阅读说明：本技术 一种添加姜黄素纳米颗粒的cmc-壳聚糖胶黏剂的制备方法 (Preparation method of CMC-chitosan adhesive added with curcumin nanoparticles ) 是由 董世良 李冉 章悦 叶明樵 陈琳 于 2021-08-23 设计创作，主要内容包括：本发明提供一种添加姜黄素纳米颗粒的CMC-壳聚糖胶黏剂的制备方法,属于胶黏剂生产技术领域,包括以下步骤：(1)姜黄素微纳米颗粒的制备；将姜黄素、乙醇混合以后制得姜黄素溶液,将酪蛋白溶液与所述姜黄素溶液搅拌混合,得到酪蛋白-姜黄素溶液,将酪蛋白-姜黄素溶液离心,得到含有姜黄素微纳米颗粒的上清液；(2)羧甲基纤维素、壳聚糖凝胶的制备；将羧甲基纤维素溶于水中,得到羧甲基纤维素溶液,加入部分上清液,搅拌均匀后加入壳聚糖、冰醋酸,搅拌均匀后得到添加姜黄素的CMC-壳聚糖胶黏剂。本发明向CMC胶黏剂中加入姜黄素微纳米颗粒、壳聚糖不会改变胶黏剂的粘度和对烟叶的初粘性,能够提高胶黏剂的抗菌性的效果。(The invention provides a preparation method of a CMC-chitosan adhesive added with curcumin nanoparticles, belonging to the technical field of adhesive production and comprising the following steps: (1) preparing curcumin micro-nano particles; mixing curcumin and ethanol to obtain curcumin solution, stirring and mixing casein solution and the curcumin solution to obtain casein-curcumin solution, and centrifuging the casein-curcumin solution to obtain supernatant containing curcumin micro-nano particles; (2) preparing carboxymethyl cellulose and chitosan gel; dissolving carboxymethyl cellulose in water to obtain carboxymethyl cellulose solution, adding part of supernatant, stirring uniformly, adding chitosan and glacial acetic acid, and stirring uniformly to obtain the CMC-chitosan adhesive added with curcumin. According to the invention, the curcumin micro-nano particles and chitosan are added into the CMC adhesive, so that the viscosity of the adhesive and the initial viscosity of the adhesive to tobacco leaves are not changed, and the antibacterial effect of the adhesive can be improved.)

1. A preparation method of CMC-chitosan adhesive added with curcumin nanoparticles is characterized by comprising the following steps:

(1) preparing curcumin micro-nano particles;

mixing curcumin and ethanol to obtain curcumin solution, stirring and mixing casein solution and the curcumin solution to obtain casein-curcumin solution, and centrifuging the casein-curcumin solution to obtain supernatant containing curcumin micro-nano particles;

(2) preparing carboxymethyl cellulose and chitosan gel;

dissolving carboxymethyl cellulose in water to obtain carboxymethyl cellulose solution, adding partial supernatant, uniformly stirring, adding chitosan and glacial acetic acid, and uniformly stirring to obtain the CMC-chitosan adhesive added with curcumin, wherein the ratio of the carboxymethyl cellulose to the chitosan is 1:0.05-0.5, and the mass ratio of the carboxymethyl cellulose to the partial supernatant is 10: 1.

2. The preparation method of the CMC-chitosan adhesive added with curcumin nanoparticles as claimed in claim 1, wherein the concentration of the curcumin solution is 15-20% g/L.

3. The method for preparing CMC-chitosan adhesive added with curcumin nanoparticles as claimed in claim 2, wherein the concentration of the casein solution is the same as that of the curcumin solution.

4. The preparation method of the CMC-chitosan adhesive added with curcumin nanoparticles as claimed in claim 3, wherein the volume ratio of the casein solution to the curcumin solution is 1: 1.

5. The method for preparing CMC-chitosan adhesive with added curcumin nanoparticles as claimed in claim 1, wherein the rotation speed of the centrifugation in step (1) is 5500-6000rpm, and the centrifugation time is 15 min.

