Composition for producing biodegradable polymer material and biodegradable polymer material on its basis

Abstract

FIELD: chemical; biochemical technology.SUBSTANCE: invention relates to the production of film-type biodegradable polymeric materials for food purposes, comprising a mixture of starch and gelatine with polyvinyl alcohol, used in the production of thermoformed packaging products and films capable of biodegradation under the influence of climatic factors and microorganisms. The invention can be used in biomedicine and pharmacology (disposable instruments, packaging materials, capsules), food industry (packaging material and essential items), agriculture (biodegradable films). A composition is described for producing a biodegradable polymer material comprising starch, polyvinyl alcohol, glycerine, water, citric acid, and additionally comprising gelatine and Jerusalem artichoke extract, wherein the Jerusalem artichoke extract is a 10% aqueous extract of Jerusalem artichoke, with the following ratio of components, wt.%: starch 0.5-1.5, gelatine 0.6-1.2, Jerusalem artichoke extract 0.1-1.0, polyvinyl alcohol 1.2-2.3, glycerine 2.5-4.0, citric acid 0.1-0.35, the rest is water. Also described is a biodegradable polymer material for a film obtained by drying a composition comprising starch, polyvinyl alcohol, glycerine, water, citric acid, additionally comprising gelatine and Jerusalem artichoke extract in the following ratio of components, wt.%: starch 5.63-16.71, gelatine 7.11-13.52, Jerusalem artichoke extract 1.16-11.19, polyvinyl alcohol 13.62-26.78, glycerine 27.85-46.21, citric acid 1.12-3.97, the rest is water.EFFECT: increase in the strength of the resulting film, namely an increase in tensile strength, a decrease in the degree of sorption of water vapor, and a reduction in the time of biodegradation in the soil.2 cl, 1 dwg, 1 tbl

Description

[0001] The invention relates to chemical and biochemical technology, specifically to the production of biodegradable food-grade polymer film materials containing a mixture of starch and gelatin with polyvinyl alcohol, used in the production of thermoformed packaging products and films capable of biodegradation under the influence of climatic factors and microorganisms. The invention can be used in biomedicine and pharmacology (disposable instruments, packaging materials, capsules), the food industry (packaging material and essential items), and agriculture (biodegradable films).

[0002] A polymer composition for the manufacture of biodegradable articles is known) [Patent 2629680 Russian Federation, IPC C08L97 / 00, C08L23 / 06, C08L23 / 08, C08L 97 / 02 Polymer composition for the manufacture of biodegradable articles / Vodyakov V.N., Shabarin A.A., Shabarin A.A., Kuzmin A.M.; applicant and patent holder Federal State Budgetary Educational Institution of Higher Education "National Research Mordovian State University named after N.P. Ogarev" (RU). - No. 2016124877; declared 21.06.2016; published 31.08.2017. Bull. [No. 25] contains a biodegradable filler (beet pulp), a processing aid (polyethylene glycol), an ethylene-vinyl acetate copolymer, and a 1:1 blend of low- and high-density polyethylene. However, the use of beet pulp as a biodegradable filler does not produce a compositionally stable mass, which contains mineral impurities in addition to the organic component.Furthermore, one of the negative qualities of beet pulp is that fresh beet pulp contains a large amount of water, which allows microorganisms to actively develop and quickly turns sour. Excessive water content in the pulp makes its transportation difficult and expensive, and also requires an additional energy-intensive stage of the production process – drying.

[0003] A food film coating is known [Patent 2532180 Russian Federation, IPC C08L 5 / 00. Biodegradable film based on pectin and chitosan / Denisova M.N., Zhuk S.G., Bukharova E.N., Rysmukhambetova G.E., Kashchenko V.F.; applicant and patent holder Federal State Budgetary Educational Institution of Higher Education "Saratov State Agrarian University named after N.I. Vavilov" (RU). - No. 2013134600 / 05; declared 23.07.2013; published 27.10.2014 Bulletin No. 30.], which contains xanthan gum, chitosan, glycerin and methylcellulose.

[0004] The disadvantages of food film coating include increased moisture absorption and water solubility, as well as insufficient strength due to the high content (50-55 wt.%) of the thickener - xanthan.

[0005] A composition for producing a biodegradable polymeric material and a biodegradable polymeric material based on it are known [Patent 2669865 Russian Federation, IPC C08L 3 / 02, C08L 29 / 04, C08K 3 / 00, C08K 5 / 05, C08L 101 / 16. Composition for producing a biodegradable polymeric material and a biodegradable polymeric material based on it / Malinkina O.N., Papkina V.Yu., Shipovskaya A.B.; applicant and patent holder Federal State Budgetary Educational Institution of Higher Education "Saratov National Research State University named after N.G. Chernyshevsky" (RU). - No. 2017136410; declared 16.10.2017; publ. 16.10.2018 Bulletin No. 29.

