Method for preparing long-side-chain terpolymer from expired drugs

Abstract

The invention discloses a method for preparing a long-side-chain terpolymer by using an expired drug, which comprises the following steps: S1, mixing an expired organic acid drug containing a benzene ring with a solvent 1, adding a catalyst, stirring, heating, adding an expired vitamin D drug, carrying out reflux reaction after adding, and carrying out post-treatment to obtain modified vitamin D ester; and S2, dissolving a polyether compound in a solvent 2 as a kettle base solution, dissolving an unsaturated organosilicon compound as a material A, dissolving an oxidizing agent in the solvent 2 as a material B, heating the kettle base solution, adding the modified vitamin D ester and a chain transfer agent, simultaneously dropwise adding the material A and the material B, and after dropwise adding, carrying out heat preservation and curing to obtain the long-side-chain ternary polymerization compound. According to the invention, expired drugs are used as raw materials to realize resource utilization of wastes, a benzene ring rigid structure, hydrolysable ester groups, polyether long side chains and bondable siloxane groups are introduced into the prepared copolymer, and when the copolymer is compounded with a polycarboxylic acid water reducer for use, the initial dispersity and long-term slump retaining performance of concrete can be remarkably improved through multiple synergistic effects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete admixtures, in particular to a method for preparing long side chain terpolymer from expired drugs. BACKGROUND

[0002] In the production process of concrete, admixtures are usually added, which mainly serves to precisely control the performance of concrete through chemical means to solve the drawbacks of simply adjusting the material mix ratio, such as reducing the strength by increasing the water consumption, so as to meet the comprehensive requirements of modern engineering on construction efficiency, structural quality and economy. In the field of modern concrete engineering technology, admixtures mainly include water reducing agents, air entraining agents, water retaining agents, retarders, expansive agents, etc. Among them, water reducing agents are the most important variety of concrete admixtures, which can be divided into ordinary water reducing agents (lignosulfonate), high efficiency water reducing agents (naphthalene, melamine, aminosulfonate, aliphatic, etc.) and high performance water reducing agents (polycarboxylic acid). As the third generation of high performance water reducing agent, polycarboxylic acid water reducing agent has the characteristics of high water reducing rate, good fluidity, strong cement adaptability and environmental protection. Its excellent dispersion ability mainly comes from the unique "comb-like" molecular structure, which realizes high-efficiency dispersion of cement particles through steric hindrance effect and electrostatic repulsion effect, and has become the main variety of concrete water reducing agent.

[0003] However, although the performance of polycarboxylic acid water reducing agent is excellent, its application in actual engineering still faces severe challenges. For example, in the construction process, high temperature in summer and long distance transportation will aggravate the failure of polycarboxylic acid water reducing agent, which shows problems such as too fast loss of slump and too large loss of fluidity over time, ultimately affecting the performance of concrete. Therefore, some enterprises optimize the structure of polycarboxylic acid water reducing agent to solve the common problems of poor adaptability to concrete materials and sensitivity to dosage of conventional polycarboxylic acid water reducing agent products. For example, patent CN119306900A discloses introducing unsaturated functional monomers containing carboxyl, carboxylate, hydroxyl, double benzene ring, phosphate, amide, bisilane and sulfonic acid groups in the synthesis of polycarboxylic acid water reducing agent; patents CN114478939B and CN120098205A disclose generating polycarboxylic acid water reducing agent by polyether and unsaturated functional monomers (methyl methacrylate). However, in addition to the influence of polycarboxylic acid water reducing agent itself, the surface properties of cement with different origins, mineral compositions and fineness are greatly different, which may lead to uneven adsorption behavior of water reducing agent and cause adaptability problems. Therefore, simply relying on optimizing the structure of polycarboxylic acid water reducing agent cannot meet all harsh engineering requirements. Developing new and efficient auxiliary materials to further improve the dispersion performance and slump retention performance of concrete through molecular design and compounding technology has become an urgent and important research direction in the field of building material chemistry and concrete technology.

