JP5939796B2 - Complex of chitin or chitosan and synthetic polymer and method for producing the same - Google Patents

Description

  The present invention relates to a technology for conjugating a natural polymer and a synthetic polymer, and more particularly to a method for producing a complex of chitin or chitosan and a synthetic polymer.

  Chitin and chitosan are natural polymers obtained from shrimp, crab, squid and the like. Moreover, it has an annual production volume next to cellulose as a biological resource, and is used in various technical fields as a material excellent in biocompatibility and biodegradability. In particular, chitosan has antibacterial properties, and chitin exhibits epidermal cell proliferation promoting effects, and thus is used for medical and life related fields.

  For example, in the medical field, a chitin fiber non-woven fabric (Patent Document 1) or a chitin / chitosan cotton-like material (Patent Document 2) having an effect of promoting the proliferation of epidermal cells is used as a wound covering protective material. Alternatively, a leukocyte removal filter (Patent Document 3) made of a nonwoven fabric coated with modified chitosan has been developed. Moreover, as an application example to a life-related field, for example, chitin / chitosan fiber having antibacterial properties is cited (Patent Document 4).

  However, all of these application examples are those that use chitin or chitosan alone, or materials that are chemically or physically combined with chitin or chitosan and other polymers by grafting or coating or mixing. Most of them are used.

  On the other hand, the use of chitosan membrane impregnated with ionic liquid has attracted attention as a membrane for high-performance and high-safety electricity storage devices. For example, the development of gel electrolytes using chitosan for electric double layer capacitors has been promoted. (Kazunori Sekita, Yuki Yamazaki, Masanori Yamazaki, Masaji Ishikawa, “Effects of non-aqueous natural polymer gels using ionic liquids on EDLC properties” 51st Battery Symposium (November 9-11, 2010 Day)).

  However, in order to put gel electrolytes using chitin and chitosan into practical use, a technique for thinning them is required. Furthermore, a thin film made only of chitin or chitosan has a problem in strength, and its manufacture itself is not easy.

  As a composite material of chitin or chitosan and other polymer, a material in which chitin and polyvinylpyrrolidone (PVP) are blended (Non-patent Document 1), or a material in which a polysarcosine chain is grafted to the chitin or chitosan skeleton (non-patent) Documents 2 and 3) are known, but it is unclear whether these have suitable physical properties as membrane materials, and composites in which dissimilar polymer compounds are dissolved in a good solvent and mixed (blended). In the conversion method, phase separation may occur when the solvent is removed.

  Therefore, for example, a novel polymer complex using chitin or chitosan having tough physical properties suitable for thin film formation and a novel method capable of producing such a polymer complex without causing phase separation are desired. It was.

Japanese Patent Publication No. 5-26498 Japanese Patent No. 3046099 Japanese Patent Laid-Open No. 10-338639 Japanese Patent No. 2822174

Miharu Miyashita, Yasuhiro Yamada, Gotaka Kimura, Yoshiyuki Nishio, Hidematsu Suzuki, “Preparation and compatibility evaluation of chitin / poly (N-vinylpyrrolidone) blends”, Journal of Textile Science, vol.51, No.8, pp. 396-399 (1995) Nakamura, R., Aoi, K. and Okada, M., "Controlled Synthesis of a Chitosan-Based Graft Copolymer Having Polysarcosine Side Chains Using the NCA Method with a Carboxylic Acid Additive", Macromolecular Rapid Communications, 27, 1725 (2006) . Nakamura, R., Aoi, K. and Okada, M., "Interactions of Enzymes and a Lectin with a Chitin-Based Graft Copolymer Having Polysarcosine Side Chains", Macromolecular Bioscience, 4, 610 (2004).

  An object of the present invention is to provide a composite of chitin or chitosan and a synthetic polymer having physical properties that cannot be obtained by chitin or chitosan alone, such as tough film properties suitable for thinning, and a method for producing the same.

The present invention provides a method for producing a complex of chitin or chitosan and a synthetic polymer, comprising the following steps:
(A) providing a chitin gel or chitosan hydrogel; and (b) polymerizing a polymerizable monomer in a liquid state in the presence of the chitin gel or chitosan hydrogel, a crosslinking agent and a polymerization initiator.

  The present invention also provides a complex of chitin or chitosan and a synthetic polymer obtained by the above production method.

  Furthermore, the present invention relates to a complex of chitin or chitosan and a synthetic polymer crosslinked, wherein the chitin chain or chitosan chain enters the three-dimensional network structure formed by the crosslinked synthetic polymer. Provided is a composite characterized in that

  By the method for producing a composite of the present invention, a composite of chitin or chitosan having a tough film property and a synthetic polymer can be obtained as compared with a film of chitin or chitosan alone. In addition, the physical properties of the resulting composite can be freely controlled according to the application by selecting the type of polymerizable monomer, crosslinking agent and polymerization initiator, and by adjusting the charging ratio of chitin or chitosan, polymerizable monomer and crosslinking agent. It becomes possible. Furthermore, since the polymerizable monomer is polymerized in the liquid state in the presence of the chitin gel or chitosan hydrogel rather than simply physically mixing the chitin or chitosan and the synthetic polymer, the chitin or chitosan can be mixed with the chitin or chitosan without causing phase separation. A homogeneous polymer composite in which a synthetic polymer is combined can be produced.

