阅读说明：本技术 一种壳聚糖-纤维素复合材料及其敷料 (Chitosan-cellulose composite material and dressing thereof ) 是由 马贵平 王良玉 陈广凯 聂俊 陈斌凌 于 2019-08-05 设计创作，主要内容包括：本发明提供的一种壳聚糖-纤维素复合材料及其制备方法,该方法以双端含氢硅氧烷、丙烯酸、壳聚糖、纤维素等为原料,分别经过硅氢加成反应、壳聚糖的酰胺化反应、纤维素的双键改性等多步骤反应完成,通过分子结构设计,调整聚合物结构以及优化聚合工艺,合成了一种新型纤维素基聚合物,并经冻干、高温处理,制得纤维素复合材料。该复合材料不仅有效解决目前纤维素性脆的应用缺陷,同时兼具抗菌抑菌的效用,可大大拓宽其应用领域。(The invention provides a chitosan-cellulose composite material and a preparation method thereof, the method takes hydrogen-containing siloxane with double ends, acrylic acid, chitosan, cellulose and the like as raw materials, and the raw materials are respectively subjected to multi-step reactions such as hydrosilylation reaction, amidation reaction of chitosan, double bond modification of cellulose and the like, a novel cellulose-based polymer is synthesized by molecular structure design, polymer structure adjustment and optimized polymerization process, and the cellulose-based polymer is prepared by freeze-drying and high-temperature treatment. The composite material not only effectively overcomes the defect of crisp application of the existing cellulose, but also has the effects of antibiosis and bacteriostasis, and can greatly widen the application field.)

1. A chitosan-cellulose composite material is characterized in that the structural formula is as follows:

wherein: n is 2-5.

2. A preparation method of a chitosan-cellulose composite material is characterized by comprising the following steps:

step 1): carrying out addition reaction on hydrogen-containing siloxane at the double ends and acrylic acid to obtain siloxane acrylic acid marked as A;

step 2): performing amidation reaction on siloxane acrylic acid A and chitosan to obtain modified chitosan, and marking as B;

step 3): reacting cellulose with olefine acid to obtain modified cellulose containing double bonds, and marking as C;

step 4): and carrying out addition reaction on the modified chitosan B and the modified cellulose C containing double bonds to obtain the chitosan-cellulose composite material.

3. The method for preparing a chitosan-cellulose composite material as claimed in claim 2, wherein: the step 1) is specifically as follows:

dissolving 1 part of hydrogen-containing double-end siloxane in 50 parts of tetrahydrofuran, and mixing 0.9-1.0 part of acrylic acid, 1 wt% of polymerization inhibitor and 10 parts of^-5Dissolving the catalyst in 10 parts of tetrahydrofuran, adding the tetrahydrofuran into a constant-pressure dropping funnel, controlling the dropping speed, stirring, reacting at 60-120 ℃ for 3-5 hours, distilling under reduced pressure to remove the solvent, adding 30 parts of toluene, excessive sodium bicarbonate and 10 parts of deionized water, stirring at 60 ℃ for 3 hours, separating a water phase, taking an organic layer, distilling under reduced pressure to remove the solvent to obtain siloxane acrylic acid, which is marked as A;

the amount of the polymerization inhibitor is 1 wt% of the mass of the acrylic acid.

4. The method for preparing a chitosan-cellulose composite material as claimed in claim 2, wherein: the step 2) is specifically as follows:

adding 1-1.2 parts of A into 0.1 wt% of a mixed solution of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, activating carboxyl for 4 hours at 4 ℃ in an ice bath, then placing the solution into an acetic acid solution dissolved with 1 part of chitosan, reacting for 10-24 hours at 4 ℃, standing for 10-24 hours at room temperature, and then carrying out suction filtration and vacuum drying on a reaction product for multiple times to obtain modified chitosan, which is marked as B;

the mass ratio of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride to the N-hydroxysuccinimide is 5:1, and the concentration of the acetic acid is 0.1 mol/L.

