Preparation method of high molecular weight poly (styrene)-co-poly (4-vinylpyridine)

Abstract

The preparation method of the high-molecular-weight poly (styrene)-co-poly (4-vinylpyridine) comprises the following steps: S1, adding deoxygenated deionized water into a container, and adding a dispersing agent while stirring to form an aqueous solution; s2, dropwise adding a toluene solution in which 4-vinylpyridine, styrene and an initiator are fully mixed into the aqueous solution, heating to a polymerization temperature of 60-90 DEG C, and carrying out a heat preservation reaction for 6 hours; and S3, cooling to room temperature, filtering, removing unreacted polymeric monomers, and carrying out vacuum drying at 50 DEG C. The polymer material (PS-co-P4VP) with high adhesive force and quick response is prepared in a suspension polymerization mode, the molecular weight of the polymer material is controllable and adjustable, the content of poly (4-vinylpyridine) and polystyrene in the polymer is highly controllable, and the polymer material has very high industrialization value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polymer synthesis, in particular to a preparation method of high molecular weight poly(styrene)-co-poly(4-vinylpyridine). BACKGROUND

[0002] 4-vinylpyridine (4VP) is a strong polar molecule, which has strong adhesion to metal ions, hydrogen ions and hydrophilic and hydrophobic surfaces. Therefore, 4-vinylpyridine 4VP is widely used in the synthesis and modification of high molecular polymers (Macromolecules, 2019, 52, 1354-1370). At present, high molecular materials containing poly(4-vinylpyridine) P4VP structure have shown their unique performance in the fields of surfactants, synthetic resin coatings, drug carriers and photosensitive resins, such as enhanced mechanical strength, extremely high stability and detection limit (Food Chem., 2020, 2333, 127504; Chem. Res., 2014, 25, 33-36). In particular, poly(4-vinylpyridine) P4VP can be used as a basic ion exchange resin and an ion exchange membrane for the adsorption and separation of trace heavy metal ions, especially the adsorption of radioactive ions in nuclear industry waste, and 4-vinylpyridine has irreplaceable advantages. With the continuous modification of polymer structure and the development and expansion of application scenarios, 4-vinylpyridine related high molecular materials will be more and more widely used in various industries. However, there are few studies on 4-vinylpyridine related resins in the industry, and the development of related applications needs further exploration.

[0003] At present, 4-vinylpyridine related polymers can be prepared by free radical polymerization, anionic polymerization and coordination polymerization. Among them, the free radical polymerization method is the most widely used (Elastomers, 2004, 14, 29-33). Generally, free radical polymerization is divided into bulk polymerization, solution polymerization and suspension polymerization. Due to the characteristics of free radical polymerization itself, the molecular weight of the polymer obtained by ordinary bulk / solution polymerization is generally low, and the molecular weight distribution is wide. High molecular weight polymerization products are often obtained by suspension polymerization: the method of free radical polymerization of monomers dissolved with initiator in the form of droplets suspended in water is called suspension polymerization; water is the continuous phase and monomers are the dispersed phase. Polymerization occurs in each small droplet, and the reaction mechanism is the same as that of bulk polymerization, but due to the reduction of chain transfer reaction, it is easier to synthesize high molecular weight polymerization products. It has the following advantages: (1) low system viscosity, easy to conduct out the polymerization heat; (2) the relative molecular mass and distribution of the product are relatively stable, and the polymerization rate and relative molecular mass are higher than those of other conventional free radical polymerization; (3) simple post-processing, low production cost, and less waste. SUMMARY

[0004] The present application is to obtain a kind of high adhesion, fast response polymer material with wide application scenarios, and aims to provide a kind of preparation method of high molecular weight poly (styrene)-co-poly (4-vinylpyridine), which realizes the random copolymerization of 4-vinylpyridine and styrene by suspension polymerization.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application comprises the following steps:

[0006] S1, in the three-necked flask equipped with mechanical stirring and reflux condenser, add deoxygenated deionized water, under stirring, add dispersant, form aqueous solution;

[0007] S2, under nitrogen protection and rapid stirring, drop the mixed toluene solution fully with 4-vinylpyridine, styrene and a small amount of initiator into the above three-necked flask, after feeding is completed, temperature is raised to polymerization temperature 60-90 DEG C and keeps for 6 hours;

[0008] S3, the reaction liquid is cooled to room temperature and filtered, and a large amount of deionized water is used for washing to remove unreacted polymer monomer, and after vacuum drying at 50 DEG C, the required high molecular weight poly (styrene)-co-poly (4-vinylpyridine) (PS-co-P4VP) is obtained.

