阅读说明：本技术 一种g-C3N4/MgCl2复合载体型丙烯聚合催化剂的制备方法 (g-C3N4/MgCl2Preparation method of composite carrier type propylene polymerization catalyst ) 是由 梁培松 江海涛 黄守忠 杨健文 刘景棠 林培喜 郭鹏虎 于 2021-10-26 设计创作，主要内容包括：本发明公开了一种g-C-(3)N-(4)/MgCl-(2)复合载体型丙烯聚合催化剂的制备方法,包括以下步骤：(1)在N-(2)保护和不断搅拌情况下,将烷基氯化镁加入到装有有机溶剂的玻璃反应器中,然后搅拌1-3小时至完全溶解；(2)然后将处理过的g-C-(3)N-(4)粉末加入氯化镁溶液中继续搅拌至充分混合反应；(3)在较低温度下,将TiCl-(4)逐滴加入到步骤(2)所得的溶液中,搅拌下充分混合反应；(4)将内给电子体加入步骤(3)所得的溶液中,逐步升温,反应第一预设时间后,滤去液体；再次加入TiCl-(4)反应第二预设时间,最后过滤洗涤干燥,得到g-C-(3)N-(4)/MgCl-(2)复合载体型丙烯聚合催化剂。本发明的制备方法操作简单,产率较高,对设备要求低,易于大规模生产,无机灰分底。(The invention discloses a g-C 3 N 4 /MgCl 2 The preparation method of the composite carrier type propylene polymerization catalyst comprises the following steps: (1) in N 2 Under the condition of protection and continuous stirring, adding alkyl magnesium chloride into a glass reactor filled with an organic solvent, and then stirring for 1-3 hours until the alkyl magnesium chloride is completely dissolved; (2) then the treated g-C 3 N 4 Adding the powder into a magnesium chloride solution, and continuously stirring until the powder is fully mixed and reacted; (3) at a lower temperature, TiCl is reacted 4 Dropwise adding the mixture into the solution obtained in the step (2), and fully mixing and reacting under stirring; (4) adding an internal electron donor into the solution obtained in the step (3), gradually heating, reacting for a first preset time, and filtering to remove liquid; adding TiCl again 4 Second step of reactionSetting time, finally filtering, washing and drying to obtain g-C 3 N 4 /MgCl 2 Composite carrier type propylene polymerization catalyst. The preparation method provided by the invention is simple to operate, high in yield, low in equipment requirement, easy for large-scale production and free of inorganic ash.)

1. g-C₃N₄/MgCl₂Composite carrier type propylene polymerizationThe preparation method of the catalyst is characterized by comprising the following steps:

(1) in N₂Under the condition of protection and continuous stirring, adding alkyl magnesium chloride into a glass reactor filled with an organic solvent, and then stirring for 1-3 hours until the alkyl magnesium chloride is completely dissolved;

(2) then the treated g-C₃N₄Adding the powder into the magnesium chloride solution, and continuously stirring until the powder is fully mixed and reacted;

(3) at a lower temperature, TiCl is reacted₄Dropwise adding the mixture into the solution obtained in the step (2), and fully mixing and reacting under stirring;

(4) adding an internal electron donor into the solution obtained in the step (3), gradually heating, reacting for a first preset time, and filtering to remove liquid; adding the TiCl again₄Reacting for a second preset time, and finally filtering, washing and drying to obtain the g-C₃N₄/MgCl₂Composite carrier type propylene polymerization catalyst.

2. The method of claim 1, wherein: in the step (1), the alkyl magnesium chloride is one of methyl magnesium chloride, ethyl magnesium chloride and propyl magnesium chloride, and the organic solvent is at least one of n-hexane, n-heptane, cyclohexane, benzene and toluene.

3. The method of claim 1, wherein: in the step (2), the g-C₃N₄The powder is light yellow powder, the particle size is 1-7 microns, the pretreatment condition is that the powder is heated at the temperature of 100-; the g to C₃N₄The molar ratio of powder to the alkyl magnesium chloride is 1: 1-30 and the reaction time is 2-20 hours.

4. The method of claim 1, wherein: in the step (3), the lower temperature is-20 to 50 ℃ and the reaction time is 3 to 18 hours.

5. The method of claim 1, wherein: in the step (4), the internal electron donor is one of di-n-butyl phthalate and diisobutyl phthalate; the gradual temperature rise refers to the temperature rise from lower temperature to 100 to 120 ℃; the molar ratio of the alkyl magnesium chloride to the internal electron donor is 1: 0.01-0.1.

Technical Field

The invention relates to the technical field of propylene polymerization catalysts, in particular to g-C₃N₄/MgCl₂A preparation method of composite carrier type propylene polymerization catalyst.

Background

The polypropylene material is widely applied to a plurality of fields of daily life, industry, agriculture and the like, and is an indispensable high polymer material with excellent performance. The catalysts are reported by Ziegler, a German scientist, and then the application range of the catalysts is expanded by Nata, a plurality of generations of propylene polymerization catalysts are developed, and the supported TiCl is mostly applied to the commercial use at present₄A catalyst. The support has a significant effect on the performance of the catalyst, and thus, the regulation of the support has attracted a wide research interest.

