CN104145987B - The preparation of ethephon controllable sustained-release material and application - Google Patents

Abstract

The invention discloses the preparation and application of a controllable slow-release material of ethephon, which solves the problem of pesticide residues caused by the use of ethephon and improves the use efficiency of ethephon in crops. The material is a composite film made of basic polymers and ethephon, and the basic polymers include: chitosan, polyacrylate, sodium alginate, etc.; the mass ratio of the basic polymer and ethephon is (10 ~30): (90~70). The ethephon controllable slow-release material of the invention can be used in air medium or buffer solution, and the slow-release speed is affected by air humidity, ethephon content and pH value of buffer solution. The material of the present invention does not directly contact with crops when used, reduces pesticide residues, improves the efficiency of ethephon in crops through slow release, and can realize controllable ripening of fruits and vegetables, and is expected to be used for ripening fruits and vegetables at home.

Description

Preparation and Application of Ethephon Controlled and Sustained Release Material

technical field

The invention belongs to the technical field of fruit and vegetable ripening, and in particular relates to the preparation and application of ethephon controllable slow-release materials.

Background technique

Ethephon is a high-quality and efficient plant growth regulator. It is mainly used as an agricultural plant growth stimulant. It has effects such as promoting fruit ripening, stimulating wound flow, and regulating gender transformation. Its main functions are: promoting female flower differentiation, promoting fruit ripening, and promoting plant growth. Dwarfing and breaking of plant dormancy. The traditional usage of ethephon is spraying and soaking. For example, to accelerate the ripening of tomatoes, 300mg/kg of ethephon can be applied to the pedicels, and 400mg/kg of ethephon can be applied to the sepals of white ripe fruit flowers and the fruit surface nearby. It can be soaked in 200mg/kg ethephon solution for 1 minute after harvesting, and then reddened; if tomato seedlings are treated with 300mg/kg ethephon solution twice when they have 3 leaves, 1 heart slice to 5 true leaves, it can Control seedling growth, control tomato growth, enhance stress resistance, and increase early yield. Irregular use of ethephon can still be harmful to human health. Ethephon can irritate the skin and eyes and have an acid-etching effect on mucous membranes after ingestion. Burning sensation occurs after ingestion by mistake, nausea and vomiting later, the vomit is brown-black, the activity of cholinesterase is reduced, and the patient is in a coma state for about 3.5 hours. . Although the state stipulates that the residue limit of ethephon is 2 mg/kg, the current domestic supervision of ethephon residues in various crops is not in place, and there are still huge risks hidden. At present, there are many studies on the slow-release effect of ethephon, which can make ethephon release ethylene reasonably without directly spraying or soaking crops or fruits and vegetables. Although it can be safe and residue-free, it also has many defects:

1. Chinese patent number: 201010539101.8, the title of the invention is: the invention of a gelling agent releasing ethylene gas discloses a gelling agent releasing ethylene gas, including the following material components: ethephon 50-90, gelling agent 5 -20, stabilizer 8-25, ethephon decomposition accelerator 5-35; the ethephon is a solid pure product ethephon solid; the gel is polyacrylic acid salt, cross-linked polyethylene oxide, alginate One or its mixture; the stabilizer is one or its mixture in anhydrous magnesium sulfate, anhydrous magnesium chloride, anhydrous potassium sulfate; the ethephon decomposition accelerator is sodium hydroxide, calcium hydroxide, carbonic acid One of sodium, sodium bicarbonate or a mixture thereof. The gel agent for releasing ethylene gas provided by the invention can make the ethylene gas evenly contact with the fruits and vegetables to be ripened, so as to achieve the purpose of uniform ripening. Although the gel described in the above patents can release ethylene when it encounters water, there are still potential safety hazards when using strong alkaline substances such as sodium hydroxide as the release agent. Alkali, resulting in strong local alkalinity, too fast release of ethylene, and the gel also has defects such as packaging, processing difficulties, and harsh storage conditions.