[0004] Meanwhile, the disposal of expired medicines is becoming a serious environmental and public health problem globally. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac, ibuprofen, and aspirin, due to their high consumption and limited shelf life, are among the main components of expired household medications. How to transform this type of organic solid waste into valuable resources and achieve high-value-added resource utilization is a focus of green chemistry and the circular economy. Currently, there are no reports of using such expired medicines, especially when combined with vitamin D drugs, through specific chemical modifications to prepare functional concrete admixtures.

[0005] Against this backdrop, there is an urgent need to develop a new method for preparing materials that can make resource-efficient use of expired drugs and can be efficiently compounded with polycarboxylate superplasticizers to improve the overall performance of concrete. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention provides a method for preparing long-side-chain terpolymers using expired drugs. This method solves the technical problems of poor adaptability to different cements, insufficient high-temperature slump retention, and low resource utilization rate of expired drugs when polycarboxylate superplasticizers are used alone in existing technologies.

[0007] To solve the above problems, the technical solution adopted by the present invention is: a method for preparing long side-chain terpolymers using expired drugs, comprising the following steps: S1. Preparation of modified vitamin D ester: Expired organic acid drugs containing benzene rings are mixed with solvent 1, catalyst is added and stirred, heated to 90-120℃ and then the expired vitamin D drugs are slowly added. After the addition is completed, the mixture is refluxed for 8-10 hours and then post-treated to obtain modified vitamin D ester. S2. Preparation of long-side-chain ternary copolymer: Dissolve a polyether compound in solvent 2 as the bottom liquid, use an unsaturated organosilicon compound as component A, and dissolve an oxidant in solvent 2 as component B. After the bottom liquid is heated to 65-75℃, add the modified vitamin D ester and chain transfer agent, and then add components A and B dropwise simultaneously. After the addition is complete, keep warm and mature to obtain the long-side-chain ternary copolymer.

[0008] Furthermore, in step S1, the amount of each component added is: 30-35 parts of expired organic acid drug containing benzene ring, 50-110 parts of expired vitamin D drug, 2-5 parts of catalyst, and 60-90 parts of solvent 1; wherein, solvent 1 is one or two of acetonitrile and tetrahydrofuran.

[0009] Furthermore, the expired organic acid drug containing a benzene ring is one or more of diclofenac, ibuprofen, and aspirin.

[0010] Furthermore, the catalyst is one or both of concentrated sulfuric acid and p-toluenesulfonic acid.

[0011] Furthermore, the expired vitamin D drug is one or both of vitamin D2 and vitamin D3.

[0012] Further, in step S2, the amount of each component added is: 100-150 parts of polyether compound, 5-10 parts of unsaturated organosilicon compound, 1-3 parts of oxidant, 10-20 parts of modified vitamin D ester, 1-3 parts of chain transfer agent and 103-160 parts of solvent 2; wherein, solvent 2 is deionized water, the polyether compound is dissolved in 100-150 parts of deionized water, and the oxidant is dissolved in 3-10 parts of deionized water.

[0013] Furthermore, the polyether compound is one or both of methyl allyl polyoxyethylene ether and isopentenyl polyethylene glycol ether.

[0014] Furthermore, the organosilicon compound is one or more of methyl vinyl dimethoxysilane, methyl vinyl diethoxysilane, and allyl methyl dimethoxysilane.

[0015] Furthermore, the oxidant is one or two of ammonium persulfate and potassium persulfate; the chain transfer agent is one or more of sodium hypophosphite, mercaptoacetic acid, mercaptopropionic acid, and mercaptoethanol.

[0016] Furthermore, in step S2, the dripping time is 2-3 hours.

[0017] Compared with the prior art, the technical solution of this application has the following beneficial effects: 1. This invention innovatively uses expired drugs as reaction raw materials, realizing the resource utilization of drug waste while ensuring the reaction effect, which is in line with the concept of green chemistry and can reduce the cost of raw materials to a certain extent.

