CN-122013444-A - Method for preparing PLA/TPU fiber membrane based on spiral airflow liquid spraying

Abstract

The invention provides a method for preparing a PLA/TPU fiber film based on spiral gas flow liquid spraying, which comprises the following steps of S1, mixing DMC and DMAc to obtain a mixed solvent, adding PLA particles and TPU particles into the mixed solvent, heating and stirring to obtain a spinning precursor solution, S2, injecting the spinning precursor solution into an injector of a liquid spraying component, and pushing the spinning precursor liquid to spray towards a spinneret plate under the air pressure condition of 0.1-0.2 mpa to form the fiber film, wherein the liquid spraying component is provided with a spiral gas nozzle, S3, placing the fiber film on a receiving plate into a constant-temperature oven to process to obtain the PLA/TPU fiber film, and introducing spiral gas flow on the basis of liquid spraying to enable the gas flow to act on the polymer solution in a rotating or vortex mode, thereby preparing the PLA/TPU fiber film with strength and toughness.

Inventors

• HUANG QIWEI
• Shao Shuoyan
• ZHOU JIAWEI
• ZHU YINCHAO
• ZHU FEICHAO

Assignees

• 浙江理工大学

Dates

Publication Date

20260512

Application Date

20260410

Claims (10)

1. 1. A method for preparing a PLA/TPU fiber film based on spiral gas flow liquid spraying, which is characterized by comprising the following steps: s1, mixing DMC and DMAc to obtain a mixed solvent, adding PLA particles and TPU particles into the mixed solvent, heating and stirring to obtain a spinning precursor solution; S2, injecting the spinning precursor solution into an injector of a liquid spraying assembly, and pushing the spinning precursor solution to spray towards a spinneret plate under the air pressure condition of 0.1-0.2 mpa to form a fiber film, wherein a spiral-port gas nozzle is arranged on the liquid spraying assembly; and S3, placing the fiber membrane on the receiving plate in a constant temperature oven for treatment to obtain the PLA/TPU fiber membrane.
2. 2. The method for preparing the PLA/TPU fiber film based on spiral gas flow liquid spraying according to claim 1, wherein the spiral mouth gas nozzle comprises a liquid spraying channel and a rotational flow guide air channel surrounding the liquid spraying channel, wherein an air channel opening of the rotational flow guide air channel is arranged around the liquid spraying opening of the liquid spraying channel, the gas flow is sprayed out from the air channel opening in a rotational vortex form through the rotational flow guide air channel, and spiral drafting and restraint are formed on the spinning jet flow sprayed out through the liquid spraying opening.
3. 3. The method for preparing a PLA/TPU fiber membrane based on spiral gas flow liquid spraying according to claim 2, wherein the liquid spraying opening is arranged protruding from the plane where the gas flow opening is located.
4. 4. The method for preparing the PLA/TPU fiber film based on spiral gas flow liquid spraying according to claim 2, wherein the diameter of the liquid spraying opening is 0.5mm, the diameter of the gas channel opening is 0.3mm, and the included angle between the rotational flow guide gas channel and the gas channel opening is 45.
5. 5. The method for preparing the PLA/TPU fiber film based on spiral gas flow liquid spraying according to claim 1, wherein the receiving distance between the nozzle and the receiving plate is set to be 15-25 cm.
6. 6. The method for preparing the PLA/TPU fiber film based on spiral gas flow liquid spraying according to claim 1, wherein the rotating speed is set to be 100-200 r/min, and the spinning environment temperature is set to be 35-45 ℃.
7. 7. The method for preparing a PLA/TPU fiber film based on spiral gas flow liquid spraying according to claim 1, wherein the humidity is below 40%.
8. 8. The method for preparing the PLA/TPU fiber film based on spiral gas flow liquid spraying according to claim 1, wherein the DMC in the mixed solvent is 60-90%.
9. 9. The method for preparing the PLA/TPU fiber film based on the spiral gas flow liquid spray, which is characterized in that the mass percentage of PLA particles and TPU particles accounting for the total content of the mixed solvent is 8 wt% -15 wt%.
10. 10. The method for preparing a PLA/TPU fiber film based on spiral gas flow liquid spraying according to claim 1, wherein after the spinning precursor liquid spraying is completed, the fiber film on the receiving plate is quickly taken down and placed in a cross-temperature oven at 60 ℃.