2. Chinese Patent No.: 201210171894.1, the title of the invention is: the invention of a drug bag capable of releasing ethylene discloses a drug bag capable of releasing ethylene, which is composed of packaging materials and medicaments, and the medicaments in the drug bag include ethephon, release agent, hygroscopic agent and auxiliary materials, the agent in the medicine bag is uniformly mixed according to a certain proportion, the packaging material is one of heat-sealed filter paper, composite paper, non-woven fabric, composite film, textured paper, Dupont paper, and the order of addition is auxiliary materials , ethephon, release agent, hygroscopic agent, and the release method of the drug pack are contact with water, and the water can be liquid or gaseous moisture, preferably the moisture produced by the respiration of fruits and vegetables. The drug pack for releasing ethylene described in the above invention has the characteristics of convenient use, stable storage and effective release, but it also has the problem of high difficulty in storage. In order to facilitate the entry of water and the release of ethylene during use, the packaging material used is a material with good water permeability. This material makes it easy for the drug pack to absorb and release ethylene during storage, making storage difficult. In addition, when the drug pack is released, it mainly depends on the water emitted by the fruits and vegetables to contact the drug pack, thereby promoting the decomposition of ethephon into ethylene for release. However, various fruits and warehouse environments are uncontrollable factors, which may cause irregular release of ethylene. In addition, the ethephon drug pack in Example 6 can completely release ethylene within 5 days, and the release period is controlled to be short, which will easily cause too fast ripening of fruits and vegetables stored in the warehouse, and the shelf life is short.

It can be seen that only controlling the release of ethylene cannot completely solve the existing problems. How to develop a "smart" ethylene release material that can control the ethylene release rate by adjusting the use environment and ensure the safety and residue-free of fruits, vegetables and crops is an important issue that needs to be solved urgently in the field of crops, fruits and vegetables preservation and ripening.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a controllable and slow-release material for ethephon, which can control the ethylene release rate by adjusting the use environment, thereby controlling the freshness of fruits and vegetables and the ripening time of crops, and finally realizing the improvement of economic benefits. The controllable and slow-release material of ethephon in the invention is easy to develop and has accurate controlled release conditions, and can solve the current defects of ethephon pollution and uncontrollable ethylene release.

The present invention is achieved through the following technical solutions:

Ethephon controllable slow-release material is composed of the following material components in parts by weight: Ethephon 70-90, basic polymer 10-30, and auxiliary materials 50-500; the material is made of basic polymer and ethephon Composite film.

The basic polymer is chitosan, polyacrylate or sodium alginate.

The auxiliary material is one of gelatin, rosin, polyvinyl styrene-acrylic emulsion, starch or a mixture thereof.

The material can be used in air medium or buffer solution, and the release rate of ethylene is controlled by air humidity, ethephon content and pH value of the buffer solution. The release rate of the ethephon controlled-release composite film is determined by the above three control factors. The single or synergistic effects of the three factors will effectively control the release rate, release time, and release amount of ethylene, thereby adjusting the degree of ripening and freshness of crops. period length etc.

Preferably, the ethephon controllable slow-release material will release ethylene when it contacts water in the air in the air medium, and the ethylene release speed will reach the best state when the air humidity is above 50%. In a closed environment, such as warehouses, storage rooms, and well-sealed greenhouses, the humidity of the closed environment can be artificially adjusted. When the air humidity reaches above 50%, the decomposition of ethephon can be effectively adjusted, and the release rate of ethylene can reach 17 days. around, and present a relatively regular release curve.

Preferably, the ethephon controllable sustained-release material releases ethylene when the pH of the buffer solution is 4-7, and the release effect reaches the best state when the pH of the buffer solution is 6-7. The ethephon controllable release composite membrane can be placed in a buffer solution with a specified pH value. When the ethephon controllable release composite membrane system reaches a pH above 4, ethylene will be released slowly. When the buffer solution pH is 6-7, the maximum In the best state, under specific humidity conditions, the release time can be effectively and regularly controlled at 179h. The buffer solution is an effective control factor for the release of the ethephon controllable slow-release composite membrane, and it can be prepared from various strong acid and weak alkali salts.