Currently, most commercially available propylene polymerization catalysts employ activated MgCl₂As TiCl₄Of a single support, TiCl₄Distributed in MgCl₂The outermost layer of the particle is a thin layer. In order to further improve the performance of the propylene polymerization catalysts, some researchers began exploring MgCl₂And other compounds, e.g. CN200510049657 discloses a MgCl₂/AlCl₃A composite supported catalyst, Wang Lu Hai, etc. discloses a MgCl₂/SiO₂Catalyst with composite carrier, CN200910265394.2 discloses MgCl₂And porous polymer microspheres. However, MgCl₂And a composite supported catalyst of a carbon material has not been reported at present. The carbon material is easily modified by N, O and other elements, so that the electricity of the carbon material can be remarkably regulatedSubstructure, while a large number of N, O may serve as sites for anchoring metals. Wherein g-C₃N₄The carbon nitride material is a graphite phase carbon nitride material, contains a large number of N sites (figure 2), is one of ideal materials as a metal catalyst carrier, and is used as one of carriers of propylene polymerization catalysts in research of the patent to further improve the performance of the catalysts.

Disclosure of Invention

Technical problem to be solved

The invention aims to pass g-C₃N₄And MgCl₂Electronic interaction between the two supports, moderating MgCl₂The electronic condition of the support, and then the activity of the Ti catalytic site is regulated through Mg-Cl-Ti bridge bonds. At the same time, the inorganic ash content of the propylene polymerization catalyst is reduced.

(II) technical scheme

In order to solve the technical problems, the invention provides the following technical scheme: g-C₃N₄/MgCl₂The preparation method of the composite carrier type propylene polymerization catalyst comprises the following steps:

(1) in N₂Under the condition of protection and continuous stirring, adding alkyl magnesium chloride into a glass reactor filled with an organic solvent, and then stirring for 1-3 hours until the alkyl magnesium chloride is completely dissolved;

(2) then the treated g-C₃N₄Adding the powder into a magnesium chloride solution, and continuously stirring until the powder is fully mixed and reacted;

(3) at a lower temperature, TiCl is reacted₄Dropwise adding the mixture into the solution obtained in the step (2), and fully mixing and reacting under stirring;

(4) adding an internal electron donor into the solution obtained in the step (3), gradually heating, reacting for a first preset time, and filtering to remove liquid; adding TiCl again₄Reacting for a second preset time, and finally filtering, washing and drying to obtain g-C₃N₄/MgCl₂Composite carrier type propylene polymerization catalyst.

Preferably, in the step (1), the alkyl magnesium chloride is one of methyl magnesium chloride, ethyl magnesium chloride and propyl magnesium chloride, and the organic solvent is at least one of n-hexane, n-heptane, cyclohexane, benzene and toluene.

Preferably, in step (2), g-C₃N₄The powder is light yellow powder, the particle size is 1-7 microns, the pretreatment condition is that the powder is heated at the temperature of 100-; g-C₃N₄The molar ratio of powder to alkyl magnesium chloride is 1: 1-30 and the reaction time is 2-20 hours.

Preferably, in step (3), the lower temperature means-20 to 50 ℃ and the reaction time is 3 to 18 hours.

Preferably, in the step (4), the internal electron donor is one of di-n-butyl phthalate and diisobutyl phthalate; the gradual temperature rise refers to the temperature rise from lower temperature to 100 to 120 ℃; the molar ratio of the alkyl magnesium chloride to the internal electron donor is 1: 0.01-0.1.

(III) advantageous effects

Compared with the prior art, the invention provides g-C₃N₄/MgCl₂The preparation method of the composite carrier type propylene polymerization catalyst has the following beneficial effects: (1) the preparation method of the invention has relatively simple operation and low equipment requirement, and is convenient for mass production; (2) the inorganic ash content of the composite carrier type propylene polymerization catalyst produced by the invention is relatively low; (3) the composite carrier type propylene polymerizing catalyst has composite carrier g-C₃N₄As inner core, outer layer is MgCl₂Wrapping, reaction product B contains Mg-Cl-Ti chemical bond and MgCl is carried by MgCl₂And g-C₃N₄The electron interaction between the Ti and the Ti can regulate the catalytic activity of the polymerization of propylene.

Drawings

FIG. 1 shows a graph of g-C of graphite-phase carbon nitride₃N₄Scanning electron microscope images of;

FIG. 2 shows the graphite phase carbon nitride g-C₃N₄A powder particle packing diagram of (a), and a chemical structure diagram;

FIG. 3 shows the graphite phase carbon nitride g-C₃N₄Powder X-ray diffraction pattern of (a);

