Method for modifying vinyl ether macromonomer by utilizing maleated rosin, obtained modified macromonomer and application

Abstract

The invention discloses a method for modifying a vinyl ether macromonomer by utilizing maleated rosin, the obtained modified macromonomer and application. The method comprises the following steps: mixing maleated rosin and a vinyl ether macromonomer according to a certain proportion, putting the mixture into a reaction kettle, stirring and reacting at 60-150 DEG C for 3-12 hours, cooling, adding water, stirring and dissolving a reaction product, filtering to remove insoluble unreacted maleated rosin, concentrating and drying (if the water reducer is directly synthesized, concentrating and drying are not needed) to obtain the product. The modified macromonomer is prepared by a solvent-free direct esterification method, and the method has the advantages of no need of special equipment, cheap and easily available modification raw materials, low production cost, mild reaction conditions, green and environment-friendly process and the like; the esterification rate reaches 97.02%, and the double bond retention rate reaches up to 96.81%. The water reducing agent produced by the modified macromonomer prepared by the method has excellent mud resistance.

Description

Technical Field

[0001] The present invention relates to a chemical modification method of an ethylene ether macromonomer for synthesizing a polycarboxylate water reducer, specifically a method for modifying an ethylene ether macromonomer with maleic rosin, and the obtained modified macromonomer and its applications. Background Art

[0002] In recent years, with the rapid development of the polycarboxylate water reducer industry, the polyether macromonomers for synthesizing water reducers have achieved great development. Some ethylene ether macromonomers with strong adaptability to sand and gravel and high polymerization activity have become the mainstream varieties for synthesizing polycarboxylate water reducers. As a polyoxyethylene ether with bifunctional groups, such ethylene ether macromonomers contain both polymerizable active ethylene groups in their structures, enabling them to participate in various free radical or photoinitiated polymerization reactions, and also have relatively large polyoxyethylene ether chain segments, making them important monomers for synthesizing polycarboxylate water reducers. Ethylene ether macromonomers such as ethylene glycol mono vinyl polyoxyethylene ether and butanediol mono vinyl polyoxyethylene ether are commonly used macromonomers in the synthesis of polycarboxylate water reducers. The polycarboxylate water reducers synthesized by copolymerizing them with other functional monomers (such as acrylic acid, methacrylic acid, etc.) can adsorb on the surface of clay particles through electrostatic interaction, and through the electrostatic repulsion of carboxyl groups on the main chain of the water reducer, the steric hindrance effect and hydration film effect of the polyoxyethylene ether side chains, effectively disperse cement particles, prevent particle re-agglomeration, so that the cement paste can obtain good fluidity and improve the workability of concrete; at the same time, through the dispersion effect of the water reducer, the wrapped water can be released, reducing the mixing water consumption of concrete, thereby improving the mechanical properties of concrete.

[0003] However, due to the increasing emphasis on environmental protection, the amount of high-quality sand and gravel available for construction is continuously decreasing. Some sand and gravel are often mixed with a certain amount of soil, the main components of which are montmorillonite, kaolin, etc., and their structures are layered crystal structures. The layer spacing of the crystals is similar to the diameter of the polyoxyethylene chain segments of the polycarboxylate water reducer molecule side chains. Therefore, the polyoxyethylene chain segments of the water reducer side chains are easily inserted into them, increasing the adsorption amount of the water reducer on the soil, thereby reducing the adsorption amount of the water reducer on the cement surface and affecting the dispersion of the water reducer on the cement particles. Therefore, in order to obtain the same fluidity, more water reducer needs to be consumed, significantly increasing the production cost of concrete. Summary of the Invention

[0004] To overcome the above problems existing in the existing polycarboxylate water reducers, reduce the adsorption amount of the water reducer on soil, reduce the dosage of the water reducer for muddy sand and gravel, and reduce the production cost of concrete, the present invention provides a method for modifying vinyl ether macromonomers with maleic rosin, the obtained modified macromonomers and their applications. By adopting the solution of modifying polyether macromonomers with inexpensive renewable resources, maleic rosin, the present invention can increase the molecular size of the polyoxyethylene ether side chain of the water reducer, making it impossible to insert into the interlayer structure of the soil, thus significantly reducing the adsorption amount of the water reducer on the soil, increasing its adsorption on cement, reducing the dosage of the water reducer, reducing the sensitivity of the water reducer to soil, and reducing the production cost. The present invention has the characteristics of simple and easy-to-implement modification process, mild reaction conditions, low production cost, green and environmental-friendly production process, and good modification effect.