[0009] Further, in S1, the dispersant is one or more combinations of hydroxyethyl cellulose, polyvinyl alcohol and sodium carboxymethyl cellulose.

[0010] Further, the concentration of the dispersant is 0.1wt%-1.0wt%, preferably 0.3wt%-0.7wt%.

[0011] Further, after forming the aqueous solution, the temperature is raised to 60 DEG C, and a salting agent is added, and after it is completely dissolved, it is cooled to room temperature. Because low molecular weight 4-vinylpyridine has a slight solubility in water, emulsification phenomenon is easy to occur during synthesis, and a salting agent needs to be added to reduce or prevent the occurrence of emulsification.

[0012] Further, the salting agent is one or more combinations of sodium sulfite, sodium chloride, potassium chloride and sodium sulfate. Further, the amount of the salting agent is 0.5wt%-10wt%, preferably 1.0wt%-3.0wt%.

[0013] Further, in S2, the water-oil ratio of the aqueous solution to the toluene solution is 3:1-20:1, preferably 5:1-10:1. Further, the monomer concentration in the toluene oil phase is 10wt%-80wt%, preferably 40wt%-60wt%.

[0014] Further, the molar ratio of 4-vinylpyridine and styrene is 4:1-15:1, preferably 6:1-10:1, preferably 8:1-9:1.

[0015] Further, the initiator is benzoyl peroxide (BPO) or azobisisobutyronitrile (AIBN); the results of the polymers obtained by the two initiators are similar under the same conditions.

[0016] Further, the amount of the initiator is 0.05wt% to 2.0wt% (relative to the total amount of monomers), preferably 0.1wt% to 0.6wt%.

[0017] Preferably, the polymerization temperature after the completion of feeding is 70 to 85°C, preferably 78 to 85°C.

[0018] Compared with the prior art, the present application adjusts the polarity, responsiveness and microstructure of the obtained polymer by introducing polystyrene (PS) segments, and a high molecular material (PS-co-P4VP) with high adhesion and fast responsiveness is prepared by using the way of suspension polymerization; under the same conditions, the morphology of the polymer is uniform between batches, and the molecular weight error is not more than 5%, and the polymer yield is not less than 80%; the content of poly(4-vinylpyridine) P4VP and polystyrene PS in the obtained polymer is highly controllable, and has high industrialization value. DETAILED DESCRIPTION

[0019] The present application will be further described in combination with specific examples. The method examples of the present application mainly include the following steps:

[0020] S1, adding deoxygenated and deionized water into a three-necked flask equipped with mechanical stirring and reflux condenser, and adding dispersant under stirring to form an aqueous solution;

[0021] S2, under nitrogen protection and rapid stirring, dropping a mixed toluene solution of 4-vinylpyridine, styrene and a small amount of initiator into the above three-necked flask, and after the completion of feeding, heating to a polymerization temperature of 60 to 90°C and keeping for 6 hours;

[0022] S3, cooling the reaction liquid to room temperature and filtering, washing with a large amount of deionized water to remove unreacted polymerization monomers, and drying under vacuum at 50°C to obtain the required PS-co-P4VP polymer product.

[0023] The specific reaction equation is as follows:

[0024]

[0025] The parameters of the polymer prepared by the method of the present application are as follows: 10×10 4 g / mol≤M w ≤70×10 4 g / mol, M w / M n≤ 2.9% ≤ PS content ≤ 11%. Wherein, the molecular weight (M w ) of the polymer is determined by GPC with DMF as the mobile phase, and a PS reference sample is used as the standard curve.

[0026] PS content determination: the polymer is dissolved in deuterated methanol, and the peak area of 8.60-7.75 ppm is 1.0 and the peak area of 7.40-6.10 ppm is y. Then the PS content in the polymer is (y-1) / (y+1.5).

[0027] Example 1:

[0028] A 2000 mL three-necked flask equipped with mechanical stirring and reflux condenser was charged with 1000 mL of deoxygenated and deionized water, and 5 g of polyvinyl alcohol was added under stirring to prepare a 0.5% aqueous solution. The temperature was raised to 60°C, and 10 g of sodium chloride was added. After complete dissolution, the temperature was lowered to room temperature.

[0029] Then 89 g of 4-vinylpyridine 4VP, 11 g of styrene St, and 0.2 g of azobisisobutyronitrile AIBN were dissolved in 120 mL of toluene. Under nitrogen protection and rapid stirring, the above-mentioned toluene solution was added dropwise into the three-necked flask. After the dropwise addition was completed, the system was heated to 80°C and reacted for 6 hours. The reaction solution was cooled to room temperature, filtered, and the polymer was washed with a large amount of distilled water to remove unreacted polymerization monomers. After vacuum drying at 50°C, the desired PS-co-P4VP polymer product (91.5 g, yield 91.5%) was obtained.