The inventor found that a large amount of data showed that the ethephon composite film developed by the invention has the following controllable laws: the slow release rate of ethylene is directly proportional to the air humidity, inversely proportional to the ethephon content, and directly proportional to the pH of the buffer solution.

The preparation method of described composite film comprises the following steps:

(1) Superfinely pulverize the original drug of ethephon, and pass through a 800-1000 mesh sieve.

(2) Prepare an alkaline polymer solution with a concentration of 0.3-1.5%, mix glycerin and 2-3.5% acetic acid solution in a weight ratio of 1:2 as a solvent, adjust the pH below 3.5, add the required auxiliary materials, and stir at a high speed for 10 Minutes, ready for use; adjust the pH below 3.5% to control ethephon will not decompose and become invalid in the composite membrane.

(3) Under high-speed stirring, add ethephon in batches to the alkaline polymer solution, add a batch within 10 minutes, and the amount of each batch is 20% of the total amount, and continue stirring for 20 minutes after the addition is completed to obtain a viscous Ethephon has a high water solubility, reaching 1kg/L. Adding ethephon in batches can ensure its dispersion in the system. Ethephon will gradually dissolve during the addition process, and then disperse in it. The viscosity of the system It will also thicken with the addition of ethephon.

(4) Pour the prepared viscous liquid into a mold, put it in an oven at 45-50°C for drying, and remove the film to obtain a controlled-release composite film of ethephon. The water content of the prepared ethephon controllable slow-release composite film is controlled below 0.05%, and the inventors found that the composite film system will not degrade under 0.05% water, because 0.05% water is not enough to ionize the system Out of OH ^- , the pH of the system will not rise.

The shape of the mold can be rectangular or circular, and the thickness of the composite film can be controlled. The mold is generally made of glass products, which can have a good release effect. The shape of the mold is selected according to the actual use or aesthetics. The control of the thickness determines the range of action of the Ethephon composite film. The greater the thickness , the greater the ethephon drug loading, the greater the controllable range, and vice versa, the smaller the controllable range.

The controllable and slow-release material of ethephon is used in the controllable ripening of crops or fruits and vegetables, and the release of ethylene is promoted by conditions during use, without direct contact with crops, safe and without residue.

Beneficial effects of the present invention:

1. The Ethephon controllable slow-release material developed by this invention is safe, environmentally friendly, pollution-free, and has no residue, which is safe for crops and operators.

2. The controllable slow-release material of ethephon developed by this invention is made into a composite film form, which can ensure the full mixing and high dispersion of ethephon and the carrier, thus ensuring the controllability of ethephon in release.

3. The ethephon controllable slow-release material developed by this invention can be released in air medium and buffer solution, which can effectively control the release of ethylene, and solve the disadvantage of irregular ethylene release in the prior art.

4. The Ethephon controllable slow-release material developed by this invention can control the release rate of ethylene through the content and the properties of the release medium, thereby prolonging the release time of ethylene and increasing the preservation time of fruits and vegetables; effectively regulating the growth process of crops, green and environmentally friendly, Safe and efficient.

5. The Ethephon controllable slow-release material developed by this invention has simple processing technology and clear controlled release elements, and is a typical "smart" product.

detailed description;

Embodiment 110% ethephon composite film preparation

(1) Weigh 100kg of ethephon original drug and ultrafinely pulverize it, and pass it through a 800-1000 mesh sieve.

(2) Weigh 10kg of chitosan, prepare a chitosan solution with a concentration of 1%, mix glycerol and 2% acetic acid solution at a weight ratio of 1:2 as a solvent, adjust the pH below 3.5, and add 880kg of auxiliary materials (starch: Polyvinyl styrene-acrylic emulsion 2:8) Stir at high speed for 10 minutes, set aside.

(3) Under high-speed stirring, add ethephon in batches to the alkaline polymer solution, add a batch within 10 minutes, and the amount of each batch is 20% of the total amount, and continue stirring for 20 minutes after the addition is completed to obtain a viscous like liquid.

(4) Pour the prepared viscous liquid into a mold, put it in an oven at 45-50°C to dry, and form a film to obtain a 10% ethephon controlled-release composite film.