[0005] The technical solution adopted by the present invention is as follows: A method for modifying vinyl ether macromonomers with maleic rosin, and the specific process steps are as follows: According to the mass ratio of maleic rosin to vinyl ether macromonomers of 10:50 - 150, add the two raw materials, maleic rosin and vinyl ether macromonomers, into a reaction kettle, introduce nitrogen to exhaust air, and react in an oil bath at 60 - 150 °C for 3 - 12 h under nitrogen protection. After cooling to below 100 °C, add deionized water according to the mass ratio of the reactants to water of 1:2.5, stir and dissolve, and filter to remove the unreacted maleic rosin that is insoluble in water; concentrate and dry the filtrate below 60 °C to obtain the solid product of maleic rosin-modified vinyl ether macromonomers.

[0006] Further, in the above method for modifying vinyl ether macromonomers with maleic rosin, the maleic rosin and vinyl ether macromonomers are of industrial grade. The vinyl ether macromonomer is any one or a mixture of any several of ethylene glycol mono vinyl polyoxyethylene ether, diethylene glycol mono vinyl polyoxyethylene ether, and butylene glycol mono vinyl polyoxyethylene ether.

[0007] Further, in the above method for modifying vinyl ether macromonomers with maleic rosin, if the filtrate obtained after filtration is directly used for synthesizing the water reducer, it can be not concentrated and dried.

[0008] On the other hand, the present invention also provides the modified macromonomers prepared according to the above method for modifying vinyl ether macromonomers with maleic rosin. The application of the modified macromonomers in synthesizing polycarboxylate water reducers.

[0009] The positive effects produced by the present invention are: 1. The macromonomer of maleic rosin modified vinyl ether prepared by the method of the present invention has an increased molecular size at the end of the polyoxyethylene ether side chain of the water reducer due to the introduction of the rosin group. When the polycarboxylate superplasticizer is prepared with it, it is difficult to insert into the layer spacing of soil crystals and the micropores of sand and gravel, which can significantly reduce the adsorption amount of the water reducer on soil and sand, reduce the sensitivity of the water reducer to soil, and has excellent anti-clay performance. Therefore, the dosage of the water reducer can be reduced, and the production cost of concrete can be saved.

[0010] 2. In the method of the present invention for modifying vinyl ether macromonomers with maleic rosin, the modifier maleic rosin is a relatively inexpensive and easily available renewable resource with high reaction activity. It can undergo an esterification reaction at a relatively low temperature without a catalyst. Using it to modify vinyl ether macromonomers has the advantages of mild reaction conditions, high esterification rate, and low production cost. Its esterification rate is as high as 97.02%, and the double bond retention rate reaches 96.81%.

[0011] 3. The macromonomer of maleic rosin modified vinyl ether is prepared by the solvent-free direct esterification method in the present invention. Its synthesis process is simple and easy to implement, with good modification effects, no special equipment required, and no environmental pollution, meeting the requirements of green chemistry. Description of the Drawings

[0012] Figure 1 are the infrared spectra of ethylene glycol mono vinyl polyoxyethylene ether and the macromolecule of maleic rosin modified ethylene glycol mono vinyl polyoxyethylene ether; Figure 1 In, the maleic rosin modified ethylene glycol mono vinyl polyoxyethylene ether has a characteristic absorption peak of ester group contraction vibration at 1730 cm -1 and a carboxylic acid C=O stretching vibration absorption peak at 1780 cm -1 . The -OH vibration absorption peak at 3470 cm -1 is significantly enhanced, indicating that the maleic rosin group is introduced into the modified product; while there is still a C=C vibration absorption peak at 1640 cm -1 , indicating that the double bond in the modified product is not damaged. Detailed Embodiments

