Novel water-soluble deodorant and preparation method thereof

Abstract

The invention discloses a novel water-soluble deodorant and a preparation method thereof, and belongs to the technical field of deodorant preparation. Comprising the following raw materials: 25-35 parts of polyvinyl alcohol, 10-20 parts of polyethylene glycol, 6-13 parts of sodium alginate, 5-12 parts of montmorillonite, 10-20 parts of polyethylene powder, 0.3-1.2 parts of an antioxidant, 2-5 parts of titanium dioxide, 3-8 parts of paraffin, 20-30 parts of plant-based deodorization powder, 3-10 parts of chitosan and 0.5-1 part of calcium chloride. According to the deodorant, raw materials except chitosan and calcium chloride are blended, extruded and granulated to form slow-release particles, embedding of a plant extract is achieved, then the mixture is added into a mixed solution of chitosan, calcium chloride and plant-based deodorization powder for surface layer cross-linking loading, the plant-based deodorization powder is powdery plant polyphenol, and the plant-based deodorization powder is a mixture of chitosan, calcium chloride and plant-based deodorization powder. According to the deodorant disclosed by the invention, through secondary loading, the drug loading capacity is greatly improved, and a long-acting release mechanism is formed.

Description

Technical Field

[0001] The present invention belongs to the technical field of deodorant preparation, and particularly relates to a novel water-soluble deodorant and a preparation method thereof. Background Art

[0002] The existing preparation technology of deodorant slow-release particles mainly serves the growing demand for odor control, especially in enclosed spaces (such as medical waste treatment stations, farms, sewage treatment facilities) and long-term protection scenarios (such as functional textiles, food packaging materials). Traditional liquid sprays or solid deodorants have defects such as short action time (usually <24 hours), easy volatilization and inactivation of active ingredients, and high risk of secondary pollution. Existing technical solutions achieve the slow-release function through biodegradable material loading and embedding technology. Specifically, a composite carrier of biodegradable polymer resin / inorganic porous material (pore size 2 - 50nm) is mixed with a plant extract (such as tea polyphenols, ellagic acid) deodorant to prepare deodorant particles with slow-release characteristics. Its slow-release mechanism depends on the degradation of the polymer caused by environmental humidity or temperature changes, thereby enabling the deodorant to have a slow-release effect.

[0003] Currently, the mainstream preparation processes include: spray drying method (inlet air temperature 180 - 220°C) to achieve the β-cyclodextrin embedding of plant essential oils (limonene, linalool); sol-gel method to construct a three-dimensional network structure in the SiO2 matrix and load nano-zinc oxide photocatalyst; extrusion granulation technology to blend humic acid and polylactic acid and prepare biodegradable slow-release particles through twin-screw melt extrusion.

[0004] However, the existing technology still has significant bottlenecks. The limited specific surface area of the carrier material leads to low drug loading efficiency. The uneven crosslinking degree of the microcapsule wall material causes a burst release effect (release amount in the first 6 hours > 40%). The residue of toxic crosslinking agents causes secondary pollution. The high-temperature and high-pressure preparation conditions (such as spray drying) cause the inactivation of heat-sensitive deodorant components (enzyme preparations, probiotics). These defects severely restrict the application of slow-release particles in high-end fields such as medical protection and cold chain logistics. There is an urgent need to develop a low-cost, high-loading, and long-term slow-release system. Summary of the Invention

[0005] The purpose of the present invention is to provide a novel water-soluble deodorant and a preparation method thereof, which can achieve long-term slow-release deodorization.

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

[0007] The present invention provides a novel water-soluble deodorant, which includes the following raw materials by mass fraction:

[0008] 25 - 35 parts of polyvinyl alcohol, 10 - 20 parts of polyethylene glycol, 6 - 13 parts of sodium alginate, 5 - 12 parts of montmorillonite, 10 - 20 parts of polyethylene powder, 0.3 - 1.2 parts of antioxidant, 2 - 5 parts of titanium dioxide, 3 - 8 parts of paraffin, 20 - 30 parts of plant - based deodorant powder, 3 - 10 parts of chitosan, 0.5 - 1 part of calcium chloride;

[0009] The deodorant is first prepared by co - extruding and granulating the raw materials excluding chitosan and calcium chloride to achieve the encapsulation of plant extracts, and then the granules are added to the mixed solution of chitosan, calcium chloride and plant - based deodorant powder for surface cross - linking and loading. The above preparation method realizes the secondary loading on the surface of the encapsulated deodorant particles. While increasing the drug - loading capacity, the dissolution of the surface of the encapsulated particles is delayed by the secondary loading, realizing long - term release.