[0030] The molecular weight of the obtained copolymer was verified by GPC and nuclear magnetic resonance to be M w 62.3 x 10 4 g / mol, M w / M n = 1.79, and the PS content was 11.0%.

[0031] Example 2:

[0032] A 2000 mL three-necked flask equipped with mechanical stirring and reflux condenser was charged with 1000 mL of deoxygenated and deionized water, and 5 g of polyvinyl alcohol was added under stirring to prepare a 0.5% aqueous solution. The temperature was raised to 60°C, and 10 g of sodium chloride was added. After complete dissolution, the temperature was lowered to room temperature.

[0033] Subsequently, 88 g of 4-vinylpyridine 4VP, 12 g of styrene St and 0.35 g of azobisisobutyronitrile AIBN were dissolved in 120 mL of toluene. The mixed solution was added dropwise into a three-neck flask under nitrogen protection and rapid stirring. After the dropwise addition was completed, the system was heated to 80°C and kept for 6 hours. The reaction solution was cooled to room temperature, filtered, and the polymer was washed with a large amount of distilled water to remove unreacted polymerized monomers. After vacuum drying at 50°C, the desired PS-co-P4VP polymer product (87.1 g, yield 87.1%) was obtained.

[0034] The molecular weight of the obtained copolymer was verified by GPC and nuclear magnetic resonance to be M w 33.6×10 4 g / mol, M w / M n = 1.64, and the PS content was 10.7%.

[0035] Example 3:

[0036] A 2000 mL three-neck flask equipped with mechanical stirring and reflux condenser was charged with 1000 mL of deoxygenated deionized water, and 6 g of polyvinyl alcohol was added under stirring to prepare a 0.6% aqueous solution. The temperature was raised to 60°C, and 20 g of sodium chloride was added. After it was completely dissolved, the temperature was cooled to room temperature.

[0037] Subsequently, 90 g of 4-vinylpyridine 4VP, 10 g of styrene St and 0.45 g of azobisisobutyronitrile AIBN were dissolved in 120 mL of toluene. The mixed solution was added dropwise into a three-neck flask under nitrogen protection and rapid stirring. After the dropwise addition was completed, the system was heated to 80°C and kept for 6 hours. The reaction solution was cooled to room temperature, filtered, and the polymer was washed with a large amount of distilled water to remove unreacted polymerized monomers. After vacuum drying at 50°C, the desired PS-co-P4VP polymer product (94.3 g, yield 94.3%) was obtained.

[0038] The molecular weight of the obtained copolymer was verified by GPC and nuclear magnetic resonance to be M w 21.7×10 4 g / mol, M w / M n = 1.59, and the PS content was 10.7%.

[0039] Example 4:

[0040] A 2000 mL three-neck flask equipped with mechanical stirring and reflux condenser was charged with 1000 mL of deoxygenated deionized water, and 5 g of polyvinyl alcohol was added under stirring to prepare a 0.5% aqueous solution. The temperature was raised to 60°C, and 15 g of sodium sulfite was added. After it was completely dissolved, the temperature was cooled to room temperature.

[0041] Subsequently, 80 g of 4-vinylpyridine 4VP, 9.5 g of styrene St and 0.3 g of azobisisobutyronitrile AIBN were dissolved into 100 mL of toluene. The mixed solution was added dropwise into a three-neck flask under nitrogen protection and rapid stirring. After the dropwise addition was completed, the system was heated to 80°C and kept for 6 hours. The reaction solution was cooled to room temperature, filtered, and the polymer was washed with a large amount of distilled water to remove unreacted polymerized monomers. After vacuum drying at 50°C, the desired PS-co-P4VP polymer product (81.2 g, yield 81.2%) was obtained.

[0042] The molecular weight of the obtained copolymer was verified by GPC and nuclear magnetic resonance to be M w 30.2×10 4 g / mol, M w / M n = 1.88, and the PS content was 10.4%.

[0043] Example 5:

[0044] In a 2000 mL three-neck flask equipped with mechanical stirring and reflux condenser, 1000 mL of deoxygenated deionized water was added, and 6 g of hydroxyethyl cellulose was added under stirring to prepare a 0.6% aqueous solution. The temperature was raised to 60°C, and 10 g of sodium chloride was added. After it was completely dissolved, it was cooled to room temperature.