5. The method for preparing a chitosan-cellulose composite material as claimed in claim 2, wherein: the step 3) is specifically as follows:

adding 50 parts of 1-allyl-3-methylchloroimidazole ionic liquid into a three-neck flask, adding 1 part of cellulose under the condition of magnetic stirring, and introducing N₂Protecting, stirring at a set temperature to promote the cellulose to be completely dissolved, adding 0.3-0.4 part of N, N-dimethylformamide, 0.3-0.4 part of olefine acid and 0.1-0.2 part of 4-dimethylaminopyridine, reacting at 90-100 ℃ for 3-5h, pouring the reaction solution into distilled water after the reaction is finished, stirring, filtering to obtain a solid, washing with distilled water, and drying in vacuum to obtain the modified cellulose containing double bonds, which is marked as C.

6. The method for preparing a chitosan-cellulose composite material as claimed in claim 2, wherein: the step 4) is specifically as follows:

dissolving 1 part of B in 50 parts of tetrahydrofuran, and mixing 1.0-1.2 parts of C, 1 wt% of polymerization inhibitor and 10 parts of^-5Dissolving a catalyst in 10 parts of tetrahydrofuran, adding the solution into a constant-pressure dropping funnel, controlling the dropping speed, reacting at 60-120 ℃ for 3-5 hours, distilling under reduced pressure to remove the solvent, adding 30 parts of toluene, excessive sodium bicarbonate and 10 parts of deionized water, stirring at 60 ℃ for 3 hours, separating a water phase, taking an organic layer, distilling under reduced pressure to remove the solvent to obtain a target product, namely a chitosan-cellulose composite material, and marking as D1;

the amount of the polymerization inhibitor is 1 wt% of the mass of the double-bond-containing modified cellulose.

7. A method of preparing a chitosan-cellulose composite as claimed in any one of claims 3, 4, or 6, wherein: the polymerization inhibitor is 2, 6-di-tert-butyl-p-methylphenol, hydroquinone or p-hydroxyanisole.

8. The method for preparing a chitosan-cellulose composite material as claimed in claim 3 or 6, wherein: the catalyst is chloroplatinic acid, carbene alkane, platinum dioxide or aluminum trichloride.

9. The method for preparing a chitosan-cellulose composite material as claimed in claim 5, wherein: the olefine acid is maleic anhydride, glutaconic acid or hexenedioic acid.

10. A chitosan-cellulose composite dressing is characterized in that: the preparation method of the chitosan-cellulose composite dressing comprises the following steps:

(1) preparing 10 wt% chitosan-cellulose composite material solution, and performing freeze-drying treatment at-20 to-4 ℃ for 10 to 24 hours to obtain a spongy chitosan-cellulose composite material;

(2) treating the spongy chitosan-cellulose composite material at the high temperature of 80-200 ℃ for 2-6h to obtain the chitosan-cellulose composite material dressing.

Technical Field

The invention relates to a chitosan-cellulose composite material and a preparation method thereof.

Background

Cellulose is a natural organic polymer with the most abundant content in nature and capable of being regenerated, and the cellulose has wide sources, including plants, marine organisms and microorganisms. The chemical structure of cellulose is a macromolecule formed by connecting glucose units by beta-1, 4-glycosidic bonds, hydroxyl groups on C2, C3 and C6 of each glucose unit can form hydrogen bonds in and among the molecules of the cellulose macromolecule, and therefore, the cellulose molecule can form a crystal structure. In nature, cotton is a substance with an extremely high cellulose content, and the main component of plant fiber cell walls is also cellulose. Cellulose is also an important chemical raw material, and has wide application value in the fields of textile, clothing, medical and health, building materials, coatings and the like.

