阅读说明：本技术 一种用于苯乙烯聚合的催化聚合体系及聚合方法与得到的聚苯乙烯 (Catalytic polymerization system and polymerization method for styrene polymerization and obtained polystyrene ) 是由 王伟 曲树璋 陈珺娴 张韬毅 刘长城 范国强 郑刚 于 2019-10-11 设计创作，主要内容包括：本发明涉及一种用于苯乙烯聚合的催化聚合体系及聚合方法与得到的聚苯乙烯,所述催化聚合体系包括单茂金属化合物、烷基铝氧烷和苯乙烯,所述单茂金属化合物的结构中含有Cp’配体以及喹啉基团。其中,所述单茂金属化合物与所述烷基铝氧烷的摩尔比为1:(50～20000),单茂金属化合物在聚合体系中的浓度为1x10～(-8)摩尔/升～1x10～(-3)摩尔/升。本发明所述聚合体系采用了具有特殊结构的单茂金属化合物为主催化剂,利用所述聚合体系可得到间规聚苯乙烯,并且,得到的聚苯乙烯具有高分子量、窄分子量分布等优点。(The invention relates to a catalytic polymerization system and a polymerization method for styrene polymerization and polystyrene obtained by the catalytic polymerization system. Wherein the molar ratio of the single metallocene compound to the alkyl aluminoxane is 1 (50-20000), and the concentration of the single metallocene compound in a polymerization system is 1x10 ‑8 Mol/l-1 x10 ‑3 Mol/l. The polymerization system of the invention adopts a single metallocene compound with a special structure as a main catalyst, syndiotactic polystyrene can be obtained by utilizing the polymerization system, and the obtained polystyrene has the advantages of high molecular weight, narrow molecular weight distribution and the like.)

1. A catalytic polymerization system for polymerizing styrene is composed of the metallocene compound shown in formula (I), alkylaluminoxane and styrene,

in the formula (I), X₁And X₂Each independently selected from an alkoxy, aryloxy, alkyl, aryl or halogen atom, Cp' is a cyclopentadienyl, indenyl or fluorenyl group substituted or unsubstituted with a hydrocarbon radical, R is a substituted or unsubstituted alkyl group¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from a hydrogen atom, a halogen atom or a C1-18 atomA substituent of a molecule.

2. The catalytic polymerization system according to claim 1, wherein, in formula (I),

X₁and X₂Each independently selected from C₁～C₅Alkoxy group of (C)₆～C₉Aryloxy group of (A), C₁～C₅Alkyl of (C)₆～C₉An aryl group or a halogen atom of (a); and/or

Cp' is selected from C₁～C₃Alkyl substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl; and/or

R¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from a hydrogen atom, a halogen atom, C₆～C₉Aryl of (C)₁～C₅Alkyl or C₁～C₅Substituted alkyl groups of (1).

3. The catalytic polymerization system according to claim 2, wherein, in formula (I),

X₁and X₂Each independently selected from a chlorine atom, a methoxy group, a phenoxy group, a methyl group, a phenyl group or a benzyl group; and/or

Cp' is selected from pentamethylcyclopentadienyl, cyclopentadienyl or indenyl; and/or

R¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from hydrogen atom, C₁～C₃Alkyl of (C)₁～C₃Halogen-substituted alkyl of (1).

4. The catalytic polymerization system according to claim 1, wherein the alkylalumoxane is selected from compounds of formula (i) and/or (ii):

in the formulae (i) and (ii), R represents an alkyl group, preferably C₁～C₆More preferably methyl; n represents an integer of 4 to 30, preferably an integer of 10 to 30.

5. The catalytic polymerization system of claim 1, wherein the molar ratio of the mono-metallocene compound to the alkylaluminoxane is 1 (50-20000), preferably 1 (200-10000), more preferably 1 (500-3000), wherein the molar amounts of the Ti element and the Al element are respectively calculated.

6. The catalytic polymerization system according to claim 1 to 5, wherein the concentration of the monometallocene compound in the polymerization system is 1X10^-8mol/l-1X 10^-2Mol/l, preferably 1X10^-7mol/l-1X 10^-3Mol/l.

7. Catalytic polymerization system according to claim 6, characterized in that it optionally further comprises an organic solvent, preferably selected from toluene and/or hexane, more preferably toluene.

8. A styrene polymerization process using the catalytic polymerization system according to any one of claims 1 to 7.

9. The styrene polymerization process according to claim 8, wherein the polymerization temperature is from-50 ℃ to 200 ℃, preferably from-20 ℃ to 150 ℃, more preferably from 0 ℃ to 100 ℃.