[0010] Polyvinyl alcohol and polyethylene glycol are biodegradable materials with almost no toxicity. Polyethylene glycol (PEG) has good water solubility and hydrophilicity, which can improve the wettability and biocompatibility of the deodorant, while polyvinyl alcohol (PVA) has high mechanical strength and good adhesion, which can enhance the mechanical properties of the deodorant particles.

[0011] Among the above raw materials of the deodorant, polyvinyl alcohol dissolves slowly in water. As a carrier, it encapsulates the deodorant to achieve a slow - release effect; sodium alginate is easily soluble in water to form a viscous colloidal solution, which promotes the adsorption of malodorous substances; montmorillonite has a large specific surface area and interlayer pores, which can load plant extracts through physical adsorption, increasing the loading capacity. Titanium dioxide has significant photocatalytic activity, which can sterilize, and titanium dioxide can be used as a photocatalyst to promote the photocatalytic degradation of polyvinyl alcohol and polyethylene, improving the slow - release performance; titanium dioxide and montmorillonite form a physical protection for the plant - based deodorant powder to prevent the decomposition and inactivation of the components of the plant - based deodorant powder; polyethylene and paraffin can ensure processing fluidity and uniform mixing of the raw materials.

[0012] Sodium alginate can form an outer network with chitosan through electrostatic cross - linking to load plant extracts, and an ionic cross - linking network is formed by using calcium chloride and sodium alginate to further enhance the stability of the load and avoid the burst - release effect.

[0013] The plant - based deodorant powder is powdered plant polyphenol. There are a large number of hydroxyl groups in plant polyphenols. The hydrogen atoms of the hydroxyl groups carry a small amount of positive charge (+δ), while the nitrogen (N) atoms of amines (such as ammonia, trimethylamine, etc.), the oxygen (O) atoms of aldehydes (such as formaldehyde, acetaldehyde, etc.) and carboxylic acids (such as acetic acid, isovaleric acid, etc.) carry negative charges (-δ) based on non - bonding electron pairs, thus chemical reactions occur to eliminate odor molecules. Although its own power is small, the more hydroxyl groups there are, the greater the bonding force. These malodorous substances will be captured by macromolecular plant polyphenols to eliminate odors.

[0014] Further, the degree of alcoholysis of the polyvinyl alcohol is 80-90%, and the higher the degree of alcoholysis, the slower the dissolution rate and the longer the dissolution time.

[0015] Further, the montmorillonite is sodium-based montmorillonite, and the particle size D50 is 5-20 μm.

[0016] Further, the average particle size of the polyethylene powder is 20-30 μm.

[0017] Further, the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0018] Further, the paraffin wax is No. 52 fully refined paraffin wax, with a molecular weight of 380-450 Da and a melting range of 52-54 °C.

[0019] Further, the plant-based deodorant powder is at least one of persimmon tannin, tea polyphenols, and curcumin.

[0020] Further, the degree of deacetylation of the chitosan is ≥85%, and the molecular weight is 50-100 kDa.

[0021] Further, the mass ratio of the polyvinyl alcohol to the sodium alginate is (1:0.5)-(1:0.2).

[0022] Further, the mass ratio of the chitosan, sodium alginate, and calcium chloride is (0.5-1):1:(0.08-0.1).

