CN111518515B - A kind of slow-release anticoagulation ice microcapsule, preparation method and application method - Google Patents

Abstract

The invention discloses a sustained-release anticoagulation ice microcapsule, a preparation method and an application method. The slow-release anticoagulant ice microcapsule comprises: a capsule core and a capsule wall covering the capsule core, the mass ratio of the capsule core and the capsule wall is 1:1-1:10, and the capsule core is a plant The non-chlorine-based snow melting agent, the capsule wall comprises: modified chitosan and urea-formaldehyde resin, and the mass ratio of the modified chitosan and the urea-formaldehyde resin is 1:6 to 1:21.7; the modified shell Polysaccharides are prepared from chitosan and a silane coupling agent. By introducing a silane coupling agent into the capsule wall material, the problem that the microcapsule material affects the performance of the emulsified asphalt mixture due to the release of small molecular organics can be well solved, so that the material can be used in micro-surface, fog sealing layer, etc. Among the road preventive maintenance technologies, the engineering cost of the existing slow-release anti-ice condensation technology is greatly reduced, and it has excellent low-temperature ice and snow melting ability, sustainable slow-release effect, excellent road performance and environmental protection.

Description

A kind of slow-release anticoagulation ice microcapsule, preparation method and application method

technical field

The invention relates to the technical field of road snow removal, in particular to a slow-release anti-coagulation ice microcapsule, a preparation method and an application method.

Background technique

Rain and snow weather in winter has become one of the serious threats to traffic safety in most areas of northern and southwestern my country. In order to overcome the harm caused by traditional salt spraying to roads, auxiliary facilities and the ecological environment, active anti-icing technology has gradually become a development trend. At present, the mature active anti-condensation materials on the market are mainly slow-release salts. By adding this material to the hot mix asphalt mixture and paving it on the road in advance, it can actively melt ice in winter rain and snow weather. Snow melting, thereby effectively reducing the personnel and capital investment in the winter snow removal process, and reducing the impact of snow melting agents on the environment. However, the slow-release salinized material has poor compatibility with emulsified asphalt, which limits its application in conventional pavement preventive maintenance technologies such as micro-surface and mist seal, and the engineering cost remains high. In addition, most of the slow-release salinoid materials still use chloride salt as the main component, which still affects the environment after long-term use, and the freezing point is generally high, generally not lower than -10 °C, so the large-scale application is greatly limited.

The main component of the plant-based environmentally friendly snow melting agent is water-soluble organic matter, which has good compatibility with emulsified asphalt and can be directly applied to various emulsified asphalt-based preventive maintenance technologies. It does not contain chloride ions and is harmless to the environment. Below -30 ℃, therefore, plant-based environmentally friendly snow melting agents can be used instead of salts. However, the main problem of this type of materials is that the plant-based environmentally friendly snow melting agents are all small molecular organic materials. When the snow melting agent material is mixed with the emulsified asphalt, the performance of the emulsified asphalt will be greatly reduced, thereby affecting the service life of the preventive maintenance technology.

SUMMARY OF THE INVENTION

The embodiments of the present invention provide a slow-release anti-coagulation ice microcapsule, a preparation method and an application method, so as to solve the problem that the performance of the emulsified asphalt will be greatly reduced when the prior art plant-based environment-friendly snow melting agent is mixed with the emulsified asphalt.

In a first aspect, a sustained-release anticoagulation ice microcapsule is provided, comprising: a capsule core and a capsule wall covering the capsule core, and the mass ratio of the capsule core and the capsule wall is 1:1 to 1:10 , the capsule core is a plant-based non-chlorine snow melting agent, the capsule wall includes: modified chitosan and urea-formaldehyde resin, and the mass ratio of the modified chitosan and the urea-formaldehyde resin is 1:6～1: 21.7; The modified chitosan is prepared from chitosan and a silane coupling agent.

