Degradable polyvinyl alcohol solid material with long-acting slow-release small molecules as well as preparation method and application of degradable polyvinyl alcohol solid material

Abstract

The invention discloses a degradable polyvinyl alcohol solid material with long-acting slow-release small molecules as well as a preparation method and application of the degradable polyvinyl alcohol solid material, and relates to the technical field of polyvinyl alcohol, the solid material comprises the following components in parts by weight: 100 parts of PVA; 5-10 parts of a plasticizer I; 5-30 parts of a plasticizer II; 0.2-15 parts of a salt solution or 0.1-5 parts of boric acid powder; 2-2.5 parts of a slow release substance; the preparation method comprises the following steps: carrying out vacuum drying on PVA to obtain dried PVA; mixing the dried PVA and a plasticizer I at 20-80 DEG C for 1-4 hours to obtain plasticized powder; mixing the plasticizing powder, a plasticizer II and a salt solution or boric acid powder at 60-80 DEG C for 1-4 hours to obtain compound plasticizing powder; adding a slow-release substance into the compound plasticizing powder, and mixing at 30-40 DEG C for 1-4 hours to obtain mixed powder; tabletting the mixed powder, and sealing and storing after tabletting to obtain the solid material, the purpose of reducing the crystallinity of the polyvinyl alcohol solid material is achieved by adopting the formula of adding the micro-crosslinking agent into the compound plasticizer, so that the effect of slowly releasing small molecules can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of polyvinyl alcohol, and in particular to a long-acting sustained-release small molecule degradable polyvinyl alcohol solid material and a preparation method and application thereof. Background Art

[0002] Polyvinyl alcohol (PVA) is one of the common polymer materials, with the advantages of water solubility, hydrophilicity, biocompatibility and biodegradability. Due to the water solubility of PVA, PVA is used in 3D printing support materials, agricultural mulch films, fertilizer slow-release coating materials, etc. At the same time, the degradable properties of PVA make it a drug delivery carrier material with great potential in biomedical research. The research and development of degradable PVA slow-release materials is one of the hot spots that meet the current development needs of green technology.

[0003] The existing market for PVA sustained-release materials is mainly divided into coated sustained-release materials and degradable sustained-release materials. Coated sustained-release materials have the disadvantages of being easily ruptured and failing, or being difficult to function due to failure to meet rupture conditions, and the sustained-release process is usually completed within a few hours; the sustained-release process of degradable sustained-release materials proceeds along with the degradation process, and therefore has a longer sustained-release process (several weeks or even months) and a lower content of sustained-release substances, but their mechanical properties are weak, and their economic and labor costs are high. Summary of the invention

[0004] The purpose of the present invention is to provide a long-acting sustained-release small molecule degradable polyvinyl alcohol solid material and its preparation method and application, to solve the following technical problems:

[0005] How to better control the sustained-release process of PVA sustained-release materials.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] In the first aspect, the present invention discloses a long-acting sustained-release small molecule degradable polyvinyl alcohol solid material, characterized in that it comprises the following raw materials in parts by weight: 100 parts of PVA; 5-10 parts of plasticizer 1; 5-30 parts of plasticizer 2; 0.2-15 parts of salt solution or 0.1-5 parts of boric acid powder; and 2-2.5 parts of sustained-release substance.

[0008] Furthermore, the PVA has a degree of polymerization of 500-3000 and a degree of alcoholysis of 90-99.99%;

[0009] Preferably, the degree of polymerization of the PVA is 1600-2500.

[0010] Furthermore, the first plasticizer is glycerol or polyethylene glycol.

[0011] Furthermore, the plasticizer is a combination of any one or more of two-dimensional triethanolamine, diethanolamine, diethylene glycol, and caprolactam.

[0012] Furthermore, the mass fraction of the salt solution is 37.5%.

[0013] Furthermore, the salt solution is a combination of any one or more of calcium chloride, magnesium chloride or sodium chloride.

[0014] Furthermore, the sustained-release substance is a high-temperature resistant organic small molecule substance, such as linalool, geraniol, eugenol, etc.