10. Polystyrene obtainable by the polymerization process according to claim 9, preferably syndiotactic polystyrene.

Technical Field

The invention belongs to the field of olefin polymerization, particularly relates to styrene polymerization, and particularly relates to a catalytic polymerization system and a polymerization method for styrene polymerization and polystyrene obtained by the catalytic polymerization system.

Background

Metallocene catalysts for olefin polymerization have been the focus of research in metallorganic chemistry, catalytic chemistry, polymer chemistry and materials science for decades. By using the metallocene catalyst, the olefin polymer with uniform molecular weight distribution and chemical composition distribution can be obtained; meanwhile, the molecular structure and molecular weight of the polymer can be highly controllable by adjusting the structure of the catalyst; in addition, by using a metallocene catalyst, olefin polymers which cannot be obtained by conventional Ziegler-Natta catalysts can also be obtained.

Styrene polymers can be classified into atactic polystyrene, isotactic polystyrene and syndiotactic polystyrene. Syndiotactic Polystyrene (SPS) is a crystalline styrene polymer in which phenyl groups are regularly and alternately arranged on both sides of a macromolecular carbon-carbon main chain, and is a new polystyrene variety developed in recent years. The melting point of SPS is high (270 ℃), the crystallization speed is high, the density is low, the elastic modulus is high, the moisture absorption rate is low, and the dielectric constant is small; is a high-electrical-insulation engineering plastic with strong resistance to organic solvents and chemical reagents. The excellent performance makes it have wide application prospect in automobile industry, electronic industry and industrial package.

The synthesis of SPS was reported as early as 1962, but the synthesis conditions are very harsh and can be obtained at-62 ℃ (J.Am.chem.Soc.1962,84,1488). In 1986, Ishihara reported the synthesis of SPS under mild conditions; CpTiCl therefor₃Forming a catalytic system with a cocatalyst MAO. Melting Point of SPS270 ℃ and the melting point of the polystyrene is 40 ℃ higher than that of isotactic polystyrene; weight average molecular weight (M) of SPS_w) 82000(Macromolecules1986,19,2465; EP210615,1987). Chien and Rausch et al use IndCl₃As a catalyst, syndiotactic polymerization of styrene was studied; with CpTiCl₃Compared with IndclI₃The activity of catalyzing the syndiotactic polymerization of styrene is higher, and the SPS accounts for a higher proportion in the polymer (Macromolecules 1993,26, 5822). In addition, they reported five Cp' Ti (O)ⁱPr)₃The catalysts are used for the catalytic syndiotactic polymerization of styrene, as a result of which it has been found that the structure of the catalyst has a significant influence on the polymerization activity, the proportion of SPS in the product and also on the molecular weight of SPS (Organometallics 1993,12, 3075). The Single metallocene Complex Cp' TiCl for Xu₃The activity of the catalyst can reach 27.0 multiplied by 10 when the catalyst is used for catalyzing the syndiotactic polymerization of styrene⁴g-SPS/mol-Ti/h, the weight average molecular weight of the polymer can reach 74 ten thousand (Macromolecules 2000,332825).

Kaminsky studied the syndiotactic polymerization of styrene using a fluorine-containing metallocene catalyst and found that Cp' TiF was used₃Polymerization activity ratio Cp' TiCl₃Tens or even hundreds of times higher. Using MeCpTiF₃SPS with a molecular weight of 142 ten thousand can be obtained as a catalyst (Macromolecules 1997,30, 7647). Ruckenstein uses Ind' TiF₃Syndiotactic polymerization of styrene was carried out and it was found that the catalytic activity of the fluorine-containing catalyst was much higher than that of the chlorine-containing catalyst, and the molecular weight of the resulting polymer was also higher than that obtained using the chlorine-containing catalyst (J.Polym.Sci.Polym.Chem.,1999,37, 2481). In addition, patent CN02117938 also discloses a fluorinated metallocene catalyst.

Monometallocene complex Cp' TiX₃The catalyst can effectively catalyze the syndiotactic polymerization of styrene, and the polymerization activity and the polymer molecular weight of the catalyst are influenced by not only Cp ligands but also X ligands. In order to obtain more satisfactory polymerization results, the researchers have modified the catalyst structure by using a mono-metallocene complex Cp' TiCl with an electron-donating ligand₂L (L ═ electron donor ligands) is of particular interest.