In the second aspect, a preparation method of the aforementioned slow-release anti-coagulation ice microcapsules is provided, comprising: dissolving a plant-based non-chlorine snow-melting agent in water, and mixing evenly to obtain a capsule core solution; The polysaccharide and the capsule core solution are reacted at a temperature of 60-70° C. to obtain the slow-release anticoagulation ice microcapsules.

A third aspect provides an application method of the aforementioned slow-release anti-coagulation ice microcapsules, comprising: uniformly mixing the slow-release anti-coagulation ice microcapsules and the micro-surface mixture to obtain the anti-coagulation ice micro-surface mixture material.

In this way, in the embodiment of the present invention, by introducing a silane coupling agent into the capsule wall material, the problem that the microcapsule material affects the performance of the emulsified asphalt mixture due to the release of small molecular organics can be well solved, so that the material can be applied to the microcapsule material. Among the various road preventive maintenance technologies such as attrition and fog sealing layer, the engineering cost of the existing slow-release anti-ice condensation technology is greatly reduced, and it has excellent low-temperature ice and snow melting ability, sustainable slow-release effect, and excellent road performance. performance and environmental friendliness.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The embodiment of the present invention discloses a sustained-release anticoagulation ice microcapsule. The sustained-release anticoagulant ice microcapsules include: a capsule core and a capsule wall covering the capsule core, forming a shell-core structure. The mass ratio of the capsule core and the capsule wall is 1:1 to 1:10. Preferably, the mass ratio of the capsule core and the capsule wall is 1:1.7˜1:2.7. In addition, the particle size of the slow-release anti-coagulation ice microcapsules of the embodiments of the present invention is less than 0.075 mm, preferably 0.05 mm, so that when applied to the road surface, the quality of road engineering will not be affected. The materials used in the project, the minimum particle size of the sieve hole is 0.075mm, the stone above 0.075mm has an impact on the grading of the mixture, and the part below 0.075mm is the bottom part of the sieve, which will not affect the mixture, so it will not affect the mixture. Project quality has an impact.

The core of the capsule is a plant-based non-chlorine snow melting agent. Preferably, the plant-based non-chlorine snow-melting agent uses resin alcohol C as the main raw material, does not contain any chloride, sulfate and nitrite, and is an environmentally friendly snow-melting agent, which has no effect on plants, microorganisms, soil, surrounding water system and environment Any toxic effect, non-corrosive to road and bridge structures such as pavement, steel structure, reinforced concrete, etc. The plant-based non-chlorine snow melting agent according to the embodiment of the present invention includes at least one of the following: glycerol, ethylene glycol, sorbitol and propylene glycol.

The capsule wall includes: modified chitosan and urea-formaldehyde resin. The mass ratio of modified chitosan and urea-formaldehyde resin is 1:6～1:21.7. Preferably, the mass ratio of modified chitosan and urea-formaldehyde resin is 1:6-1:7.2. Among them, modified chitosan is prepared from chitosan and silane coupling agent. Urea-formaldehyde resins are prepared from formaldehyde and urea. Therefore, in the embodiment of the present invention, the mass of modified chitosan can be replaced by the mass sum of chitosan and silane coupling agent, and the mass of urea-formaldehyde resin can be replaced by the mass sum of formaldehyde and urea.

Since the plant-based non-chlorine snow-melting agent used as the capsule core contains hydroxyl groups, it can undergo a dehydration reaction with the hydroxyl groups in the chitosan in the capsule wall, so that the capsule wall and the capsule core are tightly combined. When the capsule wall is ruptured to release the capsule core, due to the connection between the chitosan and the plant-based non-chlorine snow-melting agent, the bond between the two needs to be broken, which is further conducive to the slow release of the plant-based non-chlorine snow-melting agent. Extended service life. In addition, due to the above-mentioned possible dehydration reaction between chitosan and plant-based non-chlorine snow-melting agent, the amount of chitosan and capsule core needs to be considered. On the one hand, part of chitosan and plant-based non-chlorine snow-melting agent should occur On the other hand, the polycondensation reaction cannot make a large number of plant-based non-chlorine snow-melting agents undergo the above-mentioned reaction, so as to avoid insufficient release amount each time the snow-melting agent is released, and the optimal snow-melting effect cannot be achieved.