[0006] The composition for producing a biodegradable polymer material contains starch, polyvinyl alcohol (PVA), glycerin, water, L-aspartic acid, hydrochloric acid and ethyl alcohol in the following ratio of components, wt.%:

[0007] Starch………………………………….0.9–23.0

[0008] Polyvinyl alcohol…………………1.8–23.0

[0009] Glycerin……………………………3.5–11.2

[0010] L-aspartic acid………………..0.3–3.4

[0011] Hydrochloric acid…………………………0.1–1.3

[0012] Ethyl alcohol …………………………1.5–22.6

[0013] Water ………………………………………other

[0014] A biodegradable polymeric material based on a composition containing starch, polyvinyl alcohol, glycerin, water, additionally contains a reaction product of L-aspartic and hydrochloric acids in the form of L-aspartic acid hydrochloride in the following ratio of components, wt.%:

[0015] Starch………………………………………………………24.0–40.0

[0016] Polyvinyl alcohol……………………..40.0–51.0

[0017] Glycerin………………………………………………………4.1–11.7

[0018] L-aspartic acid hydrochloride…….7.7–9.9

[0019] Water……………………………………………others

[0020] The disadvantages of biodegradable polymer material are:

[0021] - insufficiently high strength of the resulting film (insufficiently high tensile stress: 0.83-2.89 MPa);

[0022] - long time of material biodegradation in soil (150 days);

[0023] - comparatively high degree of water vapor sorption.

[0024] A composition for producing a biodegradable polymeric material and a biodegradable polymeric material based on it are known [Patent 2796732 RF, IPC C 08L 3 / 02, C 08L 29 / 04, C 08L 106 / 16, C 08K 5 / 05, C 08J 5 / 18. Composition for producing a biodegradable polymeric material and a biodegradable polymeric material based on it [Text] / Nikiforova T.E., Guzenko O.A.; applicant and patent holder Ivan. state chemical-technical University - No. 2022120925; declared 01.08.2022; published 29.05.2023, Bulletin No. 16.].

[0025] The composition for producing a biodegradable polymer film material contains starch, polyvinyl alcohol, glycerin, water, ethyl alcohol, and additionally contains one of the acids: citric adipic, phosphoric, oxalic, succinic, chokeberry or cranberry juice in the following ratio of components, wt. %:

[0026] Starch……………………..…………………...0.8–1.2

[0027] Polyvinyl alcohol…………………..……...1.1–2.5

[0028] Glycerin………………………………………………………...3.5–5.5

[0029] acid…………………………………………..0.2–0.5

[0030] Ethyl alcohol ………………………………...0–8.4

[0031] Aronia or cranberry juice……….0–1

[0032] Water …………………………………………….other

[0033] The biodegradable polymer film material based on the composition contains starch, polyvinyl alcohol, glycerin, water, and additionally contains one of the acids: citric adipic, phosphoric, oxalic, chokeberry or cranberry juice in the following ratio of components, wt. %:

[0034] Starch………………………………………………………10.22–14.40

[0035] Polyvinyl alcohol………………………17.22–26.05

[0036] Glycerin………………………………………………………47.23–56.23

[0037] Acid…………………………….………2.30–5.48

[0038] Aronia or cranberry juice……….0–9.84

[0039] Water………………………………………………the rest.

[0040] The disadvantages of the composition are the insufficiently high strength of the resulting film (insufficiently high tensile stress: 3.9-12.5 MPa) and a relatively high degree of water vapor sorption (15.9-24.6).

[0041] The closest in technical essence and achieved result, that is, the prototype, is: a composition for obtaining a biodegradable polymeric material and a biodegradable polymeric material based on it [Patent 2 824624. RF, IPC C 08L 5 / 00, C 08L 3 / 02, C 08L 1 / 08, C 08L 29 / 04, C 08K 5 / 092, C 08J 5 / 18. Composition for obtaining a biodegradable polymeric material and a biodegradable polymeric material based on it [Text] / Nikiforova T.E.; applicant and patent holder Ivan. state chemical-technical University. - No. 2023124898; declared. 09.28.2023; publ. 12.08.2024, Bulletin No. 23.