In recent years, the use of cellulose for materials has been studied more and the solvent research of cellulose has been in the hot direction because natural cellulose has a crystal structure, and from NaOH solution, NMMO solution, ionic liquid and eutectic solvent, new solvent systems have been studied to break the hydrogen bonds in the cellulose crystals, promote the dissolution of natural cellulose, and develop regenerated cellulose fibers for spinning. After the cellulose is dissolved, various chemical modifications can be carried out to prepare a plurality of functional cellulose base materials; in recent years, the interest of cellulose modified preparation and functional materials thereof has been increasing. However, due to the existence of a large number of hydrogen bonds in the cellulose structure and the repeating unit of the six-membered ring structure, the defects of high rigidity, brittleness and the like of the material in use limit the wide application of the cellulose.

Disclosure of Invention

The invention aims to overcome the defects of high rigidity, crisp property and difficult wide use of cellulose materials in the prior art, and provides a chitosan-cellulose composite material and a preparation method thereof.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a chitosan-cellulose composite material has a structural formula as follows:

wherein: n is 2-5.

A preparation method of a chitosan-cellulose composite material comprises the following steps:

step 1): carrying out addition reaction on hydrogen-containing siloxane at the double ends and acrylic acid to obtain siloxane acrylic acid marked as A;

step 2): performing amidation reaction on siloxane acrylic acid A and chitosan to obtain modified chitosan, and marking as B;

step 3): reacting cellulose with olefine acid to obtain modified cellulose containing double bonds, and marking as C;

step 4): and carrying out addition reaction on the modified chitosan B and the modified cellulose C containing double bonds to obtain the chitosan-cellulose composite material.

All expressed as mole fraction of reactive functional groups

Preferably, the step 1) is specifically:

dissolving 1 part of hydrogen-containing double-end siloxane in 50 parts of tetrahydrofuran, and mixing 0.9-1.0 part of acrylic acid, 1 wt% of polymerization inhibitor and 10 parts of^-5Dissolving the catalyst in 10 parts of tetrahydrofuran, adding the tetrahydrofuran into a constant-pressure dropping funnel, controlling the dropping speed, stirring, reacting at 60-120 ℃ for 3-5 hours, distilling under reduced pressure to remove the solvent, adding 30 parts of toluene, excessive sodium bicarbonate and 10 parts of deionized water, stirring at 60 ℃ for 3 hours, separating a water phase, taking an organic layer, distilling under reduced pressure to remove the solvent to obtain siloxane acrylic acid, which is marked as A;

the amount of the polymerization inhibitor is 1 wt% of the mass of the acrylic acid.

Preferably, the step 2) is specifically:

adding 1-1.2 parts of A into 0.1 wt% of a mixed solution of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, activating carboxyl for 4 hours at 4 ℃ in an ice bath, then placing the solution into an acetic acid solution dissolved with 1 part of chitosan, reacting for 10-24 hours at 4 ℃, standing for 10-24 hours at room temperature, and then carrying out suction filtration and vacuum drying on a reaction product for multiple times to obtain modified chitosan, which is marked as B; wherein the weight average molecular weight of the chitosan is 3000-8000.

The mass ratio of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride to the N-hydroxysuccinimide is 5:1, and the concentration of the acetic acid is 0.1 mol/L;

preferably, the step 3) is specifically:

adding 50 parts of 1-allyl-3-methylchloroimidazole ionic liquid into a three-neck flask, adding 1 part of cellulose under the condition of magnetic stirring, introducing N2 for protection, stirring at a set temperature to promote the cellulose to be completely dissolved, adding 0.3-0.4 part of N, N-dimethylformamide, 0.3-0.4 part of olefine acid and 0.1-0.2 part of 4-dimethylaminopyridine, reacting at 90-100 ℃ for 3-5h, pouring the reaction solution into distilled water after the reaction is finished, stirring, filtering to obtain a solid, washing with distilled water, and drying in vacuum to obtain the modified cellulose containing double bonds, which is marked as C.