  In addition, the chitin gel and chitosan hydrogel used in the method of the present invention can be stored for a long time without causing a decrease in molecular weight, unlike chitin or chitosan dissolved in a strong acid or aqueous acid solution. Therefore, the method for producing a composite of the present invention has an advantage that it is not necessary to prepare a gel from chitin or chitosan every time a polymerization reaction is performed. In addition, since chitin gel and chitosan hydrogel have a certain degree of viscosity, they can be poured into a mold immediately after mixing with a polymerizable monomer, a crosslinking agent and a polymerization initiator.

Figure 1 shows different types of polymerization initiators: a) 2,2'-azobisisobutyronitrile (AIBN); b) hydrogen peroxide (H ₂ O ₂ ); and c) potassium persulfate (KPS). Used to show the appearance of the β-chitin / pHEMA complex prepared by the method of the present invention. FIG. 2 shows the appearance of the β-chitin / pHEMA complex of Example 3 after being immersed in distilled water for 24 hours. FIG. 3 shows a fracture surface of the β-chitin / pHEMA complex of Example 4. FIG. 4 shows the appearance when a) a tensile force and b) a compressive force are applied to the β-chitin / pHEMA complex of Example 4 in a wet state. FIG. 5 shows the appearance of the β-chitin / pHEMA complex of Example 5. FIG. 6 shows the appearance of the β-chitin / pHEMA complex of Example 6. FIG. 7 shows the effect of β-chitin / HEMA molar ratio on the mechanical properties of the composite of Example 4 in the dry state. FIG. 8 shows the effect of β-chitin / HEMA molar ratio on the mechanical properties of the composite of Example 4 in the wet state. FIG. 9 shows the effect of TEGDM content on the mechanical properties of the composite of Example 4 in the wet state. FIG. 10 shows the effect of β-chitin / HEMA molar ratio and TEGDM content on the swelling behavior of the β-chitin / pHEMA complex of Example 4. The triplet bar shows the results for distilled water, PBS buffer, and acetate buffer in order from the left. FIG. 11 shows the effect of β-chitin / HEMA molar ratio and TEGDM content on the biodegradability of the β-chitin / pHEMA complex of Example 4.

  The source of chitin used in the method for producing the complex of the present invention is not particularly limited. For example, it is obtained by removing calcium, protein, etc. from the shells of crustaceans such as shrimps and crabs and the shells of squids. Alternatively, a commercially available product may be used. In addition, both α-chitin and β-chitin can be used. The form of chitin used in the method for producing a composite according to the present invention is not particularly limited, and may be any form such as granular, flake, and powder. The molecular weight of chitin used in the method for producing a complex of the present invention is preferably about 10,000 to 1,000,000, more preferably about 50,000 to 500,000, and further about 100,000 to 300,000. preferable.

  The source of chitosan used in the method for producing the complex of the present invention is not particularly limited. For example, it may be obtained by deacetylating chitin obtained from crustacean shells such as shrimps and crabs, squid shells, etc. In addition, a commercially available product may be used. The form of chitosan used in the method for producing a composite according to the present invention is not particularly limited, and may be any form such as granular, flake, and powder. In addition, the degree of deacetylation of chitosan used in the method for producing a complex of the present invention is preferably about 75 to 98%. The molecular weight of chitosan used in the method for producing the composite of the present invention is preferably about 10,000 to 500,000, more preferably about 10,000 to 300,000, and still more preferably about 10,000 to 200,000.

  In the present specification, a synthetic polymer refers to a polymer compound that does not normally exist in nature and is synthesized by a polymerization reaction of a polymerizable monomer.

  The polymerizable monomer used in the method for producing the composite of the present invention is a compound having a structure capable of polymerization reaction, such as a reactive functional group or an unsaturated bond, such as acrylic ester, methacrylic ester, styrene, etc. The vinyl compound is mentioned. Among these polymerizable monomers, as the hydrophilic monomer, for example, hydroxyethyl methacrylate (HEMA), acrylic acid, methacrylic acid, N-vinyl lactam, N-acryloylmorpholine, and derivatives thereof can be suitably used. Of these, hydroxyethyl methacrylate (HEMA) can be particularly preferably used. In addition, as the hydrophobic monomer, for example, methyl methacrylate (MMA), methyl acrylate, vinyl compounds such as styrene, derivatives thereof, and the like can be preferably used, and methyl methacrylate (MMA) is particularly preferably used. Can do.

  The cross-linking agent used in the method for producing a composite of the present invention is a compound capable of cross-linking molecular chains formed by polymerization of a polymerizable monomer, such as a polyfunctional acrylate ester, a polyfunctional methacrylate ester, Examples thereof include polyfunctional vinyl compounds such as divinylbenzene. For example, when hydroxyethyl methacrylate (HEMA) is used as the polymerizable monomer, divinyl such as triethylene glycol dimethacrylate (TEGDM), ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, N, N-methylenebisacrylamide, or divinylbenzene is used as the crosslinking agent. A compound or the like can be preferably used, and triethylene glycol dimethacrylate (TEGDM) can be particularly preferably used.

