Preparation Of Degradable Polymer Melt Differential Electrospun Hydrophilic Fiber Membrane And Differential Irrigation

Soil moisturizing materials are not only used in agriculture and horticulture to save water and reduce costs,but also an effective means to solve land desertification.Soil moisturizing materials can transform the desert,improve the overall moisture absorption of the soil and improve the soil.Hydrophilic fiber membrane with three-dimensional network structure is an ideal soil moisturizing material.Its high porosity and high specific surface area can improve the absorption and storage of water,and the capillary effect of hydrophilic fiber membrane can transport water in different directions in the fiber.In this paper,the hydrophilic properties of fiber membrane were improved by hydrophilic modification of polylactic acid(PLA)and different post-treatment methods.Polybutylene terephthalate(PBAT)/ polyethylene glycol(PEG)blend fiber membrane was prepared to support and protect hydrophilic fiber membrane.Finally,the application of hydrophilic fiber membrane and differential irrigation is proposed to moisturize the soil and reduce the ineffective evaporation of soil moisture.The main contents of this paper are as follows:(1)PLA / PEG fiber was prepared by melt differential electrospinning technology.The optimμm ratio of PEG was determined to be 10%.At this time,the diameter of PLA / PEG fiber was 1.89μm and the standard deviation of diameter distribution was 0.70.Sodiμm dodecylbenzene sulfonate(SDBS)was added to the system as hydrophilic agent,and the electric field simulation analysis was carried out for the two receiving forms of roller receiving and polar plate receiving.Finally,the polar plate receiving was determined to be used,and the reciprocating design of the receiving device was carried out.The optimμm ratio of SDBS is 1.5%.At this time,the fiber diameter is 3.38μm and the standard deviation of diameter distribution is 0.66.Through experiments and calculations,the hydrophilic performance parameters of the fiber membrane are as follows: the water absorption ratio is 19.37,the water delivery rate is 6G / min,the wicking height is 10.23 cm,and the water contact angle is 19.56 °.(2)In order to further improve the hydrophilic property of the fiber membrane,the prepared fiber membrane was post treated in different ways,including extrusion to change the porosity of the fiber membrane,changing the reciprocating speed of the receiving plate and fiber membrane composite.The results show that after different post-treatment,the most obvious change in the hydrophilic properties of fiber membrane is the wicking height.In the post-treatment method of changing the porosity of fiber membrane by extrusion,the wicking height reached 14.4cm;In the fiber membrane composite,the wicking height reached 29.5cm.(3)Because the hydrophilic fiber membrane of PLA is the irregular accumulation of fibers on the polar plate,the mechanical properties are poor,and when the fiber membrane contacts with water,the SDBS on the fiber surface will be partially dissolved in water,resulting in the reduction or fracture of fiber diameter at random positions,so the mechanical properties are even worse.Therefore,in the later application,because PBAT is degradable and elastic,it is proposed to prepare PBAT / PEG fiber membrane with high toughness to support and protect the hydrophilic fiber membrane.Firstly,in the preliminary experiment,it is determined that PBAT can be spun in the spinning voltage range of 35-45 kv and the spinning temperature range of 240-280 ℃,and then the effects of spinning process parameters on fiber diameter and mechanical properties are explored.The research surface: under the same spinning voltage,the fiber diameter decreases and the distribution is more uniform with the increase of spinning temperature.When the spinning voltage is 35 k V and the spinning temperature is 260 ℃,the average fiber diameter is 4.06μm and the standard deviation of diameter distribution is 1.08.At the same spinning temperature,with the increase of spinning voltage,the fiber diameter decreases and the distribution is more uniform.When the spinning temperature is 260 ℃ and the spinning voltage is 45 kv,the average fiber diameter is 4.31μm and the standard deviation of diameter distribution is0.76.Then,in order to improve the interception effect of fiber membrane on water,it is necessary to reduce the pore diameter of fiber membrane.PBAT and peg are blended to reduce the fiber diameter,so as to reduce the pore diameter of fiber membrane.Finally,it is determined that the added PEG content is 5%,and the average fiber diameter is 3.75μm.(4)The application of hydrophilic fiber membrane is proposed.The water-saving irrigation system based on fiber membrane from bottom to top is proposed,and the experiment is carried out in water-saving irrigation.It is proved that hydrophilic fiber membrane can reduce the evaporation of soil water in soil,so as to expect that hydrophilic fiber membrane can transport and store water in soil.In conclusion,the hydrophilic modification of PLA was carried out in this paper,and the hydrophilic performance of the fiber membrane was improved by optimizing the process.The substrate was prepared by PBAT /PEG blended yarn to support and protect the hydrophilic fiber membrane of PLA.The application of fiber membrane in water-saving irrigation provides a new method to reduce the evaporation of soil water.The research content of this paper is the application of melt differential Electrospinning in the field of hydrophilic fibers,which provides ideas for the preparation of hydrophilic fiber membrane,improving hydrophilic properties and application direction.