Sulfonate type hydrophilic chain extender and preparation method thereof

Abstract

The invention discloses a sulfonate type hydrophilic chain extender and a preparation method thereof, and the preparation method comprises the following steps: adding a 3-mercapto-1-sodium propane sulfonate aqueous solution and a certain amount of a catalyst N, N-dimethylaniline into a reaction container, and slowly heating and stirring; and after the temperature reaches a set value, adding Z / E-1, 4-butylene glycol into the reactor. In the constant-temperature reaction process, taking samples once at set intervals, titrating the taken samples with an iodine standard solution to measure the content of double bonds in the system, and stopping the reaction until the content of the double bonds is basically unchanged. And after the reaction is finished, carrying out suction filtration on the residual solution in the reaction system to obtain a solid, washing with absolute ethyl alcohol, drying, and weighing to obtain the sulfonate type hydrophilic chain extender. The sulfonic acid type chain extender prepared by the invention is higher in ionization degree, better in thermal stability, more in variety and stronger in hydrophilicity, so that when polyurethane with equivalent hydrophilicity is prepared, the molar weight of the sulfonic acid type chain extender is less than that of carboxylic acid groups, and the viscosity rise is reduced by slowing down the hydration volume increase rate; the preparation of the high-solid-content waterborne polyurethane is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of hydrophilic chain extenders, and in particular to a sulfonate type hydrophilic chain extender and a preparation method thereof. Background Art

[0002] Waterborne polyurethane has a broad application market and great development prospects in the fields of coatings, adhesives and foams. However, the solid content of waterborne polyurethane is low, and its application and transportation costs are too high, which has caused huge cost pressure on enterprises and limited its large-scale application. Chain extenders are an important component of the hard segment of polyurethane. Sulfonic acid-type hydrophilic chain extenders can significantly increase the solid content of waterborne polyurethane, reduce the cost of enterprises, and make the application of waterborne polyester more extensive. Summary of the invention

[0003] The invention adopts the principle of thiol click chemistry (this principle has certain similarities with thiol-ene reaction) and utilizes the addition reaction of thiol and double bond to link the monomer Z / E-1,4-butenediol with hydroxyl group and sodium 3-mercapto-1-propane sulfonate with sulfonic acid group to generate sulfonic acid type hydrophilic chain extender, so as to increase the solid content of waterborne polyurethane synthesized by using the sulfo group as raw material, realize cost reduction, increase its economic value and make its application more extensive.

[0004] In order to achieve the purpose of the present invention, the specific technical scheme of the present invention is as follows:

[0005] A sulfonate type hydrophilic chain extender, and a preparation method thereof:

[0006] (1) The reaction vessel includes a thermometer, a condenser, and a magnetic stirring device. An aqueous solution of sodium 3-mercapto-1-propane sulfonate and a certain amount of catalyst are added to the reaction vessel, and the temperature is slowly raised and stirred.

[0007] (2) After the temperature reaches the set value, add Z / E-1,4-butenediol to the reactor. Take samples at regular intervals and titrate the samples with iodine standard solution to determine the double bonds. The reaction is terminated when the double bond content remains essentially unchanged.

[0008] (3) After the reaction is completed, the remaining solution in the reaction system is filtered to obtain a solid, which is washed with anhydrous ethanol, dried, and weighed to obtain the total mass of the solid.

[0009] Furthermore, the sodium 3-mercapto-1-propane sulfonate aqueous solution in step (1) is prepared by the following method:

[0010] By weight, 9.09 parts of sodium 3-mercapto-1-propane sulfonate and 43.28 to 62.38 parts of water are mixed to obtain an aqueous solution of sodium 3-mercapto-1-propane sulfonate for later use.

[0011] Furthermore, the catalyst in step (1) is N,N-dimethylaniline; and the magnetic stirring speed is 500 r / min.

[0012] Furthermore, in step (1), the sodium 3-mercapto-1-propane sulfonate aqueous solution is 52.37 to 71.47 parts by weight, and the catalyst is 0.28 to 0.4 parts by weight.

[0013] Furthermore, the temperature setting value in step (2) is 75°C.

[0014] Furthermore, in step (2), the Z / E-1,4-butenediol is 4.42 to 8.84 parts by weight.

[0015] The invention also discloses a sulfonate type hydrophilic chain extender prepared according to any one of the above preparation methods.

[0016] The reaction equation involved in the present invention is:

[0017]

[0018] The inventive principle of the present invention is:

[0019] The invention uses Z / E-1,4-butenediol and sodium 3-mercapto-1-propane sulfonate as main raw materials and synthesizes a novel sulfonate type hydrophilic chain extender through addition reaction with double bonds.