Qian uses alkoxy-coordinated CpTiCl₂OR、IndTiCl₂OR and 1-MeIndCl₂OR is carried outStyrene was syndiotactic polymerized, and as a result, it was found that both the substituent and the polymerization conditions had an influence on the polymerization activity (Eur. Polym.J.2000,36,2055; J.mol.Catal.Chem.2001,170, 67; Eur. Polym.J.2002,38,1613; CN 00127437; CN 00127438; CN 01131951). Nomura uses a phenoxy-coordinated catalyst Cp' TiCl₂OAr carries out styrene syndiotactic polymerization, the influence of the substituent on Cp and the substituent on the electron-donating ligand is examined, and the styrene syndiotactic polymerization activity of all the catalysts with the phenoxy electron-donating ligand is higher than that of the catalyst Cp' TiCl₃The catalytic activity, Cp structure and electron-donating ligand of (A) have important influences on the polymerization activity and the molecular weight of the polymer (Macromolecules 2004,37, 5520). The titanocene with imino group as ligand as shown in formula 12 is used as styrene syndiotactic polymerization catalyst, and its polymerization activity and molecular weight of the obtained polymer are much lower than those of catalysts 10 and 11 (Catal. Commun.2004,5,413).

Other mono-metallocenes containing chelating ligands are also used for the syndiotactic polymerization of styrene. Do et al, using titanocene as shown in formula (1) as a catalyst for syndiotactic polymerization of styrene, found that the polymerization activity was relatively high, but the molecular weight of the polymer was relatively low (Organometallics 1999,18, 36; Organometallics 2002,21, 1127). Li uses titanocenes as shown in formula (2) and formula (3) for syndiotactic polymerization of styrene, in which all the catalysts increase in activity with increasing polymerization temperature and the molecular weight of the polymer decreases (J.Polym.Sci., Part A: Polym.Chem.2005,43,1562; J.mol.Catal.Chem.2005,232, 1; CN 200310115936).

Chinese patents disclose a number of patents identified with Cp' Ti (OR)₃Studies on the catalysis of syndiotactic polymerization of styrene, for example CN200710032017, CN200310108170, CN02117936, CN02137452, CN02137453, CN00119775, CN99119959, CN98110855, CN98110852, CN97106587, CN97106586, CN97106585 and CN 95113341.

In view of the above, studies on syndiotactic styrene polymerization have been developed, but in order to reduce cost and improve material properties, the development and research of a polymerization system using a novel polymerization catalyst are still the main research subjects in this field.

Disclosure of Invention

The inventor provides a novel catalytic polymerization system for styrene polymerization through a great deal of experimental research, wherein a novel single metallocene compound is adopted as a main component of a catalyst, and the structure of the single metallocene compound contains Cp' ligand and quinoline group. The catalytic polymer system can obtain syndiotactic polystyrene with high molecular weight and narrow molecular weight distribution after polymerization under certain conditions.

One of the objectives of the present invention is to provide a catalytic polymerization system for styrene polymerization, comprising a mono-metallocene compound represented by formula (I), alkylaluminoxane and styrene.

In the formula (I), X₁And X₂Each independently selected from an alkoxy, aryloxy, alkyl, aryl or halogen atom, Cp' is a cyclopentadienyl, indenyl or fluorenyl group substituted or unsubstituted with a hydrocarbon radical, R is a substituted or unsubstituted alkyl group¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from a hydrogen atom, a halogen atom or a substituent containing 1 to 18 carbon atoms.

It is explained herein that said cyclopentadienyl, indenyl or fluorenyl substituted or unsubstituted with a hydrocarbyl group means a cyclopentadienyl substituted or unsubstituted with a hydrocarbyl group, an indenyl substituted or unsubstituted with a hydrocarbyl group, or a fluorenyl substituted or unsubstituted with a hydrocarbyl group, described directly as: cyclopentadienyl, indenyl or fluorenyl, substituted or unsubstituted with a hydrocarbyl group, can also be described as: cp' is cyclopentadienyl, indenyl, fluorenyl or hydrocarbyl substituted derivatives thereof.

In the invention, the single metallocene compound contains condensed heterocyclic aryloxy, and compared with common aryloxy (such as monocyclic or linked rings), the condensed ring electron donor ligand has larger steric hindrance, and can effectively inhibit chain transfer reaction in polymerization, thereby obtaining a polymer with higher molecular weight.

In a preferred embodiment, in formula (I), X₁And X₂Each independently selected from C₁～C₅Alkoxy group of (C)₆～C₉Aryloxy group of (A), C₁～C₅Alkyl of (C)₆～C₉An aryl group or a halogen atom of (a); and/or Cp' is selected from C₁～C₃Alkyl substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl; and/or, R¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from a hydrogen atom, a halogen atom, C₆～C₉Aryl of (C)₁～C₅Alkyl or C₁～C₅Substituted alkyl groups of (1).

In a further preferred embodiment, in formula (I), X₁And X₂Each independently selected from a chlorine atom, a methoxy group, a phenoxy group, a methyl group, a phenyl group or a benzyl group; and/or Cp' is selected from pentamethylcyclopentadienyl, cyclopentadienyl or indenyl; and/or, R¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from hydrogen atom, C₁～C₃Alkyl of (C)₁～C₃Halogen-substituted alkyl of (1).

