KR101417871B1

KR101417871B1 - O-acylated chitin butyrate-clay composite and antibiotic film using composite and method for preparing film

Info

Publication number: KR101417871B1
Application number: KR1020120050450A
Authority: KR
Inventors: 채규윤; 이덕희; 정진아; 송창현; 송미선; 문재정
Original assignee: 원광대학교산학협력단
Priority date: 2012-05-11
Filing date: 2012-05-11
Publication date: 2014-07-14
Also published as: KR20130126363A

Abstract

The present invention relates to an O-acylated chitin butyrate-clay complex, an antimicrobial film using the same, and a process for producing an antimicrobial film. Since the O-acylated chitin butyrate has antimicrobial properties and is biodegradable, the complex according to the present invention does not cause environmental pollution unlike petroleum-based polymer materials and has an effect of recycling resources, There are also less hygiene and safety issues. Further, clay is mixed as O-acylated chitin butyrate as a reinforcing agent, and a plasticizer is mixed, thereby forming superior thermal and mechanical characteristics, thereby forming a durable film.

Description

[0001] The present invention relates to an O-acylated chitin butyrate-clay composite, an antimicrobial film using the O-acylated chitin butyrate-clay composite,

The present invention relates to an O-acylated chitin butyrate-clay complex, an antimicrobial film using the same, and a process for producing an antimicrobial film. More particularly, the present invention relates to a process for producing an O- acylated chitin butyrate- , An antimicrobial film using the same, and a method for producing an antimicrobial film.

Chitin is a kind of mucopolysaccharide chemically, and is a natural polymeric material rich in cellulosic substances in nature, which constitutes the exoskeleton of crustaceans such as crabs, shrimp, and insects, or cell walls of fungi. Chitin is a polysaccharide composed of an amino sugar and N-acetylglucosamine is polymerized with a β-1,4 bond. It is a white powder that does not dissolve in water, has poor reactivity, and is more stable than cellulose. Chitosan can also be obtained by deacetylating chitin with a strong alkali such as sodium hydroxide. The chemical structure of chitin is similar to that of cellulose, and the chitin structure is as follows.

[Chitin]

Today, as consumers are increasingly concerned about the environmental problems and the limitations of petroleum feedstocks due to rising prices, the need for environmentally friendly, nontoxic and inexpensive new materials is being raised. In this regard, renewable biopolymers, such as starch, cellulose and chitin, can be a good alternative to petroleum feedstocks due to their low toxicity and biodegradability. In addition, films and fibers made of chitin or chitosan are known to exhibit complex functions such as antibacterial, deodorizing and moisturizing effects.

It is required to acylate chitin in order to improve the physical properties such as the biological activity of chitin or the solubility in organic solvents and it is necessary to use an acid anhydride, a mixed anhydride, an acyl chloride, Several methods have been reported for acylating chitin using benzoyl chloride and methane sulfonic acid, p-toluene sulfonyl chloride, lithium chloride, carboxylic acid, and the like. Among them, the mixed anhydride method using trifluoroacetic anhydride, phosphoric acid, and carboxylic acid was most remarkable in terms of reaction yield, reaction conditions, low cost, and recyclability of the reagent. Have been used to prepare aliphatic and aromatic ester derivatives of chitin. The structural formula of O-acylated chitin butyrate is as follows.

[O-acylated chitin butyrate]

Although the characteristics of acylated chitin butyrate are suitable for producing antimicrobial films and the like, the biopolymers such as chitin can not be completely broken or can not completely block the gas, the weak heat, There is a limit to the industrial use of materials. To overcome these limitations, studies have been reported to change the properties of biopolymers by adding plasticizers or reinforcing agents.

Plasticizers are widely used as additives in the polymer industry because they increase the flexibility and processability of polymers. Particularly, interest in plasticizers having biodegradability and low toxicity such as polyethylene glycol (PEG) is increasing. The effects of plasticizers such as polyethylene glycol on the mechanical and surface properties of chitosan films have been investigated. Chitosan films made with polyethylene glycol 20% (w / w) have flexibility and are also good for storage for 5 months. Stability.

Chitin is known to be used to make films or textiles. The durable film was obtained by solvent casting chitin on dimethyl formaldehyde. In 2009, Schoukens et al. (Schoukens et al.) Found that dibutyrylchitin was mixed with 10-20 wt% poly-caprolactone and solvent cast into acetone to obtain films with good flexibility and transparency.

Up to now, there have been no studies on O-acylated chitin butyrate complexes using polyethylene glycol and clay. Therefore, there is a desperate need for studies on O-acylated chitin butyrate complexes and films with good flexibility and transparency.

