A method for polymerizing and preparing a polystyrene derivative

Abstract

The present invention discloses a method for polymerizing a polystyrene derivative, belonging to the technical field of polymers and their preparation; Pd(II) ((L1)Pd(OAc) 2 ) is used as the metal center, combined with the Brookhart diamine ligand, namely ligand L1, and polymerization is carried out in the presence of trifluoroacetic acid; in the Pd(II) system, the presence of hydroquinone is beneficial to the progress of the polymerization reaction, improving the polymer yield, and in the Pd(II) system, by adjusting the coordination environment of the metal, Pd(II) acts as a Lewis acid to promote the cationic polymerization initiated by trifluoroacetic acid. The polymerization method of the present invention has the advantages of simple synthesis, weak sensitivity to air and water, high yield, high catalytic activity for olefin polymerization, low oxygen affinity and high tolerance to polar monomers.

Description

Technical Field

[0001] The invention belongs to the technical field of polymers and their preparation, and specifically relates to a polymerization preparation method of a polystyrene derivative. Background Art

[0002] In 1953, German chemist Ziegler discovered that TiCl 4 / AlEt 3 The catalytic system composed of the above can synthesize high-density polyethylene at room temperature and pressure, and the Italian chemist Natta used TiCl 3 / AIEt 2 The catalytic system of Kaminsky catalyst L Cl successfully prepared isotactic polypropylene and applied it to the production of polyolefin industry, thus creating a new era of polyolefin industry. With the continuous expansion of polyolefin market demand and application fields, in the mid-1980s, Kaminsky catalyst L 2 ZrCl 2 The discovery of (L=Cp, Cp*, Ind) / MAO (methylaluminoxane) has made metallocene catalysts for homogeneous polymerization of olefins a research hotspot. This type of catalyst has high activity and a single active center. Therefore, the polymer molecules can be designed and tailored according to the predetermined purpose, and the structure of the polymer can be controlled very accurately. This feature makes the relative molecular mass distribution and composition distribution of the polymer obtained by catalyzing olefin polymerization monodisperse. What is particularly noteworthy is that by changing the substituents on the catalyst ligand metallocene ring, not only can the molecular weight and distribution of polyolefins be controlled, but also α-olefins can be polymerized in a directional manner, achieving the purpose of regulating the microstructure of polyolefins.

[0003] At present, foreign countries have put into operation the equipment for producing polyolefins using metallocene catalysts. Although the emergence of metallocene catalysts has attracted widespread attention in the field of olefin polymerization research, metallocene catalysts also have the following limitations: for example, 1) the active center of the metallocene catalyst is easy to coordinate with the polar group, making the catalyst inactive, so it cannot catalyze polar monomers, especially the copolymerization of polar monomers and olefins; 2) the two cyclopentadienyl groups of the metallocene shield most of the central metal, limiting its activity in catalyzing the polymerization of α-olefins containing large groups; 3) the synthesis of metallocene catalysts is relatively complicated, the total catalyst yield is low, and during the catalytic polymerization, the amount of cocatalyst MAO is relatively large, which increases the production cost of polyolefins; 4) metallocene polyolefins generally have problems such as poor particle morphology and sticky reactor of the polymerization product. Therefore, in order to adapt to the existing olefin polymerization production equipment, the metallocene catalyst needs to be supported, and the activity of the supported metallocene catalyst is generally reduced.

[0004] Late transition metals have long been used in the research of olefin polymerization. However, due to the strong β-H elimination tendency of late transition metals, most late transition metal catalysts are only suitable for the dimerization or oligomerization of olefins, and high molecular weight polymerization products cannot be obtained. People have tried to use late transition metals to catalyze olefin polymerization, but none of them have shown the high activity of the catalytic systems of Group IVB and VB metals. Therefore, they are mainly used in the oligomerization of olefins and the coordination polymerization of diolefins.