In a preferred embodiment, the mono-metallocene compound is pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium, cyclopentadienyl-4-quinolinyloxy-titanium dichloride, pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium or pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinyloxy) -dimethoxytitanium, the structures of which are represented by the formulae (II) to (V), respectively:

in formula (II), formula (IV) and formula (V), Cp' is pentamethylcyclopentadienyl; in formula (III), Cp' is a cyclopentadienyl group.

In a preferred embodiment, the alkylaluminoxane is selected from compounds of formula (i) and/or formula (ii).

In the formulae (i) and (ii), R represents an alkyl group, preferably C₁～C₆More preferably methyl; n represents an integer of 4 to 30, preferably an integer of 10 to 30.

In a preferred embodiment, the molar ratio of the mono-metallocene compound to the alkylaluminoxane is 1 (50 to 20000), wherein the molar amounts of the Ti element and the Al element are respectively calculated.

In a further preferred embodiment, the molar ratio of the mono-metallocene compound to the alkylaluminoxane is 1 (200 to 10000), wherein the molar amounts of the Ti element and the Al element are respectively calculated.

In a further preferred embodiment, the molar ratio of the mono-metallocene compound to the alkylaluminoxane is 1 (500 to 3000), wherein the molar amounts of the Ti element and the Al element are respectively calculated.

Most preferably, the molar ratio of the mono-metallocene compound to the alkylaluminoxane is 1 (1500-2000), wherein the molar amounts of the Ti element and the Al element are respectively calculated.

In a preferred embodiment, the concentration of said mono-metallocene compound in the polymerization system is 1X10^-8mol/l-1X 10^-2Mol/l, preferably 1X10^-7mol/l-1X 10^-3Mol/l.

Most preferably, the concentration of the single metallocene compound in a polymerization system is (1-5) x10^-4Mol/l.

In a preferred embodiment, the polymerization system is used for the preparation of syndiotactic polystyrene at a polymerization temperature of from-50 ℃ to 200 ℃, preferably from-20 ℃ to 150 ℃, more preferably from 0 ℃ to 100 ℃, for example from 50 ℃ to 90 ℃.

In a preferred embodiment, the polymerization system optionally further comprises an organic solvent, preferably selected from toluene and/or hexane, more preferably toluene.

Wherein, during styrene polymerization, the alkyl aluminoxane and the mono-metallocene compound are added into a polymerization vessel together or respectively.

In another aspect, the present invention provides a process for the polymerization of styrene carried out with a polymerization system as described in one of the objects of the present invention.

In a preferred embodiment, the polymerization temperature is from-50 ℃ to 200 ℃, preferably from-20 ℃ to 150 ℃, more preferably from 0 ℃ to 100 ℃, e.g. from 50 to 90 ℃.

In a preferred embodiment, the alkylaluminoxane in the polymerization system is added to the polymerization vessel together with or separately from the monometallocene compound.

It is a third object of the present invention to provide a polystyrene, preferably a syndiotactic polystyrene, obtainable by the polymerization process described above for the second object of the present invention.

In the invention, the single metallocene compound is prepared by taking a compound shown in a formula (VI) and a compound shown in a formula (VII) as raw materials.

Wherein, in the formula (VI), X₁、X₂And X₃Each independently selected from an alkoxy group, an aryloxy group, an alkyl group, an aryl group or a halogen atom, Cp' is a cyclopentadienyl group, an indenyl group or a fluorenyl group, substituted or unsubstituted with a hydrocarbon group; in the formula (VII), R¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from a hydrogen atom, a halogen atom or a substituent containing 1 to 18 carbon atoms.

In a preferred embodiment, in formula (VI), X₁、X₂And X₃Each independently selected from C₁～C₅Alkoxy group of (C)₆～C₉OfOxy radical, C₁～C₅Alkyl of (C)₆～C₉An aryl group or a halogen atom of (a); and/or Cp' is selected from C₁～C₃Alkyl substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl; and/or, in the formula (VII), R¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from a hydrogen atom, a halogen atom, C₆～C₉Aryl of (C)₁～C₅Alkyl or C₁～C₅Substituted alkyl groups of (1).

In a further preferred embodiment, in formula (VI), X₁、X₂And X₃Each independently selected from a chlorine atom, a methoxy group, a phenoxy group, a methyl group, a phenyl group or a benzyl group; and/or Cp' is selected from pentamethylcyclopentadienyl, cyclopentadienyl or indenyl; and/or, in the formula (VII), R¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from hydrogen atom, C₁～C₃Alkyl of (C)₁～C₃Halogen-substituted alkyl of (1).