[0023] The present invention also provides a preparation method of a novel water-soluble deodorant, comprising the following steps:

[0024] Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium alginate, montmorillonite, polyethylene powder, antioxidant, titanium dioxide, and paraffin wax, and then add 90-95 wt% of the total amount of the plant-based deodorant powder for mixing, and mix evenly to obtain a mixture;

[0025] Step 2: Feed the mixture into a twin-screw extruder, and perform melt blending in a temperature range of 120-160 °C, with a screw speed of 120-250 rpm and a head pressure maintained at 8-15 MPa;

[0026] Step 3: After extrusion by the extruder, obtain slow-release particles with a particle size of 0.5-3 mm through water cooling granulation and screening, and the surface porosity thereof is 15-35%;

[0027] Step 4: Dissolve the chitosan in an acetic acid solution, add the remaining plant-based deodorant powder, stir evenly, and then add a calcium chloride ethanol solution, and stir to form a mixed solution;

[0028] Step 5: Put the sustained-release particles described in Step 3 into the mixed solution, stir and crosslink for 5 - 10 min, take out the sustained-release particles, and dry them at 50 - 60 °C in a dispersed state to obtain the novel water-soluble deodorant.

[0029] Further, the shear rate of the kneading section of the twin-screw extruder is 150 - 300 s -1 , and the residence time of the material is 90 - 150 s.

[0030] Further, the calcium chloride ethanol solution is calcium chloride dissolved in absolute ethanol with a mass concentration of 3 - 5 wt%.

[0031] Further, the mass concentration of the acetic acid solution is 1 - 3 wt%, and chitosan is dissolved in the acetic acid solution according to a mass concentration of 1 - 2 wt%.

[0032] Advantages of the present invention:

[0033] (1) The novel water-soluble deodorant provided by the present invention is secondarily loaded on the surface of the sustained-release particles encapsulating the plant-based deodorant powder. Using sodium alginate on the surface of the sustained-release particles as the cross-linking and loading substrate, through the electrostatic interaction between the amino group of chitosan and the hydroxyl group in plant polyphenols, chitosan adsorbing plant polyphenols, under the synergistic action of calcium chloride, cross-links and combines with sodium alginate, and plant polyphenols are adsorbed and loaded on the surface of the sustained-release particles, realizing the internal encapsulation and surface loading of the deodorant effective components in the deodorant particles, and greatly improving the drug loading capacity of the deodorant.

[0034] (2) The raw materials of the deodorant provided by the present invention are safe and non-toxic. By adjusting the composition ratio of the carrier material, the sustained-release effect of the deodorant is controlled. By adding the photocatalyst titanium dioxide, the photocatalytic degradation performance of the degradable material is improved, and the anti-swelling property of sodium alginate is enhanced, which can avoid the sudden release caused by the swelling and dispersion of sodium alginate in water, and initially protect the sustained-release particles containing most of the plant-based deodorant powder in the form of secondary loading, delaying the dissolution time of the sodium alginate on its surface. When the small part of the plant-based deodorant powder in the secondary loading is slowly released, the plant-based deodorant powder in the sustained-release particles is released later, forming a long-acting release mechanism. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment provides a novel water-soluble deodorant, which comprises the following raw materials by mass fraction:

[0038] 30 parts of polyvinyl alcohol (degree of alcoholysis 88%), 23.5 parts of polyethylene glycol, 10 parts of sodium alginate, 5 parts of sodium-based montmorillonite (D50 is 5 - 20 μm), 20 parts of polyethylene powder (average particle size is 20 - 30 μm), 1.2 parts of antioxidant 1010, 2.8 parts of titanium dioxide, 8 parts of fully refined paraffin wax No. 52 (molecular weight is 380 - 450 Da, melting range is 52 - 54 °C), 20 parts of persimmon tannin, 5 parts of chitosan (degree of deacetylation 85%, molecular weight is 50 - 100 kDa), 0.8 parts of calcium chloride.

[0039] Prepare raw materials according to the above ratios to prepare a novel water-soluble deodorant. The specific steps are as follows:

[0040] Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium alginate, sodium-based montmorillonite, polyethylene powder, antioxidant 1010, titanium dioxide and fully refined paraffin wax No. 52, and then add 95 wt% of the total amount of persimmon tannin for mixing. Mix evenly to obtain a mixture.

[0041] Step 2: Put the mixture into a twin-screw extruder, conduct melt blending in the temperature range of 120 - 160 °C, the screw speed is 200 rpm, the head pressure is maintained at 10 MPa, and the shear rate of the mixing section is 200 s -1 , and the residence time of the material is 120 s;

[0042] Step 3: After extrusion by the extruder, obtain slow-release particles with a particle size of 0.5 - 3 mm through water cooling granulation and screening, and the surface porosity is 15 - 35%;

[0043] Step 4: Prepare a 1 wt% acetic acid solution, dissolve chitosan in the acetic acid solution at a mass concentration of 2 wt%, add the remaining persimmon tannin and stir evenly. Dissolve calcium chloride in absolute ethanol at a mass concentration of 3 wt% to obtain a calcium chloride ethanol solution, and add the calcium chloride ethanol solution and stir to form a mixed solution.