FIG. 4 is g-C₃N₄/MgCl₂The structure of the composite carrier type propylene polymerization catalyst is shown schematically.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

a filter-type round-bottom flask with 40mL of toluene was connected to a double-calandria device and high-purity N was used₂Bubbling for 1-3 hours to drive off air, in N₂Under the protection atmosphere, 1.50mL of methyl magnesium chloride is added into a round-bottom flask and stirred for 3-8 hours to be fully dissolved. Then a certain amount of pretreated g-C₃N₄0.500.50g (purity is characterized by powder XRD, see figure 3) is added into the solution, the reaction is continued to be stirred for 5 to 15 hours at the temperature of 55 ℃, and the liquid is filtered off by suction to obtain g-C₃N₄/MgCl₂The composite carrier powder was in a flask. Adding 40mL of toluene and using high-purity N₂Bubbling for 1-3 hours to remove air, cooling to-20 ℃, and dropwise adding TiCl under stirring₄3mL, reacting for 0.5-1 hour, slowly heating to 80 ℃ for 2 hours, adding 1.0mL of di-n-butyl phthalate, continuing to react for 1-2 hours, and filtering out the liquid. Adding 25mL of anhydrous toluene, N₂Protection, addition of TiCl₄4mL, and reacting for 1-2 hours at 90 ℃ with stirring. Washing with hexane for 3-5 times, vacuum filtering to remove liquid, and vacuum drying to obtain g-C₃N₄/MgCl₂Composite carrier type propylene polymerization catalyst powder.

Example 2:

a filter-type round-bottom flask with 40mL of toluene was connected to a double-calandria device and high-purity N was used₂Bubbling for 1-3 hours to drive off air, in N₂Under the protection atmosphere, 1.50mL of methyl magnesium chloride is added into a round-bottom flask and stirred for 3-8 hours to be fully dissolved. Then a certain amount is pre-measuredTreated g-C₃N₄Adding 0.80g of the solution into the solution, continuously stirring the solution at the temperature of 55 ℃ for reaction for 5 to 15 hours, and filtering the solution to obtain g-C₃N₄/MgCl₂The composite carrier powder is in a flask. Adding 40mL of toluene and using high-purity N₂Bubbling for 1-3 hours to remove air, cooling to-20 ℃, and dropwise adding TiCl under stirring₄3mL, reacting for 0.5-1 hour, slowly heating to 80 ℃ for 2 hours, adding 1.0mL of di-n-butyl phthalate, continuing to react for 1-2 hours, and filtering out the liquid. Adding 25mL of anhydrous toluene, N₂Protection, addition of TiCl₄4mL, and reacting for 1-2 hours at 90 ℃ with stirring. Washing with hexane for 3-5 times, vacuum filtering to remove liquid, and vacuum drying to obtain g-C₃N₄/MgCl₂Composite carrier type propylene polymerization catalyst powder.

Example 3:

a filter-type round-bottom flask with 40mL of toluene was connected to a double-calandria device and high-purity N was used₂Bubbling for 1-3 hours to drive off air, in N₂Under the protection atmosphere, 2.00mL of ethyl magnesium chloride is added into a round-bottom flask, and is stirred for 3-8 hours to be fully dissolved. Then a certain amount of pretreated g-C₃N₄Adding 0.50g of the solution into the solution, continuously stirring the solution at the temperature of 55 ℃ for reaction for 5 to 15 hours, and filtering the solution to obtain g-C₃N₄/MgCl₂The composite carrier powder is in a flask. Adding 40mL of toluene and using high-purity N₂Bubbling for 1-3 hours to remove air, cooling to-20 ℃, and dropwise adding TiCl under stirring₄3mL, reacting for 0.5-1 hour, slowly heating to 80 ℃ for 2 hours, adding 1.0mL of diisobutyl phthalate, continuing to react for 1-2 hours, and filtering out liquid. Adding 25mL of anhydrous toluene, N₂Protection, addition of TiCl₄4mL, and reacting for 1-2 hours at 90 ℃ with stirring. Washing with hexane for 3-5 times, vacuum filtering to remove liquid, and vacuum drying to obtain g-C₃N₄/MgCl₂Composite carrier type propylene polymerization catalyst powder.

Example 4:

a filter-type multi-neck round-bottom flask containing 40mL of toluene was attached to a double calandria deviceFlour, using high-purity N₂Bubbling for 1-3 hours to drive off air, in N₂Under the protection atmosphere, 2.00mL of ethyl magnesium chloride is added into a round-bottom flask, and is stirred for 3-8 hours to be fully dissolved. Then a certain amount of pretreated g-C₃N₄Adding 0.80g of the solution into the solution, continuously stirring the solution at the temperature of 55 ℃ for reaction for 5 to 15 hours, and filtering the solution to obtain g-C₃N₄/MgCl₂The composite carrier powder is in a flask. Adding 40mL of toluene and using high-purity N₂Bubbling for 1-3 hours to remove air, cooling to-20 ℃, and dropwise adding TiCl under stirring₄3mL, reacting for 0.5-1 hour, slowly heating to 80 ℃ for 2 hours, adding 1.0mL of diisobutyl phthalate, continuing to react for 1-2 hours, and filtering out liquid. Adding 25mL of anhydrous toluene, N₂Protection, addition of TiCl₄4mL, and reacting for 1-2 hours at 90 ℃ with stirring. Washing with hexane for 3-5 times, vacuum filtering to remove liquid, and vacuum drying to obtain g-C₃N₄/MgCl₂Composite carrier type propylene polymerization catalyst powder.

It is to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.