Specifically, the preparation method of modified chitosan includes the following process:

The chitosan is dissolved in the acetic acid solution, the silane coupling agent is added, and the mixture is stirred evenly to obtain the modified chitosan.

It should be understood that the prepared modified chitosan is in the form of a solution. The above-mentioned stirring time is preferably 1 to 2 hours.

Wherein, the amount of chitosan is 1wt% to 2wt% of the amount of acetic acid solution, which can ensure the dissolution of chitosan. The viscosity of chitosan is 0.1 to 0.3 Pa·s. The mass ratio of silane coupling agent and chitosan is 0.27-2.5:1. The acetic acid volume fraction of the acetic acid solution is 1% to 2%. Preferably, the acetic acid volume fraction of the acetic acid solution is 1.5%.

By introducing a silane coupling agent into the capsule wall material, the problem that the microcapsule material affects the performance of the emulsified asphalt mixture due to the release of small molecular organics can be well resolved. Chitosan and urea-formaldehyde resin form the capsule wall, and the silane coupling agent is mainly used to connect the capsule wall and the stone in the micro-surface mixture. When the microcapsule material is incorporated into the emulsified asphalt mixture, the silane coupling agent is in the capsule. The coupling between the wall material and the stone forms a chemical bond, which has the effect of strengthening and toughening the emulsified asphalt mixture, thereby improving the road performance of the mixture, and completely solving the problem that the active anti-icing material cannot be used in the road preventive maintenance technology. It greatly reduces the cost of using active anti-condensation ice technology. In addition, after the silane coupling agent is added, a large number of chemical coupling bonds can be formed, so that the distance between the molecular membranes of the capsule wall gradually becomes smaller, and the permeability of the membrane becomes poor, so that the microcapsule material can be released in the same time. The amount of deicing agent is reduced to increase the number of releases and prolong the service life.

As a capsule wall material, chitosan mainly plays a role in improving the strength of the capsule wall. Therefore, under the premise of ensuring the mechanical properties of the slow-release anticoagulant ice microcapsules, the amount of chitosan can be appropriately reduced to reduce the thickness of the capsule wall, which is beneficial to reducing the particle size of the slow-release anticoagulant ice microcapsules.

The silane coupling agent of the embodiment of the present invention includes at least one of the following types of silane coupling agents: KH-550, WD-50, KH-602, A-1160, QX-1324 and KBM-7803.

Specifically, the preparation method of urea-formaldehyde resin comprises the following process:

(1) Water and dispersant are uniformly mixed to obtain a first mixed solution.

In order to make the mixing more uniform, a stirring method can be used. For example, mechanical stirring, magnetic stirring, and the like. In the preparation process, the dispersing agent is added to facilitate the dissolution of urea.

(2) sequentially adding formaldehyde and urea into the first mixed solution, and mixing uniformly until the urea is completely dissolved to obtain a second mixed solution.

In order to make the mixing more uniform, a stirring method can be used. For example, mechanical stirring, magnetic stirring, and the like. The reason for the order of adding formaldehyde first and then adding urea is: formaldehyde is easily soluble in water and is a solvent; urea is soluble in water and is a crystal; if urea is added first, the fusion speed is slow, and when the fusion is not sufficient When formaldehyde is added, agglomeration will occur, so when formaldehyde is added first, and then urea is added, there will be no agglomeration.

(3) The pH value of the second mixed solution is adjusted to 9 to 10, and the second mixed solution is heated to perform a polymerization reaction at a temperature of 60 to 70° C. to obtain a urea-formaldehyde resin.

It should be understood that the prepared urea-formaldehyde resin exists in the form of a prepolymerized liquid.