6. The preparation method of the CMC-chitosan adhesive added with curcumin nanoparticles as claimed in claim 1, wherein the rotation speed of the stirring, mixing and stirring is 600rpm, and the stirring time is 1.5-2 h.

7. The preparation method of the CMC-chitosan adhesive added with curcumin nanoparticles as claimed in claim 1, wherein the ratio of the carboxymethyl cellulose to the chitosan is 1: 0.25-0.5.

8. The preparation method of the CMC-chitosan adhesive added with curcumin nanoparticles as claimed in claim 7, wherein the mass ratio of the carboxymethyl cellulose to the chitosan is 1: 0.25.

9. The method for preparing CMC-chitosan adhesive added with curcumin nanoparticles as claimed in claim 8, wherein the mass of glacial acetic acid is 0.5 times that of carboxymethyl cellulose.

Technical Field

The invention relates to the technical field of adhesive production, and particularly relates to a preparation method of a CMC-chitosan adhesive added with curcumin nanoparticles.

Background

The adhesive bonding (bonding, adhering, cementing and gluing) refers to a technology for connecting the surfaces of homogeneous or heterogeneous objects together by using an adhesive, and has the characteristics of continuous stress distribution, light weight, sealing, low process temperature and the like. The glue joint is particularly suitable for connecting different materials, different thicknesses, ultrathin specifications and complex components. The adhesive joint is the fastest in recent development and has wide application industry. The adhesives can be classified into thermosetting type, hot melt type, room temperature curing type, pressure sensitive type and the like according to application methods, structural type, non-structural type or special adhesive according to application objects, and water soluble type, water emulsion type, solvent type, various solid types and the like according to connection forms. Synthetic chemists often prefer to classify adhesives by the chemical composition of the binder.

The kinds of adhesives are various, and the adhesives are simply classified according to different standards as follows.

1. According to the chemical properties of the adhesive binder, the adhesive binder can be classified into inorganic adhesives and organic adhesives, for example, water glass, cement, gypsum and the like can be used as the inorganic adhesives, and the adhesives using polymer materials as the binder belong to the organic adhesives.

2. According to the physical state of the adhesive, the adhesive can be classified into liquid, solid and paste adhesives, wherein the solid adhesive has powder and film shapes, and the liquid adhesive can be classified into aqueous solution type, organic solution type, aqueous emulsion type, non-aqueous medium dispersion type and the like.

3. The adhesives can be classified into natural adhesives and synthetic adhesives according to the source of the adhesives, for example, natural rubber, asphalt, rosin, gelatin, cellulose, starch glue, etc. belong to the natural adhesives, and various adhesives artificially synthesized by a polymerization method belong to the category of the synthetic adhesives.

4. Common organic adhesives can be classified into thermoplastic resins, thermosetting resins, rubber adhesives and the like according to molecular structures.

5. The adhesive can be classified into pressure-sensitive adhesive, rewetting adhesive, instant adhesive, delayed adhesive, and the like according to the application mode of the adhesive.

6. The adhesives can be classified into adhesives which are high temperature resistant, low temperature resistant and used at normal temperature from the range of the use temperature of the adhesives, and adhesives which are normal temperature curing type, medium temperature curing type and high temperature curing type according to the curing temperature of the adhesives.

7. From the field of application of adhesives, the adhesives are mainly classified into the types of adhesives for civil construction, paper and plants, automobiles, airplanes and ships, electronics and electrical, and medical health, and the like.

8. The chemical components of the adhesive can be classified into various specific adhesive types, such as epoxy resin adhesive, polyurethane adhesive, polyvinyl acetate adhesive, and the like.

In the process of cigarette production, an adhesive is used on the cigarette paper, the cigarette paper prepared from plant cellulose has strong water absorbability, and when a water-based adhesive (aqueous solution or aqueous emulsion adhesive) is used for bonding the paper, the phenomenon of paper wrinkling caused by water absorption and swelling of the cellulose occurs, so that the adhesive with low moisture content (high solid content) is used as far as possible, but the difficulty of gluing is brought because the solid content is too high.