[0005] In 1996, DuPont Company found a new type of polyolefin catalyst (nickel, palladium), which was the first example of using late transition metals for ethylene polymerization. The outstanding feature of this diimine-nickel (or palladium) catalyst is that it can directly catalyze the polymerization of ethylene to prepare high-branched polyethylene resin without the presence of comonomers. In 1998, based on the α-diimine Ni(II) and Pd(II) catalysts, Professor Brookhart, an American chemist, and Professor Gibson, a British chemist, independently discovered a new type of iron and cobalt olefin polymerization catalyst. This type of catalyst has the advantages of simple synthesis, high yield, low production cost, weak sensitivity to oxygen and polar monomers, and high catalytic activity for olefin polymerization. Based on this method, many scientists have synthesized many new tridentate ligand late transition metal iron and cobalt complexes and have conducted in-depth research on the factors affecting this type of catalyst. The discovery of Professor Brookhart is another new breakthrough in the field of polyolefins after Kaminsky discovered methylaluminoxane to achieve metallocene-catalyzed olefin polymerization, which indicates that new olefin polymerization catalysts do not have to be limited to the traditional Group IVB metals and provides another possible method for the low-cost production of polyolefin materials with a wider application range. If you want to improve the polymerization efficiency, you must select a suitable initiation system for a specific monomer. For example, introducing appropriate substitution groups on unsaturated vinyl monomers can improve the activity of their active centers, thereby obtaining polymers.

[0006] Although people have a deeper understanding of the mechanisms of various polymerization processes, at present, the type of active initiation center is often determined empirically, and the optimal reaction conditions suitable for specific monomers are found empirically. Therefore, it is necessary to try to find a new active center to catalyze polymerization and explain how the active species and dormant species coexist in a balanced manner in the late transition metal compound and acid-catalyzed polymerization systems, so as to overcome side reactions and make the polymerization process controllable and active. Summary of the Invention

[0007] The object of the present invention is to overcome the problems existing in the prior art and provide a method for the polymerization preparation of polystyrene derivatives, using Pd(II)((L1)Pd(OAc) 2)As the metal center, it is polymerized with the Brookhart diamine ligand, namely ligand L1, in the presence of trifluoroacetic acid; in the Pd(II) system, the presence of hydroquinone is beneficial to the polymerization reaction, which increases the polymer yield. Moreover, in the Pd(II) system, by adjusting the coordination environment of the metal, Pd(II) acts as a Lewis acid to promote the cationic polymerization initiated by trifluoroacetic acid.

[0008] To achieve the above object, the present invention adopts the following technical solutions: A method for polymerizing and preparing a polystyrene derivative, comprising the following steps:

[0009] S1. Synthesis of Diimine Ligand ligand:

[0010] Dissolve 2,6-diisopropylaniline in n-propanol, then add an aqueous solution of glyoxal with a concentration of 40%, n-propanol and water at room temperature. Under the condition of 70 °C, stir and react for one hour, then add water. At this time, the product precipitates. After washing, it is dried under vacuum to obtain ligand L1;

[0011] S2. Synthesis of the catalyst:

[0012] Dissolve the ligand L1 synthesized in the above step S1 in dichloromethane, and slowly add palladium acetate Pd(OAc) while stirring the ligand L1 solution 2 , let it react fully and then volatilize naturally to obtain the orange needle-shaped crystal catalyst (L1)Pd(OAc) 2 ;

[0013] S3. Copolymerization of the polymer:

[0014] Pd(II) polymerization system: Add the catalyst (L1)Pd(OAc) 2 , toluene and the olefin monomer synthesized in the above step S1 into the reaction tube. The system is stirred in an ice bath environment for 15 min, and then 0.2 - 2 mL of CF 3 COOH is added, and the reaction is carried out at 0 °C for 2 - 12 h; finally, methanol is added to quench the polymerization reaction. Then, the crude product after the reaction is dissolved in chloroform, and the acid in the system is removed by liquid separation with water. Then, the polymer-chloroform solution is rotary evaporated and concentrated. The concentrated product is dropped into methanol to precipitate the polymer, and this is repeated twice. Finally, the precipitate is filtered and dried under vacuum to obtain the polymer;

[0015] Copolymerization process: Add the catalyst (L1)Pd(OAc) 2 , toluene and styrene synthesized in the above step S1 into the reaction tube. The system is kept in an ice bath environment for 15 min, and then CF 3COOH, react under the condition of 0 °C; after the styrene reaction is complete, add p-methoxystyrene, add methanol to quench the polymerization reaction after the reaction ends, then dissolve the crude product after the reaction in chloroform, separate the liquid from water to remove the acid in the system, and then concentrate the polymer-chloroform solution by rotary evaporation, drop it into methanol to precipitate the polymer, and repeat twice. Finally, filter the precipitate and dry it under vacuum to obtain the copolymer.

