CN115972725A - Multi-layer co-extrusion super-hydrophobic polyethylene film and preparation method thereof - Google Patents

Abstract

The invention discloses a multi-layer co-extruded superhydrophobic polyethylene film and a preparation method thereof. The film is composed of two surface layers sandwiching an intermediate layer. The contact angle between the film surface and water is between 153° and 158°, and the roll angle It is less than 9°, and the adhesion rate with liquid is less than 0.1%. After 100-200 frictions on the surface of the film with a rubber loaded with 10N force, the surface contact angle still reaches 153°-156°. The preparation method includes (1) uniformly mixing low-density polyethylene particles and nano-material particles and granulating; (2) performing three-layer co-extrusion of low-density polyethylene masterbatch, high-density polyethylene particles and low-density polyethylene masterbatch (3) Stretch the three-layer co-extruded thick film into a film to obtain the product. The multi-layer co-extruded superhydrophobic polyethylene film of the present invention has stronger liquid adhesion resistance, better surface wear resistance and better superhydrophobic stability, the preparation method is suitable for large-area preparation, and has excellent industrialization prospects.

Description

Multilayer co-extruded superhydrophobic polyethylene film and preparation method thereof

technical field

The invention belongs to the field of superhydrophobic films, in particular to a multilayer co-extruded superhydrophobic polyethylene film and a preparation method thereof.

Background technique

In recent years, inspired by the lotus leaf effect, superhydrophobic films with water contact angles greater than 150° have become a research hotspot at home and abroad. The typical characteristics of super-hydrophobic films are: water droplets or aqueous liquids (spray, saliva, blood, sewage, etc.) are usually spherical on the surface of super-hydrophobic films, and it is difficult for liquids to stay stably on the surface of super-hydrophobic films, as long as they are tilted at a small angle or Under the action of a breeze or a slight external force, the liquid will quickly roll off the surface of the super-hydrophobic film, and at the same time take away dust and other pollutants on the surface of the film, thereby playing a self-cleaning role. Soaking the super-hydrophobic film in water or aqueous liquid for a long time will not allow any liquid to penetrate, and the surface will not stick to liquid droplets after being taken out, so it has strong waterproof, water-blocking, antibacterial, mildew-proof and anti-liquid properties Adhesion properties, these unique properties make super-hydrophobic films have very broad application prospects in industry, agriculture and daily life.

Polyethylene film has the advantages of non-toxic, odorless, and low price, and is widely used in packaging and industry and agriculture. However, the contact angle of ordinary polyethylene film on the market with water is usually less than 110°, and it has no self-cleaning property, and is easily contaminated by dust, Substances such as thick liquids adhere. If the surface of polyethylene film is endowed with superhydrophobicity, the adhesion of thick liquid on the surface of the film will be greatly reduced, and the surface will be easier to clean, and the market demand is huge. At present, the methods for preparing superhydrophobic polyethylene films mainly include: template method, etching method, microphase separation method, etc. However, the methods for preparing superhydrophobic polyethylene films that have been reported are currently limited to laboratories. The main reason is that there are two bottlenecks: ① the reported method is difficult to prepare superhydrophobic polyethylene film in a large area, which makes it difficult for practical application; ② the surface abrasion resistance of the superhydrophobic polyethylene film prepared by the reported method is poor, super Poor hydrophobic stability.

Therefore, it is of great significance to develop a method that can be prepared in a large area and can maintain high wear resistance and superhydrophobic stability on the surface of superhydrophobic polyethylene film.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a multi-layer co-extruded superhydrophobic film that can be prepared in a large area and can maintain high wear resistance and superhydrophobic stability on the surface of the superhydrophobic polyethylene film. Polyethylene film and its preparation method.

In order to solve the above technical problems, the present invention adopts the following technical solutions.