Embodiment 215% ethephon composite film preparation

(1) Weigh 150kg of ethephon original drug and ultrafinely pulverize it, and pass through a 800-1000 mesh sieve.

(2) Weigh 10kg of sodium polyacrylate, prepare a sodium polyacrylate solution with a concentration of 0.3%, mix glycerin and 3.5% acetic acid solution in a weight ratio of 1:2 as a solvent, adjust the pH below 3.5, and add 840kg of auxiliary materials (rosin: Polyvinyl styrene-acrylic emulsion 4:6) Stir at high speed for 10 minutes, set aside.

(3) Under high-speed stirring, add ethephon in batches to the alkaline polymer solution, add a batch within 10 minutes, and the amount of each batch is 20% of the total amount, and continue stirring for 20 minutes after the addition is completed to obtain a viscous like liquid.

(4) Pour the prepared viscous liquid into a mold, put it in an oven at 50°C to dry, and form a film to obtain a 15% ethephon controlled slow-release composite film.

Embodiment 320% ethephon composite film preparation

(1) Weigh 200kg of ethephon original drug and ultrafinely pulverize it, and pass it through a 800-1000 mesh sieve.

(2) Weigh 30kg of sodium alginate, prepare a sodium alginate solution with a concentration of 1.5%, mix glycerol and 3% acetic acid solution at a weight ratio of 1:2 as a solvent, adjust the pH below 3.5, and add 770kg of auxiliary materials (gelatin: Polyvinyl styrene-acrylic emulsion 2.5:7) Stir at high speed for 10 minutes, set aside.

(3) Under high-speed stirring, add ethephon in batches to the alkaline polymer solution, add a batch within 10 minutes, and the amount of each batch is 20% of the total amount, and continue stirring for 20 minutes after the addition is completed to obtain a viscous like liquid.

(4) Pour the prepared viscous liquid into a mold, put it in a 50°C oven to dry, and form a film to obtain a 20% ethephon controlled slow-release composite film.

Embodiment 450% ethephon composite film preparation

(1) Weigh 500kg of ethephon original drug and ultrafinely pulverize it, and pass through a 800-1000 mesh sieve.

(2) Weigh 98kg chitosan, prepare chitosan solution with a concentration of 0.8% (solvent is glycerol: water 1:2), water is 2% acetic acid solution, adjust pH below 3.5, add 400kg polyvinyl styrene Emulsion, stirred at high speed for 10 minutes, set aside.

(3) Under high-speed stirring, add ethephon in batches to the alkaline polymer solution, add a batch within 10 minutes, and the amount of each batch is 20% of the total amount, and continue stirring for 20 minutes after the addition is completed to obtain a viscous like liquid.

(4) Pour the prepared viscous liquid into a mold, put it in an oven at 50°C to dry, and form a film to obtain a 50% ethephon controlled slow-release composite film.

Example 5 Determination of Ethephon Slow-release Velocity of Different Ethephon Composite Films in Different Air Humidities

Test site: Banana storage warehouse in Shibu, Nanning, Guangxi

Test time: July 3, 2012

Test medicament: embodiment 1-3

Test method: Put the 10% ethephon controllable slow-release composite film, 15% ethephon controllable slow-release composite film and 20% ethephon controllable slow-release composite film in Examples 1-3 respectively in the warehouse for storing bananas , adjust the air humidity, and then regularly detect the amount of ethylene released. The result is as follows:

Table 1 The sustained release rate of the composite film with 10% ethephon content in air

Table 2 Ethephon content is the sustained release rate of the composite film in air of 15%

Table 3 The sustained release rate of the composite film with 20% ethephon content in air

It can be seen from the above table that when the air humidity is adjusted at 54.6%, 74.9% and 97.7%, the ethylene release rate of the composite film with different ethephon content increases with the increase of air humidity, while at the same air humidity, the slow-release rate of ethylene The rate decreased with the increase of ethephon content.

At the same time, tests have shown that the ethylene release rate in the ethephon composite film can reach 17 days before the release is complete, which also effectively avoids the risk of rapid ripening and spoilage of bananas caused by excessive ethylene release at one time.