[0016] In the step S1, preferably, 0.1 mol of 2,6-diisopropylaniline is dissolved in 100 ml of n-propanol, the amount of glyoxal in the aqueous glyoxal solution is 0.045 mol, the addition amount of n-propanol is 10 ml, and the addition amount of water is 25 ml.

[0017] In the step S1, the preferred room temperature condition for adding the aqueous glyoxal solution is 23 °C, and 100 ml of water is added in the later stage of the reaction to precipitate the product.

[0018] In the step S2, the addition amount of the ligand L1 is 1 mmol, and the addition amount of palladium acetate Pd(OAc) 2 is 0.89 mmol.

[0019] In the step S3, the olefin monomers in the Pd(II) polymerization system include styrene, p-methylstyrene, p-methoxystyrene, p-thiomethylstyrene, p-phenylstyrene, p-fluorostyrene, p-chlorostyrene, p-bromostyrene, p-iodostyrene, p-trifluorostyrene, p-ethylstyrene, p-n-propylstyrene, p-isopropylstyrene, p-tert-butylstyrene, m-methylstyrene, m-methoxystyrene, m-thiomethylstyrene, m-phenylstyrene, m-fluorostyrene, m-chlorostyrene, m-bromostyrene, m-iodostyrene, m-trifluorostyrene, m-ethylstyrene, m-tert-butylstyrene, o-methylstyrene, o-methoxystyrene, o-thiomethylstyrene, o-phenylstyrene, o-fluorostyrene, o-chlorostyrene and o-bromostyrene.

[0020] In the step S3, the addition amount of the catalyst (L1)Pd(OAc) 2 in the Pd(II) polymerization system is 0.01 mmol, the addition amount of toluene is 1 mL, the addition amount of the olefin monomer is 10 mmol, and the addition amount of methanol for quenching the polymerization reaction is 3 mL.

[0021] In the step S3, the addition amount of the catalyst (L1)Pd(OAc) 2 in the copolymerization process is 0.01 mmol, the addition amount of toluene is 5 mmol, the addition amount of styrene is 5 mmol, the addition amount of p-methoxystyrene is 1 mL, and the addition amount of methanol for quenching the polymerization reaction is 3 mL.

[0022] The beneficial effects of the present invention are:

[0023] 1) In the polymerization preparation method of the present invention, Pd(II) ((L1)Pd(OAc) 2 ) is used as the metal center, cooperating with the Brookhart diamine ligand, namely ligand L1, and carrying out polymerization in the presence of trifluoroacetic acid; in the Pd(II) system, the presence of hydroquinone is beneficial to the progress of the polymerization reaction, improving the polymer yield, and in the Pd(II) system, by adjusting the coordination environment of the metal, Pd(II) acts as a Lewis acid to promote the cationic polymerization initiated by trifluoroacetic acid.

[0024] 2) The polymerization method of the present invention is simple to operate, the raw materials used are cheap, and it has high yield and good selectivity; it has the advantages of simple synthesis, weak sensitivity to air and water, high yield, high catalytic activity for olefin polymerization, low oxophilicity and high tolerance to polar monomers. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the characterization diagram of ligand L prepared by the present invention;

[0026] Figure 2 It is the characterization diagram of the catalyst (L1)Pd(OAc) prepared by the present invention 2 characterization diagram;

[0027] Figure 3 It is the polymer structure characterization diagram prepared by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention will be further explained and described below in conjunction with the drawings and specific embodiments.

[0029] Example: A polymerization preparation method of a polystyrene derivative described in the present invention includes the following steps:

[0030] S1. Synthesis of Diimine Ligand:

[0031] Dissolve 2,6 - diisopropylaniline (17.57 g, 0.1 mol) in 100 ml of n - propanol, then add 6.48 g of 40% aqueous glyoxal solution (equivalent to 0.045 mol of glyoxal), 10 ml of n - propanol and 25 ml of water at 23°C. Stir and react at 70°C for one hour, then add 100 ml of water. At this time, the product precipitates out. After washing, it is dried under vacuum to obtain ligand L1 with a yield of 85% (14.26 g).