[0042] A composition for producing a biodegradable polymeric material containing starch, polyvinyl alcohol, glycerin, water, citric acid, sodium carboxymethylcellulose in the following ratio of components, wt. %:

[0043] Starch……………………..…………………...0.3-0.7

[0044] NaKMC..……………………………………...0.75-1.5

[0045] Polyvinyl alcohol…………………..……...0.8-1.8

[0046] Glycerin………………………………………………………...1.8-3.5

[0047] Citric acid……………………………..0.07-0.17

[0048] Water …………………………………………….others

[0049] Biodegradable polymer film material based on a composition containing starch, polyvinyl alcohol, glycerin, water, citric acid, sodium carboxymethyl cellulose in the following ratio of components, wt. %:

[0050] Starch……………………..…………………...5.17-12.73

[0051] NaKMC..………………………………………………………...10.56-27.27

[0052] Polyvinyl alcohol…………………..……...14.55-25.86

[0053] Glycerin………………………………………………………...31.03-49.30

[0054] Citric acid…………………………………1.27-2.59

[0055] Water ……………………………………………..other

[0056] The disadvantages of the prototype are:

[0057] - insufficiently high strength of the resulting film (insufficiently high tensile stress: 14.4-17.2 MPa);

[0058] - comparatively high degree of water vapor sorption (14.7-18.7).

[0059] - long time of biodegradation in soil (90 days).

[0060] The technical result of the invention is

[0061] - increasing the strength of the resulting film, namely increasing the tensile strength;

[0062] - reducing the degree of water vapor sorption;

[0063] - reduction of biodegradation time in soil.

[0064] The said result is achieved in that the composition for obtaining a biodegradable polymeric material, containing starch, polyvinyl alcohol, glycerin, water, citric acid, according to the invention, additionally contains gelatin and Jerusalem artichoke extract in the following ratio of components, wt. %:

[0065] Starch……………………..…………………...0.5-1.5

[0066] Gelatin..………………………………………...0.6-1.2

[0067] Jerusalem artichoke extract …………………………0.1-1.0

[0068] Polyvinyl alcohol…………………..……...1.2-2.3

[0069] Glycerin…………………………………………………………...2.5-4.0

[0070] Citric acid……………………………..0.1-0.35

[0071] Water …………………………………………….others

[0072] The said result is also achieved by the fact that the biodegradable polymeric material based on a composition containing starch, polyvinyl alcohol, glycerin, water, citric acid, according to the invention, additionally contains gelatin and Jerusalem artichoke extract in the following ratio of components, wt. %:

[0073] Starch……………………..…………………...5.63-16.71

[0074] Gelatin………………………………………...7.11-13.52

[0075] Jerusalem artichoke extract …………………………1.16-11.19

[0076] Polyvinyl alcohol…………………..……...13.62-26.78

[0077] Glycerin………………………………………………………...27.85-46.21

[0078] Citric acid……………………………..1.12-3.97

[0079] Water …………………………………………….others

[0080] The invention is explained by a drawing, which shows a photograph of the resulting film.

[0081] The following materials and reagents are used to implement the claimed invention:

[0082] • GOST 7699-78 Potato starch. Technical conditions.

[0083] • GOST 32159-2013 Corn starch. General specifications

[0084] Starch is mainly a mixture of two fractions of homoglucans (glucose polymers) of linear and branched structure - amylose and amylopectin.

[0085] Starch is a cheap domestic raw material produced in large quantities, obtained from annually renewable natural raw material sources (potatoes, corn, rice, etc.), and is a biodegradable material.

[0086] • GOST 10779-78 Polyvinyl alcohol. Technical conditions.

[0087] Polyvinyl alcohol (PVA) is an artificial, water-soluble, thermoplastic polymer. It plasticizes in the presence of water and is easily degraded by enzymes, mold, and soil bacteria.

[0088] • GOST 6823-2017 Natural crude glycerin. General specifications.

[0089] Glycerol is a trihydric alcohol, one of the common cheap polymer plasticizers, improves the processability and thermal stability of the polymer composition.

[0090] • GOST 908-2004 Food grade citric acid monohydrate. Technical conditions.

[0091] Citric acid is a white, odorless crystalline substance with a strong sour taste.

[0092] • GOST 11293-89 Gelatin. Specifications (with Amendment No. 1)

[0093] • Jerusalem artichoke tubers are the underground part of the Jerusalem artichoke. They contain the soluble polysaccharide inulin (16-18%), nitrogenous substances (2-3%), vitamins C and B [Great Soviet Encyclopedia. - M .: Soviet Encyclopedia 1969-1978];

[0094] The invention is carried out as follows.

[0095] The biodegradable polymer material is produced using solution technology. This technology involves producing a molding solution by mixing a prepared aqueous solution of polyvinyl alcohol, a starch paste with citric acid, a gelatin solution (gel), glycerin, and Jerusalem artichoke extract.