A multi-layer co-extruded superhydrophobic polyethylene film is composed of two surface layers sandwiching an intermediate layer, the surface layer is a nanoporous composite film layer, and the nanoporous composite film layer is composed of low-density polyethylene particles and nanomaterial particles Made of raw materials, the middle layer is a high-density polyethylene film layer; the contact angle between the surface of the multi-layer co-extruded superhydrophobic polyethylene film and water is between 153° and 158°, and the rolling angle of water droplets on the film surface is less than 9°, the adhesion rate of the multi-layer co-extruded superhydrophobic polyethylene film after contact with the liquid is less than 0.1%, and the contact angle of the film surface still reaches 153° after rubbing the surface of the film with a rubber loaded with a force of 10N for 100-200 times ~156°.

In the above-mentioned multi-layer co-extruded superhydrophobic polyethylene film, preferably, the nano material particles include one or more of nano silicon dioxide particles, nano calcium carbonate particles and nano zinc oxide particles.

For the above-mentioned multilayer co-extruded superhydrophobic polyethylene film, preferably, the average particle diameter of the nanomaterial particles is between 1 nm and 100 nm.

As a general technical conception, the present invention also provides a kind of preparation method of above-mentioned multilayer co-extruded superhydrophobic polyethylene film, comprises the following steps:

(1) uniformly mixing and granulating low-density polyethylene particles and nanomaterial particles to obtain low-density polyethylene master batches; wherein, the mass ratio of low-density polyethylene particles to nanomaterial particles is 5 to 10: 2 to 1;

(2) Put the low-density polyethylene masterbatch, high-density polyethylene particles, and low-density polyethylene masterbatch into three hoppers respectively, and perform three-layer co-extrusion to obtain a three-layer co-extrusion thick film; wherein, the low-density polyethylene The mass ratio of polyethylene masterbatch, high-density polyethylene particles, and low-density polyethylene masterbatch is 1:5-50:1, and the thickness of the three-layer co-extruded thick film is 0.2mm-1mm;

(3) Stretching the three-layer co-extruded thick film to a film with a thickness of 0.005 mm to 0.1 mm to obtain a multi-layer co-extruded superhydrophobic polyethylene film.

In the above method for preparing a multi-layer co-extruded superhydrophobic polyethylene film, preferably, in step (3), the three-layer co-extruded thick film is placed on a vertical and horizontal stretch frame for stretching.

In the present invention, low-density polyethylene particles refer to commercial low-density polyethylene particle raw materials without special treatment, with a density of 0.91-0.93 g/cm ³ .

In the present invention, high-density polyethylene particles refer to commercial high-density polyethylene particle raw materials without special treatment, with a density of 0.941-0.960 g/cm ³ .

In the present invention, the low-density polyethylene masterbatch refers to the low-density polyethylene particles formed after mixing and granulating low-density polyethylene and nanoparticles.

Compared with the prior art, the present invention has the advantages of:

1. Compared with the existing superhydrophobic film, the multilayer co-extruded superhydrophobic polyethylene film of the present invention has stronger liquid adhesion resistance, better surface wear resistance and better superhydrophobic stability. The contact angle between the surface of the multilayer co-extruded superhydrophobic polyethylene film and water is between 153° and 158°, and the rolling angle of water droplets on the surface of the film is less than 9°. The multilayer coextruded superhydrophobic polyethylene film has excellent resistance to liquid adhesion Adhesion performance, the adhesion rate of milk, tomato sauce and other liquids after contact with it is less than 0.1%. After rubbing the surface of the film with a rubber loaded with a force of 10N for 100-200 times, the contact angle of the film surface still exceeds 153°. The multi-layer co-extruded superhydrophobic polyethylene film of the present invention can greatly reduce the adhesion of thick liquid on the surface of the film, the surface is also easier to clean, and the surface of the film can also be kept dry for a long time. Sauce, etc.) packaging, glass and film, paper-plastic composite film and other fields have broader application prospects, and the market demand is huge.

2. The preparation method of the present invention has low cost, is suitable for large-area preparation, and has excellent industrialization prospects.

Description of drawings

Fig. 1 is the scanning electron micrograph of the surface of the multilayer co-extruded superhydrophobic polyethylene film obtained in Example 1 of the present invention.