  The polymerization initiator used in the method for producing a composite of the present invention is a compound that generates active species such as radicals, cations, and anions by heat, light, etc., and examples thereof include azo compounds, persulfates, and peroxides. Can be mentioned. For example, when hydroxyethyl methacrylate (HEMA) is used as the polymerizable monomer, azobisisobutyronitrile (AIBN), potassium persulfate (KPS), benzoyl peroxide (BPO), hydrogen peroxide, etc. are suitable as the polymerization initiator. Can be used. Further, polymerization may be initiated by irradiation with ultraviolet rays or radiation.

  The chitin gel used in the method for producing a complex of the present invention is a gel substance containing chitin and a liquid dispersion medium or solvent. For example, the chitin gel can be obtained by uniformly mixing while adding a dispersion medium little by little to chitin, or by dissolving the chitin in a good solvent and then removing the solvent. The chitosan hydrogel used in the method for producing the composite of the present invention is a gel-like substance containing chitosan and water. The chitosan hydrogel can be obtained, for example, by the method described below.

  In the method for producing the composite of the present invention, the step of polymerizing the polymerizable monomer is performed by mixing the chitin gel or chitosan hydrogel, the crosslinking agent and the polymerization initiator with the polymerizable monomer in the liquid state, so that the entire mixture is in the liquid state. A polymerization reaction is performed.

Method for providing chitin gel (A)
In one embodiment of the present invention, a chitin gel is provided by the following steps (hereinafter, also referred to as “chitin gel providing method (A)”):
(1) A step of uniformly mixing chitin having an average particle size of at least 1 mm and 0.8 to 100 parts by weight of a dispersion medium with respect to 1 part by weight of the chitin;
(2) a step of uniformly mixing 0.8 to 100 parts by weight of the dispersion medium with respect to 1 part by weight of chitin in step (1); and (3) the total amount of the dispersion medium is a step ( The process of obtaining a chitin gel by repeating a process (2) until it becomes 4-500 weight part with respect to 1 weight part of chitin of 1).

  The mixing method of chitin and the dispersion medium in the chitin gel providing method (A) is not particularly limited as long as both can be uniformly mixed. For example, 10,000 to 20 using an oster blender manufactured by Phoenix The chitin and the dispersion medium can be uniformly mixed by stirring at 1,000 rpm.

  In the chitin gel providing method (A), the mixing step of chitin (or a mixture of chitin and a dispersion medium) and the dispersion medium is repeated a plurality of times. In order to ensure that chitin is swollen with the dispersion medium, most of the dispersion medium added in one mixing step is absorbed by the chitin, and the mixture of chitin and the dispersion medium moves by the movement of the rotating teeth of the mixer, etc. It is preferable to move to the next mixing step with the dispersion medium at the stage where the problem disappears. Further, the step of mixing chitin and the dispersion medium is preferably repeated 3 to 10 times in total, and more preferably 3 to 7 times.

  In the chitin gel providing method (A), it is preferable to use β-chitin, which has a weaker hydrogen bond and more easily swells than α-chitin. Moreover, it is preferable that the average particle diameter of the chitin used in the chitin gel provision method (A) is at least 1 mm or more, more preferably 1 to 5 mm, and further preferably 2 to 3 mm. The average particle diameter can be calculated based on the Rosin-Rammler equation by measuring the particle size distribution by a sieving method using, for example, a general low-tap sieve shaker.

  In the chitin gel providing method (A), the amount of the dispersion medium mixed with chitin is preferably 0.8 to 100 parts by weight, more preferably 10 to 40 parts by weight, with respect to 1 part by weight of chitin per mixing step. -30 parts by weight is more preferable, and 15-25 parts by weight is particularly preferable.

  The dispersion medium used in the chitin gel providing method (A) may be either an organic solvent or an inorganic solvent, and may be either a polar or nonpolar solvent. The dispersion medium is preferably a polar solvent, and for example, water, methanol, ethanol, propanol and the like can be suitably used.

  The chitin gel obtained by the chitin gel providing method (A) is preferably such that the total amount of the dispersion medium mixed with chitin is 4 to 500 parts by weight with respect to 1 part by weight of chitin in step (1), and 6 to 400 parts by weight. Is more preferable, and what is 9 to 200 parts by weight is more preferable. The “total amount of dispersion medium” referred to here is an accumulation of the amount of dispersion medium mixed with chitin through steps (1) to (3).

Chitin gel provision method (B)
In one embodiment of the present invention, a chitin gel is provided by the following steps (hereinafter, also referred to as “chitin gel providing method (B)”):
(1) Chitin is selected from the group consisting of calcium chloride hydrate saturated methanol, dimethylacetamide-lithium chloride, N-methylmorpholine-lithium chloride, dimethylacetamide-N-methylmorpholine-lithium chloride and ionic liquid A step of dissolving in a solvent; and (2) a step of removing the solvent from the chitin solution to obtain a chitin gel in which the amount of the solvent is 50 to 90 parts by weight with respect to 1 part by weight of chitin.