[0044] Step 5: Put the slow-release particles described in Step 3 into the mixed solution, stir and crosslink for 5 min, take out the slow-release particles, and dry them at 50 °C in a dispersed state to obtain a novel water-soluble deodorant.

[0045] Example 2

[0046] The difference from Example 1 is only that the mass fraction of polyvinyl alcohol is adjusted to 35 parts, the mass fraction of sodium alginate is adjusted to 7 parts, and the mass ratio of polyvinyl alcohol to sodium alginate is 1:0.2. Other conditions and steps are the same as in Example 1.

[0047] Example 3

[0048] The difference from Example 1 is only that the mass fraction of polyvinyl alcohol is adjusted to 25 parts, the mass fraction of sodium alginate is adjusted to 12.5 parts, and the mass ratio of polyvinyl alcohol to sodium alginate is 1:0.5. Other conditions and steps are the same as those in Example 1.

[0049] Example 4

[0050] The difference from Example 1 is only that the mass fraction of chitosan is adjusted to 8 parts. Other conditions and steps are the same as those in Example 1.

[0051] Example 5

[0052] The difference from Example 1 is only that the mass fraction of chitosan is adjusted to 10 parts. Other conditions and steps are the same as those in Example 1.

[0053] Example 6

[0054] The difference from Example 4 is only that the mass fraction of calcium chloride is adjusted to 0.9 part.

[0055] This example provides a novel water-soluble deodorant, which includes the following raw materials by mass fraction:

[0056] 30 parts of polyvinyl alcohol (degree of alcoholysis is 88%), 23.5 parts of polyethylene glycol, 10 parts of sodium alginate, 5 parts of sodium-based montmorillonite (D50 is 5 - 20 μm), 20 parts of polyethylene powder (average particle size is 20 - 30 μm), 1.2 parts of antioxidant 1010, 2.8 parts of titanium dioxide, 8 parts of fully refined paraffin wax No. 52 (molecular weight is 380 - 450 Da, melting range is 52 - 54 °C), 20 parts of persimmon tannin, 8 parts of chitosan (degree of deacetylation is 85%, molecular weight is 50 - 100 kDa), 0.9 part of calcium chloride.

[0057] Prepare the raw materials according to the above ratios to prepare the novel water-soluble deodorant. The specific steps are as follows:

[0058] Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium alginate, sodium-based montmorillonite, polyethylene powder, antioxidant 1010, titanium dioxide and fully refined paraffin wax No. 52, and then add 95 wt% of the total amount of persimmon tannin for mixing. Mix evenly to obtain a mixture.

[0059] Step 2: Put the mixture into a twin-screw extruder and carry out melt blending in the temperature range of 120 - 160 °C. The screw speed is 200 rpm, the head pressure is maintained at 10 MPa, and the shear rate of the mixing section is 200 s -1 , and the residence time of the material is 120 s;

[0060] Step 3: After extrusion by the extruder, cool and cut into pellets and screen to obtain slow-release particles with a particle size of 0.5 - 3 mm, and the surface porosity is 15 - 35%;

[0061] Step 4: Prepare a 1 wt% acetic acid solution, dissolve chitosan in the acetic acid solution at a mass concentration of 2 wt%, add the remaining persimmon tannin and stir evenly. Dissolve calcium chloride in absolute ethanol at a mass concentration of 3 wt% to obtain a calcium chloride ethanol solution, add the calcium chloride ethanol solution, and stir to form a mixed solution;

[0062] Step 5: Put the slow-release particles described in Step 3 into the mixed solution, stir and crosslink for 5 min, take out the slow-release particles, and dry them at 50 °C in a dispersed state to obtain a novel water-soluble deodorant.

[0063] Example 7

[0064] The difference from Example 4 is only that the mass fraction of calcium chloride is adjusted to 1 part.