[0032] The synthesis equation of ligand L1 is:

[0033]

[0034] As Figure 1As shown, the ligand L is characterized by: 1 1H NMR (400 MHz, CDCl3) δ 1.21 (d, J = 7 Hz, 24H, CH(CH 3 )) 2 , 2.94 (sept, 4H, CH(CH 3 )) 2 , 7.07 - 7.25 (m, 6H, m-C 6 H 3 ), 8.11 (s, 2H, NCH); 13 13C NMR (400 MHz, CDCl 3 ) δ 23.4, 28.1, 123.2, 125.2, 136.7, 148.1, 163.1.

[0035] S2. Synthesis of the catalyst:

[0036] Take the ligand L1 obtained by synthesis in the above step S1 (376 mg, 1 mmol) and dissolve it in dichloromethane. While stirring the ligand L1 solution, slowly add palladium acetate Pd(OAc) 2 (224 mg, 0.89 mmol). After allowing it to react fully, let it evaporate naturally to obtain the orange needle-like crystal catalyst (L1)Pd(OAc) 2 , with a yield of 85% (510 mg).

[0037] The synthesis equation of the catalyst (L1)Pd(OAc) 2 is as follows:

[0038]

[0039] As Figure 2 shown, the catalyst (L1)Pd(OAc) 2 is characterized by: 1 1H NMR (400 MHz, acetone-d 6 ) δ 1.16 (s, 6H, OCOCH 3 ), 1.16 (d, J = 7 Hz, 12H, CH(CH 3 )) 2 , 1.47 (d, J = 7 Hz, 12H, CH(CH 3 )) 2 , 3.47 (sept, 4H, CH(CH 3 )) 2 , 7.27 (d, J = 8 Hz, 4H, m-C 6 H 3 ), 7.37 (t, 2H, p-C 6 H 3), 8.46 (s, 2H, NCH); 13 C NMR (400 MHz, acetone-d 6 ) δ 21.8, 22.4, 23.4, 24.2, 123.1, 128.6, 140.3, 143.5, 144.5, 169.9, 170.4.

[0040] S3. Copolymerization of polymers:

[0041] Pd(II) polymerization system: Add the catalyst (L1)Pd(OAc) 2 (0.006 g, 0.01 mmol), toluene (1 mL) and olefin monomer (10 mmol) into a 25 mL reaction tube. The system is stirred in an ice bath for 15 min, then 0.2 - 2 mL of CF 3 COOH is added, and the reaction proceeds at 0 °C for 2 - 12 h; finally, methanol (3 mL) is added to quench the polymerization reaction. Then the crude product after the reaction is dissolved in chloroform, and the acid in the system is removed by liquid separation with water. Then the polymer-chloroform solution is rotary evaporated and concentrated. The concentrated product is dropped into methanol to precipitate the polymer, and this is repeated twice. Finally, the precipitate is filtered and dried in vacuo to obtain the polymer. The yield is 79 - 94%, the number average molecular weight is 36000 - 231100, and the molecular weight distribution is 1.02 - 1.15.

[0042] The olefin monomer includes the following structural formula:

[0043]

[0044] (1) Styrene polymerization process

[0045] Add the catalyst (L1)Pd(OAc) 2 (0.006 g, 0.01 mmol), toluene (1 mL) and styrene (10 mmol) into a 25 mL reaction tube. The system is stirred in an ice bath for 15 min, then CF 3 COOH (0.4 mL) is added, and the reaction proceeds at 0 °C for 3 h; finally, methanol (3 mL) is added to quench the polymerization reaction. Then the crude product is dissolved in chloroform, 10 mL of water is added for liquid separation to remove the acid in the system. Then the polymer-chloroform solution is rotary evaporated and concentrated. The concentrated product is dropped into methanol to precipitate the polymer, and this is repeated twice. Finally, the precipitate is filtered and dried in vacuo to obtain the polymer; the output is 0.96 g, the yield is 92%, the number average molecular weight is 176000, and the molecular weight distribution is 1.03.

[0046] (2) p-Methylstyrene polymerization process

[0047] Different from the styrene polymerization process in (1) above: the olefin monomer is p-methylstyrene, and the addition amount of CF 3 COOH is 0.2 mL, and the reaction is carried out at 0 °C for 2 hours; the yield of the obtained polymer is 1.11 g, the yield is 94%, the number-average molecular weight is 231100, and the molecular weight distribution is 1.02.