Preferably, the step 4) is specifically:

dissolving 1 part of B in 50 parts of tetrahydrofuran, dissolving 1.0-1.2 parts of C, 1 wt% of polymerization inhibitor and 10-5 parts of catalyst in 10 parts of tetrahydrofuran, adding the mixture into a constant-pressure dropping funnel, controlling the dropping speed, reacting at 60-120 ℃ for 3-5h, carrying out reduced pressure distillation to remove the solvent, adding 30 parts of toluene, excessive sodium bicarbonate and 10 parts of deionized water, stirring at 60 ℃ for 3h, separating out a water phase, taking an organic layer, and carrying out reduced pressure distillation to remove the solvent to obtain a target product, namely the chitosan-cellulose composite material, which is recorded as D1;

the amount of the polymerization inhibitor is 1 wt% of the mass of the double-bond-containing modified cellulose.

Preferably, the polymerization inhibitor is 2, 6-di-tert-butyl-p-methylphenol (BHT), hydroquinone or p-hydroxyanisole (MEHQ).

Preferably, the catalyst is chloroplatinic acid, carbene alkane, platinum dioxide or aluminum trichloride.

Preferably, the alkenoic acid is maleic anhydride, glutaconic acid or hexenedioic acid.

A chitosan-cellulose composite dressing, a preparation method of the chitosan-cellulose composite dressing comprises the following steps:

(1) preparing 10 wt% chitosan-cellulose composite material solution, and performing freeze-drying treatment at-20 to-4 ℃ for 10 to 24 hours to obtain a spongy chitosan-cellulose composite material;

(2) treating the spongy chitosan-cellulose composite material at the high temperature of 80-200 ℃ for 2-6h to obtain the chitosan-cellulose composite material dressing.

The preparation process of the cellulose composite material provided by the invention is as follows:

the invention has the beneficial effects that:

(1) the invention provides a preparation method of a cellulose composite material by using cellulose as a matrix, chitosan and cross-linking of hydrogen-containing siloxane at two ends.

(2) According to the preparation method of the chitosan-cellulose composite material, provided by the invention, hydrogen-containing siloxane at the double ends is used as a crosslinking material, on one hand, the bond energy of a silicon-oxygen bond in the siloxane is very large, so that the thermal stability of the siloxane is very good; on the other hand, the long bond length of the silicon-oxygen bond and the large angle of the silicon-oxygen bond make the molecular chain very soft and provide sufficient flexibility.

(3) According to the preparation method of the chitosan-cellulose composite material, provided by the invention, double-end hydrogen-containing siloxane is used as a crosslinking material, wherein the number of (n ═ 2-5) silicon atoms in the double-end hydrogen-containing siloxane is controlled to be 4-7, so that the molecular weight is lower and the reaction activity is higher; on the other hand, too high or too low molecular weight may result in the rigidity and toughness of the composite material not reaching a proper balance point.

(4) According to the preparation method of the chitosan-cellulose composite material, the high-temperature treatment temperature after freeze-drying is set to be 80-200 ℃, so that on one hand, complete unfolding of siloxane is guaranteed, the maximum elasticity is achieved, and on the other hand, slow degradation of silicon-oxygen bonds caused by high-temperature baking at the temperature of more than 200 ℃ is effectively avoided.

(5) According to the chitosan-cellulose composite material provided by the invention, chitosan and cellulose are subjected to composite crosslinking, so that on one hand, the chitosan is also a high-molecular polysaccharide polymer widely existing in nature, and the biocompatibility is good; on the other hand, has the function of antibacterial flocculation due to the structure of the antibacterial flocculant.

(6) The chitosan-cellulose composite material provided by the invention has higher rigidity and elasticity, has the effects of resisting bacteria and sterilizing, and solves the problems existing in the conventional application process of cellulose. Meanwhile, the product cost is controllable, the cellulose.

Drawings

The invention is further illustrated with reference to the following figures and examples.

Fig. 1 is a chitosan-cellulose composite dressing prepared by the application example 1 of the present invention.

The specific implementation mode is as follows:

the present invention will be described in detail with reference to examples. It is to be understood, however, that the following examples are illustrative of embodiments of the present invention and are not to be construed as limiting the scope of the invention.