  Solvents that can be used in the chitin gel providing method (B) include, for example, calcium chloride hydrate saturated methanol, calcium chloride hydrate saturated ethanol, dimethylacetamide-lithium chloride, N-methylmorpholine-lithium chloride, dimethylacetamide-N- Examples include methylmorpholine-lithium chloride and ionic liquid. Among these, calcium chloride hydrate saturated methanol is preferable because it is relatively safe and has a low environmental impact, and calcium chloride dihydrate saturated methanol is particularly preferably used from the viewpoint of solubility. be able to. Various types of ionic liquids are known depending on the kind of cation and anion. In the method (B) for providing a chitin gel, for example, 1-allyl-3-methylimidazolium bromide, 1-butyl-3-methyl is available. Imidazolium chloride or the like can be used as a solvent for chitin.

  The amount of the solvent for dissolving chitin in step (1) of the chitin gel providing method (B) is not particularly limited, but is preferably 55 to 200 parts by weight, more preferably 60 to 150 parts by weight with respect to 1 part by weight of chitin.

  The method for removing the solvent from the chitin solution in step (2) of the chitin gel providing method (B) is not particularly limited, but the solvent can be removed by heating, decompression, centrifugation, air drying, or the like. The conditions for removing the solvent from the chitin solution by heating are not limited to these, but examples include conditions such as 100 ° C. for 3 hours and 80 ° C. for 5 hours. The conditions for removing the solvent from the chitin solution by reducing the pressure are not limited to these. For example, a condition such as 1 hour at 0.01 atm using a vacuum pump is used, and heating at about 40 ° C. is used in combination. May be.

  In the chitin gel obtained by the chitin gel providing method (B), the amount of the solvent in the chitin gel is preferably 50 to 90 parts by weight with respect to 1 part by weight of chitin, more preferably 50 to 80 parts by weight, What is 50-70 weight part is further more preferable.

Method for Providing Chitosan Hydrogel In one embodiment of the present invention, the chitosan hydrogel is provided by the following steps (hereinafter also referred to as “chitosan hydrogel provision method”):
(1) a step of dissolving chitosan in an acid aqueous solution;
(2) adjusting the pH of the aqueous chitosan solution in step (1) to 7-12;
(3) collecting the precipitate produced in step (2); and (4-a) washing the precipitate collected in step (3) with water until the pH is 6.0 to 7.5, or (4-b) A step of dialysis of the liquid obtained by dispersing the precipitate collected in step (3) in water until the pH becomes 6.0 to 7.5.

  In the above chitosan hydrogel providing method, the method for dissolving chitosan in the acid aqueous solution is not particularly limited, and it may be dissolved by a conventional method such as stirring. What is necessary is just to let the temperature at the time of melt | dissolution be room temperature, for example, 15-40 degreeC. The dissolution time varies depending on the shape of chitosan, the molecular weight, the degree of deacetylation, etc., but it is generally dissolved by stirring for 4 to 5 hours.

  Although the kind of acid aqueous solution used in the said chitosan hydrogel provision method is not specifically limited, For example, acetic acid aqueous solution, hydrochloric acid, lactic acid aqueous solution etc. are mentioned, Preferably it is acetic acid aqueous solution. When using an acetic acid aqueous solution, the concentration is preferably 2 to 6% by weight, more preferably 3.5 to 4.5% by weight. For example, the pH of an aqueous chitosan solution obtained by dissolving in a 2% by weight acetic acid aqueous solution is usually about 3.5 to 4.0.

Step (2) in the chitosan hydrogel providing method is a step of adjusting the pH of the chitosan aqueous solution to 7 to 12, preferably 8 to 10. The pH can be adjusted by a conventional method in the art, for example, addition of a basic substance, preferably dropwise addition of an aqueous solution of the basic substance. At this time, it is preferable to vigorously stir the aqueous solution. Basic materials that can be used include, but are not limited to, NaOH, KOH, NH ₄ OH, and the like.

  Step (4-a) in the chitosan hydrogel providing method is a step of washing the collected precipitate with water until the pH becomes 6.0 to 7.5, preferably 6.8 to 7.2. The washing method is not particularly limited. For example, a method in which a suspension obtained by dispersing the collected precipitate in water is stirred, and the precipitate is collected by centrifugation, filtration, or the like, or the precipitate in the column is collected. For example, a large amount of water can be passed.

  In the step (4-b) in the chitosan hydrogel providing method, a solution in which the collected precipitate is dispersed in water is put into a dialysis membrane, and the pH is adjusted to 6.0 to 7.5, preferably 6.8 to 7.2. It is a process of dialysis against water until it becomes. The amount of the dispersion used for dialysis is preferably 0.1 to 1.0 part by weight with respect to 100 parts by weight of the dialysate (that is, water). The chitosan content in the dispersion is preferably about 0.1 to 2.0% by weight. The number of dialysis varies depending on the amount of dialysate and the pH of the dispersion, but is preferably about 2 to 5 times. The dialysis temperature may be room temperature, for example, about 10 to 20 ° C. The dialysis membrane to be used is not particularly limited, and various dialysis membranes such as cellulose and synthetic polymer can be used.

  As water used in the step (4-a) or (4-b) of the chitosan hydrogel providing method, it is preferable to use purified water such as deionized water or distilled water.

  In addition, the water content of the chitosan hydrogel provided by the method for providing chitosan hydrogel is preferably 90 to 99.8% by weight, more preferably 95 to 99.5% by weight, and 95 to 99% by weight. More preferably. The water content of the chitosan hydrogel can be changed to a desired value by centrifugation or filtration.

