| Waterproof,breathable and breathable material,as a special fabric that can unidirectionally guide moisture and unidirectional waterproofing,has broad application prospects in the fields of medical isolation,thermal protection,health care,etc.It is one of the most important materials for the new crown epidemic.Protective clothing,its basic raw material is a waterproof,moisture-permeable and breathable material with a protective function.With the complex changes in the global new crown epidemic,there is a large demand for medical protection,personal protective equipment,etc.,and the demand for waterproof and breathable materials will continue to increase,which requires sufficient waterproof and breathable materials to meet the demand.At present,the main waterproof and breathable materials are difficult to achieve a balance between waterproof,moisture permeability and comfort,and the production technology is mainly in the hands of foreign companies,and the cost of use is relatively high,which restricts the development of domestic related industries.In view of the relevant needs and development bottlenecks,this paper realizes thermoplastic polyurethane(TPU),two-component polylactic acid(PLA),polypropylene(PP)and PP/PLA composite hot-pressed waterproof and breathable breathable membrane by melt differential electrospinning technology.The three key properties of air permeability,moisture permeability and water pressure resistance of fibers and hot-pressed waterproof and moisture-permeable breathable membranes were studied.Firstly,the TPU waterproof,moisture-permeable and breathable fiber membrane was prepared by melt differential electrospinning technology.The experimental results show that when the spinning voltage is 55k V and the auxiliary airflow speed is 30m/s,the smallest fiber diameter is 3.93μm,and the smallest fiber membrane pore size is 3.81μm;when the spinning time is10min,the water infiltration time is at least 9m12s,at this time,the water-wetting performance is the strongest.At the same time,when the spinning voltage is 55k V and the auxiliary airflow speed is 30m/s,the moisture permeability can reach 6045g/(m2·24h),and the air permeability can reach 97mm/s;When the spinning time is 60min,the water pressure resistance value can reach 8.5KPa.Compared with the comparative sample,while ensuring the waterproof and moisture permeability,the air permeability of the waterproof and moisture-permeable breathable membrane has been greatly improved,which solves the problem.Generally,the waterproof and moisture-permeable membrane has poor air permeability.In order to prepare a green and degradable waterproof and moisture-permeable breathable membrane,and to solve the problem of insufficient mechanical properties of a single grade of PLA material,a two-component PLA waterproof and moisture-permeable breathable fiber membrane was prepared by melt differential electrospinning technology.The effects of parameters and hot-pressing parameters on the microscopic properties of the membrane were systematically analyzed.The experimental results show that when the spinning voltage is 55k V,the hot-pressing pressure is 6MPa,and the hot-pressing temperature is 50℃,the optimal comprehensive performance of waterproof,moisture-permeable and air-permeable is achieved.).At the same time,the waterproof and moisture-permeable breathable membrane of melt differential electrospinning is adopted,the maximum tensile strength can reach 29.64MPa,and the elongation at break can reach 84.6%.For the first time,the green preparation of high-strength,high moisture-permeable,and degradable waterproof and moisture-permeable breathable membranes has been achieved.Finally,in order to prepare a material that can achieve both high water resistance and high moisture permeability and air permeability,a PP waterproof,moisture-permeable and breathable hot-pressed film was prepared by melt differential electrospinning technology,and a PP/PLA composite hot-pressed film was prepared.One-way hydrophobic channel.The effects of spinning parameters and hot-pressing parameters on the microscopic properties of the membrane were investigated experimentally,and the fiber diameter,fiber membrane pore size,surface hydrophilicity and hydrophobicity,water wettability,and the PP/PLA composite of different groups of PP and PLA hot-pressed membranes were systematically analyzed.The performance of PLA composite hot-pressed film is waterproof,moisture-permeable and breathable.The test results show that for the PP waterproof,moisture-permeable and breathable hot-pressed film,when the spinning voltage is 41k V,the hot-pressing pressure is 6MPa,and the hot-pressing temperature is 130℃,the optimal comprehensive performance of waterproof,moisture-permeable and breathable is obtained,and the air permeability reaches 82mm/s.The moisture permeability reaches 8109.23g/(m~2·24h);at the same time,for the PP/PLA composite waterproof,moisture-permeable and breathable hot-pressed film,it guarantees a high moisture permeability of7077.29g/(m~2·24h)and good air permeability.Under the condition of16.3mm/s,the water pressure resistance value reaches 15.3KPa,which exceeds the water pressure resistance performance of pure PLA and pure PP waterproof,moisture-permeable and breathable hot-pressed film,and realizes the optimization of the comprehensive performance of waterproof,moisture-permeable and breathable.In conclusion,the melt differential electrospinning waterproof and moisture-permeable and breathable fiber membrane has excellent performance,strong material adaptability and high efficiency.It can meet the performance requirements in terms of water resistance and moisture permeability,and at the same time,its air permeability far exceeds traditional processes such as solution spinning,which solves the problem of poor air permeability of protective materials;at the same time,it realizes the development of PLA degradable material waterproof and moisture-permeable breathable film,to solve the current problems of environmental pollution and recycling of traditional protective materials;at the same time,a PP/PLA waterproof and breathable breathable membrane with a composite structure was developed,which realized the efficient preparation of green and environmentally friendly membranes with high moisture permeability and high waterproofness.The research content of this paper is the new application of melt electrospinning technology in the field of protective materials,which is expected to provide new ideas for the efficient preparation of green high-performance waterproof and moisture-permeable materials. |
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