[0048] (3) p-Methoxystyrene polymerization process:

[0049] Different from the styrene polymerization process in (1) above: the olefin monomer is p-methoxystyrene, and the addition amount of CF 3 COOH is 0.2 mL; the yield of the obtained polymer is 1.15 g, the yield is 86%, the number-average molecular weight is 223400, and the molecular weight distribution is 1.03.

[0050] (4) p-(Methylthio)styrene polymerization process:

[0051] Different from the styrene polymerization process in (1) above: the olefin monomer is p-(methylthio)styrene, and the addition amount of CF 3 COOH is 2 mL; the yield of the obtained polymer is 1.35 g, the yield is 91%, the number-average molecular weight is 321100, and the molecular weight distribution is 1.02.

[0052] (5) p-Phenylstyrene polymerization process:

[0053] Different from the styrene polymerization process in (1) above: the olefin monomer is p-phenylstyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 4 hours; the yield of the obtained polymer is 1.69 g, the yield is 94%, the number-average molecular weight is 236200, and the molecular weight distribution is 1.02.

[0054] (6) p-Fluorostyrene polymerization process:

[0055] Different from the styrene polymerization process in (1) above: the olefin monomer is p-fluorostyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 8 hours; the yield of the obtained polymer is 1.00 g, the yield is 82%, the number-average molecular weight is 132100, and the molecular weight distribution is 1.07.

[0056] (7) p-Chlorostyrene polymerization process:

[0057] Different from the styrene polymerization process in (1) above: the olefin monomer is p-chlorostyrene, and the addition amount of CF 3 COOH is 2 mL; the yield of the obtained polymer is 1.23 g, the yield is 89%, the number-average molecular weight is 86400, and the molecular weight distribution is 1.11.

[0058] (8) Polymerization process of p-bromostyrene:

[0059] Different from the styrene polymerization process in (1) above: The olefin monomer is p-bromostyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 8 hours; The yield of the obtained polymer is 1.60 g, the yield is 88%, the number-average molecular weight is 86000, and the molecular weight distribution is 1.12.

[0060] (9) Polymerization process of p-iodostyrene:

[0061] Different from the styrene polymerization process in (1) above: The olefin monomer is p-iodostyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 8 hours; The yield of the obtained polymer is 2.05 g, the yield is 89%, the number-average molecular weight is 101100, and the molecular weight distribution is 1.09.

[0062] (10) Polymerization process of p-trifluorostyrene:

[0063] Different from the styrene polymerization process in (1) above: The olefin monomer is p-trifluorostyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 12 hours; The yield of the obtained polymer is 1.39 g, the yield is 81%, the number-average molecular weight is 36000, and the molecular weight distribution is 1.05.

[0064] (11) Polymerization process of p-ethylstyrene:

[0065] Different from the styrene polymerization process in (1) above: The olefin monomer is p-ethylstyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 2 hours; The yield of the obtained polymer is 1.234 g, the yield is 93%, the number-average molecular weight is 223100, and the molecular weight distribution is 1.05.

[0066] (12) Polymerization process of p-n-propylstyrene:

[0067] Different from the styrene polymerization process in (1) above: The olefin monomer is p-n-propylstyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 2 hours; The yield of the obtained polymer is 0.694 g, the yield is 92%, the number-average molecular weight is 189100, and the molecular weight distribution is 1.04.

[0068] (13) Polymerization process of p-isopropylstyrene:

[0069] Different from the styrene polymerization process in (1) above: The olefin monomer is p-isopropylstyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 2 hours; the yield of the obtained polymer is 1.34 g, the yield is 92%, the number-average molecular weight is 178,200, and the molecular weight distribution is 1.04.

[0070] (14) p-tert-Butylstyrene polymerization process:

[0071] Different from the styrene polymerization process in (1) above: The olefin monomer is p-tert-butylstyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 2 hours; the yield of the obtained polymer is 1.42 g, the yield is 89%, the number-average molecular weight is 184,500, and the molecular weight distribution is 1.05.

[0072] (15) m-Methylstyrene polymerization process:

[0073] Different from the styrene polymerization process in (1) above: The olefin monomer is m-methylstyrene, and the addition amount of CF 3 COOH is 2 mL; the yield of the obtained polymer is 1.07 g, the yield is 91%, the number-average molecular weight is 171,300, and the molecular weight distribution is 1.04.

