Disclosure of Invention
In view of the above, the technical problem to be solved by the present invention is to provide a synthesis method of water-soluble imidazoline, which does not require xylene or toluene or other water-carrying agents, has good environmental protection performance, is simple in preparation process, has good controllability and stability, and is more suitable for popularization and application of large-scale production.
The invention provides a synthetic method of water-soluble imidazoline, which comprises the following steps:
1) under the condition of continuously introducing gas, reacting lauric acid, diethylenetriamine and boric acid, and then heating for continuous reaction to obtain oil-soluble imidazoline;
2) and mixing the oil-soluble imidazoline obtained in the step with isopropanol, adding dimethyl phosphite for reacting again to obtain the water-soluble imidazoline.
Preferably, the gas comprises nitrogen and/or an inert gas;
the flow rate of the introduced gas is 0.4-0.6L/min.
Preferably, the gas is introduced by introducing gas from a liquid phase;
the molar ratio of the lauric acid to the diethylenetriamine is 1: (1-2).
Preferably, the mass ratio of the lauric acid to the boric acid is 1: (0.05-0.1).
Preferably, the reaction temperature is 150-160 ℃;
the reaction time is 2-5 h.
Preferably, the temperature rise is 215-225 ℃;
the continuous reaction time is 1-3 h.
Preferably, the mass ratio of the oil-soluble imidazoline to the isopropanol is 1: (1.5-2).
Preferably, the molar ratio of the oil-soluble imidazoline to the dimethyl phosphite is 1: (1.2-1.8).
Preferably, the temperature of the secondary reaction is 60-70 ℃;
the time for the secondary reaction is 1-2 h.
Preferably, the step 1) does not contain a water-carrying agent;
the re-reaction mode comprises condensation reflux reaction.
The invention provides a synthetic method of water-soluble imidazoline, which comprises the following steps of firstly, reacting lauric acid, diethylenetriamine and boric acid under the condition of continuously introducing gas, and then heating for continuous reaction to obtain oil-soluble imidazoline; and then mixing the oil-soluble imidazoline obtained in the step with isopropanol, adding dimethyl phosphite for reacting again to obtain the water-soluble imidazoline. Compared with the prior art, the synthesis method provided by the invention does not need xylene or toluene or other water-carrying agents, has good environmental protection property and high greening degree, and better conforms to the current production process concept of green sustainable development; and has higher slow release rate in subsequent application; meanwhile, the preparation process is simple, has better controllability and stability, and is more suitable for popularization and application of large-scale production.
Experimental results show that the synthetic method of the water-soluble imidazoline does not need benzene and other water-carrying agents, and the slow release rate of the synthesized corrosion inhibitor is higher than that of a commercially available corrosion inhibitor.
Detailed Description
For a further understanding of the invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are included only to further illustrate the features and advantages of the invention and not to limit the claims of the invention.
All of the starting materials of the present invention, without particular limitation as to their source, may be purchased commercially or prepared according to conventional methods well known to those skilled in the art.
All the raw materials of the present invention are not particularly limited in purity, and the present invention preferably employs industrial purity or purity which is conventional in the field of preparation of water-soluble imidazoline.
All the noun expressions and acronyms of the invention belong to the conventional noun expressions and acronyms in the field, each noun expression and acronym is clearly and definitely clear in the relevant application field, and a person skilled in the art can clearly, exactly and uniquely understand the noun expressions and acronyms.
The invention provides a synthetic method of water-soluble imidazoline, which comprises the following steps:
1) under the condition of continuously introducing gas, reacting lauric acid, diethylenetriamine and boric acid, and then heating for continuous reaction to obtain oil-soluble imidazoline;
2) and mixing the oil-soluble imidazoline obtained in the step with isopropanol, adding dimethyl phosphite for reacting again to obtain the water-soluble imidazoline.
According to the invention, under the condition of continuously introducing gas, lauric acid, diethylenetriamine and boric acid are reacted, and then the temperature is raised for continuous reaction, so that oil-soluble imidazoline is obtained.
In the present invention, the gas preferably comprises nitrogen and/or an inert gas, more preferably nitrogen or an inert gas such as argon.
In the invention, the flow rate of the introduced gas is preferably 0.4-0.6L/min, more preferably 0.44-0.58L/min, and more preferably 0.48-0.52L/min.
In the present invention, the means for introducing gas preferably includes introducing gas from a liquid phase.
In the present invention, the molar ratio of lauric acid to diethylenetriamine is preferably 1: (1-2), more preferably 1: (1.2 to 1.8), more preferably 1: (1.4-1.6).
