscosity of PPS and the serious influence of temperature,it is difficult to prepare fibers by melt electrospinning.For this reason,the electrospinning of PPS was studied by using capillary electrospinning device.The results showed that the average diameter of PPS fibers was 14.21?m under suitable spinning parameters.The effects of spinning temperature,spinning voltage and spinning distance on the diameter of PPS fibers were studied.The optimum spinning parameters were determined as follows:the spinning temperature is 320?,spinning voltage is 45 kV and spinning distance is 8 cm.Under this condition,the ultrafine PPS fibers with an average diameter of 9.82?m are successfully prepared.The melt viscosity has a direct influence on the diameter of melt electrospinning fibers.In order to obtain ultrafine PPS electrospinning fibers,PP was used to improve the fluidity of PPS spinning raw materials.The effect of PP content on the diameter of fibers was discussed through experiments.It was found that when the mass ratio of PPS/PP was70/30,the diameter of PPS ultrafine fibers was 4.12?m.In order to further refine the fibers,hyperbranched resin was used to reduce the viscosity of PPS raw materials.The experiments of melt differential electrospinning and melt differential centrifugal electrospinning of PPS were carried out.The average diameter of PPS ultrafine fibers was 1.38 and 1.36 ?m,respectively.At last,PPS fibers were tested for air filtration.Under the condition of similar weight,the filtration efficiency of PPS ultrafine fiber membrane prepared by electrospinning was 98.97%,which was much higher than that of PPS filter bags sold in the market at present.The results show that it is feasible to make filter bags from PPS ultrafine fibers obtained by melt electrospinning,which not only provides a new idea for the preparation of new filter bags for PPS,but also provides a new field for the application of melt electrospinning.