[0065] This example provides a novel water-soluble deodorant, which includes the following raw materials by mass fraction:

[0066] Polyvinyl alcohol (degree of alcoholysis 88%) 30 parts, polyethylene glycol 23.5 parts, sodium alginate 10 parts, sodium-based montmorillonite (D50 is 5 - 20 μm) 5 parts, polyethylene powder (average particle size is 20 - 30 μm) 20 parts, antioxidant 1010 1.2 parts, titanium dioxide 2.8 parts, 52# fully refined paraffin wax (molecular weight is 380 - 450 Da, melting range is 52 - 54 °C) 8 parts, persimmon tannin 20 parts, chitosan (degree of deacetylation 85%, molecular weight is 50 - 100 kDa) 8 parts, calcium chloride 1 part.

[0067] Prepare the raw materials according to the above proportions and prepare a novel water-soluble deodorant. The specific steps are as follows:

[0068] Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium alginate, sodium-based montmorillonite, polyethylene powder, antioxidant 1010, titanium dioxide and 52# fully refined paraffin wax, and then add 95 wt% of the total amount of persimmon tannin for mixing. Mix evenly to obtain a mixed material;

[0069] Step 2: Put the mixed material into a twin-screw extruder, carry out melt blending in the temperature range of 120 - 160 °C, the screw speed is 200 rpm, the head pressure is maintained at 10 MPa, and the shear rate of the mixing section is 200 s -1 , and the residence time of the material is 120 s;

[0070] Step 3: After extrusion by the extruder, cool and cut into pellets and screen them to obtain slow-release particles with a particle size of 0.5 - 3 mm, and the surface porosity is 15 - 35%;

[0071] Step 4: Prepare a 1 wt% acetic acid solution. Dissolve chitosan in the acetic acid solution at a mass concentration of 2 wt%, add the remaining persimmon tannin and stir evenly. Dissolve calcium chloride in absolute ethanol at a mass concentration of 3 wt% to obtain a calcium chloride ethanol solution, add the calcium chloride ethanol solution, and stir to form a mixture;

[0072] Step 5: Put the sustained-release particles described in Step 3 into the mixture, stir and crosslink for 5 min, take out the sustained-release particles, and dry them at 50 °C in a dispersed state to obtain a novel water-soluble deodorant.

[0073] Example 8

[0074] The difference from Example 6 is only that the mass fraction of persimmon tannin is adjusted to 25 parts.

[0075] This example provides a novel water-soluble deodorant, which includes the following raw materials by mass fraction:

[0076] Polyvinyl alcohol (degree of alcoholysis 88%) 30 parts, polyethylene glycol 23.5 parts, sodium alginate 10 parts, sodium-based montmorillonite (D50 is 5 - 20 μm) 5 parts, polyethylene powder (average particle size is 20 - 30 μm) 20 parts, antioxidant 1010 1.2 parts, titanium dioxide 2.8 parts, 52# fully refined paraffin wax (molecular weight is 380 - 450 Da, melting range is 52 - 54 °C) 8 parts, persimmon tannin 25 parts, chitosan (degree of deacetylation 85%, molecular weight is 50 - 100 kDa) 8 parts, calcium chloride 0.9 part.

[0077] Prepare the raw materials according to the above proportions and prepare a novel water-soluble deodorant. The specific steps are as follows:

[0078] Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium alginate, sodium-based montmorillonite, polyethylene powder, antioxidant 1010, titanium dioxide and 52# fully refined paraffin wax, and then add 95 wt% of the total amount of persimmon tannin for mixing. Mix evenly to obtain a mixture;

[0079] Step 2: Put the mixture into a twin-screw extruder, carry out melt blending in the temperature range of 120 - 160 °C, the screw speed is 200 rpm, the head pressure is maintained at 10 MPa, and the shear rate of the mixing section is 200 s -1 , and the residence time of the material is 120 s;

[0080] Step 3: After extrusion by the extruder, cool and cut into pellets and screen to obtain sustained-release particles with a particle size of 0.5 - 3 mm, and the surface porosity is 15 - 35%;

[0081] Step 4: Prepare a 1 wt% acetic acid solution. Dissolve chitosan in the acetic acid solution at a mass concentration of 2 wt%, add the remaining persimmon tannin and stir evenly. Dissolve calcium chloride in absolute ethanol at a mass concentration of 3 wt% to obtain a calcium chloride ethanol solution, add the calcium chloride ethanol solution, and stir to form a mixture;

[0082] Step 5: Put the sustained-release particles described in Step 3 into the mixture, stir and crosslink for 5 min, take out the sustained-release particles, and dry them at 50 °C in a dispersed state to obtain a new water-soluble deodorant.