[0018] 2. This invention utilizes expired drugs such as diclofenac, ibuprofen, or aspirin to undergo an esterification reaction with vitamin D2 or vitamin D3 to obtain a modified vitamin D ester containing a benzene ring structure. On one hand, this ester slowly hydrolyzes in the alkaline environment of concrete, releasing carboxyl groups and generating new electrostatic repulsion. After a period of time, this can further disperse agglomerated cement particles, improving the slump retention of the concrete. On the other hand, the benzene ring, as a rigid structure, provides a rigid framework support for the subsequently prepared long-side-chain terpolymer, preventing excessive entanglement or coiling between molecular chains. This allows the terpolymer admixture prepared in this invention to effectively unfold in concrete, enabling the hydrophilic side chains to extend more effectively into the liquid phase, forming a thicker and more stable three-dimensional protective layer, preventing cement particles from approaching each other. The benzene ring structure in the terpolymer molecule undergoes hydrophobic and π-electron interactions with the surface of cement particles, assisting the carboxyl groups in the molecule to be more firmly adsorbed onto the surface of the cement particles, adjusting the hydrophilic-lipophilic balance of the molecule. Combined with the strong steric hindrance effect of the benzene ring, this effectively prevents the flocculation of cement particles and improves dispersibility.

[0019] 3. The siloxane groups in the terpolymer of the present invention can undergo hydrolysis under alkaline conditions of concrete and bond with the silanol groups on the surface of cement particles. This chemical anchoring effect greatly improves the adsorption amount and adsorption strength of the terpolymer on the cement surface, thereby significantly enhancing its dispersion ability on cement particles.

[0020] 4. The long side chains of polyoxyethylene ether contained in the terpolymer of this invention have strong steric hindrance, preventing cement particles from approaching and agglomerating. Furthermore, its hydrophilic portion can form a denser and more stable protective layer on the cement particles, working synergistically with the benzene ring and siloxane group. These three elements complement each other, ensuring the high dispersion of the terpolymer in concrete. In practical applications, when used in combination with polycarboxylate superplasticizer, it can effectively improve the dispersibility and slump retention of concrete. Attached Figure Description

[0021] Figure 1 This is a process flow diagram of a method for preparing long side-chain terpolymers using expired drugs. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: This embodiment of the invention discloses a method for preparing long-side-chain terpolymers using expired drugs, referring to... Figure 1 : S1: Weigh 35 parts of expired aspirin and 60 parts of tetrahydrofuran into a three-necked flask, add 3.5 parts of p-toluenesulfonic acid, start stirring, heat to 100°C, and after the temperature is reached, slowly add 110 parts of expired vitamin D2. After the vitamin D2 is added, continue to reflux for 8 hours, remove the solvent by rotary evaporation, and obtain the modified vitamin D2 ester.

[0024] S2: Dissolve 100 parts of methyl allyl polyoxyethylene ether (HPEG) in 100 parts of deionized water, and record this as the bottom material; weigh 5 parts of methyl vinyl dimethoxysilane, and record this as material A; weigh 1.3 parts of ammonium persulfate and dissolve this as material B. After the bottom liquid is heated to 65°C, add 10 parts of the modified vitamin D2 ester prepared in S1 and 1.1 parts of mercaptoacetic acid, respectively. Then, add materials A and B dropwise simultaneously. Material A is added dropwise for 2.5 h, and material B is added dropwise for 2.5 h. After the addition is completed, keep warm and mature for 1 h to obtain a long side-chain terpolymer.

[0025] The terpolymer obtained from S2 was compounded with commercially available HPEG type polycarboxylate superplasticizer, and concrete performance testing experiments were conducted.

[0026] Example 2 S1: Weigh 30 parts of expired ibuprofen and 90 parts of tetrahydrofuran into a three-necked flask, add 5 parts of p-toluenesulfonic acid, start stirring, heat to 95°C, and after the temperature is reached, slowly add 65 parts of expired vitamin D2. After the vitamin D2 is added, continue to reflux for 8 hours, remove the solvent by rotary evaporation, and obtain the modified vitamin D2 ester.

[0027] S2: Dissolve 110 parts of isopentenyl polyethylene glycol ether (TPEG) in 110 parts of deionized water, and record this as the bottom material; weigh 6 parts of methylvinyldiethoxysilane, and record this as material A; weigh 1 part of ammonium persulfate and dissolve this as material B. After the bottom liquid is heated to 65°C, add 12 parts of the modified vitamin D2 ester prepared in S1 and 3 parts of sodium hypophosphite, respectively. Then, add materials A and B dropwise simultaneously. Add material A for 3 hours and material B for 3 hours. After the addition is completed, keep warm and mature for 1 hour to obtain a long side-chain terpolymer.