Wherein, the dispersant in the embodiment of the present invention includes at least one of the following: polyethylene glycol, polyvinyl alcohol and methylcellulose gelatin. The mass ratio of urea to formaldehyde is 1:0.5～1:1.5. Preferably, the mass ratio of urea to formaldehyde is 1:0.8. Formaldehyde can be a liquid formaldehyde solution of any purity. The dosage of the dispersant is 0.8wt% to 1.5wt% of the total dosage of urea and formaldehyde. Preferably, the dosage of the dispersant is 1.2 wt% of the total dosage of urea and formaldehyde. Specifically, the time of the polymerization reaction is preferably 1 to 2 hours.

By controlling the amount of the silane coupling agent and the preparation process of the capsule wall material, the microcapsule material can maintain a good slow-release characteristic under the condition that the microcapsule material has a certain snow melting ability. The ability to melt snow and ice can reach more than 2 times that of ordinary sodium chloride snow melting agent, and it still has good ice and snow melting ability at -30 °C; in the case of ice and snow, the snow melting agent can be released continuously, preventing the secondary icing of the road and extending the material. The ability to melt snow and ice, and the expected service life can reach more than 5 years.

To sum up, the slow-release anti-coagulation ice microcapsules in the embodiments of the present invention can well solve the problem that the microcapsule materials affect the performance of the emulsified asphalt mixture due to the release of small molecular organics, and can be applied to micro-surfaces, fog sealing layers, etc. Among various road preventive maintenance technologies, the engineering cost of the existing slow-release anti-ice condensation technology is greatly reduced, and it has excellent low-temperature ice and snow melting ability, sustainable slow-release effect and excellent road performance.

The embodiment of the present invention also discloses a preparation method of the sustained-release anticoagulation ice microcapsule described in the above embodiment. Specifically, the preparation method includes the following processes:

(1) Dissolve the plant-based non-chlorine snow-melting agent in water, and mix evenly to obtain a capsule core solution.

In order to make the mixing more uniform, a stirring method can be used. For example, mechanical stirring, magnetic stirring, and the like. The plant-based non-chlorine snow-melting agent of the embodiment of the present invention is an alcohol component, which is easily soluble in water and is not easy to agglomerate.

(2) The urea-formaldehyde resin, the modified chitosan and the capsule core solution are reacted at a temperature of 60-70° C. to obtain slow-release anti-coagulation ice microcapsules.

It should be understood that the urea-formaldehyde resin and the modified chitosan can be prepared by the methods of the above embodiments, and will not be repeated here. The above reaction is an interfacial polymerization reaction, so that the encapsulation effect of the formed microcapsules is better.

In order to make the reaction more sufficient, a stirring method can be adopted. For example, mechanical stirring, magnetic stirring, and the like. Preferably, the stirring rate is 600-800r/min, and the reaction time is 2-3h. The pH value of this mixing process is 2-3. Since acetic acid is added during the preparation of the modified chitosan, it can neutralize the alkaline environment for preparing the urea-formaldehyde resin, so that the pH value of the mixing process is 2-3.

The product obtained by the reaction is suction filtered with distilled water, washed 3 to 5 times, and ventilated and dried in an oven.

To sum up, the preparation method of the sustained-release anticoagulation ice microcapsules of the embodiments of the present invention can prepare the sustained-release anticoagulation ice microcapsules with excellent effects of the above embodiments, and the preparation method is simple.

The embodiment of the present invention also discloses an application method of the sustained-release anticoagulation ice microcapsule described in the above embodiment. Specifically, the application method includes the following processes:

The slow-release anticoagulation ice microcapsules and the microsurface mixture are mixed uniformly to obtain the anticoagulation ice microsurface mixture.

Preferably, the micro-surface mixture is obtained by mixing 0-3mm stone, 3-6mm stone, polymer modified emulsified asphalt, cement and water. Specifically, the mass ratio of 0-3mm stone, 3-6mm stone, polymer modified emulsified asphalt, cement, water and slow-release anti-coagulation ice microgel is 60:40:11.5:1.5:5.5:3.

To sum up, the application method of the slow-release anticoagulant ice microcapsules in the embodiment of the present invention can prepare the anticoagulant ice micro-surface mixture by preparing the slow-release anticoagulation ice microcapsules of the above-mentioned embodiments, so that it can be applied to the micro-surface. , fog seal layer and other road preventive maintenance technologies.