[0074] (16) m-Methoxystyrene polymerization process:

[0075] Different from the styrene polymerization process in (1) above: The olefin monomer is m-methoxystyrene, and the addition amount of CF 3 COOH is 2 mL; the yield of the obtained polymer is 1.17 g, the yield is 87%, the number-average molecular weight is 156,300, and the molecular weight distribution is 1.05.

[0076] (17) m-(Methylthio)styrene polymerization process:

[0077] Different from the styrene polymerization process in (1) above: The olefin monomer is m-(methylthio)styrene, and the addition amount of CF 3 COOH is 2 mL; the yield of the obtained polymer is 0.694 g, the yield is 91%, the number-average molecular weight is 98,400, and the molecular weight distribution is 1.06.

[0078] (18) m-Phenylstyrene polymerization process:

[0079] Different from the styrene polymerization process in (1) above: The olefin monomer is m-phenylstyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 2 hours; the yield of the obtained polymer is 0.694 g, the yield is 76.6%, the number-average molecular weight is 187,100, and the molecular weight distribution is 1.03.

[0080] (19) Polymerization process of m-fluorostyrene:

[0081] Different from the styrene polymerization process in (1) above: The olefin monomer is m-fluorostyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 10 hours; the yield of the obtained polymer is 0.694 g, the yield is 76.6%, the number-average molecular weight is 89,000, and the molecular weight distribution is 1.09.

[0082] (20) Polymerization process of m-chlorostyrene

[0083] Different from the styrene polymerization process in (1) above: The olefin monomer is m-chlorostyrene, and the addition amount of CF 3 COOH is 0.2 mL, and the reaction is carried out at 0 °C for 10 hours; the yield of the obtained polymer is 1.11 g, the yield is 94%, the number-average molecular weight is 51,500, and the molecular weight distribution is 1.08.

[0084] (21) Polymerization process of m-bromostyrene

[0085] Different from the styrene polymerization process in (1) above: The olefin monomer is m-bromostyrene, and the addition amount of CF 3 COOH is 0.2 mL, and the reaction is carried out at 0 °C for 10 hours; the yield of the obtained polymer is 1.11 g, the yield is 94%, the number-average molecular weight is 91,300, and the molecular weight distribution is 1.07.

[0086] (22) Polymerization process of m-iodostyrene

[0087] Different from the styrene polymerization process in (1) above: The olefin monomer is m-iodostyrene, and the addition amount of CF 3 COOH is 0.2 mL, and the reaction is carried out at 0 °C for 7 hours; the yield of the obtained polymer is 1.11 g, the yield is 94%, the number-average molecular weight is 51,300, and the molecular weight distribution is 1.05.

[0088] (23) Polymerization process of m-trifluorostyrene

[0089] Different from the styrene polymerization process in (1) above: The olefin monomer is m-trifluorostyrene, and the addition amount of CF 3 COOH is 0.2 mL, and the reaction is carried out at 0 °C for 12 hours; the yield of the obtained polymer is 1.11 g, the yield is 94%, the number-average molecular weight is 37,200, and the molecular weight distribution is 1.10.

[0090] (24) Polymerization process of m-ethylstyrene

[0091] Different from the styrene polymerization process in (1) above: the olefin monomer is m-ethylstyrene, and the addition amount of CF 3 COOH is 0.2 mL, and the reaction is carried out at 0 °C for 5 hours; the yield of the obtained polymer is 1.11 g, the yield is 94%, the number-average molecular weight is 185100, and the molecular weight distribution is 1.03.

[0092] (25) m-tert-Butylstyrene polymerization process

[0093] Different from the styrene polymerization process in (1) above: the olefin monomer is m-tert-butylstyrene, and the addition amount of CF 3 COOH is 0.2 mL, and the reaction is carried out at 0 °C for 5 hours; the yield of the obtained polymer is 1.11 g, the yield is 94%, the number-average molecular weight is 168900, and the molecular weight distribution is 1.03.

[0094] (26) o-Methylstyrene polymerization process:

[0095] Different from the styrene polymerization process in (1) above: the olefin monomer is o-methylstyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 6 hours; the yield of the obtained polymer is 1.07 g, the yield is 91%, the number-average molecular weight is 45000, and the molecular weight distribution is 1.11.