[0020] The thiol group in sodium 3-mercapto-1-propane sulfonate is deprotonated by N,N-dimethylaniline, and the H + It temporarily combines with N,N-dimethylaniline to form a conjugate acid, and the thiol salt intermediate that loses proton attacks the double bond in Z / E-1,4-butenediol to produce an anionic intermediate, which then reacts with the previous conjugate acid to obtain the target product.

[0021] The beneficial effects of the present invention are:

[0022] Compared with carboxylic acid chain extenders, sulfonic acid chain extenders have higher degree of ionization, better thermal stability, more types, and stronger hydrophilicity. Therefore, when preparing polyurethanes with equivalent hydrophilicity, the molar amount of sulfonic acid chain extenders used will be less than that of carboxylic acid groups, which slows down the rate of increase in hydration volume to reduce the increase in viscosity, which is beneficial to the preparation of high-solid content water-based polyurethanes, achieves cost reduction, increases its economic value, and makes it more widely used.

[0023] In order to check the progress of the reaction, the extent of the reaction is determined by measuring the change in the double bond content in the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the infrared spectrum of sodium 3-mercapto-1-propane sulfonate;

[0025] Figure 2 is the infrared spectrum of Z / E-1,4-butenediol;

[0026] Figure 3 This is the infrared spectrum of sulfonate type hydrophilic chain extender;

[0027] Figure 4 This is the TG diagram of the initial product sulfonate type hydrophilic chain extender. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If no specific conditions are specified in the embodiments or examples, the conventional conditions or the conditions recommended by the manufacturer are followed. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0029] Example 1

[0030] A sulfonate type hydrophilic chain extender and preparation method thereof

[0031] Each raw material is mixed according to the following mass proportions:

[0032] Sodium 3-mercapto-1-propanesulfonate: 9.09 g;

[0033] N,N-dimethylaniline: 0.28g;

[0034] Z / E-1,4-butenediol: 4.42 g;

[0035] Water: 43.28 g;

[0036] (1) A reaction vessel including a thermometer, a condenser, and a magnetic stirring device is added to the reaction vessel. A sodium 3-mercapto-1-propane sulfonate aqueous solution (prepared by mixing sodium 3-mercapto-1-propane sulfonate and water) and 0.28 g of a catalyst N,N-dimethylaniline are added to the reaction vessel. A rotor is added to the three-necked flask, the temperature is slowly raised to 75° C., the magnetic stirring is turned on, and the speed is set to 500 r / min.

[0037] (2) After the temperature reaches the set value, add 4.42 g of Z / E-1,4-butenediol into the reactor. Take samples at regular intervals and titrate them with iodine standard solution to determine the double bond content of the system. When the double bond content remains basically unchanged, stop the reaction.

[0038] (3) After the reaction is completed, the remaining solution in the reaction system is filtered to obtain a solid, which is washed with anhydrous ethanol, dried, and weighed to obtain a sulfonate-type hydrophilic chain extender.

[0039] Example 2

[0040] A sulfonate type hydrophilic chain extender and preparation method thereof

[0041] Each raw material is mixed according to the following mass proportions:

[0042] Sodium 3-mercapto-1-propanesulfonate: 9.09 g;

[0043] N,N-dimethylaniline: 0.33g;

[0044] Z / E-1,4-butenediol: 6.188 g;

[0045] Water: 49.22 g;

[0046] (1) A reaction vessel including a thermometer, a condenser, and a magnetic stirring device is added to the reaction vessel. A sodium 3-mercapto-1-propane sulfonate aqueous solution (prepared by mixing sodium 3-mercapto-1-propane sulfonate and water) and 0.33 g of a catalyst N,N-dimethylaniline are added to the reaction vessel. A rotor is added to the three-necked flask, the temperature is slowly raised to 75° C., the magnetic stirring is turned on, and the speed is set to 500 r / min.

[0047] (2) After the temperature reaches the set value, add 6.188 g of Z / E-1,4-butenediol into the reactor. Take samples at regular intervals and titrate them with iodine standard solution to determine the double bond content of the system. When the double bond content remains basically unchanged, stop the reaction.

[0048] (3) After the reaction is completed, the remaining solution in the reaction system is filtered to obtain a solid, which is washed with anhydrous ethanol, dried, and weighed to obtain a sulfonate-type hydrophilic chain extender.

[0049] Example 3

[0050] A sulfonate type hydrophilic chain extender and preparation method thereof

[0051] Each raw material is mixed according to the following mass proportions:

[0052] Sodium 3-mercapto-1-propanesulfonate: 9.09 g;

[0053] N,N-dimethylaniline: 0.4g;

[0054] Z / E-1,4-butenediol: 8.84 g;

[0055] Water: 62.38 g;

[0056] (1) A reaction vessel including a thermometer, a condenser, and a magnetic stirring device is added to the reaction vessel. A sodium 3-mercapto-1-propane sulfonate aqueous solution (prepared by mixing sodium 3-mercapto-1-propane sulfonate and water) and 0.4 g of a catalyst N,N-dimethylaniline are added to the reaction vessel. A rotor is added to the three-necked flask, the temperature is slowly raised to 75° C., the magnetic stirring is turned on, and the speed is set to 500 r / min.