The technical solutions of the present invention will be further described below with specific examples.

Example 1

First, 100 g of water and 0.2 g of polyvinyl alcohol were added to the reaction dish, and stirred evenly to obtain a first mixed solution. Next, 15 g of formaldehyde was added to the first mixed solution, and the water bath was heated to 70° C., stirred uniformly, and the formaldehyde was fully dissolved. Then, 10 g of urea was added, and the mixture was magnetically stirred until completely dissolved to obtain a second mixed solution. Then add triethanolamine to the second mixed solution, adjust the pH value to 9, and carry out a polymerization reaction for 90 min to obtain a urea-formaldehyde resin prepolymerized solution. Add 0.9 g of chitosan to 50 ml of 1.5% acetic acid solution, dissolve uniformly under magnetic stirring, add 0.25 g of silane coupling agent KH-550, and stir for 2 hours to obtain a modified chitosan solution. Dissolve 10 g of plant-based non-chlorine snow-melting agent in 100 g of water, and place it in a mixer to fully stir for 30 minutes to obtain a capsule core solution. Add the urea-formaldehyde resin prepolymerization solution, the modified chitosan solution and the capsule core solution together into the reaction flask, heat to a constant temperature of 60 ° C, pH is 2.5, mix the solution evenly under the action of electric stirring at 600 r/min, and wait for the reaction After 3 hours, the obtained product was suction filtered with distilled water, washed 3 times, and then air-dried in an oven to obtain a slow-release anti-coagulation ice microcapsule powder material.

Example 2

First, 100 g of water and 0.2 g of polyvinyl alcohol were added to the reaction dish, and stirred evenly to obtain a first mixed solution. Next, 10 g of formaldehyde was added to the first mixed solution, and the water bath was heated to 65° C., and stirred uniformly to fully dissolve the formaldehyde. Then, 10 g of urea was added, and the mixture was magnetically stirred until completely dissolved to obtain a second mixed solution. Then add triethanolamine to the second mixed solution, adjust the pH value to 9, and carry out a polymerization reaction for 60 minutes to obtain a urea-formaldehyde resin prepolymerized solution. Add 0.8g chitosan to 50ml of 1.5% acetic acid solution, dissolve uniformly under magnetic stirring, add 0.5g silane coupling agent (the mass ratio of KH-550 and A-1160 is 1:2), stir for 2h, A modified chitosan solution was obtained. Dissolve 10 g of plant-based non-chlorine snow-melting agent in 100 g of water, and place it in a mixer to fully stir for 30 minutes to obtain a capsule core solution. Add the urea-formaldehyde resin prepolymerization solution, the modified chitosan solution and the capsule core solution together into the reaction flask, heat to a constant temperature of 65 ° C, pH is 2.5, and mix the solution evenly under the action of electric stirring at 600 r/min. After 3 hours, the obtained product was suction filtered with distilled water, washed 3 times, and then air-dried in an oven to obtain a slow-release anti-coagulation ice microcapsule powder material.

Example 3

First, 100 g of water and 0.2 g of polyvinyl alcohol were added to the reaction dish, and stirred evenly to obtain a first mixed solution. Next, add 8 g of formaldehyde to the first mixed solution, heat the water bath to 70° C., stir evenly to fully dissolve the formaldehyde, then add 10 g of urea, and magnetically stir until completely dissolved to obtain a second mixed solution. Then add triethanolamine to the second mixed solution, adjust the pH value to 10, and carry out a polymerization reaction for 120 min to obtain a urea-formaldehyde resin prepolymerized solution. Add 0.6 g of chitosan into 50 ml of 1.5% acetic acid solution, dissolve uniformly under magnetic stirring, add 1 g of silane coupling agent KH-602, and stir for 2 hours to obtain a modified chitosan solution. Dissolve 10 g of plant-based non-chlorine snow-melting agent in 100 g of water, and place it in a mixer to fully stir for 30 min to obtain a capsule core solution. Add the urea-formaldehyde resin prepolymer solution, the modified chitosan solution and the capsule core solution together into the reaction flask, heat to a constant temperature of 65 ° C, pH is 3, and mix the solution evenly under the action of electric stirring at 700 r/min. After 3 hours, the obtained product was suction filtered with distilled water, washed 3 times, and then air-dried in an oven to obtain a slow-release anti-coagulation ice microcapsule powder material.