[0083] Example 9

[0084] The difference from Example 6 is only that the mass fraction of persimmon tannin is adjusted to 30 parts.

[0085] This example provides a new water-soluble deodorant, which includes the following raw materials by mass fraction:

[0086] Polyvinyl alcohol (degree of alcoholysis 88%) 30 parts, polyethylene glycol 23.5 parts, sodium alginate 10 parts, sodium-based montmorillonite (D50 is 5 - 20 μm) 5 parts, polyethylene powder (average particle size is 20 - 30 μm) 20 parts, antioxidant 1010 1.2 parts, titanium dioxide 2.8 parts, 52# fully refined paraffin wax (molecular weight is 380 - 450 Da, melting range is 52 - 54 °C) 8 parts, persimmon tannin 30 parts, chitosan (degree of deacetylation 85%, molecular weight is 50 - 100 kDa) 8 parts, calcium chloride 0.9 parts.

[0087] Prepare the raw materials according to the above proportions and prepare a new water-soluble deodorant. The specific steps are as follows:

[0088] Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium alginate, sodium-based montmorillonite, polyethylene powder, antioxidant 1010, titanium dioxide and 52# fully refined paraffin wax, and then add 95 wt% of the total amount of persimmon tannin for mixing, and mix evenly to obtain a mixture;

[0089] Step 2: Put the mixture into a twin-screw extruder, carry out melt blending in the temperature range of 120 - 160 °C, the screw speed is 200 rpm, the head pressure is maintained at 10 MPa, and the shear rate of the mixing section is 200 s -1 , and the residence time of the material is 120 s;

[0090] Step 3: After extrusion by the extruder, cool and cut into pellets, and screen to obtain sustained-release particles with a particle size of 0.5 - 3 mm, and the surface porosity is 15 - 35%;

[0091] Step 4: Prepare a 1 wt% acetic acid solution. Dissolve chitosan in the acetic acid solution at a mass concentration of 2 wt%, add the remaining persimmon tannin and stir evenly. Dissolve calcium chloride in absolute ethanol at a mass concentration of 3 wt% to obtain a calcium chloride ethanol solution, add the calcium chloride ethanol solution, and stir to form a mixture;

[0092] Step 5: Put the sustained-release particles described in Step 3 into the mixture, stir and crosslink for 5 min, take out the sustained-release particles, and dry them at 50 °C in a dispersed state to obtain a novel water-soluble deodorant.

[0093] Comparative Example 1

[0094] The difference from Example 1 is that sodium alginate in the raw materials is replaced with polyethylene glycol of equal mass.

[0095] This comparative example provides a novel water-soluble deodorant, which, by mass fraction, comprises the following raw materials:

[0096] Polyvinyl alcohol (degree of alcoholysis 88%) 30 parts, polyethylene glycol 33.5 parts, sodium-based montmorillonite (D50 is 5 - 20 μm) 5 parts, polyethylene powder (average particle size is 20 - 30 μm) 20 parts, antioxidant 1010 1.2 parts, titanium dioxide 2.8 parts, 52# fully refined paraffin wax (molecular weight is 380 - 450 Da, melting range is 52 - 54 °C) 8 parts, persimmon tannin 20 parts, chitosan (degree of deacetylation 85%, molecular weight is 50 - 100 kDa) 5 parts, calcium chloride 0.8 parts.

