Synthesis of ziegler-natta catalyst based on spherical magnesium ethoxide with improved morphology for propylene polymerization

Abstract

A novel method for synthesizing spherical magnesium ethoxide (MGE) with enhanced morphology, mechanical strength, and surface smoothness is described. The process utilizes a double-jacketed reactor, equipped with a mechanical stirrer, condenser, and flow meter. Magnesium powder (60–300 microns, 17–25 wt%) and iodine (0.5–1 wt%) as an initiator are reacted with ethanol at a magnesium-to- ethanol weight ratio of 8:1 to 14:1. The reactor is maintained at 60°C for 6 hours, with stirring at 250 rpm for 5–30 minutes to initiate alkoxylation. Additional magnesium and ethanol are introduced at 10–30 minute intervals to control reaction kinetics and nucleation. A titanium tetraalkoxide modifier is added during precipitation-recrystallization. The reaction proceeds under ethanol reflux until hydrogen gas production ceases, followed by ethanol removal, heptane washing, and vacuum-drying at 70°C.

Description

DescriptionTitle of Invention: Synthesis of Ziegler-Natta catalyst based on spherical magnesium ethoxide with improved morphology for propylene polymerization | Technical Field

[0001] The present invention is in the field of chemistry and catalysts, particularly Ziegler-Natta catalysts for the polymerization of olefins such as ethylene and propylene.Background Art

[0002] The following background information may present examples of specific aspects of the prior art that, while expected to be helpful to further teach the reader as to extra features of the prior art, is not to be understood as limiting the present invention, or any embodiments thereof, to anything stated or implied therein or inferred accordingly.

[0003] In 1953, the research conducted by Ziegler and his colleagues on organometallic compounds and their application in ethylene polymerization led to the discovery of Ziegler-Natta catalysts, marking one of the greatest scientific achievements in the field of polymer synthesis chemistry. Catalysts based on the reaction products of magnesium alkoxides with transition metals are highly active catalysts for the polymerization of ethylene and propylene, derived from the reaction between titanium tetrachloride and magnesium alkoxides. During this reaction, the initial structure of the alkoxide is broken down, resulting in new fragments with a large surface area.

[0004] Magnesium alkoxides, particularly magnesium ethoxide (MGE), are regarded as one of the best supports for Ziegler-Natta catalysts and are widely utilized in industries for producing catalysts for ethylene and propylene polymerization. The process of producing magnesium alkoxide with spherical morphology through the alkoxidation of magnesium metal — via the direct reaction of metallic magnesium with alcohol — is well- established. Additionally, the reaction of metallic magnesium with a mixture of alcohols at a temperature below the boiling point of the alcohol mixture, inthe presence of an iodine initiator, has been used to produce spherical magnesium alkoxide. The reaction between magnesium and alcohol is accompanied by the release of hydrogen gas, during which the oxidation state of the metal particle surfaces is minimized. Consequently, the reaction is preferably conducted in a neutral atmosphere, such as nitrogen, to protect the metal surface from oxidation.

[0005] Despite numerous efforts to control catalyst morphology, there remains a need to address this issue more precisely and provide solutions for the shortcomings of previous inventions. In all registered patents, process control parameters — such as the ratio of raw materials, the type and proportion of initiators, and modifications to thermal processes — have been employed to refine and improve morphology. However, in the present invention, titanium tetraalkoxide compounds have been used as morphology modifiers during the synthesis of magnesium ethoxide particles, yielding significant results.

[0006] The objective of this invention is to synthesize magnesium ethoxide that is resistant to abrasion while enhancing its morphology and mechanical strength. To achieve this, titanium tetraalkoxide compounds were utilized as morphology modifiers in the MGE synthesis process. By controlling the molar ratios of reactants and modifiers, along with other process parameters, magnesium ethoxide with improved morphology was successfully synthesized.