[0096] Solution 1 is a gelatin solution (gel), which is prepared as follows: a weighed amount of gelatin is placed in cold water, allowed to swell for 30-40 minutes, then slowly heated until completely dissolved for 10-15 minutes, without bringing to a boil, and cooled to room temperature.

[0097] Solution 2 is a starch solution (paste) prepared by mixing a sample of potato or corn starch with distilled water at room temperature, adding a citric acid solution, and then cross-linking the starch with citric acid at 95-100ºC for 10-15 minutes. After this time, the solution is cooled to room temperature.

[0098] Solution 3 is a solution of polyvinyl alcohol in distilled water, which is prepared by adding a weighed amount of PVA to water at room temperature and heating at a temperature of 70-90°C with constant stirring until completely dissolved.

[0099] Solution 4 is a 10% aqueous extract of Jerusalem artichoke, which is obtained by heating the crushed mass of Jerusalem artichoke tubers in distilled water to boiling, followed by maintaining it at boiling for 10 minutes, cooling to room temperature and filtering.

[0100] The composition (molding solution) for obtaining a biodegradable polymer film material is prepared by mixing solutions of gelatin, starch with citric acid and PVA, adding glycerin and Jerusalem artichoke extract to the resulting mixture and stirring for 15-30 minutes at room temperature.

[0101] To obtain a biodegradable polymer material, the finished composition (molding solution) containing a mixture of solutions of gelatin, starch with citric acid, PVA, as well as glycerin and Jerusalem artichoke extract, is cast onto a glass substrate (in Petri dishes) in an amount of 20 ml and dried at room temperature for 48 hours until completely dry and a film is formed.

[0102] For the obtained samples of biodegradable polymer film materials, the following characteristics are determined: tensile strength MPa, degree of water vapor sorption, %, biodegradation time, days.

[0103] The composition of the components in the finished biodegradable polymer material was calculated by recalculating the initial composition of the components of the composition (molding solution), taking into account the residual moisture content of the resulting material, weighing accuracy ±0.0001g.

[0104] To determine the breaking strength of packaging materials obtained from biodegradable polymer material, a tensile testing machine type 2099P-5 with an electric drive of an active grip and an electronic force meter was used.

[0105] Breaking stress, MPa, characterizes the breaking load per unit cross-sectional area. The tensile testing machine speed is set at 20 mm / min. During testing, the breaking load was recorded using an electronic force meter.

[0106] The sorption properties of the materials with respect to water vapor were assessed in a hermetically sealed desiccator, partially (1 / 20) filled with distilled water, at a temperature of 21±2°C and atmospheric pressure. The amount of sorbed vapor was determined gravimetrically by recording the mass of the swollen sample on an analytical balance with a weighing accuracy of ±0.0001 g.

[0107] The material's biodegradability was assessed in vitro in a model soil environment (pH 5.0-6.0) at 21±2°C, natural light and aeration, atmospheric pressure, and humid conditions for 90 days. Prepared film samples measuring 50×15 mm were placed in a polypropylene container filled with soil. Humid conditions were maintained in the container by watering it with water every 3 days. After every 10 days of exposure to soil, the samples were removed from the container, mechanically cleaned of soil, and their weight was determined on an analytical balance. The rate of biodegradation was assessed based on the mass loss of the samples.

[0108] The invention is carried out as follows.

[0109] Example 1.

[0110] Solution 1. Prepare a 5% gelatin solution (gel) by dissolving 1.2 g of gelatin in 22.8 ml of distilled water and allowing the resulting solution to swell for 30-40 minutes at room temperature. Heat slowly for 10 minutes until completely dissolved, without bringing to a boil, then cool to room temperature.

[0111] Solution 2. Prepare a 2% starch solution (paste) by mixing 0.5 g of potato starch with 24.5 ml of distilled water at room temperature, to which a solution of citric acid (0.3 g of citric acid and 1.7 ml of water) is added, heated at a temperature of 95ºC for 12 minutes, after which the solution is cooled to room temperature.

[0112] Solution 3. To prepare a 4% solution of polyvinyl alcohol, a 1.8 g sample of PVA is dissolved in 43.2 ml of distilled water at room temperature, heated to a temperature of 75°C, kept stirring for 20 minutes and then cooled to room temperature.

[0113] A composition for obtaining a biodegradable polymer film material is prepared by mixing solutions of gelatin and starch with citric acid, a PVA solution and adding 3.5 g of glycerin and 0.5 g of Jerusalem artichoke extract to the resulting mixture and stirring for 20 minutes at room temperature.