The present inventors have found that by reacting O-acylated chitin butyrate, clay and plasticizer having antibacterial properties and biodegradability in an organic solvent, it is possible to produce a film having improved thermal and mechanical properties as compared with a conventional film made of chitin or chitosan The present inventors have found out the fact and have completed the present invention.

Accordingly, the present invention seeks to provide an O-acylated chitin butyrate-clay complex.

The present invention also provides an antibacterial film using the complex and a method for producing the same.

The present invention provides O-acylated chitin butyrate-clay complexes.

The present invention also provides an antimicrobial film using the complex and a method of producing the same.

The O-acylated chitin butyrate-clay complex according to the present invention is characterized in that O-acylated chitin butyrate has antimicrobial properties and biodegradability, so that it does not cause environmental pollution unlike petroleum-based polymer materials, There is little problem of hygiene and safety when used as food packaging. Further, clay is mixed as O-acylated chitin butyrate as a reinforcing agent, and a plasticizer is mixed, thereby forming superior thermal and mechanical characteristics, thereby forming a durable film.

Brief Description of the Drawings Fig. 1 shows FT-IR measurement results of a film using O-acylated chitin butyrate-clay.
2 is a diagram showing the DSC measurement result of a film using O-acylated chitin butyrate-clay.
FIG. 3 shows TGA measurement results of a film using O-acylated chitin butyrate-clay. FIG.
FIG. 4 is a diagram showing Young's modulus measurement results of a film using O-acylated chitin butyrate-clay. FIG.
( CBPC-25A : O-acylated chitin butyrate 75% + polyethylene glycol 20% + cholanite 25A 5%, CBPC-30B : O-acylated chitin butyrate 75% + polyethylene glycol 20% , CBPC-NA ^+: O- acylated chitin butyrate 75% + 20% + polyethylene glycol claw site NA ⁺ 5%, CBP: O- acylated chitin butyrate + 80% polyethylene glycol 20%, CB: Oh O- 100% of actualized chitin butyrate)

The present invention provides O-acylated chitin butyrate-clay complexes.

The O-acylated chitin butyrate is prepared by mixing butyric acid, trifluoroacetic anhydride, phosphoric acid, and chitin, adding ethyl alcohol, mixing, filtering, and precipitating with diethyl ether.

The clay is preferably, but not limited to, closite 30B, claw site 25A, or claw site Na ⁺ .

The present invention also provides an antibacterial film comprising the complex.

In addition,

1) mixing butyric acid, trifluoroacetic anhydride, phosphoric acid, and chitin;

2) adding ethyl alcohol to the mixture of the first step and mixing, filtering and precipitating with diethyl ether to obtain O-acylated chitin butyrate;

3) dissolving the O-acylated chitin butyrate obtained in the second step in an organic solvent, adding a plasticizer and then adding clay to prepare an O-acylated chitin butyrate-clay complex; And

4) solvent casting the composite of step 3) to form a film;

And a method for producing the antimicrobial film.

Hereinafter, a method of producing the antibacterial film according to the present invention will be described in detail in stages.

The above steps 1) and 2) are the steps of preparing O-acylated chitin butyrate. First, butyric acid and trifluoroacetic anhydride are mixed, and then 70-95% phosphoric acid, preferably 85% phosphoric acid, Mix. The chitin is then added thereto and the reaction mixture is stirred for 1 to 10 days at 1 to 10 DEG C, preferably at 5 DEG C for 3 days. Ethyl alcohol is added to the mixture, mixed and filtered. It is then dissolved in diethyl ether to precipitate the product. The product is filtered, washed repeatedly with diethyl ether and water, and filtered to obtain in the form of a solid powder. The resulting powder is dried for 1 to 5 days, preferably for 3 days to produce O-acylated chitin butyrate.

The step 3) is a step of preparing an O-acylated chitin butyrate-clay complex. The O-acylated chitin butyrate prepared in the step 2) is added to an organic solvent and heated at 20 to 30 ° C for 10 to 30 hours Preferably at room temperature for 24 hours, and then stirred at 30 to 70 DEG C for 1 to 5 hours, preferably at 50 DEG C for 2 hours, filtered and then the plasticizer is added. The clay is then added to the organic solvent and stirred for 2 to 3 days, preferably 2 days. The clay solution is added to the reaction solution and stirred at 20 to 30 ° C for 2 to 3 days, preferably at room temperature for 2 days To prepare a composite solution.

Examples of the organic solvent include organic solvents such as chloroform, dichloromethane, ethyl acetate, methanol, hexane, acetonitrile, toluene, benzene, carbon tetrachloride, pentane, acetone, dimethyl sulfoxide, polycaprolactone, tetrahydrofuran, and dimethylformaldehyde , But is not limited thereto.

The plasticizer includes, but is not limited to, polyethylene glycol, dioctyl phthalate, and dibutyl phthalate.