[0097] Prepare the raw materials according to the above proportions and prepare a novel water-soluble deodorant. The specific steps are as follows:

[0098] Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium-based montmorillonite, polyethylene powder, antioxidant 1010, titanium dioxide and 52# fully refined paraffin wax, and then add 95 wt% of the total amount of persimmon tannin for mixing. Mix evenly to obtain a mixture;

[0099] Step 2: Put the mixture into a twin-screw extruder and carry out melt blending in the temperature range of 120 - 160 °C. The screw speed is 200 rpm, the head pressure is maintained at 10 MPa, and the shear rate of the mixing section is 200 s -1 , and the residence time of the material is 120 s;

[0100] Step 3: After extrusion by the extruder, cool and cut into pellets and screen to obtain sustained-release particles with a particle size of 0.5 - 3 mm, and the surface porosity is 10 - 25%;

[0101] Step 4: Prepare a 1 wt% acetic acid solution. Dissolve chitosan in the acetic acid solution at a mass concentration of 2 wt%, add the remaining persimmon tannin and stir evenly. Dissolve calcium chloride in absolute ethanol at a mass concentration of 3 wt% to obtain a calcium chloride ethanol solution, add the calcium chloride ethanol solution, and stir to form a mixed solution;

[0102] Step 5: Put the slow-release particles described in Step 3 into the mixed solution, stir and crosslink for 5 min, take out the slow-release particles, and dry them at 50 °C in a dispersed state to obtain a novel water-soluble deodorant.

[0103] Comparative Example 2

[0104] The difference from Example 1 is that chitosan and calcium chloride are not added to the raw materials, Steps 4 and 5 are omitted in the preparation process, and secondary loading is not carried out.

[0105] This comparative example provides a novel water-soluble deodorant, which includes the following raw materials by mass fraction:

[0106] 30 parts of polyvinyl alcohol (degree of alcoholysis 88%), 23.5 parts of polyethylene glycol, 10 parts of sodium alginate, 5 parts of sodium-based montmorillonite (D50 is 5 - 20 μm), 20 parts of polyethylene powder (average particle size is 20 - 30 μm), 1.2 parts of antioxidant 1010, 2.8 parts of titanium dioxide, 8 parts of 52# fully refined paraffin wax (molecular weight is 380 - 450 Da, melting range is 52 - 54 °C), 20 parts of persimmon tannin.

[0107] Prepare the raw materials according to the above ratios and prepare a novel water-soluble deodorant. The specific steps are as follows:

[0108] Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium alginate, sodium-based montmorillonite, polyethylene powder, antioxidant 1010, titanium dioxide and 52# fully refined paraffin wax, and then add persimmon tannin for mixing. Mix evenly to obtain a mixed material;

[0109] Step 2: Put the mixed material into a twin-screw extruder, carry out melt blending in the temperature range of 120 - 160 °C, the screw speed is 200 rpm, the head pressure is maintained at 10 MPa, and the shear rate of the mixing section is 200 s -1 , and the residence time of the material is 120 s;

[0110] Step 3: After extrusion by the extruder, cool and cut into pellets, and screen to obtain slow-release particles with a particle size of 0.5 - 3 mm, that is, the deodorant, and its surface porosity is 15 - 35%;

[0111] Perform performance tests on the deodorants prepared in Examples 1 - 9 and Comparative Examples 1 - 2, and the results are shown in Table 1.

[0112] Detection method of release amount: Take 8 g of deodorant and place it in a beaker. Add 1 L of water as the release medium, place it under light conditions, and sample at regular intervals to detect the concentration of persimmon tannin.

[0113] Detection method of ammonia removal rate: Place the deteriorated and odorous fish tank water in a closed space, add deodorant to the water at a concentration of 8 g / L, detect the ammonia concentration in the gas released before and 24 hours after adding the deodorant to the water body, and calculate the removal rate.

[0114] Table 1

[0115]

[0116] It can be seen from Table 1 that in Examples 1 - 3, when the mass ratio of polyvinyl alcohol to sodium alginate increases, the proportion of polyvinyl alcohol increases, the release amount at the initial stage of the deodorant decreases, and the deodorizing effect in a short time decreases. When the mass ratio of polyvinyl alcohol to sodium alginate decreases, the proportion of polyvinyl alcohol decreases. At this time, the proportion of components easily soluble in water in the deodorant increases, and the release amount at the initial stage increases, which is not conducive to stable and continuous long-term release. In Examples 4 and 5, as the chitosan content increases, due to the enhanced adsorption and loading force, the initial release amount decreases slightly, ensuring a relatively balanced release amount in the previous stage and the latter stage. In Examples 6 and 7, as the dosage of calcium chloride increases, its cross-linking effect increases, and the stability of the secondary loading is better. The initial release amount of the deodorant decreases significantly. Appropriately reducing the initial release amount is beneficial to the long-term release of the active ingredients. In Examples 8 and 9, on the basis of Example 6, the content of the active ingredient persimmon tannin is increased, and the overall release amount increases. In Comparative Examples 1 and 2, due to the lack of sodium alginate or chitosan, the secondary loading cannot be effectively achieved, resulting in a large amount of initial active ingredient release. In the long-term treatment of actual applications, the release of the active ingredient in the later stage is limited, the service life is shortened, and the effect of long-term effective deodorization cannot be achieved.