[0015] In a second aspect, the present invention discloses a method for preparing the above-mentioned long-acting sustained-release small molecule degradable polyvinyl alcohol solid material, characterized in that it comprises the following steps:

[0016] S1. Prepare raw materials according to weight ratio, vacuum dry PVA to obtain dry PVA;

[0017] S2, mixing the dried PVA and plasticizer 1 at 40-60° C. for 2-4 hours to obtain a plasticized powder;

[0018] S3, mixing the plasticizer powder, plasticizer 2, salt solution or boric acid powder at 60-80° C. for 1-4 hours to obtain a compound plasticizer powder;

[0019] S4, adding the sustained-release substance to the compound plasticizing powder, mixing at 30-40° C. for 1-4 hours to obtain a mixed powder;

[0020] S5, tableting the mixed powder, and sealing and storing the tablets to obtain the solid material.

[0021] Furthermore, in step S1, the vacuum drying temperature is 60-80°C, and the drying time is 2-4h.

[0022] Further, in step S5, the tableting temperature is 180-210°C, the tableting pre-compression pressure is 2-4MPa, the tableting pressure is 5-8MPa, and the tableting time is 7-10min;

[0023] Preferably, the tableting temperature is 190° C., the tableting pre-compression pressure is 3 MPa, the tableting pressure is 8 MPa, and the tableting time is 8 min.

[0024] In the third aspect, the present invention also discloses an application of the above-mentioned long-acting sustained-release small molecule degradable polyvinyl alcohol solid material, which is used in the fields of agriculture, fishery, tobacco, medicine or cosmetics; when applied to agriculture and fishery, the solid material can be prepared into films, sheets, particles, etc. through simple processing; when applied to tobacco, medicine or cosmetics, small molecule aromatic substances can be used as sustained-release substances to produce a good sustained-release effect.

[0025] Beneficial effects of the present invention:

[0026] 1. In the preparation process of the long-acting slow-release small molecule degradable polyvinyl alcohol solid material of the present invention, the purpose of reducing the crystallinity of the polyvinyl alcohol solid material is achieved by adopting a compound plasticizer (a mixture of multiple plasticizers) and adding a micro-crosslinking agent (salt solution or boric acid powder), so that it can play the role of slow-release small molecules; the compound plasticizer can reduce the crystallinity of the PVA solid material. For example, in a PVA system containing a binary compound plasticizer of caprolactam and glycerol, the hydroxyl groups of the PVA molecules, the hydroxyl groups of the glycerol molecules and the amide groups of the caprolactam molecules form hydrogen bonds in pairs, which can destroy the internal structure of the PVA molecules and reduce their crystallinity; at the same time, the addition of the micro-crosslinking agent to the polyvinyl alcohol has the ability to change the morphological structure and performance of the PVA. For example, the electron acceptor such as Mg in the salt solution 2+ When combining with the oxygen atom on the -OH in PVA, it will destroy the hydrogen bonding within and between the PVA molecular chains; boric acid can form a lightly cross-linked network with PVA, thereby reducing the crystallinity of PVA and achieving the effect of sustained release of small molecules.

[0027] 2. During the preparation process of the long-acting sustained-release small molecule biodegradable polyvinyl alcohol solid material of the present invention, a two-step plasticization method is adopted to achieve the purpose of fully mixing the compound plasticizer, micro-crosslinking agent and polyvinyl alcohol. The two-step plasticization method can make the PVA swell fully, which is conducive to the uniform mixing of PVA and various plasticizers, so that the PVA can be completely plasticized during the tableting process.

[0028] 3. The long-acting sustained-release small molecule degradable polyvinyl alcohol solid material prepared by the method of the present invention releases small molecules evenly on the surface during sustained release. Compared with the coated sustained-release material, the material prepared by this method releases more evenly and slowly, avoiding leakage caused by sudden rupture of PVA as a coating material. At the same time, compared with degradable sustained-release materials that require a long time to decompose before exerting their effects and have limited loads, the material prepared by this method has a more obvious effect.