  The method for producing a composite of the present invention further includes a step of replacing the dispersion medium or solvent in the provided chitin gel or chitosan hydrogel with another dispersion medium or solvent before the step (b) of polymerizing the polymerizable monomer. May be included. Through this process, the type of dispersion medium or solvent in the chitin gel or chitosan hydrogel can be changed to an optimum one according to the type of polymerizable monomer, etc., and chitin or chitosan and the synthetic polymer are more uniformly combined. It becomes possible. For example, when the dispersion medium in the chitin gel is a polar solvent such as water, if a hydrophobic monomer is used as the polymerizable monomer, the chitin and the synthetic polymer may not be complexed uniformly. In this case, by replacing the dispersion medium in the chitin gel with a low polarity or nonpolar solvent, it is possible to uniformly combine the synthetic polymer formed from the hydrophobic polymerizable monomer and chitin.

  Examples of a method for replacing the dispersion medium or solvent in the chitin gel or chitosan hydrogel include a method in which a solvent close to the polarity of water is first added, stirring and centrifuging are repeated, and the same operation is repeated using a solvent having a lower polarity. It is done.

  In the complex of chitin or chitosan obtained by the method for producing a complex of the present invention and a synthetic polymer, the chitin chain or chitosan chain has entered the three-dimensional network structure formed by the crosslinked synthetic polymer. It has a structure. Such a structure is commonly referred to in the art as a semi-IPN structure.

  When using chitin, the manufacturing method of the composite_body | complex of this invention includes the process of providing a chitin gel by dissolving chitin in a solvent or swelling chitin using a dispersion medium etc. as one characteristic. By such a step, it is possible to loosen a strong crystal structure of chitin caused by hydrogen bonds within and between molecular chains. Then, it is possible to obtain a complex having a uniform semi-IPN structure by polymerizing a polymerizable monomer in a liquid state in the presence of a chitin gel in a state where molecular chains are loosened. Similarly, in the case of using chitosan, a polymerizable monomer is polymerized in a neutral solution state in which the chitosan hydrogel is dissolved in a minimum amount of acid by providing a chitosan hydrogel having a loose molecular chain. This makes it possible to obtain a complex having a uniform semi-IPN structure. The uniform semi-IPN structure is considered to contribute to the tough film properties of the complex of chitin or chitosan obtained by the method for producing the complex of the present invention and the synthetic polymer.

  Further, as a modification of the method for producing the composite of the present invention, a chitosan solution prepared from a chitin solution or a chitosan powder is used instead of chitin gel or chitosan hydrogel, and polymerization is performed in the presence of the solution, a crosslinking agent and a polymerization initiator. It is also possible to produce a complex of chitin or chitosan and a synthetic polymer by polymerizing monomers.

  Since the chitin gel and chitosan hydrogel used in the method for producing the complex of the present invention are substantially free of acid, they can be stored for a long time without causing a decrease in molecular weight. Further, it is possible to prevent a decrease in the molecular weight of chitin or chitosan even during the polymerization of the polymerizable monomer.

  The method for producing the composite of the present invention can be achieved by selecting the types of the polymerizable monomer, the crosslinking agent and the polymerization initiator, and adjusting the preparation ratio of chitin or chitosan, the polymerizable monomer and the crosslinking agent, to improve the physical properties of the resulting composite. It can be freely controlled. For example, increasing the ratio of chitin or chitosan to polymerizable monomer tends to increase the biodegradability and degree of swelling of the resulting composite. Further, when the amount of the crosslinking agent used for the polymerization reaction is increased, the biodegradability and the degree of swelling tend to decrease. Furthermore, when the amount of the crosslinking agent used for the polymerization reaction is increased, the tensile strength and the tensile elongation at break tend to decrease.

  As an example of the charging ratio, a complex is produced with the molar ratio of chitin or chitosan to the polymerizable monomer in the range of 0.001 to 0.027, 0.022 to 0.110, 0.022 to 0.072, etc. Can do. Moreover, the amount of the crosslinking agent to be subjected to the polymerization reaction is, for example, 0.227 to 2.273 mol%, 2.27 to 13.3 with respect to the total amount of chitin or chitosan, the polymerizable monomer, the crosslinking agent and the polymerization initiator. The composite can be produced in the range of 6 mol% or the like.

  Further, in the method for producing a composite of the present invention, when an azo compound is used as a polymerization initiator, a porous sponge-like structure may be formed by nitrogen gas generated with generation of radicals.

  In the method for producing a composite of the present invention, the reaction conditions for polymerizing the polymerizable monomer are not particularly limited, and can be appropriately set according to the type and amount of the polymerizable monomer to be used. In addition, the treatment for generating active species such as radicals (UV light, heat, etc.) can be appropriately set according to the type and amount of the polymerization initiator used.