The published Chinese patent with the application number of CN201410156021.2 provides an adhesive for cigarettes, which is prepared from the following components in parts by weight: 30-40 parts of cassava starch, 30-40 parts of carboxymethyl starch, 5-10 parts of isocyanate, 2-5 parts of sodium trimetaphosphate, 0.1-0.5 part of uric acid, 10-30 parts of polyvinyl alcohol, 10-15 parts of bentonite, 0.1-0.5 part of sodium dodecyl sulfate and 150-200 parts of water. The invention also provides a preparation method of the adhesive for cigarettes. The cigarette adhesive prepared by oxidizing, crosslinking and modifying the starch for the adhesive for cigarettes by polyvinyl alcohol has various properties meeting the indexes of the cigarette adhesive, has good product performance, and has the characteristics of corrosion resistance, low cost, no harm to human bodies, simple process and the like.

CMC is a common adhesive for the existing cigars. However, in the long-term storage process of the cigars, microorganisms such as mold and the like are generated at the adhesive part, thereby influencing the appearance and storage of the cigars. The carboxymethyl cellulose adhesive is prepared by mixing carboxymethyl cellulose (CMC) and a proper amount of water, has good transparency, has higher viscosity in an aqueous solution, does not cause gel due to temperature change, and has strong stability to heat and light. Wherein the carboxymethyl cellulose is prepared by reacting monochloroacetic acid with cellulose under alkaline conditions, and is tasteless, odorless and nontoxic white powder, and the etherification degree of a common product is about 0.5-0.8. However, since cigars are often stored for a long time, they are alcoholized because the use of adhesives can cause the cigars to deteriorate and mildew.

Disclosure of Invention

In view of the above, the invention provides a preparation method of a CMC-chitosan adhesive added with curcumin nanoparticles, the adhesive prepared by the invention has good antibacterial property, the effect of improving the antibacterial property of the adhesive is realized by adding the curcumin nanoparticles into the adhesive, the antibacterial property of cigars can be improved when the adhesive is applied to cigar production, and the cigars cannot mildew after being stored for a long time.

The invention relates to a preparation method of a CMC-chitosan adhesive added with curcumin nanoparticles, which comprises the following steps:

(1) preparing curcumin micro-nano particles;

mixing curcumin and ethanol to prepare a curcumin solution, wherein the concentration of the curcumin solution is 15-20% g/L, stirring and mixing a casein solution and the curcumin solution at the rotating speed of 600rpm for 1.5-2h to obtain a casein-curcumin (NPs) solution, wherein the concentration of the casein solution is the same as that of the curcumin solution, the volume ratio of the casein solution to the curcumin solution is 1:1, centrifuging the casein-curcumin (NPs) solution, and centrifuging at the rotating speed of 5500-6000rpm for 15min to obtain a supernatant containing micro-nano particles;

(2) preparing carboxymethyl cellulose and chitosan gel;

dissolving carboxymethyl cellulose in water to obtain carboxymethyl cellulose solution, adding part of supernatant, uniformly stirring, adding chitosan and glacial acetic acid, and uniformly stirring to obtain the CMC-chitosan adhesive added with curcumin, wherein the ratio of the carboxymethyl cellulose to the chitosan is 1:0.05-0.5, for example: the ratio of the carboxymethyl cellulose to the chitosan can be 1:0.25-0.5 or 1:0.25, the mass of the glacial acetic acid is 0.5 times of that of the carboxymethyl cellulose, and the mass ratio of the carboxymethyl cellulose to part of the supernatant is 10: 1.