Example 4

First, 100 g of water and 0.2 g of polyvinyl alcohol were added to the reaction dish, and stirred evenly to obtain a first mixed solution. Next, add 5 g of formaldehyde to the first mixed solution, heat the water bath to 60° C., stir evenly to fully dissolve the formaldehyde, then add 10 g of urea, and magnetically stir until completely dissolved to obtain a second mixed solution. Then add triethanolamine to the second mixed solution, adjust the pH value to 9.5, and carry out a polymerization reaction for 120 min to obtain a urea-formaldehyde resin prepolymerized solution. Add 0.6 g of chitosan into 50 ml of 1.5% acetic acid solution, dissolve uniformly under magnetic stirring, add 1.5 g of WD-50, and stir for 1.5 h to obtain a modified chitosan solution. Dissolve 10 g of the plant-based non-chlorine snow melting agent in 100 g of water, and place it in a mixer to fully stir for 30 minutes to obtain a capsule core solution. Add the urea-formaldehyde resin prepolymerization solution, the modified chitosan solution and the capsule core solution together into the reaction flask, heat to a constant temperature of 70 ° C, pH is 2, and mix the solution evenly under the action of electric stirring at 800 r/min. After 3 hours, the obtained product was suction filtered with distilled water, washed 3 times, and then air-dried in an oven to obtain a slow-release anti-coagulation ice microcapsule powder material.

Example 5

First, 100 g of water and 0.2 g of polyvinyl alcohol were added to the reaction dish, and stirred evenly to obtain a first mixed solution. Next, add 8 g of formaldehyde to the first mixed solution, heat the water bath to 65° C., stir evenly to fully dissolve the formaldehyde, then add 10 g of urea and stir magnetically until completely dissolved to obtain a second mixed solution. Then add triethanolamine to the second mixed solution, adjust the pH value to 9, and carry out a polymerization reaction for 120 min to obtain a urea-formaldehyde resin prepolymerized solution. 0.5g of chitosan was added to 50ml of 1.5% acetic acid solution, dissolved uniformly under magnetic stirring, 2.5g of KBM-7803 was added, and the stirring time was 2h to obtain a modified chitosan solution. Dissolve 10 g of plant-based non-chlorine snow-melting agent in 100 g of water, and place it in a mixer to fully stir for 30 min to obtain a capsule core solution. Add the urea-formaldehyde resin prepolymer solution, the modified chitosan solution and the capsule core solution together into the reaction flask, heat to a constant temperature of 65 ° C, pH is 3, and mix the solution evenly under the action of electric stirring at 700 r/min. After 3 hours, the obtained product was suction filtered with distilled water, washed 3 times, and then air-dried in an oven to obtain a slow-release anti-coagulation ice microcapsule powder material.

The slow-release anti-coagulation ice microcapsule powder materials obtained in Examples 1 to 5 were applied to the micro-surface mixture, and the performance was compared with the micro-surface mixture without the addition of the slow-release anti-coagulation ice microcapsule powder material. The application method is as follows: 0-3mm stone, 3-6mm stone, polymer modified emulsified asphalt, cement, water, slow-release anti-coagulation ice microcapsule powder material according to the quality of 60:40:11.5:1.5:5.5:3 The mixture is mixed according to the proportion to obtain the anti-coagulation ice micro-surface mixture. The mechanical properties and melting ice and snow performance tests were carried out on the above 6 kinds of micro-surface mixtures according to the "Micro-surface and Slurry Sealing Technical Guidelines", and the results are shown in Table 1:

Table 1 Mechanical properties and ice and snow melting properties of the mixture at the micro-surface

As can be seen from Table 1, the mixing time of each embodiment is greater than the specified 120s, indicating that the anti-coagulation ice micro-surface mixture of each embodiment meets the requirements of mixing production; the 1h cohesion value of each embodiment is greater than the specification The required 2.0N·m, and the sample did not crack; the 1-h wet wheel wear value of each example was less than 540g/m ² required by the specification, indicating that the anti-condensation ice micro-surface mixture of each example has good performance. It can be seen from the 3h ice melting rate test that the ice melting rate of each embodiment is more than 70%, and the number of cycles of ice melting is more than 9 times, which has excellent melting ice and snow and slow release effect.

In addition, it can be seen from the changes in the content of each constituent material in Examples 1 to 4 that the content of formaldehyde and chitosan shows a decreasing change, which is manifested as a decrease in the components of the capsule wall and a decrease in the surface area of the microcapsules. The contact area decreases, which indirectly affects the ice melting rate, and the ice melting rate decreases gradually after 3h. In addition, it can be seen from Example 3 and Example 5 that when the quality of the capsule wall material composed of chitosan, urea and formaldehyde is almost the same, with the increase of the silane coupling agent, the ice melting rate decreases and the ice melts increased frequency. Therefore, although some studies have pointed out that increasing the amount of chitosan in the shell layer is beneficial to the sustained release effect, there is no such rule in the microcapsule material of the embodiment of the present invention, with the reduction of the content of chitosan, The slow release effect is better. This is because the silane coupling agent is introduced in the embodiment of the present invention, the amount of the silane coupling agent increases, the chemical coupling bond increases gradually, the distance between the molecular membranes of the capsule wall gradually decreases, the permeability of the membrane is worse, and the The less snow-melting agent released by the capsule material in a single time, the number of ice-melting cycles increases gradually; in addition, the silane coupling agent in the embodiment of the present invention is an alcohol, and the silane coupling agent contains a large number of hydroxyl groups, and these hydroxyl groups can be connected to the chitosan The free hydroxyl groups in the sugar make the microcapsule material and the stone bond closely, and the other free hydroxyl groups in the silane coupling agent can improve the sustained release effect. Therefore, the less chitosan, the more silane coupling agent, the more silane coupling agent The less hydroxyl groups combined with chitosan, the more free hydroxyl groups of the silane coupling agent, and the better the sustained release effect.

At the same time, it can also be seen that although the type of silane coupling agent and preparation process are different, with the increase of the amount of silane coupling agent, the mechanical properties of the mixture on the anti-coagulation ice micro-surface generally show an increase first and then decrease. The trend of cohesion first increases and then decreases, and the wet wheel wear value first decreases and then increases, mainly due to the formation of a strong chemical bond between the silane coupling agent and the stone. With the increase of the amount of silane coupling agent The stronger the binding force, the better the mechanical properties. When it exceeds a certain range, the formation of stress concentration will affect the mechanical properties of the mixture at the micro-surface.

Therefore, in the embodiment of the present invention, the dosage of chitosan, silane coupling agent, urea and formaldehyde needs to be comprehensively considered, and the number of times of ice melting is increased on the premise of ensuring the required mechanical properties of the applied pavement.

In addition, the slow-release anti-coagulation ice microcapsule of the present invention has a very significant effect on saving the cost of deicing and snow on the road in winter. The engineering cost of comparing the embodiment of the present invention and the existing two kinds of deicing and snow technologies is as follows:

(1) For the traditional salt-spreading and snow-removing technology, the total cost of materials, manpower, equipment rental, etc. invested in each snow is about 1.0-1.2 yuan/day/m ² , based on an average of 5 snows per year, each snow lasts 2 Calculated from the sky, the annual cost of deicing and snow removal per square meter of road surface is about (1.0 ~ 1.2) × 5 × 2 = 10 ~ 12 yuan.