[0029] 4. The method of the present invention allows small molecules to enter the interior of the PVA tablet sample by blending small molecule organic matter (sustained-release substance) with a plasticizer, so that the polyvinyl alcohol solid material sample is loaded with small molecules. Compared with coated sustained-release materials, it has the advantages of simple processing method and low cost. The product prepared by the method of the present invention is a solid material with certain strength and extrusion resistance, and can realize the preparation of products of various morphologies to adapt to various application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the accompanying drawings.

[0031] Figure 1 It is a comparison curve chart of the sustained release rate of the polyvinyl alcohol solid material samples prepared in Examples 1-7 of the present invention and Comparative Examples 1-4. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0034] Example 1

[0035] 100 parts of PVA (polymerization degree 1700, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours, mixed with 7 parts of glycerol, and stirred at 50°C for 3 hours to obtain a plasticized powder. The plasticized powder was mixed with 15 parts of caprolactam and 10 parts of 37.5% calcium chloride solution at 70°C and stirred for 3 hours to obtain a compound plasticized powder. 2.2 parts of linalool were added to the compound plasticized powder and stirred at 35°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was tableted at a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 8min to obtain a polyvinyl alcohol solid material sample.

[0036] Example 2

[0037] 100 parts of PVA (polymerization degree 1700, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours, mixed with 7 parts of glycerol, and stirred at 50°C for 3 hours to obtain a plasticized powder. The plasticized powder was mixed with 15 parts of triethanolamine and 10 parts of 37.5% calcium chloride solution at 70°C for 3 hours to obtain a compound plasticized powder. 2.2 parts of linalool were added to the compound plasticized powder and stirred at 40°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was pressed under the conditions of a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 10min to obtain a polyvinyl alcohol solid material sample.

[0038] Example 3

[0039] 100 parts of PVA (polymerization degree 1700, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours, mixed with 7 parts of glycerol, and stirred at 50°C for 3 hours to obtain a plasticized powder. The plasticized powder was mixed with 5 parts of diethylene glycol, 10 parts of diethanolamine, and 10 parts of 37.5% sodium chloride solution by mass and stirred at 70°C for 3 hours to obtain a compound plasticized powder. 2.2 parts of linalool were added to the compound plasticized powder and stirred at 40°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was tableted at a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 10min to obtain a polyvinyl alcohol solid material sample.

[0040] Example 4

[0041] 100 parts of PVA (polymerization degree 2400, alcoholysis degree 99%) were vacuum dried at 60°C for 4 hours and then mixed with 5 parts of glycerol, and stirred at 40°C for 4 hours to obtain a plasticized powder. The plasticized powder was mixed with 2 parts of diethylene glycol, 3 parts of diethanolamine, and 0.2 parts of boric acid at 80°C and stirred for 1 hour to obtain a compound plasticized powder. Then 2 parts of linalool were added to the compound plasticized powder and stirred at 40°C for 1 hour to obtain a mixed powder. Finally, the mixed powder was pressed under the conditions of a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 10min to obtain a polyvinyl alcohol solid material sample.

[0042] Example 5

[0043] 100 parts of PVA (polymerization degree 1700, alcoholysis degree 99%) were vacuum dried at 80°C for 2 hours, mixed with 10 parts of polyethylene glycol, and stirred at 60°C for 2 hours to obtain a plasticized powder. The plasticized powder was mixed with 30 parts of caprolactam and 15 parts of 37.5% magnesium chloride solution by mass and stirred at 80°C for 1 hour to obtain a compound plasticized powder. 2.5 parts of linalool were added to the compound plasticized powder and stirred at 40°C for 1 hour to obtain a mixed powder. Finally, the mixed powder was tableted at a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 10min to obtain a polyvinyl alcohol solid material sample.

[0044] Example 6

[0045] 100 parts of PVA (polymerization degree 2400, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours, mixed with 5 parts of polyethylene glycol, and stirred at 50°C for 3 hours to obtain a plasticized powder. The plasticized powder was mixed with 10 parts of triacetamide and 5 parts of 37.5% calcium chloride solution at 50°C and stirred for 2 hours to obtain a compound plasticized powder. 2 parts of linalool were added to the compound plasticized powder and stirred at 40°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was tableted at a tableting temperature of 190°C, a tableting pre-compression pressure of 2MPa, a tableting pressure of 5MPa, and a tableting time of 10min to obtain a polyvinyl alcohol solid material sample.