In a preferred embodiment, in formula (VI), X₁、X₂And X₃Each independently selected from a chlorine atom or a methoxy group; and/or Cp' is selected from pentamethylcyclopentadienyl or cyclopentadienyl; and/or, in the formula (VII), R¹、R²、R³、R⁴、R⁵、R⁶Each independently selected from a hydrogen atom, a methyl group or a fluoromethyl group.

In a further preferred embodiment, the compound of formula (VI) is selected from pentamethylcyclopentadienyl-trimethoxytitanium and/or cyclopentadienyltitanium trichloride and the compound of formula (VII) is selected from at least one of 4-hydroxy-1-quinoline, 2-methyl-4-hydroxy-1-quinoline and 2, 8-bis (trifluoromethyl) -4-hydroxy-1-quinoline.

In a preferred embodiment, when a compound of formula (VI) is used, X₁、X₂And X₃Independently selected from alkoxy, aryloxy, alkyl and aryl, and a process for preparing the sameThe method comprises the following steps:

step 1, mixing a compound shown as a formula (VII) and a compound shown as a formula (VI) in a protective atmosphere, and stirring;

step 2, carrying out reduced pressure reaction at a set temperature, and filling protective gas after the reaction is finished, and cooling;

and 3, adding a solvent, carrying out crystallization treatment, removing a mother solution after crystallization, and drying the solid in vacuum to obtain the mono-metallocene compound.

Wherein the protective atmosphere is preferably nitrogen.

In a further preferred embodiment, in step 2, the reaction is carried out under reduced pressure at 50 to 90 ℃ (e.g., 70 ℃), preferably with a vacuum of less than 1 mm Hg.

In a still further preferred embodiment, in step 3, the solvent is selected from a mixed solvent of toluene and hexane, and the crystallization is performed at-10 ℃ or lower (preferably-25 ℃ or lower).

Wherein the amount of toluene is based on complete dissolution of the compound and the addition of hexane serves to promote crystallization.

In a preferred embodiment, in step 1, the compound of formula (VII) and the compound of formula (VI) are used in a molar ratio of 1: 1.

In a preferred embodiment, when a compound of formula (VI) is used, X₁、X₂And X₃When selected from halogen atoms, the preparation method of the mono-metallocene compound comprises the following steps:

step 1', placing a compound shown as a formula (VII) in a solvent under a protective atmosphere, stirring, dropwise adding an alkyl lithium compound at a temperature of below 0 ℃, naturally heating to room temperature after dropwise adding, and reacting to obtain a reaction mixture;

step 2 ', adding a compound shown as a formula (VI) into a solvent in a protective atmosphere, dropwise adding the reaction mixture obtained in the step 1' at the temperature of below 0 ℃, slowly heating to room temperature after dropwise adding, and continuing to react;

and 3', carrying out post-treatment to obtain the single metallocene compound.

Wherein the protective atmosphere is preferably nitrogen, and the room temperature is 20-30 ℃.

In a preferred embodiment, in step 1 'and step 2', the solvent is an organic solvent, including toluene, hexane, and tetrahydrofuran, preferably toluene.

In a preferred embodiment, in step 1 'and step 2', the reaction is carried out for 12 to 24 hours respectively.

In a preferred embodiment, the post-treatment of step 3' is carried out as follows: sequentially carrying out solvent removal, dilution dissolution and filtration treatment, then taking filtrate to crystallize at the temperature of below-10 ℃ (preferably below-25 ℃), removing mother liquor after crystallization, and drying the solid in vacuum to obtain the mono-metallocene compound.

In a further preferred embodiment, the post-treatment of step 3' is carried out as follows: removing the solvent in vacuum, adding toluene for redissolving, filtering by using a diatomite filter aid, freezing and crystallizing the filtrate at the temperature below-25 ℃, removing the mother liquor after crystallization, and drying the rest solid in vacuum to obtain the mono-metallocene compound.

In a preferred embodiment, the molar ratio of the compound of formula (VII) in step 1 'to the compound of formula (VI) in step 2' is 1: 1.

In a preferred embodiment, in step 1', the molar ratio of the alkyl lithium compound to the compound represented by formula (VII) is (1-1.1): 1, preferably (1.02 to 1.05): 1.

compared with the prior art, the invention has the following beneficial effects: the polymerization system adopts the single metallocene compound with a special structure, the raw materials for preparing the polymerization system are cheap, the preparation is simple, safe and efficient, and the syndiotactic polystyrene can be obtained by utilizing the polymerization system, and has the advantages of high molecular weight, narrow molecular weight distribution and the like.

Drawings

FIG. 1 shows the nuclear magnetic spectrum of the polymer obtained in example 5.

Detailed Description

While the present invention will be described in detail with reference to the following examples, it should be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the present invention.