  For example, 20 g of chitin gel (chitin 1.5%, calcium chloride dihydrate saturated methanol 98.5%), 0.41 g of triethylene glycol dimethacrylate (TEGDM) and 0.12 g of azobisisobutyronitrile (AIBN) When 4.1 g of hydroxyethyl methacrylate (HEMA) is polymerized in the presence, it is not limited to these conditions, but by reacting at 60 to 70 ° C. for 12 to 24 hours, or 70 to 80 ° C. for 6 to 12 hours. A complex of chitin and polyhydroxyethyl methacrylate (pHEMA) can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Production Example 1 (Preparation of SW-β-chitin gel)
1 g of β-chitin (molecular weight 150,000, average particle size 1 mm) and 20 ml of distilled water were placed in a mini bottle (capacity 50 ml) for oster blender (Phoenix Phoenix Blender) and stirred using the blender (rotation speed: 16,800 rpm, room temperature). At that time, β-chitin swelled into a gel and stirring was continued until the mixture of β-chitin and distilled water stopped rotating (about 1 minute). Next, 20 ml of distilled water was added to the mixture and stirred in the same manner with a blender (rotation speed: 16,800 rpm) to further swell β-chitin. Similarly, the operation of adding 20 ml of distilled water and stirring at 16,800 rpm when the mixture stopped rotating was repeated three more times to obtain β-chitin gel. If the loss is ignored, the moisture content of the gel is 99% (100 parts by weight of water per 1 part by weight of chitin). The chitin gel thus produced is hereinafter referred to as “SW (swelling) -β-chitin gel”.

Production Example 2 (Preparation of HT-β-chitin gel)
1 g of β-chitin was added to 100 g of saturated calcium chloride dihydrate methanol (concentration 1 wt%) and stirred vigorously for 30 minutes using an Oster blender (Phoenix Phoenix Blender) (rotation speed: 16,800 rpm, room temperature). . Thereafter, the mixture was stirred overnight with a motor (rotation speed: 60 rpm, room temperature) to obtain a viscous β-chitin solution. Next, the β-chitin solution was heat-treated at 100 ° C. for 3 hours using a heater (Corning, PC-4200), and then cooled to room temperature to obtain a β-chitin gel. The β-chitin gel weighed 67 g (that is, 66 parts by weight of calcium chloride, water and methanol with respect to 1 part by weight of chitin). The β-chitin gel thus prepared is hereinafter referred to as “HT (heat treatment) -β-chitin gel”.

Production Example 3 (Preparation of chitosan hydrogel)
3.06 g of chitosan powder (molecular weight 40,000, deacetylation degree 84%) was dissolved in 100 ml of 4% by weight aqueous acetic acid solution by stirring at room temperature for 5 to 7 hours. The pH of the obtained aqueous chitosan solution was 3.85. The chitosan aqueous solution was filtered to remove insoluble parts, and then a 10 wt% NaOH aqueous solution was added under high-speed stirring with a mixer to adjust the pH to 11.0 to 12.0. The produced precipitate was collected by centrifugation and then dispersed in distilled water to obtain a 1000 ml dispersion. The dispersion was put into a dialysis bag and dialyzed against 1000 ml of distilled water until the pH reached 6.0 to 7.5 to obtain chitosan hydrogel (distilled distilled water was changed 5 times). The water content of the gel was 95%.

Example 1
HEMA (hydroxyethyl methacrylate) and TEGDM (triethylene glycol dimethacrylate) in the amounts shown in Table 1 were added to 20 g of SW-β-chitin gel of Production Example 1 and stirred at room temperature for 1 hour. Next, 0.24 mol% AIBN (azobisisobutyronitrile) with respect to HEMA was added to the obtained mixture and stirred, and then cast into a 40 × 40 mm Teflon (registered trademark) frame. Was allowed to stand in the oven for 12 hours for polymerization. As a result, it was possible to obtain a complex of β-chitin and HEMA without causing phase separation in any amount of samples 1 to 10. A photograph of the appearance of the composite prepared with the charge amount of Sample 2 is shown in FIG.

Example 2
HEMA and TEGDM in the amounts shown in Table 1 above were added to 20 g of the SW-β-chitin gel of Production Example 1 and stirred at room temperature for 1 hour. Next, 0.24 mol% hydrogen peroxide (H ₂ O ₂ ) was added to the HEMA, and the resulting mixture was stirred, cast into a 40 × 40 mm Teflon frame, and placed in an oven at 70 ° C. The polymerization was carried out by standing for 12 hours. As a result, it was possible to obtain a complex of β-chitin and HEMA without causing phase separation in any amount of samples 1 to 10. An external appearance photograph of the composite prepared with the charge amount of Sample 2 is shown in FIG.

Example 3
HEMA and TEGDM in the amounts shown in Table 1 above were added to 20 g of the SW-β-chitin gel of Production Example 1 and stirred at room temperature for 1 hour. Next, 1 ml of 0.24% KPS (potassium persulfate) aqueous solution was added to the obtained mixture, stirred for 2 hours, cast into a 40 × 40 mm Teflon frame, and left in an oven at 70 ° C. for 12 hours. Polymerization was performed. As a result, it was possible to obtain a complex of β-chitin and HEMA without causing phase separation in any amount of samples 1 to 10. The appearance photograph of the composite prepared with the charge amount of Sample 2 is shown in FIG. The composites thus obtained (samples 1 to 10) were all hard and strong in the dry state, whereas they exhibited soft and tough properties in the water absorption state (FIG. 2). .