[0007] The US Pat.application No. US 2001 / 0039241 entitled " Magnesium / titanium alkoxide compounds and method of preparation" pertains to magnesium / titanium alkoxide compounds and their preparation method. It discloses magnesium and titanium alkoxide complexes that are useful as precursors for olefin polymerization procatalysts, procatalysts containing these complexes, and their use as a catalyst component for the polymerization of olefin monomers. The complexes are prepared by reacting a magnesium alkoxide and a titanium alkoxide in the presence of a clipping agent to form a solid complex. This solid complex can then be used to form a procatalyst by contacting it with a halogenating agent, optionally a tetravalent titanium halide, and optionally an electron donor. The procatalystcan subsequently be converted into an olefin polymerization catalyst by contacting it with a cocatalyst and, if desired, a selectivity control agent. In the aforementioned invention, procatalysts are produced that can be transformed into catalysts for polyolefin polymerization. The synthesis method for these procatalysts is entirely different from the synthesis method in the present invention, as titanium tetraethoxide is used in the catalyst preparation stage. In contrast, the present invention focuses on synthesizing magnesium ethoxide (as a Ziegler-Natta catalyst support) with improved morphology. In this invention, titanium tetraethoxide is utilized during the magnesium ethoxide synthesis stage, resulting in a new type of catalyst support that enhances particle surface quality, increases sphericity, and improves bulk density.

[0008] The US Pat.application No. US20140296454 entitled " CATALYST SYSTEM FOR THE PRODUCTION OF ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE" pertains to a catalyst system for producing ultra-high molecular weight polyethylene. It comprises:

[0009] A solid reaction product obtained from the reaction of:

[0010] (a) A hydrocarbon solution containing an organic oxygen compound with magnesium or a halogen-containing magnesium compound and an organic oxygen compound with titanium, and

[0011] (b) A mixture comprising a metal compound with the formula MeRnX3-n, where X is a halogen, Me is a metal from Group III of Mendeleev’s Periodic Table of Chemical Elements, R is a hydrocarbon radical containing 1-10 carbon atoms, and 0 < n < 3, and a silicon compound with the formula RmSiCI4-m, where 0 < m < 2 and R is a hydrocarbon radical containing 1-10 carbon atoms, with the molar ratio of the metal from (b) to titanium from (a) being less than 1:1.

[0012] An organic aluminum compound with the formula AIR3, where R is a hydrocarbon radical containing 1-10 carbon atoms.

[0013] An external electron donor selected from the group consisting of 1,2- dialkoxyalkanes, 1,2-dialkoxyalkenes, or a polymeric external electron donor.

[0014] In the aforementioned invention, the synthesized catalyst is used for the polymerization of ultra-high molecular weight polyethylene, whereas in the present invention, the synthesized catalyst is intended for propylene polymerization. Additionally, the above invention makes no mention of the synthesis of magnesium ethoxide.

[0015] The US. Patent No. 5965478 entitled " Solid catalyst component and catalyst for polymerization of olefins" " pertains to a solid catalyst component for olefin polymerization, prepared by reacting a titanium halide, a diester of an aromatic dicarboxylic acid, and a dialkoxy magnesium compound with a bulk density of at least 0.25 g / mL and an average particle size of 1 to 100 micrometers. The average rate of temperature increase, from the temperature at which the titanium halide is allowed to contact the dialkoxy magnesium to the temperature at which the reaction begins, ranges from 0.5 to 20°C per minute. Such a catalyst may include an organic aluminum compound and an organic silicon compound. The use of this catalyst enables the efficient production of a polyolefin with high stereoregularity, high bulk density, and excellent particle properties. The reaction is carried out by continuously adding the reaction components (both magnesium and ethanol) to the reactor at the boiling point of ethanol, and the resulting product is used to prepare a Ziegler-Natta catalyst for gas-phase propylene polymerization.

[0016] The aforementioned invention uses a mixture of alcohols — ethanol, methanol, and isopropanol — at the boiling point of the alcohol mixture to produce the catalyst support, and no morphology-modifying compounds are employed in its production process. Therefore, it differs from the invention presented in the current patent document in terms of the type of alcohol used, process conditions, final particle morphology, as well as internal and external donors.