[0096] (27) o-Methoxystyrene polymerization process:

[0097] Different from the styrene polymerization process in (1) above: the olefin monomer is o-methoxystyrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 6 hours; the yield of the obtained polymer is 1.21 g, the yield is 90%, the number-average molecular weight is 56400, and the molecular weight distribution is 1.09.

[0098] (28) o-(Methylthio)styrene polymerization process:

[0099] Different from the styrene polymerization process in (1) above: the olefin monomer is o-(methylthio)styrene, and the addition amount of CF 3 COOH is 2 mL, and the reaction is carried out at 0 °C for 6 hours; the yield of the obtained polymer is 1.31 g, the yield is 87%, the number-average molecular weight is 43000, and the molecular weight distribution is 1.11.

[0100] (29) o-Phenylstyrene polymerization process:

[0101] Different from the styrene polymerization process in (1) above: the olefin monomer is o-phenylstyrene, and the addition amount of CF 3The addition amount of COOH was 2 mL, and the reaction was carried out at 0 °C for 6 hours; the yield of the obtained polymer was 1.46 g, the yield was 81%, the number-average molecular weight was 40200, and the molecular weight distribution was 1.12.

[0102] (30) Polymerization process of o-fluorostyrene:

[0103] Different from the styrene polymerization process in (1) above: the olefin monomer is o-fluorostyrene, CF 3 The addition amount of COOH was 2 mL, and the reaction was carried out at 0 °C for 11 hours; the yield of the obtained polymer was 0.98 g, the yield was 80%, the number-average molecular weight was 39200, and the molecular weight distribution was 1.07.

[0104] (31) Polymerization process of o-chlorostyrene

[0105] Different from the styrene polymerization process in (1) above: the olefin monomer is o-chlorostyrene, CF 3 The addition amount of COOH was 0.2 mL, and the reaction was carried out at 0 °C for 12 hours; the yield of the obtained polymer was 1.15 g, the yield was 83%, the number-average molecular weight was 38100, and the molecular weight distribution was 1.05.

[0106] (32) Polymerization process of o-bromostyrene

[0107] Different from the styrene polymerization process in (1) above: the olefin monomer is o-bromostyrene, CF 3 The addition amount of COOH was 0.2 mL, and the reaction was carried out at 0 °C for 12 hours; the yield of the obtained polymer was 1.58 g, the yield was 87%, the number-average molecular weight was 45100, and the molecular weight distribution was 1.05.

[0108] Copolymerization process: The catalyst (L1) Pd(OAc) synthesized in step S1 above 2 Take (0.006 g, 0.01 mmol), toluene (5 mmol) and styrene (5 mmol) and add them into the reaction tube. The system is kept in an ice bath environment for 15 min, and then CF 3 COOH (2 mL) is added, and the reaction is carried out at 0 °C; after the styrene reacts completely, p-methoxystyrene (1 mL) is added. After the reaction is completed, methanol (3 mL) is added to quench the polymerization reaction. Then the crude product after the reaction is dissolved in chloroform, and the acid in the system is removed by liquid separation with water. Then the polymer-chloroform solution is rotary evaporated and concentrated, and dropped into methanol to precipitate the polymer, and this is repeated twice. Finally, the precipitate is filtered and dried in vacuo to obtain the copolymer.

[0109] Polymer structure characterization: NMR ( 1 H and 13 C) spectra in CDCl3 or DMSO-d 6 The solution was collected on a 400 MHz NMR (Bruker DRX400) instrument with tetramethylsilane as the internal standard.

[0110] From Figure 3 It can be seen that the catalytic system of the present invention realizes the highly selective polymerization of styrene and p-methoxystyrene and the highly selective copolymerization of styrene and p-methoxystyrene. This polymerization method is simple, and the obtained polymer has the characteristics of concentrated molecular weight distribution and high stereoregularity, and has high application value.