It is to be further understood that the various features described in the following detailed description may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

The starting materials for the inventive and comparative examples are commercially available.

EXAMPLE 1 Synthesis of pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium

Putting the magnetons into a dry 250 ml three-mouth bottle, and putting the bottle into an oil bath temperature-controlled magnetic stirring device; the three-necked flask was evacuated and flushed with nitrogen repeatedly three times. And 2.02 g of pentamethylcyclopentadienyl-trimethoxy titanium and 1.06 g of 4-hydroxy-1-quinoline are added under the nitrogen atmosphere, and the mixture is stirred and reacted for 2 hours under vacuum (less than 1 mm Hg) at the temperature of 70 ℃. Charging nitrogen, adding a small amount of 20mL of toluene to dissolve, then dropwise adding 2mL of hexane, placing in a freezer for freezing crystallization, precipitating yellow solid at the bottom of a bottle, removing solvent mother liquor by a needle head, and performing vacuum drying to obtain 2.61 g of yellow powder, namely pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium, wherein the molar yield is 92%.

¹H-NMR(CDCl₃,25℃):δ＝1.75(Cp*,15H),3.39(CH₃O,6H),7.6(1H),7.9～8.2(2H),8.3～8.5(2H),9.1～9.2(1H)。

EXAMPLE 2 Synthesis of cyclopentadienyl-4-quinolinyloxy-titanium dichloride

Putting magnetons into a dry 250 mL three-necked bottle, vacuumizing the three-necked bottle, flushing the three-necked bottle with nitrogen, repeating the steps for three times, adding 0.73g of 4-hydroxy-1-quinoline, placing the bottle in an ice bath, adding 40mL of toluene, and stirring to dissolve. Slowly dropwise adding 2.2 ml of n-butyllithium (2.5 mol per liter of n-hexane solution), naturally heating to room temperature, and reacting overnight; putting the magnetons into another dry 250 mL three-necked bottle, vacuumizing the three-necked bottle, flushing the three-necked bottle with nitrogen, repeating the steps for three times, adding 1.10g of cyclopentadienyl titanium trichloride, adding 60mL of toluene to dissolve the cyclopentadienyl titanium trichloride, placing the solution in an ice bath, slowly dropwise adding the reaction solution in the previous three-necked bottle, naturally heating the solution to room temperature, and reacting the solution overnight; all solvents were removed in vacuo, toluene was added for redissolution, filtered, the filter cake was washed with toluene and the solution was crystallized by freezing. 1.18 g of a red solid was obtained, namely cyclopentadienyl-4-quinolinyloxy-titanium dichloride, in a molar yield of 72%.

¹H-NMR(CDCl₃,25℃):δ＝6.58(Cp,5H),7.6(1H),8.0～8.2(2H),8.3～8.5(2H),9.1～9.2(1H)。

EXAMPLE 3 Synthesis of pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium

Putting the magnetons into a dry 250 ml three-mouth bottle, and putting the bottle into an oil bath temperature-controlled magnetic stirring device; the three-necked flask was evacuated and flushed with nitrogen repeatedly three times. And 1.12 g of pentamethylcyclopentadienyl-trimethoxy titanium and 0.65 g of 2-methyl-4-hydroxy-1-quinoline are added under the nitrogen atmosphere, and the mixture is stirred and reacted for 2 hours under vacuum (less than 1 mm Hg) at the temperature of 70 ℃. Filling nitrogen, adding 20mL of toluene for dissolving, then dropwise adding 2mL of hexane, placing in a freezer for freezing and crystallizing, precipitating yellow solid at the bottom of a bottle, pumping out solvent mother liquor by a needle head, and performing vacuum drying to obtain 1.15 g of light yellow powder, namely pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium, wherein the molar yield is 70%.

¹H-NMR(CDCl₃,25℃):δ＝1.75(Cp*,15H),2.5(CH₃,3H),3.39(CH₃O,6H),6.6(1H),7.7～7.9(3H),8.2(1H)。

EXAMPLE 4 Synthesis of pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinoxy) -dimethoxytitanium

Putting the magnetons into a dry 250 ml three-mouth bottle, and putting the bottle into an oil bath temperature-controlled magnetic stirring device; the three-necked flask was evacuated and flushed with nitrogen repeatedly three times. And 1.15 g of pentamethylcyclopentadienyl-trimethoxy titanium and 1.17 g of 2, 8-bis (trifluoromethyl) -4-hydroxy-1-quinoline are added under nitrogen atmosphere, and the reaction is stirred at 70 ℃ under vacuum (less than 1 mm Hg) for 2 hours. Filling nitrogen, adding 20mL of toluene for dissolving, then dropwise adding 2mL of hexane, placing in a freezer for freezing and crystallizing, precipitating yellow solid at the bottom of a bottle, pumping out solvent mother liquor by a needle head, and performing vacuum drying to obtain 1.49 g of yellow powder, namely pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinyloxy) -dimethoxytitanium, wherein the molar yield is 68%.