[0046] Example 7

[0047] 100 parts of PVA (polymerization degree 2400, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours, mixed with 5 parts of polyethylene glycol, and stirred at 50°C for 3 hours to obtain a plasticized powder. The plasticized powder was mixed with 10 parts of triacetamide and 5 parts of boric acid powder at 50°C and stirred for 2 hours to obtain a compound plasticized powder. Then, 2 parts of linalool were added to the compound plasticized powder and stirred at 40°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was tableted at a tableting temperature of 190°C, a tableting pre-compression pressure of 4MPa, a tableting pressure of 7MPa, and a tableting time of 10min to obtain a polyvinyl alcohol solid material sample.

[0048] Comparative Example 1

[0049] 100 parts of PVA (polymerization degree 1700, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours and then mixed with 7 parts of glycerol, and stirred at 50°C for 3 hours to obtain a plasticized powder. The plasticized powder was mixed with 25 parts of deionized water and stirred at 70°C for 3 hours to obtain a compound plasticized powder. 2.2 parts of linalool were added and stirred at 40°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was pressed under the conditions of a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 10min to obtain a polyvinyl alcohol solid material sample.

[0050] Comparative Example 2

[0051] 100 parts of PVA (polymerization degree 1700, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours, and then mixed with 7 parts of glycerol, 15 parts of caprolactam, and 10 parts of 37.5% calcium chloride solution at 70°C for 3 hours to obtain a compound plasticizer powder. 2.2 parts of linalool were added to the compound plasticizer powder and stirred at 35°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was tableted at a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 8min to obtain a polyvinyl alcohol solid material sample.

[0052] Comparative Example 3

[0053] 100 parts of PVA (polymerization degree 1700, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours and then mixed with 7 parts of glycerol, and stirred at 50°C for 3 hours to obtain a plasticized powder. The plasticized powder was mixed with 10 parts of a 37.5% calcium chloride solution at 70°C and stirred for 3 hours, and then 2.2 parts of linalool were added and stirred at 35°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was pressed under the conditions of a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 8min to obtain a polyvinyl alcohol solid material sample.

[0054] Comparative Example 4

[0055] 100 parts of PVA (polymerization degree 1700, alcoholysis degree 99%) were vacuum dried at 70°C for 3 hours, mixed with 7 parts of glycerol, and stirred at 50°C for 3 hours to obtain a plasticized powder. The plasticized powder was mixed with 15 parts of caprolactam and stirred at 70°C for 3 hours to obtain a compound plasticized powder. 2.2 parts of linalool were added to the compound plasticized powder and stirred at 35°C for 3 hours to obtain a mixed powder. Finally, the mixed powder was tableted at a tableting temperature of 190°C, a tableting pre-compression pressure of 3MPa, a tableting pressure of 8MPa, and a tableting time of 8min to obtain a polyvinyl alcohol solid material sample.

[0056] The sustained-release effects of the polyvinyl alcohol solid material samples obtained in Examples 1-7 and Comparative Examples 1-4 were grouped and tested respectively. The testing method was as follows: a PVA solid material sample with uniform thickness was cut, and the mass was recorded as M0; the solid sample was placed in a constant temperature and humidity chamber, the temperature was set to 65°C, and the humidity was 55% RH. Every 24 hours, the film surface was wiped with an alcohol cotton ball and the alcohol was completely evaporated. The mass was recorded as Mn, and the test was continued until the mass remained substantially unchanged or the sustained-release rate reached 100%; the sustained-release rate of the film was calculated, and the sustained-release rate ΔM was calculated as follows: ΔM = (Mn-M0) / M, where M is the total mass of the sustained-release substance in the film. Three samples were tested in each group of experiments, and the final result was the average of the three results, as shown in the following figure. Figure 1 The sustained release rate curve comparison diagram is shown, and the sustained release rate of each group of polyvinyl alcohol solid material samples at 4, 8, 12 and 16 days is recorded.