Example 4
6 g of distilled water was added to 20 g of HT-β-chitin gel of Production Example 2 and heated at 121 ° C. for 30 minutes using an autoclave. Next, the HT-β-chitin gel after autoclaving was stirred for 1 hour until uniform. During this time, HEMA monomers, TEGDM and AIBN in the amounts shown in Table 2 were mixed by stirring to prepare a HEMA solution. Then, the HEMA solution was added to the stirred HT-β-chitin gel, stirred for 4 hours, cast into a 40 × 40 mm Teflon frame, and then allowed to stand in an oven at 70 ° C. for 24 hours for polymerization. . As a result, it was possible to obtain a complex of β-chitin and HEMA without causing phase separation in any amount of samples 1 to 10. The composites thus obtained (samples 1 to 10) were all sponge-like composites having a three-dimensional porous structure (for example, sample 4 and FIG. 3). These composites were in the form of a hard plastic in the dry state, but in the wet state, they were as flexible as rubber and very strong sponges (for example, Sample 4 and FIG. 4).

Example 5
6 g of distilled water was added to 20 g of HT-β-chitin gel of Production Example 2 and heated at 121 ° C. for 30 minutes using an autoclave. Next, the HT-β-chitin gel after autoclaving was stirred for 1 hour until uniform. During this time, HEMA monomers, TEGDM and hydrogen peroxide in the amounts shown in Table 3 were mixed by stirring to prepare a HEMA solution. Then, the HEMA solution was added to the stirred HT-β-chitin gel, stirred, cast into a 40 × 40 mm Teflon frame, and then allowed to stand in an oven at 70 ° C. for 2 days for polymerization. As a result, it was possible to obtain a complex of β-chitin and HEMA without causing phase separation in any amount of samples 1 to 4. FIG. 5 shows a photograph of the appearance of the composite prepared with the amount of sample 1 charged.

Example 6
6 g of distilled water was added to 20 g of HT-β-chitin gel of Production Example 2 and heated at 121 ° C. for 30 minutes using an autoclave. Next, the HT-β-chitin gel after autoclaving was stirred for 1 hour until uniform. During this time, HEMA monomers and TEGDM in the amounts shown in Table 4 were mixed by stirring to prepare a HEMA solution. Then, 1 ml of 0.24% KPS aqueous solution was added to the stirred HT-β-chitin gel and stirred for 1 hour, and then the HEMA solution was added and stirred for 2 hours. After adding 0.1 ml of 10% TMEDA (tetramethylethylenediamine) aqueous solution to the obtained mixture and stirring for about 10 seconds, it was quickly cast into a 40 × 40 mm Teflon frame and left in an oven at 70 ° C. for 2 days. Polymerization was performed. As a result, it was possible to obtain a complex of β-chitin and HEMA without causing phase separation in any amount of samples 1 to 7. FIG. 6 shows a photograph of the appearance of the composite prepared with the amount of sample 1 charged.

Example 7
To 5 g of the chitosan hydrogel of Production Example 3, 0.3 g of 1M acetic acid was added and dissolved, and 1 ml of 0.24% KPS aqueous solution was further added and stirred for 1 hour. A separately prepared HEMA solution (mixed with 5.0 g of HEMA monomer and 0.49 g of TEGDM) was added and stirred for 2 hours. Then, 0.1 ml of 10% TMEDA aqueous solution was added and stirred for about 2 minutes, and then quickly cast into a 40 × 40 mm Teflon frame and left in an oven at 70 ° C. for 2 days for polymerization. As a result, a complex of chitosan and HEMA could be obtained without causing phase separation.

Example 8
6 g of ethylene glycol was added to 20 g of HT-β-chitin gel of Production Example 2 and heated at 121 ° C. for 30 minutes using an autoclave. Next, the HT-β-chitin gel after autoclaving was stirred for 1 hour until uniform. During this time, 1.89 g of MMA (methyl methacrylate) monomer, 0.24 g of TEGDM, 0.07 g of AIBN, and 0.01 g of Triton X-100 as a surfactant were mixed by stirring to prepare an MMA solution. Then, the MMA solution was added to the stirred HT-β-chitin gel, stirred for 4 hours, cast into a 40 × 40 mm Teflon frame, and then allowed to stand in an oven at 70 ° C. for 48 hours for polymerization. As a result, a complex of β-chitin and MMA could be obtained without causing phase separation.

Mechanical properties For the composites of Examples 4 (samples 1 to 8), mechanical properties (tensile strength and tensile elongation at break using a desktop material testing machine (STA-1150, manufactured by A & D Co., Ltd.)) Degree). The sample to be measured was cut out based on the standard of JIS (K7162), and measured in a dry and wet state. In addition, the wet state sample used what was immersed in distilled water for 1 week. The measurement results are shown in FIGS. 7 to 9 (FIG. 7 is a dry state, and FIGS. 8 and 9 are results in a wet state). As the ratio of β-chitin to HEMA increased, the strength and elongation of the resulting composites in the dry state tended to decrease. However, in the wet state, the molar ratio of β-chitin to HEMA was 0.043. When showed the maximum. Furthermore, when the amount of TEGDM used for the polymerization reaction was increased, the tensile strength and the tensile elongation at break tended to decrease.