¹H-NMR(CDCl₃,25℃):δ＝1.75(Cp*,15H),3.39(CH₃O,6H),6.6(1H),7.8(1H),8.2～8.4(2H)。

EXAMPLE 5 polymerization of styrene Using pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 70 ℃, 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of methylaluminoxane toluene solution (containing 7.5 mmol of methylaluminoxane), and 1.0 ml of pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium catalyst toluene solution (containing 5. mu. mol of catalyst) in example 1 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, drying a filter cake at 60 ℃ for 24 hours in vacuum, and weighing to obtain 0.73g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.70 g of SPS polymer.

Polymer weight average molecular weight Mw 4.71x10⁵g/mol, MWD of 1.86, and melting point of 270 deg.C.

Nuclear magnetic resonance analysis of the polymer obtained in example 5 (nuclear magnetic resonance spectrometer Bruker AVANCEIII-400MHz, solvent d)₂-1,1,2, 2-tetrachloroethane, tested at 125 ℃), the results are shown in fig. 1, and it can be seen from fig. 1 that syndiotactic polystyrene is successfully obtained, wherein the peak at 70-80 ppm is the solvent peak.

EXAMPLE 6 polymerization of styrene Using pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 70 ℃, 8.0 ml of toluene, 5.0 ml of styrene, 6.0 ml of methylaluminoxane toluene solution (containing 10.0 mmol of methylaluminoxane), and 1.0 ml of pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium catalyst toluene solution (containing 5. mu. mol of catalyst) in example 1 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, drying a filter cake at 60 ℃ for 24 hours in vacuum, and weighing to obtain 0.26 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.24 g of SPS polymer.

Polymer weight average molecular weight Mw 1.74x10⁵g/mol, MWD 2.10, and melting point 271 deg.C.

EXAMPLE 7 polymerization of styrene Using pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 70 ℃, 6.5 ml of toluene, 5.0 ml of styrene, 7.5 ml of methylaluminoxane toluene solution (containing 12.5 mmol of methylaluminoxane), and 1.0 ml of pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium catalyst toluene solution (containing 5. mu. mol of catalyst) in example 1 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, drying a filter cake at 60 ℃ for 24 hours in vacuum, and weighing to obtain 0.28 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.26 g of SPS polymer.

Polymer weight average molecular weight Mw 1.49x10⁵g/mol, MWD of 1.78, and melting point of 272 ℃.

EXAMPLE 8 polymerization of styrene Using pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 55 ℃ 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of a toluene solution of methylaluminoxane (containing 7.5 mmol of methylaluminoxane) and 1.0 ml of a toluene solution of pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium catalyst (containing 5. mu. mol of catalyst) in example 1 were sequentially added to start timekeeping. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, drying a filter cake at 60 ℃ for 24 hours in vacuum, and weighing to obtain 0.06g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.05 g of SPS polymer.

Polymer weight average molecular weight Mw 7.18x10⁴g/mol, MWD of 1.70, and melting point of 272 ℃.

EXAMPLE 9 polymerization of styrene Using pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 85 ℃ 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of a toluene solution of methylaluminoxane (containing 7.5 mmol of methylaluminoxane) and 1.0 ml of a toluene solution of pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium catalyst (containing 5. mu. mol of catalyst) in example 1 were sequentially added to start timekeeping. After the polymerization time is 2200 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, vacuum-drying a filter cake at 60 ℃ for 24 hours, and weighing to obtain 0.29 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.27 g of SPS polymer.

Polymer weight average molecular weight Mw 1.37x10⁵g/mol, MWD 1.66, polymer melting point 272 ℃.

EXAMPLE 10 polymerization of styrene Using pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 55 ℃ 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of a toluene solution of methylaluminoxane (containing 7.5 mmol of methylaluminoxane), and 1.0 ml of a toluene solution of pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium catalyst (containing 5. mu. mol of catalyst) in example 3 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, vacuum-drying a filter cake at 60 ℃ for 24 hours, and weighing to obtain 0.16 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.14 g of SPS polymer.

Polymer weight average molecular weight Mw 1.79x10⁵g/mol, MWD 1.87, and melting point 271 deg.C.

EXAMPLE 11 polymerization of styrene Using pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 70 ℃, 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of methylaluminoxane toluene solution (containing 7.5 mmol of methylaluminoxane), and 1.0 ml of pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium catalyst toluene solution (containing 5. mu. mol of catalyst) in example 3 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, vacuum-drying a filter cake for 24 hours at 60 ℃, and weighing to obtain 0.31 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.29 g of SPS polymer.