[0114] To produce biodegradable films, the prepared composition (molding solution), containing a mixture of gelatin and starch solutions with citric acid, a PVA solution, glycerin, and Jerusalem artichoke extract, is cast onto a glass substrate (in Petri dishes) in a quantity of 20 ml and dried at room temperature for 48 hours until a film structure is achieved. The film is then removed from the substrate and kept for another 24 hours at room temperature.

[0115] The appearance of the biodegradable polymer material in the form of a finished film is shown in the drawing.

[0116] Characteristics of the finished film:

[0117] The resulting film is elastic, flexible, and translucent: it does not crack when bent.

[0118] - breaking stress 18.5±0.6MPa;

[0119] - degree of water vapor sorption 13.4±5.0%.

[0120] - biodegradation time 80 days.

[0121] The composition of the components in the molding solution is, wt. %:

[0122] Starch……………………..…………………...0.5

[0123] Gelatin..………………………………………...1,2

[0124] Jerusalem artichoke extract …………………………0.5

[0125] Polyvinyl alcohol…………………..……...1.8

[0126] Glycerin…………………………………………………………...3.5

[0127] Citric acid……………………………..0.3

[0128] Water……………………………………………………….92.2

[0129] Composition of components in the biodegradable polymer film material based on the composition, wt. %:

[0130] Starch……………………..…………………...5.63

[0131] Gelatin..………………………………………...13.52

[0132] Jerusalem artichoke extract …………………………5.63

[0133] Polyvinyl alcohol…………………..……...20.28

[0134] Glycerin…………………………………………………………...39.44

[0135] Citric acid……………………………..3.38

[0136] Water………………………………………………………..12,12

[0137] Example 2.

[0138] Solution 1. Prepare a 2.5% gelatin solution (gel) by dissolving 0.6 g of gelatin in 23.4 ml of distilled water and allowing the resulting solution to swell for 30-40 minutes at room temperature. Heat slowly for 10 minutes until completely dissolved, without bringing to a boil, then cool to room temperature.

[0139] Solution 2. Prepare a 3% starch solution (paste) by mixing 1.0 g of corn starch with 32.0 ml of distilled water at room temperature, to which a solution of citric acid (0.2 g of citric acid and 1.1 ml of water) is added, heated at a temperature of 96ºC for 15 minutes, after which the solution is cooled to room temperature.

[0140] Solution 3. To prepare a 4% solution of polyvinyl alcohol, a 1.5 g sample of PVA is dissolved in 36 ml of distilled water at room temperature, heated to a temperature of 70°C, kept stirring for 25 minutes and then cooled to room temperature.

[0141] A composition for obtaining a biodegradable polymer film material is prepared by mixing solutions of gelatin and starch with citric acid, a PVA solution and adding 4.0 g of glycerin and 0.2 g of Jerusalem artichoke extract to the resulting mixture and stirring for 15 minutes at room temperature.

[0142] To obtain a biodegradable polymer film, the prepared composition (molding solution) containing a mixture of NaCMC and starch solutions with citric acid, PVA solution, and glycerin was cast onto a glass substrate (in Petri dishes) in a quantity of 20 ml and dried at room temperature for 48 hours until a film structure was achieved. The film was then removed from the substrate and kept for another 24 hours at room temperature.

[0143] The appearance of the finished material in the form of a film is shown in the drawing.

[0144] Characteristics of the finished biodegradable polymer material in the form of a film:

[0145] The resulting film is elastic, flexible, translucent and does not crack when bent.

[0146] - breaking stress 15.8±0.3 MPa;

[0147] - degree of water vapor sorption 16.6±5.0%.

[0148] - biodegradation time 80 days.

[0149] The composition of the components in the molding solution is, wt.%:

[0150] Starch……………………..…………………...1.0

[0151] Gelatin………………………………………...0.6

[0152] Jerusalem artichoke extract …………………………0.2

[0153] Polyvinyl alcohol…………………..……...1.5

[0154] Glycerin………………………………………………………...4.0

[0155] Citric acid……………………………..0.2

[0156] Water……………………………………………………….92.5

[0157] Composition of components in the biodegradable polymer film material based on the composition, wt. %:

[0158] Starch……………………..…………………...11.85

[0159] Gelatin………………………………………...7.11

[0160] Jerusalem artichoke extract …………………………2.37

[0161] Polyvinyl alcohol…………………..……...17.77

[0162] Glycerin…………………………………………………………...46.21

[0163] Citric acid……………………………..2.37

[0164] Water……………………………………………………….12.32

[0165] Example 3.