[0013] The following is a further description of the present invention in conjunction with embodiments. Example 1

[0014] A method for modifying ethylene ether macromonomers with maleic rosin, and the specific process steps are as follows: According to the mass ratio of maleic rosin to ethylene glycol mono vinyl polyoxyethylene ether macromonomer of 10:50, add the two raw materials into the reaction kettle, introduce nitrogen to exhaust the air, and react in an oil bath at 60 °C for 12 h under nitrogen protection. Then cool it to below 100 °C, add deionized water according to the mass ratio of reactants to water of 1:2.5, stir and dissolve, and filter to remove the unreacted maleic rosin insoluble in water. Concentrate and dry the filtrate below 60 °C to obtain the solid product of maleic rosin-modified ethylene ether macromonomer, with an esterification rate of 96.80% and a double bond retention rate of 96.53%.

[0015] Example 2 A method for modifying ethylene ether macromonomers with maleic rosin, and the specific process steps are as follows: According to the mass ratio of maleic rosin to ethylene glycol mono vinyl polyoxyethylene ether macromonomer of 10:150, add the two raw materials into the reaction kettle, introduce nitrogen to exhaust the air, and react in an oil bath at 150 °C for 3 h under nitrogen protection. Then cool it to below 100 °C, add deionized water according to the mass ratio of reactants to water of 1:2.5, stir and dissolve, and filter to remove the unreacted maleic rosin insoluble in water. Concentrate and dry the filtrate below 60 °C to obtain the solid product of maleic rosin-modified ethylene ether macromonomer, with an esterification rate of 95.49% and a double bond retention rate of 93.71%. Example 3

[0016] A method for modifying ethylene ether macromonomers with maleic rosin, and the specific process steps are as follows: According to the mass ratio of maleic rosin to ethylene glycol mono vinyl polyoxyethylene ether macromonomer of 10:70, add the two raw materials into the reaction kettle, introduce nitrogen to exhaust the air, and react in an oil bath at 120 °C for 5 h under nitrogen protection. Then cool it to below 100 °C, add deionized water according to the mass ratio of reactants to water of 1:2.5, stir and dissolve, and filter to remove the unreacted maleic rosin insoluble in water. Concentrate and dry the filtrate below 60 °C to obtain the solid product of maleic rosin-modified ethylene ether macromonomer, with an esterification rate of 96.59% and a double bond retention rate of 94.54%.

[0017] Example 4 A method for modifying vinyl ether macromonomers with maleic rosin, and the specific process steps are as follows: According to the mass ratio of maleic rosin to ethylene glycol mono vinyl polyoxyethylene ether macromonomer of 10:100, add the two raw materials into the reaction kettle, introduce nitrogen to exhaust the air, and react in an oil bath at 80 °C for 7 h under nitrogen protection. After cooling to below 100 °C, add deionized water according to the mass ratio of the reactants to water of 1:2.5, stir to dissolve, and filter to remove the unreacted maleic rosin that is insoluble in water. Concentrate and dry the filtrate below 60 °C to obtain a solid product of maleic rosin-modified vinyl ether macromonomer, with an esterification rate of 96.02% and a double bond retention rate of 96.21%. Example 5

[0018] A method for modifying vinyl ether macromonomers with maleic rosin, and the specific process steps are as follows: According to the mass ratio of maleic rosin to diethylene glycol mono vinyl polyoxyethylene ether macromonomer of 10:90, add the two raw materials into the reaction kettle, introduce nitrogen to exhaust the air, and react in an oil bath at 100 °C for 8 h under nitrogen protection. After cooling to below 100 °C, add deionized water according to the mass ratio of the reactants to water of 1:2.5, stir to dissolve, and filter to remove the unreacted maleic rosin that is insoluble in water. Concentrate and dry the filtrate below 60 °C to obtain a solid product of maleic rosin-modified vinyl ether macromonomer, with an esterification rate of 96.34% and a double bond retention rate of 96.58%. Example 6