[0057] (2) After the temperature reaches the set value, add 8.84 g of Z / E-1,4-butenediol into the reactor. Take samples at regular intervals and titrate them with iodine standard solution to determine the double bond content of the system. When the double bond content remains basically unchanged, stop the reaction.

[0058] (3) After the reaction is completed, the remaining solution in the reaction system is filtered to obtain a solid, which is washed with anhydrous ethanol, dried, and weighed to obtain a sulfonate-type hydrophilic chain extender.

[0059] Test Example 1

[0060] Sulfonate type hydrophilic chain extender experimental data:

[0061] The raw materials Z / E-1,4-butenediol, sodium 3-mercapto-1-propane sulfonate, and preliminary products of the reaction were detected by infrared spectrometer. The presence of special functional groups was determined based on the peaks in the substances. Conclusions were drawn after analysis and summary. Figure 1 , Figure 2 , Figure 3 shown.

[0062] Depend on Figure 1 It can be seen that in the infrared spectrum of the raw material mercaptosulfonate, 2555cm -1 The peak at 1196 cm -1 , 1062cm -1 , 620cm -1 , 530cm -1 The peaks of etc. are characteristic peaks of sulfonic acid groups. Figure 2 It can be seen that in the infrared spectrum of the raw material butene diol, 3383 cm -1 The peak at 1658 cm is the hydroxyl functional group. -1 is the characteristic peak of double bond. Figure 3 It can be seen that in the infrared spectrum of the product, 2555cm -1 The characteristic peaks of thiol at 1658 cm -1 The double bond characteristic peak has disappeared, and the peak at 3200-3700cm -1 The characteristic peak of hydroxyl groups appears in the range 500-1200cm -1The characteristic peak of sulfonic acid group appeared in the interval. In summary, it can be preliminarily judged that the thiol in the mercaptosulfonate reacted with the double bond in the butene glycol to obtain the target product, and the reaction was relatively complete.

[0063] Depend on Figure 4 It can be seen that: through observation and analysis, several relatively obvious peaks are obtained. The first two peaks are within the range of 100°C and the peak area is relatively small, which may be caused by residual ethanol in the product during washing and residual water that is not completely dried; there is a peak at 230°C, but the peak area is small. Combined with the melting point of the raw salt is about 220°C, it is preliminarily judged that it may be caused by residual sodium 3-mercapto-1-propane sulfonate; a peak with a large height and width appears at about 300°C, and this peak may be caused by the product sulfonate type hydrophilic chain extender.

[0064] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A method for preparing a sulfonate type hydrophilic chain extender, comprising: (1) adding an aqueous solution of sodium 3-mercapto-1-propane sulfonate and a catalyst to a reaction container, slowly heating and magnetically stirring to obtain a first intermediate substance; (2) After the temperature reaches the set value, Z / E-1,4-butenediol is added to the first intermediate material, samples are taken regularly, and the samples are titrated with an iodine standard solution to determine the double bond content of the system until the double bond content remains substantially unchanged, and then the reaction is stopped; (3) After the reaction is completed, the remaining solution in the reaction system is filtered to obtain a solid, which is washed with anhydrous ethanol and dried to obtain a sulfonate-type hydrophilic chain extender.

2. The preparation method according to claim 1, wherein: The sodium 3-mercapto-1-propane sulfonate aqueous solution in step (1) is prepared by the following method: By weight, 9.09 parts of sodium 3-mercapto-1-propane sulfonate and 43.28 to 62.38 parts of water are mixed to obtain an aqueous solution of sodium 3-mercapto-1-propane sulfonate for later use.

3. The preparation method according to claim 1, wherein: The catalyst in step (1) is N,N-dimethylaniline; The magnetic stirring speed is 500 r / min.

4. The preparation method according to claim 1, wherein: In step (1), the sodium 3-mercapto-1-propane sulfonate aqueous solution is 52.37 to 71.47 parts by weight, and the catalyst is 0.28 to 0.4 parts by weight.

5. The preparation method according to claim 1, wherein: The temperature setting value of step (2) is 75°C.

6. The preparation method according to claim 1, wherein: The Z / E-1,4-butenediol in step (2) is 4.42 to 8.84 parts by weight.

7. A sulfonate type hydrophilic chain extender prepared according to the preparation method according to any one of claims 1 to 6.

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