[0166] Solution 1. Prepare a 5% gelatin solution (gel) by dissolving 1.0 g of gelatin in 19.0 ml of distilled water and allowing the resulting solution to swell for 30-40 minutes at room temperature. Heat slowly for 10 minutes until completely dissolved, without bringing to a boil, then cool to room temperature.

[0167] Solution 2. Prepare a 2.5% starch solution (paste) by mixing 0.8 g of potato starch with 31.2 ml of distilled water at room temperature, to which a solution of citric acid (0.1 g of citric acid and 1.9 ml of water) is added, heated at 100ºC for 10 minutes, after which the solution is cooled to room temperature.

[0168] Solution 3. To prepare a 5% solution of polyvinyl alcohol, a 2.1 g sample of PVA is dissolved in 39.9 ml of distilled water at room temperature, heated to a temperature of 80°C, kept stirring for 18 minutes and then cooled to room temperature.

[0169] A composition for obtaining a biodegradable polymer film material is prepared by mixing solutions of gelatin and starch with citric acid, a PVA solution and adding 3 g of glycerin, 1 g of Jerusalem artichoke extract to the resulting mixture and stirring for 25 minutes at room temperature.

[0170] To produce a biodegradable polymer film, the prepared composition (molding solution) containing a mixture of NaCMC and starch solutions with citric acid, PVA solution, and glycerin is cast onto a glass substrate (in Petri dishes) in a quantity of 20 ml and dried at room temperature for 48 hours until a film structure is achieved. The film is then removed from the substrate and kept for another 24 hours at room temperature.

[0171] The appearance of the finished film is shown in the drawing.

[0172] Characteristics of the finished film:

[0173] The resulting film is elastic, flexible, translucent and does not crack when bent.

[0174] - breaking stress 17.2±0.5 MPa;

[0175] - degree of water vapor sorption 15.3±5.0%.

[0176] - biodegradation time 80 days.

[0177] The composition of the components in the molding solution is, wt.%:

[0178] Starch……………………..…………………...0.8

[0179] Gelatin………………………………………...1.0

[0180] Jerusalem artichoke extract …………………………1.0

[0181] Polyvinyl alcohol…………………..……...2.1

[0182] Glycerin…………………………………………………………...3.0

[0183] Citric acid……………………………..0.1

[0184] Water……………………………………………………….92.0

[0185] Composition of components in the biodegradable polymer film material based on the composition, wt. %:

[0186] Starch……………………..…………………...8.95

[0187] Gelatin..………………………………………...11.19

[0188] Jerusalem artichoke extract …………………………11.19

[0189] Polyvinyl alcohol…………………..……...23.49

[0190] Glycerin………………………………………………………...33.56

[0191] Citric acid……………………………..1.12

[0192] Water……………………………………………………….10.50

[0193] Example 4.

[0194] Solution 1. Prepare a 4% gelatin solution (gel) by dissolving 0.8 g of gelatin in 19.2 ml of distilled water and allowing the resulting solution to swell for 30-40 minutes at room temperature. Heat slowly for 10 minutes until completely dissolved, without bringing to a boil, then cool to room temperature.

[0195] Solution 2. Prepare a 3% starch solution (paste) by mixing 1.3 g of corn starch with 41.7 ml of distilled water at room temperature, to which a solution of citric acid (0.35 g of citric acid and 2.45 ml of water) is added, heated at 95ºC for 15 minutes, after which the solution is cooled to room temperature.

[0196] Solution 3. To prepare a 4% solution of polyvinyl alcohol, a 1.2 g sample of PVA is dissolved in 28.8 ml of distilled water at room temperature, heated to a temperature of 90°C, kept stirring for 15 minutes and then cooled to room temperature.

[0197] A composition for obtaining a biodegradable polymer film material is prepared by mixing solutions of gelatin and starch with citric acid, a PVA solution and adding 3.9 g of glycerin and 0.3 g of Jerusalem artichoke extract to the resulting mixture and stirring for 30 minutes at room temperature.

[0198] To produce a biodegradable polymer film, the prepared composition (molding solution) containing a mixture of gelatin and starch solutions with citric acid, a PVA solution, glycerin, and Jerusalem artichoke extract was cast onto a glass substrate (in Petri dishes) in a quantity of 20 ml and dried at room temperature for 48 hours until a film structure was achieved. The film was then removed from the substrate and kept for another 24 hours at room temperature.

[0199] The appearance of the finished film is shown in the drawing.

[0200] Characteristics of finished film:

[0201] The resulting film is elastic, flexible, translucent and does not crack when bent.

[0202] - breaking stress 17.7±0.5 MPa;

[0203] - degree of water vapor sorption 14.8±5.0%.