[0117] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variation thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0118] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A novel water-soluble deodorant, characterized in that, By mass fraction, it includes the following raw materials: 25-35 parts of polyvinyl alcohol, 10-20 parts of polyethylene glycol, 6-13 parts of sodium alginate, 5-12 parts of montmorillonite, 10-20 parts of polyethylene powder, 0.3-1.2 parts of antioxidant, 2-5 parts of titanium dioxide, 3-8 parts of paraffin, 20-30 parts of plant-based deodorant powder, 3-10 parts of chitosan, 0.5-1 part of calcium chloride; The deodorant is first co-mixed and extruded into pellets by the raw materials except chitosan and calcium chloride to achieve the encapsulation of plant extracts, and then added into the mixed solution of chitosan, calcium chloride and plant-based deodorant powder for surface cross-linking and loading; The plant-based deodorant powder is powdered plant polyphenol.

2. The novel water-soluble deodorant according to claim 1, characterized in that, The degree of alcoholysis of the polyvinyl alcohol is 80-90%.

3. A novel water-soluble deodorant according to claim 1, characterized in that, The montmorillonite is sodium-based montmorillonite with a particle size D50 of 5-20 μm; The average particle size of the polyethylene powder is 20-30 μm.

4. A novel water-soluble deodorant according to claim 1, characterized in that The paraffin is No. 52 fully refined paraffin with a molecular weight of 380-450 Da and a melting range of 52-54 °C.

5. A novel water-soluble deodorant according to claim 1, characterized in that, The plant-based deodorant powder is at least one of persimmon tannin, tea polyphenol and curcumin.

6. A novel water-soluble deodorant according to claim 1, characterized in that, The degree of deacetylation of the chitosan is ≥85% and the molecular weight is 50-100 kDa.

7. A novel water-soluble deodorant according to claim 1, characterized in that, The mass ratio of the polyvinyl alcohol to the sodium alginate is (1:0.5)-(1:0.2).

8. A novel water-soluble deodorant according to claim 1, characterized in that, The mass ratio of the chitosan, sodium alginate and calcium chloride is (0.5-1):1:(0.08-0.1).

9. A preparation method of a novel water-soluble deodorant according to any one of claims 1-8, characterized in that, It includes the following steps: Step 1: Mix polyvinyl alcohol, polyethylene glycol, sodium alginate, montmorillonite, polyethylene powder, antioxidant, titanium dioxide and paraffin, and then add 90-95 wt% of the total amount of the plant-based deodorant powder for mixing to obtain a mixed material; Step 2: Put the mixed material into a twin-screw extruder and carry out melt blending in the temperature range of 120-160 °C, the screw speed is 120-250 rpm, and the head pressure is maintained at 8-15 MPa; Step 3: After extrusion by the extruder, it is cooled by water, cut into pellets and screened to obtain slow-release particles with a particle size of 0.5-3 mm and a surface porosity of 15-35%; Step 4: Dissolve chitosan in acetic acid solution, add the remaining plant-based deodorant powder, stir evenly and then add calcium chloride ethanol solution and stir to form a mixed solution; Step 5: Put the slow-release particles described in Step 3 into the mixed solution, stir and cross-link for 5-10 min, take out the slow-release particles, and dry them at 50-60 °C in a dispersed state to obtain a new water-soluble deodorant.

10. The preparation method of a novel water-soluble deodorant according to claim 9, characterized in that, The shear rate of the mixing section of the twin-screw extruder is 150 - 300 s -1 , and the residence time of the material is 90 - 150 s.

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