[0028] The terpolymer obtained from S2 was compounded with commercially available TPEG-type polycarboxylate superplasticizer, and concrete performance tests were conducted.

[0029] Example 3 S1: Weigh 32 parts of expired diclofenac and 85 parts of acetonitrile into a three-necked flask, add 2 parts of concentrated sulfuric acid, start stirring, heat to 120°C, and after the temperature is reached, slowly add 60 parts of expired vitamin D3. After the vitamin D3 is added, continue to reflux for 9 hours, remove the solvent by rotary evaporation, and obtain the modified vitamin D3 ester.

[0030] S2: Dissolve 120 parts of methyl allyl polyoxyethylene ether (HPEG) in 120 parts of deionized water, and record this as the bottom material; weigh out 7 parts of allyl methyl dimethoxysilane, and record this as material A; weigh out 2 parts of potassium persulfate and dissolve this as material B. After the bottom liquid is heated to 70°C, add 12 parts of the modified vitamin D3 ester prepared in S1 and 2 parts of mercaptoethanol, respectively. Then, add materials A and B dropwise simultaneously. Add material A for 3 hours and material B for 3 hours. After the addition is completed, keep warm and mature for 1 hour to obtain a long side-chain terpolymer.

[0031] The terpolymer obtained from S2 was compounded with commercially available HPEG type polycarboxylate superplasticizer, and concrete performance testing experiments were conducted.

[0032] Example 4 S1: Weigh 30 parts of expired ibuprofen and 80 parts of acetonitrile into a three-necked flask, add 5 parts of p-toluenesulfonic acid, start stirring, heat to 120°C, and after the temperature is reached, slowly add 62 parts of expired vitamin D3. After the vitamin D3 is added, continue to reflux for 10 h, remove the solvent by rotary evaporation, and obtain the modified vitamin D3 ester.

[0033] S2: Dissolve 125 parts of methyl allyl polyoxyethylene ether (HPEG) in 125 parts of solvent, denoted as the bottom material; weigh 6 parts of methyl vinyl dimethoxysilane, denoted as material A; weigh 2.5 parts of potassium persulfate and dissolve in 8 parts of solvent, denoted as material B. After the bottom liquid is heated to 70℃, add 11 parts of the modified vitamin D3 ester prepared in S1 and 3 parts of sodium hypophosphite, respectively. Then, add materials A and B dropwise simultaneously. Material A is added dropwise for 2.5 h, and material B is added dropwise for 2.5 h. After the addition is completed, keep warm and mature for 1 h to obtain a long side-chain terpolymer.

[0034] The terpolymer obtained from S2 was compounded with commercially available HPEG type polycarboxylate superplasticizer, and concrete performance testing experiments were conducted.

[0035] Example 5 S1: Weigh 35 parts of expired aspirin and 90 parts of tetrahydrofuran into a three-necked flask, add 2.3 parts of p-toluenesulfonic acid, start stirring, heat to 105℃, and after the temperature is reached, slowly add 93 parts of expired vitamin D3. After the vitamin D3 is added, continue to reflux for 9.5 h, remove the solvent by rotary evaporation, and obtain the modified vitamin D3 ester.

[0036] S2: Dissolve 150 parts of isopentenyl polyethylene glycol ether (TPEG) in 150 parts of deionized water, and record this as the bottom material; weigh 10 parts of allyl methyl dimethoxysilane, and record this as material A; weigh 3 parts of potassium persulfate and dissolve this as material B. After the bottom liquid is heated to 75°C, add 18 parts of the modified vitamin D3 ester prepared in S1 and 2.8 parts of sodium hypophosphite, respectively. Then, add materials A and B dropwise simultaneously. Material A is added dropwise for 2.5 h, and material B is added dropwise for 2.5 h. After the addition is completed, keep warm and mature for 1 h to obtain a long side-chain terpolymer.