Description

Method for preparing PLA/TPU fiber membrane based on spiral airflow liquid spraying Technical Field The invention relates to the technical field of high polymer material processing, in particular to a method for preparing a PLA/TPU fiber membrane based on spiral airflow liquid spraying. Background Polylactic acid (PLA) is used as a bio-based degradable polymer, has good biocompatibility, processability and higher mechanical strength, and has wide application prospect in the fields of biomedical materials, filtration separation, environment-friendly packaging and the like. However, the PLA molecular chain has the structural characteristics of high rigidity and low flexibility, so that the PLA molecular chain is high in inherent brittleness, low in elongation at break and poor in impact resistance and fatigue resistance, cannot meet the use requirements of high toughness and high rebound resilience of materials in a flexible scene, is severely restricted to be applied in the large-scale field, and is mainly used for improving the problem of insufficient toughness of PLA, and an elastomer blending modification technical path is mainly adopted in the industry, wherein Thermoplastic Polyurethane (TPU) becomes one of the preferred elastomer materials for PLA toughening modification by virtue of excellent elastic deformability, wear resistance, flexibility and interfacial compatibility, and the composite fiber film is hopefully prepared by blending PLA and TPU, so that the cooperative regulation and control of the tensile strength and toughness of the materials are hopefully realized, and the performance bottleneck of a single polymer is broken through. At present, the mainstream preparation technology for preparing the PLA/TPU composite fiber film mainly comprises three major types of melt spinning, melt blowing spinning and electrostatic spinning, however, for melt blowing or melt spinning, PLA and TPU are not compatible with each other, macroscopic phase separation is easily caused by simple blending, a coarse uneven structure is formed, stress defect points are formed, and the material is broken too early when being stressed, so that the toughening efficiency is low, while the electrostatic spinning technology can be used for preparing the PLA/TPU fiber film, but the problems of low production efficiency, insufficient strength of the fiber film and the like generally exist, and the obtained fiber film is poor in mechanical property or limited in toughness improvement and cannot meet the application requirement on strict mechanical property requirement. In order to solve the technical bottleneck, a solution jet spinning (abbreviated as liquid jet) technology gradually enters the field of industry, and the technology relies on high-speed air flow to carry out high-speed drawing on polymer precursor solution extruded from a spinneret orifice, and solidification into fibers is realized along with rapid volatilization of a solvent. Compared with a melt spinning/melt blowing technology, the liquid blowing technology can finish the fiber forming process under the condition of room temperature to middle and low temperature, has low requirement on the thermal stability of the polymer, can effectively avoid the thermal degradation of the polymer, can obviously inhibit the macroscopic phase separation of a PLA/TPU blending system by quick volatilization of a solvent and realize the uniform dispersion of blending components, and compared with an electrostatic spinning technology, the liquid blowing technology depends on high-speed airflow driving, does not need a high-voltage electrostatic field, has high production safety, can improve the spinning efficiency by 2-3 orders of magnitude, has good applicability on a low-conductivity polymer solution, has wider raw material adaptation range and has the application potential of large-scale industrialization. However, the existing conventional direct injection solution jet spinning technology still has significant technical defects: Firstly, the conventional linear high-speed airflow has single drafting action on polymer jet flow, the drafting efficiency is limited, the stable controllable preparation of submicron superfine fiber is difficult to realize, and the jet flow is easy to diverge and disorder in a high-speed airflow field, so that the fiber diameter distribution is wide and the uniformity is poor; Secondly, the fibers obtained by conventional liquid spraying are mostly of linear structures, and the problems of compact stacking, low porosity, insufficient air permeability and insufficient specific surface area of the fiber films can not meet the requirements of high-end filtration, medical dressing and other fields on high bulk and high porosity of the materials; Thirdly, entanglement among linear type fibers is weak, mechanical strength and rebound resilience of a fiber film are difficult to synchronously improve, collaborative optimization of tensile strength and to