[0111] As described above, it is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made by those of ordinary skill in the art to the technical solution of the present invention shall be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for polymerizing and preparing a polystyrene derivative, characterized in that: It includes the following steps: S1. Synthesis of Diimine Ligand ligand: Dissolve 2,6-diisopropyl aniline in n-propanol, and then add an aqueous solution of glyoxal with a concentration of 40%, n-propanol and water at room temperature. At 70 o °C, after stirring and reacting for one hour, add water. At this time, the product precipitates. After washing, it is dried under vacuum to obtain the ligand L1; S2. Synthesis of the catalyst: Dissolve the ligand L1 obtained by synthesis in step S1 above in dichloromethane, and slowly add palladium acetate Pd(OAc) while stirring the ligand L1 solution 2 , allow it to react fully and then volatilize naturally to obtain the orange needle-shaped crystal catalyst (L1)Pd(OAc) 2 ; S3. Preparation of the polymer: Pd(II) polymerization system: Add the catalyst (L1) Pd(OAc) synthesized in the above step S2 2 , toluene and olefin monomer into the reaction tube. The system is stirred in an ice bath for 15 min, and then 0.2 - 2 mL of CF 3 COOH is added. The reaction proceeds at 0 o °C for 2 - 12 h. Finally, methanol is added to quench the polymerization reaction. Then, the crude product after the reaction is dissolved in chloroform, and the acid in the system is removed by liquid separation with water. Then, the polymer-chloroform solution is rotary evaporated and concentrated. The concentrated product is dropped into methanol to precipitate the polymer, and this is repeated twice. Finally, the precipitate is filtered and dried under vacuum to obtain the polymer; The olefin monomers in the Pd(II) polymerization system include styrene, p-methylstyrene, p-methoxystyrene, p-thiomethylstyrene, p-phenylstyrene, p-fluorostyrene, p-chlorostyrene, p-bromostyrene, p-iodostyrene, p-ethylstyrene, p-n-propylstyrene, p-isopropylstyrene, p-tert-butylstyrene, m-methylstyrene, m-methoxystyrene, m-thiomethylstyrene, m-phenylstyrene, m-fluorostyrene, m-chlorostyrene, m-bromostyrene, m-iodostyrene, m-ethylstyrene, m-tert-butylstyrene, o-methylstyrene, o-methoxystyrene, o-thiomethylstyrene, o-phenylstyrene, o-fluorostyrene, o-chlorostyrene and o-bromostyrene; Copolymerization process: Add the catalyst (L1) Pd(OAc) synthesized in step S2 above 2 , toluene and styrene into the reaction tube. The system is maintained in an ice bath environment for 15 min, and then CF 3 COOH is added, and the reaction is carried out at 0 o °C; After the styrene reaction is complete, p-methoxystyrene is added. After the reaction, methanol is added to quench the polymerization reaction. Then the crude product after the reaction is dissolved in chloroform, and the acid in the system is removed by liquid separation with water. Then the polymer-chloroform solution is rotary evaporated and concentrated, and dropped into methanol to precipitate the polymer, and this is repeated twice; Finally, the precipitate is filtered and dried under vacuum to obtain the copolymerized polymer.

2. The method for polymerizing and preparing a polystyrene derivative according to claim 1, characterized in that: In the step S1, preferably, 0.1 mol of 2,6-diisopropylaniline is dissolved in 100 ml of n-propanol, the amount of glyoxal in the aqueous glyoxal solution is 0.045 mol, the addition amount of n-propanol is 10 ml, and the addition amount of water is 25 ml.

3. The method for polymerizing and preparing a polystyrene derivative according to claim 1, characterized in that: In the step S1, the addition of the glyoxal aqueous solution is preferably carried out at room temperature of 23 o °C, and 100 ml of water is added in the later stage of the reaction to precipitate the product.

4. The method for polymerizing and preparing a polystyrene derivative according to claim 1, characterized in that: In the step S2, the addition amount of the ligand L1 is 1 mmol, and the addition amount of palladium acetate Pd(OAc) 2 is 0.89 mmol.

5. The method for polymerizing and preparing a polystyrene derivative according to claim 1, characterized in that: In the step S3, the addition amount of the catalyst (L1) Pd(OAc) in the Pd(II) polymerization system 2 is 0.01 mmol, the addition amount of toluene is 1 mL, the addition amount of the olefin monomer is 10 mmol, and the addition amount of methanol for quenching the polymerization reaction is 3 mL.

6. The method for polymerizing and preparing a polystyrene derivative according to claim 1, characterized in that: In the step S3, during the copolymerization process, the addition amount of the catalyst (L1) Pd(OAc) 2 is 0.01 mmol, the addition amount of toluene is 5 mmol, the addition amount of styrene is 5 mmol, the addition amount of p-methoxystyrene is 1 mL, and the addition amount of methanol for quenching the polymerization reaction is 3 mL.

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