CN112094443B - Preparation method of bacterial cellulose composite material with ordered woven structure - Google Patents

Abstract

The invention provides a preparation method of a bacterial cellulose composite material with an ordered woven structure, which comprises the following steps: A) processing the hydrogel to obtain a plurality of strip-shaped hydrogels; the hydrogel is selected from one or two of bacterial cellulose hydrogel and bacterial cellulose composite material hydrogel; B) orderly weaving the plurality of strip-shaped hydrogels; C) compressing the hydrogel obtained in the step B) to obtain the bacterial cellulose composite material with an ordered woven structure. According to the method, the bacterial cellulose composite material with low thermal expansion rate, light weight, high strength and high toughness is obtained.

Description

A kind of preparation method of bacterial cellulose composite material with ordered woven structure

technical field

The invention relates to the technical field of new material development and research, in particular to a preparation method of a bacterial cellulose composite material with an ordered woven structure.

Background technique

Bacterial cellulose (BC) is a natural polymer material with a three-dimensional nano-network structure synthesized by microbial fermentation; it is a linear molecule composed of β-D-glucose through β-1,4-glycosidic bonds. , so it is also called β-1,4-glucan. Since the British scientist Brown discovered in 1986, bacterial cellulose has gradually attracted widespread attention because of its unique physical and chemical properties.

In the three-dimensional nanonetwork of bacterial cellulose, the diameter of nanocellulose fibers is between 20 and 100 nm, which is 2 to 3 orders of magnitude smaller than that of plant cellulose (10 μm). Cellulose, lignin, etc.

How to realize specific functions based on structural design is the basis for the development of new materials, and it is also a development trend.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is to provide a method for preparing a bacterial cellulose composite material with an ordered woven structure. The bacterial cellulose composite material prepared in the present application has the characteristics of low thermal expansion rate, anisotropy, light weight and high strength.

In view of this, the present application provides a method for preparing a bacterial cellulose composite material with an ordered woven structure, comprising the following steps:

A) processing the hydrogel to obtain several long strips of hydrogel; the hydrogel is selected from one or both of bacterial cellulose hydrogel and bacterial cellulose composite hydrogel;

B) orderly weaving the several elongated hydrogels;

C) compressing the hydrogel obtained in step B) to obtain a bacterial cellulose composite material with an ordered woven structure.

Preferably, the bacterial cellulose hydrogel is selected from bacterial cellulose hydrogel obtained by bacterial fermentation, and the bacterial cellulose composite hydrogel is selected from one of macromolecules and nanomaterials and bacterial cellulose composite hydrogels.

Preferably, the hydrogel has a thickness of 0.1 mm to 50 mm and a water content of 5% to 90%.

Preferably, the strip-shaped hydrogel has a width of 0.5-30 mm and a length of >5 cm.

Preferably, step B) is specifically:

Orderly weaving several long strips of bacterial cellulose hydrogels;

Or, orderly weaving several long strips of bacterial cellulose composite hydrogels;

Or, orderly weaving several long strips of bacterial cellulose hydrogels and several long strips of bacterial cellulose composite hydrogels.

Preferably, the ordered weaving is an ordered three-dimensional weaving.

Preferably, the compression temperature is 0˜200° C., and the compression pressure is 1˜800 MPa.

Preferably, the compression temperature is 50-150° C., and the compression pressure is 50-300 MPa.

The present application provides a method for preparing a bacterial cellulose composite material with an ordered weave structure. First, the hydrogel is processed to obtain several long strips of hydrogels, and then the several strips of The hydrogel is woven in an orderly manner and finally compressed to obtain a bacterial cellulose composite material with an ordered woven structure. In the above process, one or both of bacterial cellulose hydrogel and bacterial cellulose composite hydrogel are woven into an ordered structure, and at the same time, strong hydrogen bonds are formed between the inner nanocellulose, and the surface of the hydrogel is The effect of forming hydrogen bonds between the contacting interfaces of the nanocellulose makes the obtained bacterial cellulose composite material with low expansion rate, light weight, high strength and high impact resistance.