Swelling degree About the composite body (samples 1-9) of Example 4, the swelling degree was measured according to the following procedures. The composite of Example 4 in a dry state was cut into a size of 5 mm × 5 mm × 2 mm to prepare a sample. The sample was immersed in distilled water, PBS buffer (pH = 7.4) or acetate buffer (pH = 5.5), and incubated at 37 ° C. for 1 week using a constant temperature shaker. Thereafter, the weight of the sample was measured, and the degree of swelling was calculated by the following formula. The results are shown in FIG.

Swelling degree (%) = (weight after immersion−weight when dried) / weight when dried × 100

As the ratio of β-chitin to HEMA increased, the degree of swelling of the resulting complex tended to increase. Moreover, when the amount of TEGDM to be subjected to the polymerization reaction was increased, the swelling degree of the resulting composite was observed to decrease.

Biodegradability About the composite_body | complex (samples 1-9) of Example 4, biodegradability was evaluated in accordance with the following procedures. The composite of Example 4 in a dry state was cut into a size of 5 mm × 5 mm × 2 mm to prepare a sample. The sample was placed in a PBS buffer containing 0.01% (w / v) lysozyme and incubated at 37 ° C. for 1 week using a constant temperature shaker. The sample was then washed with distilled water and dried in an oven at 60 ° C. for 2 days. Thereafter, the weight of the sample was measured, and the decomposition weight was calculated by the following formula. The results are shown in FIG.

Decomposition weight (%) = (weight before lysozyme treatment−weight after lysozyme treatment) / weight before lysozyme treatment × 100

As the ratio of β-chitin to HEMA increased, the biodegradability of the resulting complex tended to increase. Moreover, when the amount of TEGDM used for the polymerization reaction was increased, the biodegradability of the resulting composites tended to decrease.

Methanol extraction The composite of Example 4 (Sample 4) was treated with methanol in a Soxhlet extractor for one week. As a result, there was no change in the weight of the complex even after the treatment, and nothing remained even after the methanol was distilled off. This result suggests that in the complex obtained by the method of the present invention, chitin and HEMA polymer are not present alone, but have an IPN structure in which both molecular chains are intertwined. .

  The composite obtained by the production method of the present invention can be used as a high-performance novel gel electrolyte for an electricity storage device such as an electric double layer capacitor or a lithium ion battery, and also has an effect of promoting the proliferation of epidermal cells of chitin and the antibacterial property of chitosan. It can be applied to various products in medical and life related fields as a new polymer composite incorporated.

Claims (7)

(A ) providing a chitin gel or chitosan hydrogel; and (b) polymerizing a polymerizable monomer that is a vinyl compound in the liquid state in the presence of the chitin gel or chitosan hydrogel, a crosslinking agent, and a polymerization initiator.
A method for producing a composite of chitin or chitosan and a vinyl compound polymer, comprising:
The step (A) of providing a chitin gel comprises
(A1) A step of uniformly mixing chitin having an average particle diameter of at least 1 mm and 0.8 to 100 parts by weight of a dispersion medium with respect to 1 part by weight of the chitin;
(A2) A step of uniformly mixing the obtained mixture with 0.8 to 100 parts by weight of a dispersion medium with respect to 1 part by weight of chitin in step (A1);
(A3) A step of obtaining a chitin gel by repeating step (A2) until the total amount of the dispersion medium is 4 to 500 parts by weight with respect to 1 part by weight of chitin in step (A1).
Including, or
(A1 ′) dissolving chitin in a solvent selected from the group consisting of calcium chloride hydrate saturated methanol, dimethylacetamide-lithium chloride and ionic liquid;
(A2 ′) A step of removing a solvent from the chitin solution to obtain a chitin gel in which the amount of the solvent is 50 to 90 parts by weight with respect to 1 part by weight of chitin.
Including, and
Providing the chitosan hydrogel (B) comprises:
(B1) A step of dissolving chitosan in an acid aqueous solution;
(B2) adjusting the pH of the aqueous chitosan solution in step (B1) to 7-12;
(B3) collecting the precipitate produced in step (B2); and
(B4) A step of washing the precipitate collected in step (B3) with water until the pH reaches 6.0 to 7.5, or a solution in which the precipitate collected in step (B3) is dispersed in water Dialysis against water until 6.0-7.5
The manufacturing method of the composite_body | complex containing . The method according to claim 1 , wherein in the step (A) of providing a chitin gel, the dispersion medium is water. The method according to claim 1 , wherein in step (A) of providing a chitin gel, the solvent is calcium chloride dihydrate saturated methanol. Prior to step (b), further comprising the step of replacing a dispersion medium or solvent Kichingeru or chitosan hydrogel gel provided in step (a) to another dispersion medium or a solvent, to claim 1-3 The method described. The method according to any one of claims 1 to 4, wherein the polymerizable monomer is an acrylic ester , a methacrylic ester or styrene . The method according to any one of claims 1 to 5, wherein the crosslinking agent is a polyfunctional acrylic ester , a polyfunctional methacrylate, or divinylbenzene . Polymerization initiator, azobisisobutyronitrile, hydrogen peroxide, a radical polymerization initiator selected from the group consisting of potassium persulfate and benzoyl peroxide, The method according to any one of claims 1-6.

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