In the present invention, the mass ratio of lauric acid to boric acid is preferably 1: (0.05 to 0.1), more preferably 1: (0.06-0.09), more preferably 1: (0.07-0.08).
In the invention, the reaction temperature is preferably 150-160 ℃, more preferably 152-158 ℃, and more preferably 154-156 ℃.
In the invention, the reaction time is preferably 2-5 h, more preferably 2.5-4.5 h, and more preferably 3-4 h.
In the invention, the temperature of the temperature rise (i.e. the temperature of the continuous reaction) is preferably 215-225 ℃, more preferably 217-223 ℃, and more preferably 219-221 ℃.
In the invention, the continuous reaction time is preferably 1-3 h, more preferably 1.8-2.8 h, more preferably 1.5-2.5 h, and more preferably 1.8-2.3 h.
According to the invention, the oil-soluble imidazoline obtained in the above steps is mixed with isopropanol, and then dimethyl phosphite is added for reaction again to obtain water-soluble imidazoline.
In the present invention, the mass ratio of the oil-soluble imidazoline to the isopropanol is preferably 1:
(1.5-2), more preferably 1: (1.6-1.9), more preferably 1: (1.7-1.8).
In the present invention, the molar ratio of the oil-soluble imidazoline to the dimethyl phosphite is preferably 1: (1.2 to 1.8), more preferably 1: (1.3 to 1.7), more preferably 1: (1.4-1.6).
In the invention, the temperature of the secondary reaction is preferably 60-70 ℃, more preferably 62-68 ℃, and more preferably 64-66 ℃.
In the invention, the time for the secondary reaction is preferably 1 to 2 hours, more preferably 1.2 to 1.8 hours, and more preferably 1.4 to 1.6 hours.
In the present invention, particularly, the step 1) preferably does not contain a water-carrying agent, more preferably does not contain a benzene-based water-carrying agent, and specifically may be a toluene or xylene-based water-carrying agent.
In the present invention, the manner of the re-reaction preferably includes a condensation reflux reaction.
The invention is a complete and refined integral preparation process, better ensures the slow release rate of the product in subsequent application, and the specific steps of the synthesis method of the water-soluble imidazoline can be as follows:
1. synthesis of imidazolines
Adding lauric acid, diethylenetriamine and boric acid serving as a catalyst into a four-neck flask with a thermometer and a stirring device, introducing nitrogen, controlling the reaction temperature at 150-160 ℃, reacting for 2-5 hours, heating to 215-225 ℃, and reacting for 1-3 hours to obtain the oil-soluble imidazoline.
2. Synthesis of imidazoline quaternary ammonium salt
Sequentially adding imidazoline and isopropanol into a four-neck flask with a thermometer, a stirrer and a condenser, adding dimethyl phosphite after the imidazoline is dissolved, reacting at the temperature of 60-70 ℃ for 1-2 h, and obtaining the water-soluble imidazoline.
The invention provides a synthetic method of water-soluble imidazoline through the steps. According to the invention, specific reaction raw materials and catalysts are adopted, and an optimized proportion is combined, and a water-carrying mode of introducing nitrogen gas into a liquid phase is adopted, so that water-soluble imidazoline is obtained in a shorter total reaction time, and the traditional water-carrying agents such as dimethylbenzene or methylbenzene are not needed, so that the environment-friendly performance is good, the green degree is high, and the production process concept of the current green sustainable development is more met; and has higher slow release rate in subsequent application; meanwhile, the preparation process is simple, has better controllability and stability, and is more suitable for popularization and application of large-scale production.
Experimental results show that the synthetic method of the water-soluble imidazoline does not need benzene and other water-carrying agents, and the slow release rate of the synthesized corrosion inhibitor is higher than that of a commercially available corrosion inhibitor.
For further illustration of the present invention, the following will describe in detail a method for synthesizing water-soluble imidazoline according to the present invention with reference to the following examples, but it should be understood that these examples are carried out on the premise of the technical solution of the present invention, and the detailed embodiments and specific procedures are given, only for further illustration of the features and advantages of the present invention, not for limitation of the claims of the present invention, and the scope of the present invention is not limited to the following examples.
Example 1
Adding 100g of lauric acid, 61.8g of diethylenetriamine and 8g of boric acid into a 500mL four-neck flask with a thermometer and a stirring device, introducing nitrogen into a liquid phase, controlling the reaction temperature at 150-160 ℃, reacting for 3h, heating to 220 ℃, and reacting for 2h to obtain the oil-soluble imidazoline.
And (2) sequentially adding 133.5g of imidazoline and 200.25g of isopropanol into a four-neck flask with a thermometer, a stirrer and a condensing tube, after the imidazoline is dissolved, adding 55g of dimethyl phosphite, reacting at the temperature of 60-70 ℃ for 2 hours to obtain water-soluble imidazoline # 1.