[0037] The terpolymer obtained from S2 was compounded with commercially available TPEG-type polycarboxylate superplasticizer, and concrete performance tests were conducted.

[0038] Comparative Example 1 A commercially available HEPG type polycarboxylate superplasticizer.

[0039] Comparative Example 2 A commercially available TPEG type polycarboxylate superplasticizer.

[0040] Referring to standard GB / T 50080-2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures", at room temperature (20±5)℃, the initial slump / spread and slump / spread at 3 h and 4 h of the concrete from Examples 1-5 of this invention (referring to the compounded products) and Comparative Examples 1-2 were compared. The concrete used was Hongshi PO 42.5 cement, and the mix proportions are shown in Table 1. The concrete test results are shown in Table 2.

[0041] Table 1 Concrete mix proportions (kg / m³) 3 )

[0042] Table 2 Concrete performance data of the samples

[0043] Results analysis: Table 2 shows that, under the same folded-solid content (0.2%), the concrete products (Examples 1-5) using the terpolymer obtained in this invention combined with polycarboxylate superplasticizer exhibit better initial slump and spread than those using polycarboxylate superplasticizer alone (Comparative Examples 1-2). More importantly, at 3 h and 4 h, Examples 1-5 show higher slump and spread retention rates and less time loss. This fully demonstrates that combining the long-side-chain terpolymer of this invention with polycarboxylate superplasticizer can significantly improve the initial dispersibility and long-term slump retention of concrete.

[0044] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing long-side-chain terpolymers using expired drugs, characterized in that: Includes the following steps: S1. Preparation of modified vitamin D ester: Expired organic acid drugs containing benzene rings are mixed with solvent 1, catalyst is added and stirred, heated to 90-120℃ and then the expired vitamin D drugs are slowly added. After the addition is completed, the mixture is refluxed for 8-10 h and then post-treated to obtain modified vitamin D ester. S2. Preparation of long-side-chain ternary copolymer: Dissolve a polyether compound in solvent 2 as the bottom liquid, use an unsaturated organosilicon compound as component A, and dissolve an oxidant in solvent 2 as component B. After the bottom liquid is heated to 65-75℃, add the modified vitamin D ester and chain transfer agent, and then add components A and B dropwise simultaneously. After the addition is complete, keep warm and mature to obtain the long-side-chain ternary copolymer.

2. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: In step S1, the amount of each component added is: 30-35 parts of expired organic acid drug containing benzene ring, 50-110 parts of expired vitamin D drug, 2-5 parts of catalyst, and 60-90 parts of solvent 1; wherein, solvent 1 is one or two of acetonitrile and tetrahydrofuran.

3. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: The expired organic acid drug containing a benzene ring is one or more of diclofenac, ibuprofen, and aspirin.

4. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: The catalyst is one or both of concentrated sulfuric acid and p-toluenesulfonic acid.

5. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: The expired vitamin D medication is one or both of vitamin D2 and vitamin D3.

6. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: In step S2, the amount of each component added is as follows: 100-150 parts of polyether compound, 5-10 parts of unsaturated organosilicon compound, 1-3 parts of oxidant, 10-20 parts of modified vitamin D ester, 1-3 parts of chain transfer agent, and 103-160 parts of solvent 2; wherein, solvent 2 is deionized water, the polyether compound is dissolved in 100-150 parts of deionized water, and the oxidant is dissolved in 3-10 parts of deionized water.

7. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: The polyether compound is one or both of methyl allyl polyoxyethylene ether and isopentenyl polyethylene glycol ether.

8. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: The organosilicon compound is one or more of methyl vinyl dimethoxysilane, methyl vinyl diethoxysilane, and allyl methyl dimethoxysilane.

9. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: The oxidant is one or two of ammonium persulfate and potassium persulfate; the chain transfer agent is one or more of sodium hypophosphite, mercaptoacetic acid, mercaptopropionic acid, and mercaptoethanol.

10. The method for preparing long-side-chain terpolymers using expired drugs according to claim 1, characterized in that: In step S2, the dripping time is 2-3 hours.

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