Description of drawings

1 is a photo of the bacterial cellulose composite material prepared in Example 1 of the present invention;

2 is a microscopic photo of the bacterial cellulose composite material prepared in Example 1 of the present invention;

3 is a graph showing the compressive stress of the bacterial cellulose composite material prepared in Example 1 of the present invention under different strains.

Detailed ways

In order to further understand the present invention, the preferred embodiments of the present invention are described below in conjunction with the examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

In view of the properties of bacterial cellulose itself, the present application provides a method for preparing a bacterial cellulose composite material with an ordered woven structure, and the bacterial cellulose composite material prepared by the method has good mechanical properties. Specifically, the preparation method of the bacterial cellulose composite material with an ordered woven structure described in this application includes the following steps:

A) processing the hydrogel to obtain several long strips of hydrogel; the hydrogel is selected from one or both of bacterial cellulose hydrogel and bacterial cellulose composite hydrogel;

B) orderly weaving the several elongated hydrogels;

C) compressing the hydrogel obtained in step B) to obtain a bacterial cellulose composite material with an ordered woven structure.

In the above-mentioned process of preparing the bacterial cellulose composite material with an ordered woven structure, the present application first processes the hydrogel to obtain several long hydrogels; in order to obtain the long hydrogels, the above-mentioned The processing method is the processing method well-known in the art and persons, and can be carried out by cutting, that is, the hydrogel is cut into several strips of hydrogel, and then several strips of hydrogels are obtained. Follow-up action.

The hydrogel involved in this application is one or both of bacterial cellulose hydrogel and bacterial cellulose composite hydrogel, wherein the bacterial cellulose hydrogel can be cut into long strips, and the bacterial cellulose hydrogel can be cut into strips. The cellulose composite hydrogel is cut into long strips, and both the bacterial cellulose hydrogel and the bacterial cellulose hydrogel composite hydrogel can be cut into long strips. The bacterial cellulose hydrogel is selected from the bacterial cellulose hydrogel obtained by bacterial fermentation, and the bacterial cellulose composite hydrogel is selected from one of macromolecules and nanomaterials and the composite water of bacterial cellulose. gel. The source of the bacterial cellulose hydrogel and the bacterial cellulose composite hydrogel is not particularly limited in this application. The thickness of the hydrogel described in the present application is 0.1 mm to 50 mm, and the water content is 5% to 90%. The strip-shaped hydrogel has a width of 0.5-30 mm and a length of more than 5 cm.

In the present application, the above-mentioned several long hydrogels are then woven in an orderly manner, and the orderly weaving method can be any weaving method, for example, a three-dimensional weaving method can be used; manual weaving or machine weaving can be used. During the weaving process, several long strips of bacterial cellulose hydrogels can be woven in an orderly manner, several long strips of bacterial cellulose composite hydrogels can be woven in an orderly manner, and several long strips of bacterial cellulose composite hydrogels can be woven in an orderly manner. Bacterial cellulose hydrogels and several long strips of bacterial cellulose composite hydrogels are woven in an orderly manner.

Finally, the obtained hydrogel is compressed to obtain a bacterial cellulose composite material with an ordered woven structure. The compression mode is a compression mode well known to those skilled in the art, and the technical mode thereof is not particularly limited in this application. The compression temperature is 0˜200° C., and the compression pressure is 1˜800 MPa; more specifically, the compression temperature is 50˜150° C., and the compression pressure is 50˜300 MPa.

The present application provides a method for preparing a bacterial cellulose composite material with an ordered weave structure. In the preparation process, the bacterial cellulose hydrogel and/or the bacterial cellulose composite material hydrogel are first cut into strips, and then the The elongated bacterial cellulose hydrogel and or bacterial cellulose composite hydrogel are woven in an orderly manner, and after compression, a bacterial cellulose composite material with an ordered woven structure is obtained, and the composite material has a very low thermal expansion rate , Lightweight, high strength, high impact resistance. The raw material used in this application is natural nanocellulose, which is safe, non-toxic and harmless, and can be naturally degraded.

In order to further understand the present invention, the preparation method of the bacterial cellulose composite material provided by the present invention with an ordered woven structure will be described in detail below with reference to the examples, and the protection scope of the present invention is not limited by the following examples.