The surface of the chitosan is provided with abundant amino, which is the key of the antibacterial property of the chitosan. At present, a large number of researchers have researched the influence factors on the antibacterial property of chitosan, and research finds that the source, the degree of deacetylation, the molecular mass, the concentration and the like of chitosan have great influence on the antibacterial effect, and meanwhile, the pH, the water content, the solvent and other external factors of the environment also have obvious influence on the antibacterial property of chitosan. The chitosan can be dissolved in acetic acid solution, and under acidic environment, CS is dissolved to make-NH₂Is protonated to form-NH₃ ⁺Forming polycation, and generating-COO after CMC is dissolved^-Polyanion is formed, a stable polyelectrolyte network structure is easily formed due to the electrostatic action among ions, and the adhesive can be stabilized, so that the shearing force of the CMC adhesive added with other substances cannot be changed. Curcumin can inhibit the growth of bacteria such as Streptococcus, Staphylococcus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella, inhibit the formation of bacterial biofilm, increase the ability of organism to remove bacteria, and reduce injury by reducing inflammatory cell aggregation, cytokine overexpression, and increasing active oxygen scavenging ability. The film formed by the adhesive formed by mixing curcumin and chitosan after film formation has good antibacterial property, the first reason is that electrostatic interaction is generated between chitosan molecules with positive charges and bacterial cell membranes with negative charges, so that the property of the bacterial surface film is changed and damaged, the metabolism of bacteria is inhibited, the bacteria die, and the bactericidal effect is achieved; the second is that chitosan penetrates cell walls and membranes into human bacteriaInside the cell, binding to DNA prevents transcription of DNA; and the third is that chitosan is chelated with metal ions, so that the uptake of trace elements required by the growth of microorganisms is reduced. After the curcumin is added, the curcumin and the curcumin have synergistic effect, and the antibacterial effect of the membrane is enhanced.

According to the invention, the curcumin micro-nano particles are added into the adhesive, and play antibacterial and bacteriostatic roles together with chitosan, so that the effect of improving the antibacterial property of the adhesive is realized, the antibacterial property of cigars can be improved when the curcumin micro-nano particles are applied to cigar production, and the curcumin micro-nano particles can be stored for a long time without mildewing.

Drawings

Fig. 1 is a shear viscosity test result chart of an adhesive prepared by a preparation method of a CMC-chitosan adhesive added with curcumin nanoparticles according to an embodiment of the present invention;

fig. 2 is a test result graph of initial adhesion force of tobacco leaves of the adhesive prepared by the preparation method of the CMC-chitosan adhesive added with curcumin nanoparticles according to the embodiment of the present invention;

fig. 3 is a graph of the measurement result of the antibacterial property of the adhesive prepared by the preparation method of the CMC-chitosan adhesive added with curcumin nanoparticles in the embodiment of the present invention.

Detailed Description

The present invention will be described in detail with reference to specific embodiments.

Example 1

A preparation method of CMC-chitosan adhesive added with curcumin nanoparticles comprises the following steps:

(1) preparing curcumin micro-nano particles;

mixing curcumin and ethanol to prepare a curcumin solution, wherein the concentration of the curcumin solution is 15% g/L, stirring and mixing a casein solution and the curcumin solution at the rotation speed of 600rpm for 1.5h to obtain a casein-curcumin (NPs) solution, wherein the concentration of the casein solution is the same as that of the curcumin solution, the volume ratio of the casein solution to the curcumin solution is 1:1, centrifuging the casein-curcumin (NPs) solution at the rotation speed of 5500rpm for 15min to obtain a supernatant containing curcumin micro-nano particles, and wrapping a beaker by using tinfoil paper in the stirring process;

(2) preparing carboxymethyl cellulose and chitosan gel;

dissolving carboxymethyl cellulose in water to obtain carboxymethyl cellulose solution, adding part of the supernatant, stirring, adding chitosan and glacial acetic acid, and stirring for 10 min. And sealing and standing overnight at room temperature, and uniformly stirring to obtain the CMC-chitosan adhesive added with curcumin, wherein the ratio of the carboxymethyl cellulose to the chitosan is 1:0.05, the mass of the glacial acetic acid is 0.5 time of that of the carboxymethyl cellulose, and the mass ratio of the carboxymethyl cellulose to part of the supernatant is 10: 1.