The release rate of embodiment 6 ethephon composite film in buffer solution

The inventor placed the 50% ethephon composite film in Example 4 under the premise that the air humidity was set to 50%, placed it in buffer solutions of pH6.0, pH6.5, and pH7.0, and regularly detected the amount of ethylene released. The result as follows:

Table 4 In pH=6.0 buffer solution, the rate of sustained release of ethylene from the composite membrane

Table 5 in pH = 6.5 buffer solution, the rate of sustained release of ethylene from the composite membrane

Table 6 In pH=7.0 buffer solution, the rate of sustained release of ethylene from the composite membrane

The data in the table shows that the release rate of the ethephon composite membrane is accelerated with the increase of the pH value of the buffer solution. When the pH is 7.0, the ethylene release rate reaches 98% in 71 hours, while the pH 6.0 and 6.5 only release 57.4% and 74.7% in 71 hours. %, 93.8% and 98.4% were released after 179h.

From Examples 5 and 6, it can be seen that the release of the ethephon composite film in different ethephon contents, air humidity and buffer solutions is a regular release, specifically as follows: the slow release rate of ethylene is proportional to the air humidity, and is proportional to the ethephon. The content is inversely proportional to the pH of the buffer solution. The specific manifestations are: Ethephon controllable slow-release material will release ethylene when it contacts water in the air in the air medium, and when the air humidity is above 50%, the release rate of ethylene reaches the best state; Ethephon controllable slow-release material is in the buffer Ethylene is released when the pH of the solution is 4-7, and the release effect reaches the best state when the pH of the buffer solution is 6-7.

Example 7 Detection of Ethephon Residues in Ripening Fruits

The bananas in Example 5 were detected according to the Agricultural Industry Standard of the People's Republic of China "NY/T1016-2006 Determination of Ethephon Residues in Fruits and Vegetables by Gas Chromatography", but no ethephon residues were detected.

Claims (4)

1. A controllable slow-release material of ethephon, characterized in that: the material is a composite film, composed of the following material components in parts by weight: 70-90 parts of ethephon, 10-30 parts of basic polymer and 50 parts of auxiliary materials -500 parts; the basic polymer is chitosan, polyacrylate or sodium alginate; the auxiliary material is one of gelatin, rosin, polyvinyl styrene-acrylic emulsion, starch or a mixture thereof. 2. The controllable slow-release material of ethephon according to claim 1, characterized in that: the material is used in air medium or buffer solution, and the release rate of ethylene is controlled by air humidity, ethephon content and buffer solution pH value The method of using the material in the air medium is: the controllable slow-release material of ethephon will release ethylene when it contacts the water in the air, and when the air humidity is above 50%, the release rate of ethylene reaches the best state; The method of use in the buffer solution is: the ethephon controllable slow-release material releases ethylene when the buffer solution is pH 4-7, and the release effect reaches the best state when the buffer solution is pH 6-7; The sustained release speed of the material is directly proportional to the air humidity, inversely proportional to the ethephon content, and directly proportional to the pH of the buffer solution. 3. The preparation method of the ethephon controllable slow-release material according to claim 1, characterized in that: the steps are as follows: (1) Superfinely pulverize the original drug of ethephon, and pass through a 800-1000 mesh sieve; (2) Prepare an alkaline polymer solution with a concentration of 0.3-1.5%, mix glycerin and 2-3.5% acetic acid solution in a weight ratio of 1:2 as a solvent, adjust the pH below 3.5, add the required auxiliary materials, and stir at a high speed for 10 minutes, spare; (3) Under high-speed stirring, add ethephon in batches to the alkaline polymer solution, add a batch within 10 minutes, and the amount of each batch is 20% of the total amount, and continue stirring for 20 minutes after the addition is completed to obtain a viscous Liquid; (4) Pour the prepared viscous liquid into a mold, put it in an oven at 45-50°C to dry, and form a film to obtain a controlled-release composite film of ethephon. 4. The preparation method of the ethephon controllable slow-release material according to claim 3, characterized in that: the shape of the mold is rectangular or circular, and the thickness of the composite film is controlled as required.