[0057] The test results are listed in Table 1. Table 1 is as follows:

[0058] Table 1

[0059]

[0060] right Figure 1 By analyzing the data in Table 1, it can be seen that compared with Comparative Examples 1-4, the polyvinyl alcohol solid material samples prepared in Examples 1-7 have a slower sustained release rate.

[0061] Next, the mechanical properties of the polyvinyl alcohol solid material samples obtained in Examples 1-7 and Comparative Examples 1-4 were grouped and tested respectively, and the testing method was as follows:

[0062] Tensile strength and elongation at break: tested on an electronic universal testing machine in accordance with GB / T 1040.3-2006, with a tensile speed of 100 mm / min, a distance between fixtures of 100 mm, and a specimen width of 15 mm.

[0063] Each group of experiments tested 3 samples, and the final result was the average of the 3 results and recorded in Table 2. Table 2 is as follows:

[0064] Table 2

[0065] Tensile strength(MPa) Elongation at break (MPa) Example 1 42 376 Example 2 34 349 Example 3 35 320 Example 4 45 282 Example 5 37 346 Example 6 51 324 Example 7 52 306 Comparative Example 1 66 109 Comparative Example 2 35 232 Comparative Example 3 39 214 Comparative Example 4 21 176

[0066] By analyzing the data in Table 2, it can be seen that compared with Comparative Examples 1-4, the polyvinyl alcohol solid material samples prepared in Examples 1-7 have stronger mechanical properties.

[0067] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A degradable polyvinyl alcohol solid material with long-term sustained release of small molecules, characterized in that: The raw materials include the following in parts by weight: 100 parts of PVA; 5-10 parts of plasticizer 1; 5-30 parts of plasticizer 2; 0.2-15 parts of salt solution or 0.1-5 parts of boric acid powder; and 2-2.5 parts of sustained-release substance.

2. The long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to claim 1, characterized in that: The PVA has a polymerization degree of 500-3000 and an alcoholysis degree of 90-99.99%.

3. The long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to claim 1, characterized in that: The first plasticizer is glycerol or polyethylene glycol.

4. The long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to claim 1, characterized in that: The plasticizer is a combination of any one or more of triethanolamine, diethanolamine, diethylene glycol and caprolactam.

5. The long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to claim 1, characterized in that: The mass fraction of the salt solution is 37.5%.

6. The degradable polyvinyl alcohol solid material for long-term sustained release of small molecules according to claim 5, characterized in that: The salt solution is any one or more of calcium chloride, magnesium chloride or sodium chloride.

7. The long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to claim 1, characterized in that: The sustained-release substance is a high-temperature resistant organic small molecule substance.

8. A method for preparing a long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to any one of claims 1 to 7, characterized in that: The steps include: S1. Prepare raw materials according to weight ratio, vacuum dry PVA to obtain dry PVA; S2, mixing the dried PVA and plasticizer 1 at 40-60° C. for 2-4 hours to obtain a plasticized powder; S3, mixing the plasticizer powder, plasticizer 2, salt solution or boric acid powder at 60-80° C. for 1-4 hours to obtain a compound plasticizer powder; S4, adding the sustained-release substance to the compound plasticizing powder, mixing at 30-40° C. for 1-4 hours to obtain a mixed powder; S5, tableting the mixed powder, and sealing and storing the tablets to obtain the solid material.

9. The method for preparing the long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to claim 8, characterized in that: In step S1, the vacuum drying temperature is 60-80°C, and the drying time is 2-4 hours.

10. The method for preparing the long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to claim 8, characterized in that: In step S5, the tableting temperature is 180-210° C., the tableting pre-compression pressure is 2-4 MPa, the tableting pressure is 5-8 MPa, and the tableting time is 7-10 min.

11. An application of the long-acting sustained-release small molecule degradable polyvinyl alcohol solid material according to any one of claims 8 to 10, characterized in that: Used in agriculture, fisheries, tobacco, medicine or cosmetics.

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