Fig. 2 is the test diagram of the contact angle on the surface of the multilayer co-extruded superhydrophobic polyethylene film obtained in Example 1 of the present invention.

Fig. 3 is the test diagram of the contact angle on the surface of the multilayer co-extruded superhydrophobic polyethylene film obtained in Example 2 of the present invention.

Fig. 4 is a test diagram of the contact angle on the surface of the multilayer co-extruded superhydrophobic polyethylene film obtained in Example 3 of the present invention.

Fig. 5 is a test diagram of the contact angle on the surface of the multilayer co-extruded superhydrophobic polyethylene film obtained in Example 4 of the present invention.

Fig. 6 is a test diagram of the contact angle on the surface of the multilayer co-extruded superhydrophobic polyethylene film obtained in Example 5 of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. All materials and instruments used in the following examples are commercially available.

Example 1

A kind of preparation method of multilayer co-extruded superhydrophobic polyethylene film of the present invention, comprises the following steps:

(1) the low-density polyethylene particles and the average particle diameter are mixed and granulated according to the mass ratio of 5:2 to form the low-density polyethylene masterbatch;

(2) Weigh the low-density polyethylene masterbatch, high-density polyethylene granules, and low-density polyethylene masterbatch respectively according to the mass ratio of 1:5:1, and put them into corresponding hoppers respectively, and extrude them through a three-layer co-extrusion machine. Produce a three-layer co-extrusion thick film with a thickness of 0.2mm;

(3) Place the three-layer co-extruded thick film on a vertical and horizontal stretching frame and stretch it to a film with a thickness of 0.005mm at a uniform speed to obtain a multi-layer co-extruded superhydrophobic polyethylene film. The scanning electron microscope image of the surface morphology of the film is as follows Figure 1 shows.

The multi-layer co-extruded superhydrophobic polyethylene film of this embodiment consists of two surface layers (outer layers) sandwiching an intermediate layer, that is, surface layer-middle layer-surface layer, the two surface layers are nanoporous composite film layers, and the nanoporous composite film layer It is made of low-density polyethylene particles and nano-material particles, and the middle layer is a high-density polyethylene film layer. As shown in Figure 2, the contact angle test results show that the contact angle of water droplets on the surface of the multilayer co-extruded superhydrophobic polyethylene film of this embodiment is 153°, and the rolling angle of water droplets on the surface of the film is 8°. The adhesion rate of milk after contact with the surface of the multilayer co-extruded superhydrophobic polyethylene film is less than 0.1%. After rubbing the surface of the film with a rubber loaded with a force of 10N for 100 times, the contact angle of the film surface remains at 153°, which reflects the extreme Good resistance to liquid sticking and abrasion.

Example 2

A kind of preparation method of multilayer co-extruded superhydrophobic polyethylene film of the present invention, comprises the following steps:

(1) the low-density polyethylene particles and the average particle diameter are mixed and granulated according to the mass ratio of 10:1 to form the low-density polyethylene masterbatch;

(2) Weigh the low-density polyethylene masterbatch, high-density polyethylene granules, and low-density polyethylene masterbatch respectively according to the mass ratio of 1:50:1, and put them into corresponding hoppers respectively, and pass through the three-layer co-extruder Extrude a three-layer co-extruded thick film with a thickness of 1mm;

(3) Place the three-layer co-extruded thick film on a vertical and horizontal stretching frame and stretch it at a uniform speed to a film thickness of 0.1 mm to obtain a multi-layer co-extruded superhydrophobic polyethylene film.

The multi-layer co-extruded superhydrophobic polyethylene film of this embodiment is composed of two surface layers sandwiching an intermediate layer. The two surface layers are nanoporous composite film layers, and the nanoporous composite film layer is made of low-density polyethylene particles and nanomaterial particles. Made, the middle layer is a high-density polyethylene film layer. As shown in Figure 3, the contact angle test results show that the water drop contact angle on the surface of the multilayer co-extruded superhydrophobic polyethylene film of the present embodiment is 158 °, and the rolling angle of the water drop on the film surface is 2 °, and the film surface is in contact with tomato sauce The final adhesion rate is less than 0.08%. After 200 frictions on the surface of the film with a rubber loaded with a force of 10N, the contact angle of the film surface remains at 155°, reflecting excellent resistance to liquid adhesion and abrasion.