[0204] - biodegradation time 80 days.

[0205] The composition of the components in the molding solution is, wt.%:

[0206] Starch……………………..…………………...1,3

[0207] Gelatin………………………………………...0.8

[0208] Jerusalem artichoke extract …………………………0.3

[0209] Polyvinyl alcohol…………………..……...1.2

[0210] Glycerin…………………………………………………………...3.9

[0211] Citric acid……………………………..0.35

[0212] Water……………………………………………………….92.15

[0213] Composition of components in the biodegradable polymer film material based on the composition, wt. %:

[0214] Starch……………………..…………………...14.76

[0215] Gelatin………………………………………...9.08

[0216] Jerusalem artichoke extract …………………………3.41

[0217] Polyvinyl alcohol…………………..……...13.62

[0218] Glycerin…………………………………………………………...44.27

[0219] Citric acid……………………………..3.97

[0220] Water……………………………………………………….10.89

[0221] Example 5.

[0222] Solution 1. Prepare a 5.5% gelatin solution (gel) by dissolving 1.1 g of gelatin in 18.9 ml of distilled water and allowing the resulting solution to swell for 30-40 minutes at room temperature. Heat slowly for 10 minutes until completely dissolved, without bringing to a boil, and then cool to room temperature.

[0223] Solution 2. Prepare a 3.75% starch solution (paste) by mixing 1.5 g of potato starch with 38.5 ml of distilled water at room temperature, to which a citric acid solution (0.25 g of citric acid and 4.55 ml of water) is added, heated at a temperature of 98ºC for 12 minutes, after which the solution is cooled to room temperature.

[0224] Solution 3. To prepare a 6.25% solution of polyvinyl alcohol, a 2 g sample of PVA is dissolved in 30.0 ml of distilled water at room temperature, heated to a temperature of 75°C, kept stirring for 20 minutes and then cooled to room temperature.

[0225] A composition for obtaining a biodegradable polymer film material is prepared by mixing solutions of gelatin and starch with citric acid, a PVA solution, adding 2.5 g of glycerin and 0.7 g of Jerusalem artichoke extract to the resulting mixture and stirring for 20 minutes at room temperature.

[0226] To produce biodegradable films, the prepared composition (molding solution) containing a mixture of gelatin and starch solutions with citric acid, a PVA solution, glycerin, and Jerusalem artichoke extract was cast onto a glass substrate (in Petri dishes) in a quantity of 20 ml and dried at room temperature for 48 hours until a film structure was achieved. The film was then removed from the substrate and kept for another 24 hours at room temperature.

[0227] The appearance of the finished film is shown in the drawing.

[0228] Characteristics of finished film:

[0229] The resulting film is elastic, flexible, translucent and does not crack when bent.

[0230] - breaking stress 15.7±0.4 MPa;

[0231] - degree of water vapor sorption 16.7±5.0%.

[0232] - biodegradation time 80 days.

[0233] The composition of the components in the molding solution is, wt.%:

[0234] Starch……………………..…………………...1.5

[0235] Gelatin..………………………………………...1.1

[0236] Jerusalem artichoke extract …………………………0.7

[0237] Polyvinyl alcohol…………………..……...2.0

[0238] Glycerin…………………………………………………………...2.5

[0239] Citric acid……………………………..0.25

[0240] Water……………………………………………………….91.95

[0241] Composition of components in the biodegradable polymer film material based on the composition, wt. %:

[0242] Starch……………………..…………………...16.71

[0243] Gelatin..………………………………………...12.26

[0244] Jerusalem artichoke extract …………………………7.80

[0245] Polyvinyl alcohol…………………..……...22.28

[0246] Glycerin………………………………………………………...27.85

[0247] Citric acid……………………………..2.79

[0248] Water……………………………………………………….10.31

[0249] Example 6.

[0250] Solution 1. Prepare a 2.8% gelatin solution (gel) by dissolving 0.7 g of gelatin in 24.3 ml of distilled water and allowing the resulting solution to swell for 30-40 minutes at room temperature. Heat slowly for 10 minutes until completely dissolved, without bringing to a boil, then cool to room temperature.

[0251] Solution 2. Prepare a 2% starch solution (paste) by mixing 0.6 g of corn starch with 29.4 ml of distilled water at room temperature, to which a solution of citric acid (0.1 g of citric acid and 1 ml of water) is added, heated at a temperature of 97ºC for 14 minutes, after which the solution is cooled to room temperature.

[0252] Solution 3. To prepare a 5.75% solution of polyvinyl alcohol, a 2.3 g sample of PVA is dissolved in 37.7 ml of distilled water at room temperature, heated to a temperature of 75°C, kept stirring for 20 minutes and then cooled to room temperature.

