The Prospect Of Thermoplastic Nanofiber Industry Is Developing Well.

Nanofiber is a linear material whose diameter is less than 100nm and its length is longer. In practice, the material whose diameter is less than 1000nm is also known as nanofiber. Its specific surface area is 100 times higher than that of micron fiber.

Research and development of modified functional nanofibers and their membrane products will bring new thinking to fast, efficient and environmentally friendly nonwoven products.

Melt extrusion phase separation overcomes traditional electrospinning problems

The common methods of preparing nanofibers include melt blown method, island spinning method and electrostatic spinning method.

Melt blown method is mainly applied to polypropylene materials with high melt index. Island technology can only produce PET and PA66 fibers with diameters of 700nm or more. The production of nanofibers mainly depends on electrostatic spinning. However, electrospinning still has problems such as low production efficiency and high processing cost.

In addition, electrospinning requires the use of some organic solvents to bring about environmental friendliness and increase the cost of recycling equipment.

Based on this, the research group developed a new manufacturing technology of high yield and environment-friendly thermoplastic nanofibers, namely melt extrusion phase separation method, and produced nanofibers such as polyester, polyolefin, polyamide, polyolefin copolymer and thermoplastic polyurethane, and the fiber diameter can be controlled in the range of 80nm to 500nm.

This method successfully conquered the traditional electrospinning technology which was difficult to prepare thermoplastic polymer nanofiber materials, and melted shotcrete method, fused electrospinning method and unable to prepare a series of technical problems of diameter less than 700nm fiber.

The basic principle of melt extrusion phase separation method is to melt and blend two kinds of thermodynamically incompatible polymers in a twin screw melt extruder. The polymer melt melted and extruded in the extruder and spinneret is stretched and deformed to form nanofiber bundles under the action of shear and tensile force field.

Finally, the matrix polymer was removed to obtain the desired type of thermoplastic nanofibers.

In the preparation process of thermoplastic nanofibers, cellulose ester was used as the polymer matrix.

The biggest advantage of cellulose ester is that it is incompatible with most thermoplastic polymers, and it can easily remove acetone from the mixed phase in subsequent processes, and the cellulose ester can be recycled.

At present, the use of cellulose ester and

The research team has successfully and efficiently prepared several thermoplastic nanofibers, including polyester, polyolefin and several functional copolymers.

The thermoplastic nanofibers prepared by this method are a series of axial aligned nanofiber assemblies, which have the characteristics of polymer structure regulation and compatibility with existing fiber production equipment.

In addition, nanofiber films with different nonwovens matrix structures were successfully prepared by coating nanofibers on different substrate surfaces.

Many high-end applications are yet to be developed.

Functionalization of thermoplastic polymer nanofibers containing functional groups can be applied in many fields.

At present, the research group has made progress in the application of nanofibers in biosensors, filtration, separation, antibacterial and antifouling.

Biosensor.

Biosensor (Biosensor) is an instrument that is sensitive to bioactive molecules and converts its concentration to electrical signals.

Polyethylene glycidyl methacrylate (PE-co-GMA) nanofibers were successfully prepared by melt extrusion phase separation method.

Because PE-co-GMA is a thermoplastic material with an active epoxy group, the active epoxy group can react with protein and enzyme through ring opening reaction.

The amino acids in active macromolecules are connected. Therefore, the preparation of biosensors using this nanofiber has great potential.

Filtration separation field.

Due to the unique large surface area, good biocompatibility and low flow resistance of nanofibers, many scholars at home and abroad are committed to the application of nanofibers in improving the efficiency of filtration membrane.

In the study group, the filtration capacity of nanofiber membrane prepared by the suspension ratio of TiO2 suspension was as high as 99.6%.

In addition, the research shows that nanofiber membrane will have obvious advantages in the field of filtration and separation.

In addition, the hydrophilic PVA-co-PE nanofibers were prepared by melt extrusion phase separation method, and the surface was activated by cyanuric chloride. Subsequently, IDA was grafted onto the surface of nanofibers by nucleophilic substitution reaction. The hydrophilic PVA-co-PE nanofibers with surface curing IDA were successfully prepared, and the nanofibers were prepared by coating the nanofibers.

Anti pollution area.

Compared with the traditional micron scale, nanofibers with high specific surface area have important application potential in the field of antibacterial fibers.

The surface of PVA-co-PE nanofiber membrane containing amphoteric sulfonamide ion was prepared by surface atom pfer radical polymerization (SI-ATRP) method, and the antibacterial properties of the new anti fouling nanofiber membrane were explored.

It is found that the number of bacterial membranes on the surface of amphoteric sulfonamide ions is much less than that of pure nanofibers.

The antibacterial rate reached 99.46% through calculation.

Therefore, the nanofibrous membrane grafted with amphoteric sulfonamide ions also has excellent antibacterial properties.

In addition, polymer nanofiber materials have wider application potential in military, bioengineering, industrial protective clothing, enzyme catalysis, lithium battery separator, cosmetics, air and water filtration and so on.

In future research, we should also pay attention to the problems of economy, environment friendliness, recyclability of recycling, and safety certification of products.