The clay includes, but is not limited to, closite 30B, clawsite 25A, and clawsite Na ⁺ .

In step 4), the complex solution prepared in step 3) is placed in a petri dish and solvent casting is performed. The solution is then subjected to solvent casting for 2 to 5 days at 40 to 70 ° C, preferably 4 The film is dried at 50 DEG C for a day.

The film comprising the O-acylated chitin butyrate-clay composite produced in the above-described manner is not only polluting the environment unlike the petroleum-based polymer material because O-acylated chitin butyrate has antimicrobial activity and biodegradability, Resources are recycled, and hygiene and safety are less problematic when used as food packaging. Further, clay is mixed as O-acylated chitin butyrate as a reinforcing agent, and a plasticizer is mixed, thereby forming superior thermal and mechanical characteristics, thereby forming a durable film. Thus, the film comprising the O-acylated chitin butyrate-clay complex of the present invention can be usefully used in packaging materials for foods and the like.

Hereinafter, preferred embodiments and experimental examples are provided to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited by the examples.

Example 1. Preparation of O-acylated chitin butyrate-clay complexes

Preparation of 1-1 O-acylated chitin butyrate-clay (Clausite 25A) complex

1. Preparation of sample

Chitin (molecular weight: 3772, degree of substitution: 2.04) was purchased from Tokyo Chemicals Inc. and Trifluoroacetic anhydride (TFAA) was purchased from Acros Organics. Clay (Closite 25A, Closite 30B, Closite Na ⁺ ) was purchased from a southern clay product (Gonzales, TX, USA) in butyric acid, polyethylene glycol 1000 (PEG 1000), and 85% phosphoric acid in Sigma Aldrich. Other chemicals were used in the reagent grade, and the used samples were used without further purification.

2. Synthesis of O-acylated chitin butyrate

37 mL of butyric acid and 56 mL of trifluoroacetic anhydride were mixed, and then 3.4 mL of 85% phosphoric acid was mixed with a freezing point bath. After adding 10 g of chitin to the well mixed solution, the reaction mixture was stirred at 5 DEG C for 72 hours. Thereafter, 300 mL of ethyl alcohol was added and mixed, followed by filtration and precipitation with 300 mL of diethyl ether to obtain a product. The product was filtered, washed repeatedly with diethyl ether and water, and filtered to give in the form of a solid powder. The resulting powder was dried for 3 days to synthesize O-acylated chitin butyrate.

3. Preparation of O-acylated chitin butyrate-clay (Clausite 25A) complex

Acylated chitin butyrate (1.5 g) was added to the dimethylformaldehyde solvent, and the mixture was stirred at room temperature for 24 hours to dissolve. The mixture was further stirred at 50 DEG C for 2 hours, and then filtered. 400 mg of polyethylene glycol 1000 (PEG 1000) was mixed with the O-acylated chitin butyrate solution. 100 mg of clawsite 25A was added to 10 mL of dimethylformaldehyde, and the mixture was stirred for 2 days. Then, the solution was added to the solution, and the mixture was further stirred at room temperature for 2 days to prepare a composite solution.

1-2. Preparation of O-acylated chitin butyrate-clay (Clo Site 30B) complex

An O-acylated chitin butyrate-clay (Clausite 30B) complex solution was prepared in the same manner as in Example 1-1, except that Clausite 30B was used instead of Clausite 25A in Example 1-1.

1-3. O-acylated chitin butyrate-clay (Clozite NA ⁺ ) Preparation of complex

O-acylated chitin butyrate-clay (Clausite NA ⁺ ) complex solution was prepared in the same manner as in Example 1-1, except that Clausite NA ⁺ was used instead of Clausite 25A in Example 1-1 .

Example 2. Preparation of films using O-acylated chitin butyrate-clay complexes

Each of the composite solutions prepared in Examples 1-1 to 1-3 was placed in Petri dishes, solvent casted, and dried at 50 DEG C for 4 days to prepare a film.

Experimental Example 1. Fourier transform infrared (FT-IR) analysis

The Fourier transform infrared spectra of the film using the O-acylated chitin-clay composite prepared in Example 2 were measured with a Shimadzu Prestige-21 FT-IR spectrometer. Samples were prepared with KBr pellets and scanned at wavelengths between 4000 and 500 cm < ^-1 > as compared to blank KBr pellets.

FT-IR results of the film using the O-acylated chitin butyrate-clay composite of the present invention are shown in FIG.

As shown in Fig. 1, it can be seen that the absorption position of the ester carbonyl group in the O-acylated chitin-clay complex appears at 1740 cm ^-1 .