[0019] A method for modifying vinyl ether macromonomers with maleic rosin, and the specific process steps are as follows: According to the mass ratio of maleic rosin to diethylene glycol mono vinyl polyoxyethylene ether macromonomer of 10:140, add the two raw materials into the reaction kettle, introduce nitrogen to exhaust the air, and react in an oil bath at 140 °C for 5 h under nitrogen protection. After cooling to below 100 °C, add deionized water according to the mass ratio of the reactants to water of 1:2.5, stir to dissolve, and filter to remove the unreacted maleic rosin that is insoluble in water. Concentrate and dry the filtrate below 60 °C to obtain a solid product of maleic rosin-modified vinyl ether macromonomer, with an esterification rate of 95.39% and a double bond retention rate of 93.64%. Example 7

[0020] A method for modifying vinyl ether macromonomers with maleic rosin, and the specific process steps are as follows: Add the two raw materials into a reaction kettle according to the mass ratio of maleic rosin to butanediol mono vinyl polyoxyethylene ether macromonomer of 10:60. Introduce nitrogen to exhaust the air, and react in an oil bath at 145 °C for 3.5 h under nitrogen protection. Then cool it to below 100 °C, add deionized water according to the mass ratio of the reactants to water of 1:2.5, stir to dissolve, and filter to remove the unreacted maleic rosin insoluble in water. Concentrate and dry the filtrate below 60 °C to obtain a solid product of maleic rosin-modified vinyl ether macromonomer, with an esterification rate of 96.48% and a double bond retention rate of 94.45%. Example 8

[0021] A method for modifying vinyl ether macromonomers with maleic rosin, and the specific process steps are as follows: Add the two raw materials into a reaction kettle according to the mass ratio of maleic rosin to butanediol mono vinyl polyoxyethylene ether macromonomer of 10:130. Introduce nitrogen to exhaust the air, and react in an oil bath at 75 °C for 11 h under nitrogen protection. Then cool it to below 100 °C, add deionized water according to the mass ratio of the reactants to water of 1:2.5, stir to dissolve, and filter to remove the unreacted maleic rosin insoluble in water. Concentrate and dry the filtrate below 60 °C to obtain a solid product of maleic rosin-modified vinyl ether macromonomer, with an esterification rate of 95.89% and a double bond retention rate of 96.37%.

Claims

1. A method for modifying vinyl ether macromonomers using maleic rosin, characterized in that: The specific process steps are as follows: adding maleic rosin and vinyl ether macromolecular monomers into a reaction kettle at a mass ratio of 10:50-150, introducing nitrogen to exhaust the air, reacting in an oil bath at 60-150° C. for 3-12 hours under nitrogen protection, cooling to below 100° C., adding deionized water at a mass ratio of 1:2.5 between the reactant and water, stirring to dissolve, filtering to remove the unreacted maleic rosin insoluble in water; concentrating and drying the filtrate at below 60° C. to obtain a solid product of maleic rosin-modified vinyl ether macromolecular monomer.

2. The method of modifying vinyl ether macromonomers using maleated rosin according to claim 1, characterized in that: The vinyl ether macromolecular monomer is any one of ethylene glycol monovinyl polyoxyethylene ether, diethylene glycol monovinyl polyoxyethylene ether, butanediol monovinyl polyoxyethylene ether, or a mixture of any several of them.

3. The method of modifying vinyl ether macromonomers using maleated rosin according to claim 1, characterized in that: If the filtrate obtained after filtration is directly used for synthesizing water reducing agent, it does not need to be concentrated or dried.

4. The modified macromonomer obtained by the method of modifying vinyl ether macromonomer using maleic rosin as claimed in any one of claims 1 to 3.

5. Use of the modified macromolecular monomer as claimed in claim 4 in the synthesis of polycarboxylic acid water-reducing agent.

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