In the process: the molar ratio of the lauric acid to the diethylenetriamine is 1:1.2, and the molar ratio of the oil-soluble imidacloprid to the dimethyl phosphite is 1: 1.2.
Example 2
Adding 100g of lauric acid, 72.1g of diethylenetriamine and 6g of boric acid into a 500mL four-neck flask with a thermometer, a condensing device and a stirring device, introducing nitrogen into a liquid phase, controlling the reaction temperature at 150-160 ℃, reacting for 3h, then heating to 220 ℃, and reacting for 2.5h to obtain the oil-soluble imidazoline.
160.2g of imidazoline and 272.34g of isopropanol are sequentially added into a four-neck flask with a thermometer, a stirrer, a condenser pipe and a water separator, 92.4g of dimethyl phosphite is added after the imidazoline is dissolved, the reaction temperature is 60-70 ℃, and the reaction is carried out for 2 hours to obtain water-soluble imidazoline # 2.
In the process: the molar ratio of the lauric acid to the diethylenetriamine is 1:1.4, and the molar ratio of the oil-soluble imidacloprid to the dimethyl phosphite is 1: 1.4.
Example 3
Adding 140g of lauric acid, 120.96g of diethylenetriamine and 11.2g of boric acid into a 500mL four-neck flask with a thermometer and a stirring device, introducing nitrogen into a liquid phase, controlling the reaction temperature at 150-160 ℃, reacting for 4.5h, then heating to 220 ℃, and reacting for 3h to obtain the oil-soluble imidazoline.
And (2) sequentially adding 133.5g of imidazoline and 226.95g of isopropanol into a four-neck flask with a thermometer, a stirrer, a condensation pipe and a water separator, adding 88g of dimethyl phosphite after the imidazoline is dissolved, reacting at the temperature of 60-70 ℃ for 2 hours, and obtaining the water-soluble imidazoline # 3.
In the process: the molar ratio of the lauric acid to the diethylenetriamine is 1:1.6, and the molar ratio of the oil-soluble imidacloprid to the dimethyl phosphite is 1: 1.6.
Example 4
Adding 80g of lauric acid, 77.76g of diethylenetriamine and 4g of boric acid into a 500mL four-neck flask with a thermometer and a stirring device, introducing nitrogen into a liquid phase, controlling the reaction temperature at 150-160 ℃, reacting for 2h, heating to 220 ℃, and reacting for 2h to obtain the oil-soluble imidazoline.
106.8g of imidazoline and 202.92g of isopropanol are sequentially added into a four-neck flask with a thermometer, a stirrer and a condenser, 79.2g of dimethyl phosphite is added after the imidazoline is dissolved, the reaction temperature is 60-70 ℃, and the reaction is carried out for 2 hours, so that the water-soluble imidazoline # 4 is obtained.
In the process: the molar ratio of the lauric acid to the diethylenetriamine is 1:1.8, and the molar ratio of the oil-soluble imidacloprid to the dimethyl phosphite is 1: 1.8.
Evaluation of sustained Release Performance
Taking the synthesized water-soluble imidazole line, dissolving with distilled water to prepare corrosion inhibition liquid with the concentration of 100 mg/L; 1000mg/L HCl-1000mg/L H is prepared2And S is corrosive liquid.
And testing by adopting a static hanging piece weight loss method. Placing the treated hanging pieces in flasks respectively, adding corrosive liquid into the flasks, sealing and standing, finally placing the beakers in water baths at 90 +/-2 ℃, refluxing and condensing for 6 hours, taking out test pieces, weighing after cleaning and drying, and calculating the corrosion inhibition rate according to the mass loss of the test pieces.
The slow release rate calculation formula is as follows: eta [ (. DELTA.m) ]0-△m1)/△m0]×100%。
Referring to table 1, table 1 shows the sustained release performance of the water-soluble imidazoline prepared according to the example of the present invention.
TABLE 1
Corrosion inhibitor
|
1#
|
2#
|
3#
|
4#
|
Commercially available corrosion inhibitors
|
Sustained release rate (%)
|
93
|
97
|
95
|
94
|
87 |
As can be seen from table 1, the molar ratio of the oil-soluble imidazoline to the dimethyl phosphite is 1: when 1.4 hours, the slow release rate is highest, and the slow release rate of the synthesized corrosion inhibitor is higher than that of the corrosion inhibitor sold on the market
The foregoing has outlined, in detail, the principles and embodiments of the present invention using specific examples that are set forth herein to provide an understanding of the principles of the invention and its core, including the best mode, and to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.