Example 3

A kind of preparation method of multilayer co-extruded superhydrophobic polyethylene film of the present invention, comprises the following steps:

(1) the low-density polyethylene particles and the average particle diameter are mixed and granulated according to the mass ratio of 8:2 to form the low-density polyethylene masterbatch;

(2) Weigh low-density polyethylene masterbatch, high-density polyethylene granules, and low-density polyethylene masterbatch respectively according to the mass ratio of 1:10:1, and put them into corresponding hoppers respectively, and extrude them through a three-layer co-extrusion machine. Produce a three-layer co-extrusion thick film with a thickness of 0.5mm;

(3) Place the three-layer co-extruded thick film on a vertical and horizontal stretching frame and stretch it at a uniform speed to a film thickness of 0.05 mm to obtain a multi-layer co-extruded superhydrophobic polyethylene film.

The multi-layer co-extruded superhydrophobic polyethylene film of this embodiment is composed of two surface layers sandwiching an intermediate layer. The two surface layers are nanoporous composite film layers, and the nanoporous composite film layer is made of low-density polyethylene particles and nanomaterial particles. Made, the middle layer is a high-density polyethylene film layer. As shown in Figure 4, the contact angle test results show that the contact angle of water droplets on the surface of the film is 157°, and the rolling angle of water droplets on the surface of the film is 3°. The adhesion rate of milk after contact with the surface of the multilayer co-extruded superhydrophobic polyethylene film is less than 0.05%. After rubbing the surface of the film with a rubber loaded with a force of 10N for 100 times, the contact angle of the film surface remains at 156°, which reflects the extreme Good resistance to liquid sticking and abrasion.

Example 4

A kind of preparation method of multilayer co-extruded superhydrophobic polyethylene film of the present invention, comprises the following steps:

(1) the low-density polyethylene particles and the average particle diameter are mixed and granulated according to the mass ratio of 9:2 to form the low-density polyethylene masterbatch;

(2) Weigh the low-density polyethylene masterbatch, high-density polyethylene granules, and low-density polyethylene masterbatch respectively according to the mass ratio of 1:20:1, and put them into corresponding hoppers respectively, and extrude them through a three-layer co-extrusion machine. Produce a three-layer co-extrusion thick film with a thickness of 0.6mm;

(3) Place the three-layer co-extruded thick film on a vertical and horizontal stretching frame and stretch it at a uniform speed to a film thickness of 0.08 mm to obtain a multi-layer co-extruded superhydrophobic polyethylene film.

The multi-layer co-extruded superhydrophobic polyethylene film of this embodiment is composed of two surface layers sandwiching an intermediate layer. The two surface layers are nanoporous composite film layers, and the nanoporous composite film layer is made of low-density polyethylene particles and nanomaterial particles. Made, the middle layer is a high-density polyethylene film layer. As shown in Figure 5, the contact angle test results show that the contact angle of water droplets on the surface of the multilayer co-extruded superhydrophobic polyethylene film of this embodiment is 155°, and the rolling angle of water droplets on the surface of the film is 5°. The adhesion rate of milk after contact with the surface of the multilayer co-extruded superhydrophobic polyethylene film is less than 0.03%. After rubbing the surface of the film with a rubber loaded with a force of 10N for 150 times, the contact angle of the film surface remains at 153°, which reflects the extreme Good resistance to liquid sticking and abrasion.

Example 5

A kind of preparation method of multilayer co-extruded superhydrophobic polyethylene film of the present invention, comprises the following steps:

(1) the low-density polyethylene particles and the average particle diameter are mixed and granulated according to the mass ratio of 9:1 to form the low-density polyethylene masterbatch;

(2) Weigh low-density polyethylene masterbatch, high-density polyethylene granules, and low-density polyethylene masterbatch respectively according to the mass ratio of 1:30:1, and put them into corresponding hoppers respectively, and extrude them through a three-layer co-extrusion machine. Produce a three-layer co-extrusion thick film with a thickness of 0.8mm;

(3) Place the three-layer co-extruded thick film on a vertical and horizontal stretching frame and stretch it at a uniform speed to a film thickness of 0.01 mm to obtain a multi-layer co-extruded superhydrophobic polyethylene film.