Experimental Example 2. Differential scanning calorimetry (DSC) analysis

Differential scanning calorimetry of the film using the O-acylated chitin butyrate-clay composite prepared in Example 2 was measured by TA instruments Q20 differential scanning calorimeter. 5 mg of the dried pulverized sample (moisture of 2% or less) was put on a stainless DSC fan and heated from 30 占 폚 to 400 占 폚 at 10 占 폚 / min in an inert gas (nitrogen gas). The glass transition temperature (T _g ) appears at the inflection point of the DSC thermograph.

The DSC results of the film using the O-acylated chitin butyrate-clay composite of the present invention are shown in FIG.

As shown in Fig. 2, CB is 220 ℃, CBP is 250 ℃, CBPC Na ⁺ is 240 ℃, CBPC 20A it can be seen that the oxidative thermal decomposition appears in 230 ℃.

Experimental Example 3: Thermogravimetric analysis (TGA) analysis

The thermogravimetric analysis of the film using the O-acylated chitin butyrate-clay complex prepared in Example 2 was measured by TA instruments Q50 thermogravimetric analysis. The temperature was raised from 20 占 폚 to 600 占 폚 in an inert gas (nitrogen gas) at 10 占 폚 / min. The onset temperature was calculated by TGA software.

The TGA results of the film using the O-acylated chitin butyrate-clay composite of the present invention are shown in FIG.

As shown in FIG. 3, CB and CBP without clay started pyrolysis at about 220 ° C., and CBPC Na ⁺ , CBPC 20A and CBPC 30B containing clay were pyrolyzed at about 235 ° C. to 240 ° C. . Thus, it can be seen that the durability of the film containing the clay is better.

Experimental Example 4. Mechanical Characterization

The mechanical properties of the film using the O-acylated chitin butyrate-clay composite prepared in Example 2 were measured with a Universal Testing Machine (UTM, 5567A, Inston CO., USA) according to ASTM D638. The tensile strength, elastic modulus and elongation at break were measured at an overhead movement speed of 50 mm / min. Measurements were repeated 10 times and expressed as GPa, MPa, and percent, respectively. Then, the average value was calculated by the following equation.

Tensile strength (MPa) = maximum load (N) / initial crossed sectional areas (m2)

Elastic modulus (%) = stress / strain X 100

The elastic modulus is defined as the slope of the stress-strain curve.

The mechanical properties of the film using the O-acylated chitin butyrate-clay composite of the present invention are shown in Table 1 below. Also, the Young's modulus measurement result of the film using the O-acylated chitin butyrate-clay composite is shown in FIG.

( CBPC-25A : O-acylated chitin butyrate 75% + polyethylene glycol 20% + cholanite 25A 5%, CBPC-30B : O-acylated chitin butyrate 75% + polyethylene glycol 20% , CBPC-NA ^+: O- acylated chitin butyrate 75% + 20% + polyethylene glycol claw site NA ⁺ 5%, CBP: O- acylated chitin butyrate + 80% polyethylene glycol 20%, CB: Oh O- 100% of actualized chitin butyrate)

film Elastic modulus (GPa) Tensile Strength (MPa) Elongation at break (%) CB 0.42 42.2 2.05 CBP 0.12 21.4 9.59 CBPC-25A 0.21 18.4 3.03 CBPC-Na ⁺ 0.18 17.1 2.68 CBPC-30B 0.22 13 2.53

As shown in FIG. 4 and Table 1, the modulus of elasticity was significantly increased in the CBPC added with clay compared to CB, and the tensile strength was significantly increased in the other clay composites except CBPC Na ⁺ . Also, elongation at fracture was 4% in CB, while it increased more than 40% in CBPC with clay.

Therefore, it can be seen that the mechanical strength of the composite film to which the clay is added is superior to that of the clay-free CB.

Claims

delete

1) mixing butyric acid, trifluoroacetic anhydride, phosphoric acid, and chitin;
2) adding ethyl alcohol to the mixture of the first step and mixing, filtering and precipitating with diethyl ether to obtain O-acylated chitin butyrate;
3) dissolving the O-acylated chitin butyrate obtained in the second step in an organic solvent, adding a plasticizer and a clay to prepare an O-acylated chitin butyrate-clay complex; And
4) solvent casting the composite of step 3) to form a film;
&Lt; / RTI >

The method according to claim 5, wherein the organic solvent in step 3) is at least one selected from the group consisting of chloroform, dichloromethane, ethyl acetate, methanol, hexane, acetonitrile, toluene, benzene, carbon tetrachloride, pentane, acetone, dimethyl sulfoxide, polycaprolactone, And at least one member selected from the group consisting of furan and dimethyl formaldehyde.

[6] The method of claim 5, wherein the plasticizer in step 3) comprises at least one selected from the group consisting of polyethylene glycol, dioctyl phthalate, and dibutyl phthalate.

The method according to claim 5, wherein the clay in step 3) is closite 30B, claw site 25A, or claw site Na ⁺ .