Example 1

A) The bacterial cellulose hydrogel with a thickness of 0.5 mm, a width of 45 cm and a length of 45 cm is cut into pieces to obtain a strip of hydrogel with a thickness of 0.5 mm, a length of 45 cm and a width of 2 mm;

B) orderly and three-dimensionally weaving the bacterial cellulose hydrogel strip in step A), specifically three-dimensional weaving based on spatial P3 symmetry;

C) Put the mixture obtained in step B) into a mold, and compress it at a temperature of 80° C. and a pressure of 100 MPa to obtain a bacterial cellulose composite block with an ordered weave structure.

Fig. 1 is a photo of the bacterial cellulose composite material block with an ordered weaving structure prepared in the present embodiment; Fig. 2 is a microphotograph of the bacterial cellulose composite material block with an ordered weaving structure prepared in the present embodiment. After calculation, it can be known that, The density of the bacterial cellulose composite material block with the ordered woven structure prepared in this example is 1.15 g·cm ^-3 , and the thermal expansion coefficient is about 5 ppm/K.

The mechanical properties of the bacterial cellulose composite material block with ordered weaving structure prepared in this example are tested, as shown in Figure 3. Figure 3 The bacterial cellulose composite material block with ordered weaving structure prepared in this example is The compressive stress curve under strain, it can be seen from the figure that the bending strength of the bacterial cellulose composite material block with ordered woven structure prepared in this example can reach 90MPa, which is higher than that of the unwoven structure (thickness is 0.5mm, width is 45cm) , the bacterial cellulose hydrogel with a length of 45 cm is stacked to 100 layers, and the structure obtained by compression at a temperature of 80 ° C and a pressure of 100 MPa) is slightly reduced, but the strain corresponding to the maximum stress reaches 25%, an increase of ~ 10 times, the corresponding elongation at break reaches 45% when the strength is 25MPa.

Example 2

A) The bacterial cellulose/nanoclay sheet hydrogel with a nanoclay sheet content of 20%, a thickness of 1 mm, a width of 40 cm and a length of 50 cm is cut into pieces to obtain a thickness of 1 mm, a length of 50 cm and a width of 2 mm. hydrogel strips;

B) orderly and three-dimensionally weaving the bacterial cellulose hydrogel strip in step A), specifically three-dimensional weaving based on spatial R3 symmetry;

C) Put the mixture obtained in step B) into a mold, and compress at a temperature of 80° C. and a pressure of 100 MPa to obtain a bacterial cellulose composite block with an ordered weave structure.

After adding nanoclay flakes, the refractory performance of the block is significantly improved, and it can reach the standard of self-extinguishing from fire.

The descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (5)

1. a preparation method of a bacterial cellulose composite material with an ordered weave structure, comprising the following steps: A) processing the hydrogel to obtain several long strips of hydrogel; the hydrogel is selected from one or both of bacterial cellulose hydrogel and bacterial cellulose composite hydrogel; The water content of the hydrogel is 5-90%; B) orderly three-dimensional weaving of the several elongated hydrogels; C) compressing the hydrogel obtained in step B) to obtain a bacterial cellulose composite material with an ordered woven structure; The compression temperature is 50-150°C, and the compression pressure is 50-300 MPa. 2. preparation method according to claim 1 is characterized in that, described bacterial cellulose hydrogel is selected from bacterial cellulose hydrogel obtained by bacterial fermentation, and described bacterial cellulose composite hydrogel is selected from A composite hydrogel of one of macromolecular and nanomaterials and bacterial cellulose. 3 . The preparation method according to claim 1 , wherein the thickness of the hydrogel is 0.1 mm˜50 mm. 4 . 4 . The preparation method according to claim 1 , wherein the long hydrogel has a width of 0.5-30 mm and a length of >5 cm. 5 . 5. preparation method according to claim 1, is characterized in that, step B) is specially: Orderly weaving several long strips of bacterial cellulose hydrogels; Or, orderly weaving several long strips of bacterial cellulose composite hydrogels; Or, orderly weaving several long strips of bacterial cellulose hydrogels and several long strips of bacterial cellulose composite hydrogels.

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