The multi-layer co-extruded superhydrophobic polyethylene film of this embodiment is composed of two surface layers sandwiching an intermediate layer. The two surface layers are nanoporous composite film layers, and the nanoporous composite film layer is made of low-density polyethylene particles and nanomaterial particles. Made, the middle layer is a high-density polyethylene film layer. As shown in Figure 6, the contact angle test results show that the contact angle of water droplets on the surface of the multilayer co-extruded superhydrophobic polyethylene film of this embodiment is 154°, and the rolling angle of water droplets on the surface of the film is 7°. The adhesion rate of ketchup to the surface of the multi-layer co-extruded superhydrophobic polyethylene film is less than 0.08%. After rubbing the surface of the film with a rubber loaded with a force of 10N for 160 times, the contact angle of the film surface remains at 153°, which reflects the Excellent resistance to liquid sticking and abrasion.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art, without departing from the spirit and technical solutions of the present invention, can use the methods and technical content disclosed above to make many possible changes and modifications to the technical solutions of the present invention, or modify them to be equivalent Variations of equivalent embodiments. Therefore, any simple modifications, equivalent replacements, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention, which do not deviate from the technical solutions of the present invention, still fall within the protection scope of the technical solutions of the present invention.

Claims (5)

1. a multi-layer co-extruded superhydrophobic polyethylene film is characterized in that, it is made of two surface layers sandwiching an intermediate layer, the surface layer is a nanoporous composite film layer, and the nanoporous composite film layer is made of low density polyethylene Particles and nanomaterial particles are made of raw materials, and the middle layer is a high-density polyethylene film layer; the contact angle between the surface of the multi-layer co-extruded superhydrophobic polyethylene film and water is between 153° and 158°, and the water droplet is between 153° and 158° The rolling angle of the film surface is less than 9°, and the adhesion rate of the multilayer co-extruded superhydrophobic polyethylene film after contacting with the liquid is less than 0.1%. The contact angle still reaches 153°～156°. 2. multilayer co-extruded superhydrophobic polyethylene film according to claim 1, is characterized in that, described nanomaterial particle comprises one or more in nano-silicon dioxide particle, nano-calcium carbonate particle and nano-zinc oxide particle kind. 3. The multilayer co-extruded superhydrophobic polyethylene film according to claim 1 or 2, characterized in that, the average particle diameter of the nanomaterial particles is between 1nm and 100nm. 4. a preparation method of the multilayer co-extruded superhydrophobic polyethylene film as described in any one of claims 1 to 3, is characterized in that, comprises the following steps: (1) uniformly mixing and granulating low-density polyethylene particles and nanomaterial particles to obtain low-density polyethylene master batches; wherein, the mass ratio of low-density polyethylene particles to nanomaterial particles is 5 to 10: 2 to 1; (2) Put the low-density polyethylene masterbatch, high-density polyethylene particles, and low-density polyethylene masterbatch into three hoppers respectively, and perform three-layer co-extrusion to obtain a three-layer co-extrusion thick film; wherein, the low-density polyethylene The mass ratio of polyethylene masterbatch, high-density polyethylene particles, and low-density polyethylene masterbatch is 1:5-50:1, and the thickness of the three-layer co-extruded thick film is 0.2mm-1mm; (3) Stretching the three-layer co-extruded thick film to a film with a thickness of 0.005 mm to 0.1 mm to obtain a multi-layer co-extruded superhydrophobic polyethylene film. 5. the preparation method of multi-layer co-extrusion superhydrophobic polyethylene film according to claim 4 is characterized in that, in step (3), described three-layer co-extrusion thick film is placed on the longitudinal and transverse stretch frame and draws stretch.

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