Polymer weight average molecular weight Mw 1.66x10⁵g/mol, MWD 1.79, polymer melting point 272 ℃.

EXAMPLE 12 polymerization of styrene Using pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 85 ℃ 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of a toluene solution of methylaluminoxane (containing 7.5 mmol of methylaluminoxane), and 1.0 ml of a toluene solution of pentamethylcyclopentadienyl- (3-methyl-4-quinolinyloxy) -dimethoxytitanium catalyst (containing 5. mu. mol of catalyst) in example 3 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, drying a filter cake at 60 ℃ for 24 hours in vacuum, and weighing to obtain 0.42 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.40 g of SPS polymer.

Polymer weight average molecular weight Mw 1.47x10⁵g/mol, MWD 1.81, and melting point 271 deg.C.

EXAMPLE 13 polymerization of styrene Using pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinyloxy) -dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 55 ℃ 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of methylaluminoxane toluene solution (containing 7.5 mmol of methylaluminoxane), and 1.0 ml of pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinyloxy) -dimethoxytitanium catalyst toluene solution (containing 5. mu. mol of catalyst) in example 4 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, drying a filter cake at 60 ℃ for 24 hours in vacuum, and weighing to obtain 0.03 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.01 g of SPS polymer.

Polymer weight average molecular weight Mw 2.23x10⁵g/mol, MWD 1.91, polymer melting point 269 ℃.

EXAMPLE 14 polymerization of styrene Using pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinyloxy) -dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 70 ℃ 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of methylaluminoxane toluene solution (containing 7.5 mmol of methylaluminoxane), and 1.0 ml of pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinyloxy) -dimethoxytitanium catalyst toluene solution (containing 5. mu. mol of catalyst) in example 4 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, drying a filter cake at 60 ℃ for 24 hours in vacuum, and weighing to obtain 0.05 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.03 g of SPS polymer.

Polymer weight average molecular weight Mw 2.02x10⁵g/mol, MWD of 1.86, and melting point of 270 deg.C.

EXAMPLE 15 polymerization of styrene Using pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinyloxy) -dimethoxytitanium as catalyst

The dried polymerization bottle is vacuumized and repeatedly flushed with nitrogen for three times; at a polymerization temperature of 85 ℃ 9.5 ml of toluene, 5.0 ml of styrene, 4.5 ml of methylaluminoxane toluene solution (containing 7.5 mmol of methylaluminoxane), and 1.0 ml of pentamethylcyclopentadienyl- (3, 5-bis (trifluoromethyl) -4-quinolinyloxy) -dimethoxytitanium catalyst toluene solution (containing 5. mu. mol of catalyst) in example 4 were sequentially added to start timing. After the polymerization time is 20 minutes, carefully pouring the reaction solution into a beaker, adding acidified ethanol, stirring for more than 6 hours, filtering to obtain a polymer, drying a filter cake at 60 ℃ for 24 hours in vacuum, and weighing to obtain 0.05 g of the polymer; the polymer was refluxed in boiling acetone for 2 hours, filtered while hot to give a solid polymer, which was dried under vacuum at 60 ℃ for 24 hours to give 0.03 g of SPS polymer.

Polymer weight average molecular weight Mw 1.89x10⁵g/mol, molecular weight fractionThe MWD is 1.88, and the melting point of the polymer is 270 ℃.

Comparative example 1 Synthesis of pentamethylcyclopentadienyl-phenoxy-dimethoxytitanium

The procedure of example 1 was repeated except that: phenol was used instead of 4-hydroxy-1-quinoline. Obtaining pentamethylcyclopentadienyl-phenoxy-dimethoxy titanium with the yield of 90 percent,¹H-NMR(CDCl₃,25℃):δ＝1.75(Cp*,15H),3.39(CH₃O,6H),6.8-7.3(5H)。

comparative example 2 polymerization of styrene Using pentamethylcyclopentadienyl-phenoxy-dimethoxy titanium as catalyst

The procedure of example 5 was repeated except for using the pentamethylcyclopentadienyl-phenoxy-dimethoxytitanium obtained in comparative example 1 in place of pentamethylcyclopentadienyl-4-quinolinyloxy-dimethoxytitanium. 0.06g of a polymer was obtained.

Gel permeation chromatography detection of weight average molecular weight Mw of polymer 6.2x10⁴g/mol, MWD of 2.02, and melting point of polymer of 270 deg.C by differential scanning calorimetry.

Comparing this comparative example 2 with example 5, it can be seen that example 5, using the catalyst polymerization system of the present invention, yields polystyrene having a higher molecular weight and a narrower molecular weight distribution.