(2) For the existing slow-release salinized material deicing and snow technology, the market price of slow-release salinized material is about 15,000 yuan/ton, which is used in 4cm thick AC-13 type hot mix asphalt mixture (density of 2.55 tons/cubic meter), the dosage is 5%, and the service life is 3 years, the annual cost of deicing and snow removal per square meter of road surface is about: 0.04 × 2.55 × 5% × 15000/3 = 25.5 yuan.

(3) For the slow-release anti-coagulation ice microcapsule deicing and snow removal technology of the present invention, the unit price of the material is about 10,000 yuan, and it is applied to the MS-2 type micro-surface (mineral material is about 15kg/m ² ), and the dosage is 3 %, if the service life is 3 years, the annual cost of deicing and snow removal materials per square meter of road surface is about: 15 × 3% × 10/3 = 1.5 yuan (the mixture at the micro-surface is converted to about 10 yuan/kg·m ² ).

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (10)

1. A slow-release anti-freezing microcapsule is characterized by comprising: the snow-melting agent comprises a capsule core and a capsule wall coating the capsule core, the mass ratio of the capsule core to the capsule wall is 1: 1-1: 10, the capsule core is a plant-based non-chlorine snow-melting agent, and the capsule wall comprises: the modified chitosan and the urea-formaldehyde resin are mixed according to the mass ratio of 1: 6-1: 21.7; the modified chitosan is prepared from chitosan and a silane coupling agent, and the mass ratio of the silane coupling agent to the chitosan is 0.27-2.5: 1.

2. The slow-release anti-icing microcapsule according to claim 1, wherein the preparation method of the modified chitosan comprises the following steps:

dissolving chitosan in acetic acid solution, adding a silane coupling agent, and uniformly stirring to obtain the modified chitosan.

3. The slow release anticoagulant ice microcapsule according to claim 2, wherein: the dosage of the chitosan is 1 to 2 weight percent of the dosage of the acetic acid solution, and the volume fraction of acetic acid in the acetic acid solution is 1 to 2 percent.

4. The slow-release anticoagulant ice microcapsule according to claim 2, wherein the silane coupling agent comprises at least one of the following types of silane coupling agents: KH-550, WD-50, KH-602, A-1160, QX-1324 and KBM-7803.

5. The slow-release anti-icing microcapsule according to claim 1, wherein the preparation method of the urea-formaldehyde resin comprises the following steps:

uniformly mixing water and a dispersant to obtain a first mixed solution;

sequentially adding formaldehyde and urea into the first mixed solution, and uniformly mixing until the urea is completely dissolved to obtain a second mixed solution;

and adjusting the pH value of the second mixed solution to 9-10, and heating the second mixed solution to enable the second mixed solution to perform polymerization reaction at the temperature of 60-70 ℃ to obtain the urea-formaldehyde resin.

6. The sustained-release anti-icing microcapsule according to claim 5, wherein: the mass ratio of the urea to the formaldehyde is 1: 0.5-1: 1.5, and the dosage of the dispersing agent is 0.8 wt% -1.5 wt% of the total dosage of the urea and the formaldehyde.

7. The sustained-release anti-icing microcapsule according to claim 5, wherein the dispersing agent comprises at least one of: polyethylene glycol, polyvinyl alcohol and methylcellulose gelatin.

8. The slow-release anti-icing microcapsule according to claim 1, wherein said plant-based non-chlorine snow-melting agent comprises at least one of: glycerol, ethylene glycol, sorbitol and propylene glycol.

9. A method for preparing a sustained-release anti-icing microcapsule according to any one of claims 1 to 8, comprising:

dissolving a plant-based non-chlorine snow melting agent in water, and uniformly mixing to obtain a capsule core solution;

reacting urea resin, modified chitosan and the capsule core solution at the temperature of 60-70 ℃ to obtain the slow-release anti-freezing microcapsule.

10. A method of using a slow release anti-icing microcapsule according to any of claims 1 to 8, comprising:

and uniformly mixing the slow-release anti-freezing microcapsules and the micro-surfacing mixture to obtain the anti-freezing micro-surfacing mixture.