Example 2

A preparation method of CMC-chitosan adhesive added with curcumin nanoparticles comprises the following steps:

(1) preparing curcumin micro-nano particles;

mixing curcumin and ethanol to prepare a curcumin solution, wherein the concentration of the curcumin solution is 20% g/L, stirring and mixing the casein solution and the curcumin solution at the rotation speed of 600rpm for 2 h. Obtaining a casein-curcumin (NPs) solution, wherein the concentration of the casein solution is the same as that of the curcumin solution, the volume ratio of the casein solution to the curcumin solution is 1:1, centrifuging the casein-curcumin (NPs) solution, and centrifuging for 15min at the rotating speed of 6000rpm to obtain a supernatant containing curcumin micro-nano particles;

(2) preparing carboxymethyl cellulose and chitosan gel;

dissolving carboxymethyl cellulose in water to obtain carboxymethyl cellulose solution, adding part of the supernatant, stirring, adding chitosan and glacial acetic acid, and stirring for 10 min. And sealing and standing overnight at room temperature, and uniformly stirring to obtain the CMC-chitosan adhesive added with curcumin, wherein the ratio of the carboxymethyl cellulose to the chitosan is 1: 0.5, the mass of the glacial acetic acid is 0.5 time of that of the carboxymethyl cellulose, and the mass ratio of the carboxymethyl cellulose to part of the supernatant is 10: 1.

Example 3

A preparation method of CMC-chitosan adhesive added with curcumin nanoparticles comprises the following steps:

(1) preparing curcumin micro-nano particles;

mixing curcumin and ethanol to prepare a curcumin solution, wherein the concentration of the curcumin solution is 17% g/L, stirring and mixing a casein solution and the curcumin solution at the rotation speed of 600rpm for 1.7h to obtain a casein-curcumin (NPs) solution, wherein the concentration of the casein solution is the same as that of the curcumin solution, the volume ratio of the casein solution to the curcumin solution is 1:1, centrifuging the casein-curcumin (NPs) solution, and centrifuging at the rotation speed of 5600rpm for 15min to obtain a supernatant containing curcumin micro-nano particles;

(2) preparing carboxymethyl cellulose and chitosan gel;

dissolving carboxymethyl cellulose in water to obtain carboxymethyl cellulose solution, adding partial supernatant, adding chitosan and glacial acetic acid after uniformly stirring, continuously stirring for 10min to obtain the CMC-chitosan adhesive added with curcumin after uniformly stirring, wherein the ratio of the carboxymethyl cellulose to the chitosan is 1:0.25, the mass of the glacial acetic acid is 0.5 time of that of the carboxymethyl cellulose, and the mass ratio of the carboxymethyl cellulose to the partial supernatant is 10: 1.

Example 4

A preparation method of CMC-chitosan adhesive added with curcumin nanoparticles comprises the following steps:

(1) preparing curcumin micro-nano particles;

mixing curcumin and ethanol to prepare a curcumin solution, wherein the concentration of the curcumin solution is 18% g/L, stirring and mixing a casein solution and the curcumin solution at the rotation speed of 600rpm for 2h to obtain a casein-curcumin (NPs) solution, wherein the concentration of the casein solution is the same as that of the curcumin solution, the volume ratio of the casein solution to the curcumin solution is 1:1, centrifuging the casein-curcumin (NPs) solution, and centrifuging at the rotation speed of 6000rpm for 15min to obtain a supernatant containing micro-nano curcumin particles;

(2) preparing carboxymethyl cellulose and chitosan gel;

dissolving carboxymethyl cellulose in water to obtain carboxymethyl cellulose solution, adding partial supernatant, uniformly stirring, adding chitosan and glacial acetic acid, and uniformly stirring to obtain the CMC-chitosan adhesive added with curcumin, wherein the ratio of the carboxymethyl cellulose to the chitosan is 1:0.4, the mass of the acetic acid is 0.5 time of that of the carboxymethyl cellulose, and the mass ratio of the carboxymethyl cellulose to the partial supernatant is 10: 1.