[0045] Subsequently, 89 g of 4-vinylpyridine 4VP, 11 g of styrene St and 0.3 g of benzoyl peroxide BPO were dissolved into 120 mL of toluene. The mixed solution was added dropwise into a three-neck flask under nitrogen protection and rapid stirring. After the dropwise addition was completed, the system was heated to 80°C and kept for 6 hours. The reaction solution was cooled to room temperature, filtered, and the polymer was washed with a large amount of distilled water to remove unreacted polymerized monomers. After vacuum drying at 50°C, the desired PS-co-P4VP polymer product (89.5 g, yield 89.5%) was obtained. The molecular weight of the obtained copolymer was verified by GPC and nuclear magnetic resonance to be M w 59.5×10 4 g / mol, M w / M n = 1.80, and the PS content was 10.7%.

[0046] Example 6:

[0047] In a 2000 mL three-neck flask equipped with mechanical stirring and reflux condenser, 1000 mL of deoxygenated deionized water was added, and 6 g of polyvinyl alcohol was added under stirring to prepare a 0.6% aqueous solution. The temperature was raised to 60°C, and 10 g of sodium chloride was added. After it was completely dissolved, it was cooled to room temperature.

[0048] Subsequently, 80 g of 4-vinylpyridine 4VP, 9.5 g of styrene St and 0.7 g of azobisisobutyronitrile AIBN were dissolved into 120 mL of toluene. Under nitrogen protection and rapid stirring, the above-mentioned toluene solution was added dropwise into a three-necked flask. After the dropwise addition was completed, the system was heated to 85°C and incubated for 6 hours. The reaction liquid was cooled to room temperature, filtered, and the polymer was washed with a large amount of distilled water to remove unreacted polymerized monomers, and then dried in vacuum at 50°C to obtain the desired PS-co-P4VP polymer product (86.3 g, yield 86.3%).

[0049] The molecular weight of the obtained copolymer was M w 13.2×10 4 g / mol, M w / M n = 1.60, and the PS content was 10.4%.

[0050] The present application adjusts the polarity, responsiveness and microstructure of the obtained polymer by introducing polystyrene (PS) segments, and prepares a high molecular material (PS-co-P4VP) with high adhesion and fast responsiveness. The prepared high molecular weight PS-co-P4VP can be widely used in targeted medical treatment (pH-responsive micelles), electronic materials (nano-patterned devices) and intelligent materials (probe and electrode modification), etc., and has high industrialization value.

Claims

1. A method for preparing high molecular weight poly(styrene)-co-poly(4-vinylpyridine), characterized in that: S1, add deoxygenated deionized water to a container, and add dispersant while stirring to form an aqueous solution; S2, a toluene solution containing 4-vinylpyridine, styrene and initiator is added dropwise to the above aqueous solution. After the addition is complete, the temperature is raised to the polymerization temperature of 60-90°C and the reaction is maintained for 6 hours. S3. Cool the reaction solution to room temperature and filter it. Wash it to remove unreacted monomers and dry it under vacuum at 50°C to obtain the desired product.

2. The method according to claim 1, characterized in that: In S1, the dispersant is one or more combinations of hydroxyethyl cellulose, polyvinyl alcohol, and sodium carboxymethyl cellulose. And / or, the concentration of the dispersant is 0.1 wt% to 1.0 wt%, or 0.3 wt% to 0.7 wt%.

3. The method according to claim 1, characterized in that: In S1, after forming an aqueous solution, the temperature is raised to 60°C, a salting-out agent is added, and after it is completely dissolved, it is cooled to room temperature. And / or, the salting-out agent is one or more combinations of sodium sulfite, sodium chloride, potassium chloride, and sodium sulfate; And / or, the amount of salting-out agent used is 0.5wt% to 10wt%, or 1.0wt% to 3.0wt%.

4. The method according to claim 1, characterized in that: In S2, the water-to-oil ratio of the aqueous solution to the toluene solution is 3:1 to 20:1, or 5:1 to 10:

1.

5. The method according to claim 1 or 4, characterized in that: The monomer concentration in the toluene oil phase is 10 wt% to 80 wt%, or 40 wt% to 60 wt%.

6. The method according to claim 1, characterized in that: In S2, the molar ratio of 4-vinylpyridine to styrene is 4:1 to 15:1, or 6:1 to 10:1, or 8:1 to 9:

1.

7. The method according to claim 1, characterized in that: In S2, the initiator is benzoyl peroxide or azobisisobutyronitrile; And / or, the amount of initiator relative to the total amount of monomer is 0.05wt% to 2.0wt%, or 0.1wt% to 0.6wt%.

8. The method according to claim 1, characterized in that: In S2, the polymerization temperature after feeding is 70-85℃ or 78-85℃.

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