[0253] A composition for obtaining a biodegradable polymer film material is prepared by mixing solutions of gelatin and starch with citric acid, a PVA solution and adding 3.8 g of glycerin and 0.1 g of Jerusalem artichoke extract to the resulting mixture and stirring for 25 minutes at room temperature.

[0254] To produce biodegradable films, the prepared composition (molding solution) containing a mixture of gelatin and starch solutions with citric acid, a PVA solution, glycerin, and Jerusalem artichoke extract was cast onto a glass substrate (in Petri dishes) in a quantity of 20 ml and dried at room temperature for 48 hours until a film structure was achieved. The film was then removed from the substrate and kept for another 24 hours at room temperature.

[0255] The appearance of the finished film is shown in the drawing.

[0256] Characteristics of finished film:

[0257] The resulting film is elastic, flexible, translucent and does not crack when bent.

[0258] - breaking stress 15.5±0.3 MPa;

[0259] - degree of water vapor sorption 17.0±5.0%.

[0260] - biodegradation time 80 days.

[0261] The composition of the components in the molding solution is, wt.%:

[0262] Starch……………………..…………………...0.6

[0263] Gelatin………………………………………...0.7

[0264] Jerusalem artichoke extract …………………………0.1

[0265] Polyvinyl alcohol…………………..……...2.3

[0266] Glycerin………………………………………………………...3.8

[0267] Citric acid……………………………..0.1

[0268] Water……………………………………………………….92.4

[0269] Composition of components in the biodegradable polymer film material based on the composition, wt. %:

[0270] Starch……………………..…………………...6.98

[0271] Gelatin………………………………………...8.15

[0272] Jerusalem artichoke extract …………………………1.16

[0273] Polyvinyl alcohol…………………..……...26.78

[0274] Glycerin………………………………………………………...44.24

[0275] Citric acid……………………………..1.16

[0276] Water……………………………………………………….11.53

[0277] The test results with the characteristics of the obtained samples in comparison with the prototype are presented in the table.

[0278] Table

[0279] Sample Breaking stress MPa Degree of water vapor sorption, % Biodegradation time, days Examples Sample No. 1 18,5±0,6 13,4±5.0 80 Sample No. 2 15,8±0,3 16,6±5.0 80 Sample No. 3 17,2±0,5 15,3±5.0 80 Sample No. 4 17,7±0,5 14,8±5.0 80 Sample No. 5 15,7±0,4 16,7±5.0 80 Sample No. 6 15,5±0,3 17.0±5.0 80 Prototype Sample No. 1 17,2±0,6 14,7±5.0 90 Sample No. 2 14,5±0,3 18,3±5.0 90 Sample No. 3 16,0±0,5 17,5±5.0 90 Sample No. 4 16,5±0,5 16,0±5.0 90 Sample No. 5 14,6±0,4 17,9±5.0 90 Sample No. 6 14,4±0,3 18.7±5.0 90

[0280] Thus, from the data presented in the table and in the examples, it follows that the proposed composition makes it possible to obtain on its basis a biodegradable polymer material in the form of a film, characterized by a higher tensile strength (greater strength by 7-8%), a lower degree of water vapor sorption (by 1.2-2.2%) and a shorter time of biodegradation of films in the soil (by 10 days).

Claims

1. A composition for producing a biodegradable polymer film material containing starch, polyvinyl alcohol, glycerin, water, citric acid, characterized in that it additionally contains gelatin and Jerusalem artichoke extract, wherein the Jerusalem artichoke extract is a 10% aqueous extract of Jerusalem artichoke, which is obtained by heating the crushed mass of Jerusalem artichoke tubers in distilled water to boiling, followed by maintaining it at boiling for 10 minutes, cooling to room temperature and filtering, with the following ratio of components, wt. %: Starch 0,5-1,5 Gelatin 0,6-1,2 Jerusalem artichoke extract 0,1-1,0 Polyvinyl alcohol 1,2-2,3 Glycerol 2,5-4,0 Citric acid 0,1-0,35 Water rest 2. A biodegradable polymeric material for a film obtained by drying the composition according to paragraph 1, containing starch, polyvinyl alcohol, glycerin, water, citric acid, characterized in that it additionally contains gelatin and Jerusalem artichoke extract in the following ratio of components, wt. %: Starch 5,63-16,71 Gelatin 7,11-13,52 Jerusalem artichoke extract 1,16-11,19 Polyvinyl alcohol 13,62-26,78 Glycerol 27,85-46,21 Citric acid 1,12-3,97 Water rest

Images