The particle size of the curcumin micro-nano particles in examples 1 to 4 was measured. A part of supernatant containing curcumin micro-nano particles is diluted, hydrodynamic diameter of the supernatant is measured by using an Anton Paar microtisizer 500 and a dynamic light scattering method GmbH, samples in each embodiment are measured for 5 times, and then an average value is taken, wherein the measurement result is as follows:

shear viscosity test

The CMC-chitosan adhesive with curcumin added in examples 1 to 4 was subjected to a viscosity test using Anton Paar MCR302 rheometer at 20 ℃ using PP50, and a CMC adhesive was selected as a control group under conditions of log-law change in shear rate: 0.1-10001/s. After 2 replicates per experiment, the mean was calculated. The specific test results are shown in FIG. 1. It can be seen that the addition of chitosan and micro curcumin had no effect on the shear viscosity of the CMC adhesive.

Measurement of initial adhesion of CMC-chitosan adhesive added with curcumin to tobacco leaves

Tobacco leaves were cut into a rectangle having a length of 10cm × a width of 2cm, 0.4g of the curcumin-added CMC-chitosan adhesive prepared in examples 1 to 4 and the CMC adhesive (as a control group) were weighed, and the adhesive was uniformly applied to one side of the leaf by hand, with the amount of adhesive per unit area being 0.02g/cm²Before gluing, the moisture of the tobacco leaves is controlled to be about 33 percent by a watering can. MiningInitial adhesion was measured using a Texture Profile Analysis instrument (5 Kg sensor) and a P/55 mm Dia Cylinder Probe. The pre-measurement speed was set to 0.50mm/sec, the post-measurement speed was set to 5mm/sec, the applied force was 200g, the return distance was 5mm, the contact time was 10sec, and the trigger force was 5 g. Each tobacco leaf strip was measured at 6 points randomly, and each set of experiments was repeated twice. The average value of the initial adhesion was calculated from 24 data points. The measured result refers to fig. 2, and it can be seen that the addition of chitosan and micro curcumin has no influence on the initial adhesion of the CMC adhesive to tobacco leaves, and the initial adhesion of the CMC adhesive to tobacco leaves is not reduced.

Measurement of antibacterial property of adhesive on tobacco leaves

According to GB 4789.15-2016. Cutting 1g of tobacco leaves, uniformly coating the adhesives prepared in examples 1 to 4 and CMC adhesive (used as a control group) on the surface of the tobacco leaves (3.2 g of adhesive per g of tobacco leaves) and standing for 20min, additionally arranging a group of blank groups, coating clear water on the blank groups, soaking the tobacco leaves in a beaker filled with 49mL of sterile liquid for 20min to elute microorganisms on the tobacco leaves, diluting, and preparing 10 g of tobacco leaves^-1，10^-2，10^-3Series of gradient samples. Adding 20-25 mL of sterile culture medium, namely potato dextrose agar (PDA, chloramphenicol), into each plate, taking 1mL of sterile culture medium for each dilution, and simultaneously sucking 1mL of sterile dilution as a blank control. And (3) uniformly coating, after the plate is dried, putting the plate into a 30 ℃ biochemical incubator for culture for 5d, and then counting colonies. The measurement result is shown in fig. 3, the use of the CMC adhesive can increase microorganisms on the surface of the tobacco leaves by 12 times, the adhesive prepared by the method can greatly inhibit the growth of microorganisms on the surface of the tobacco leaves, can kill 99% of microorganisms on the surface of the tobacco leaves, and has great antibacterial superiority.

The adhesive prepared by the invention has good antibacterial property, the viscosity of the adhesive and the initial viscosity of tobacco leaves cannot be changed by adding the curcumin micro-nano particles and the chitosan into the CMC adhesive, the antibacterial property of the adhesive can be improved, the antibacterial property of cigars can be improved when the adhesive is applied to cigar production, and the cigars cannot mildew after being stored for a long time.

The present invention is not limited to the above-described specific embodiments, and various modifications and variations are possible. Any modifications, equivalents, improvements and the like made to the above embodiments in accordance with the technical spirit of the present invention should be included in the scope of the present invention.