[0017] The US application No. US20040254063 entitled " Magnesium dichloride-alcohol adducts and catalyst components obtained therefrom" pertains to magnesium dichloride-alcohol adducts and the catalyst components derived from them. This invention relates to an adduct comprising MgCI2, an alcohol (ROH) where R is a C1-C10 hydrocarbongroup, and a compound containing a transition metal M selected from Groups 3 to 11 or the lanthanide or actinide groups of the periodic table, in an amount such that the weight of the metal M constitutes less than 10% of the total weight of the adduct. The catalyst components obtained from the reaction of these adducts with halogenating agents exhibit exceptionally high specific activity.

[0018] In present invention, to reduce catalyst abrasion, a small amount of elements from the lanthanide and actinide groups is used in the reaction to produce a catalyst resistant to abrasion and mechanical stress. Catalyst abrasion is the primary cause of fine particle generation during polymerization, and by increasing the catalyst’s resistance to abrasion, the amount of fine polymer produced is reduced. Although this invention aims to enhance the catalyst’s resistance to mechanical stresses likely encountered during polymerization, it differs from the invention presented in the current patent document in terms of the type of catalyst support (magnesium chloride adduct), the modifying compounds (lanthanides and actinides), and the stage of their application (catalyst production stage).

[0019] Antoine Klaue et al. " Insight into the Synthesis Process of an Industrial Ziegler-Natta Catalyst", Industrial & Engineering Chemistry Research, Vol.58 / Issue 2, describes the synthesis process of an industrial Ziegler-Natta catalyst. In Ziegler-Natta catalysis, the particle size of the catalyst not only affects its performance but also significantly impacts the morphology and particle size distribution of the final polymer. Therefore, a fundamental understanding of the catalyst particle formation process is of industrial importance when addressing specific requirements for the final products. In the present work, a single-step catalyst preparation process is thoroughly characterized, involving the reactive precipitation of a MgCI2-supported Ziegler-Natta catalyst through the decomposition of a hetero-bimetallic complex, Mg(OR)2-Ti(OR)4. The evolution of the concentrations of metals (Mg, Ti, Al) and chlorine in the liquid phase, as well as the size of the formed catalyst particles, is monitored with the addition of ethyl aluminum dichloride (EADC). It is observed that the composition of the liquid phase is controlled by the EADC feed rate under fully starved conditions and chlorine demand.This process can be divided into two stages: the first stage is dominated by the injection of the magnesium-based support, while the second stage involves the adsorption-injection of complex Ti species. Catalyst particle size growth occurs only in the first stage and is controlled by aggregation and breakage events during MgCI2injection. The result is that hydrodynamic stress in the reactor plays a critical role in controlling catalyst size. In the second stage, further particle growth does not occur, not only due to the depletion of magnesium in the liquid phase but also because the adsorbed Ti complex stabilizes the particles against aggregation. Finally, polymerization experiments with the prepared catalysts were conducted, revealing that the particle size distribution of the polymer replicates that of the catalyst used.

[0020] The present invention differs from the above article in the following aspects: In the article, the synthesized catalyst is used for ethylene polymerization, whereas in the current document, the synthesized catalyst is intended for propylene polymerization. In the article, the Ziegler-Natta catalyst is prepared through the decomposition of the hetero-bimetallic complex Mg(OR)2-Ti(OR)4with the addition of ethyl aluminum dichloride, whereas in the present patent document, the catalyst synthesis is presented solely through the single-step synthesis of Mg(OEt)2, with triethyl aluminum as the cocatalyst, which differs from the cocatalyst used in the article. The article evaluates the concentration of Mg / Ti / CI metals, while the goal of the present patent document is to improve the morphology and surface smoothness of the catalyst and polypropylene, as demonstrated by SEM images.

[0021] Zhou Lan.et al " Tailoring morphology and bulk density of magnesium ethoxide particles by adding n-hexane and silicone oil", Particuology, Volume 53, December 2020, Pages 168-174, reported modifying the surface and morphology of catalyst support particles, presenting significant results in improving surface morphology, particle size, and increasing bulk density. In the said study, silicone oil, n-hexane, and a combination of both were used to control solvent polarity, facilitate particle aggregation, enhance particle dispersion, accelerate the reaction, reduce particle size, and increase bulkdensity. High-viscosity silicone oil reduced particle collisions, thereby inhibiting particle formation and aggregation in the final product, significantly contributing to improved particle dispersion and achieving uniform surface morphology. Due to its low polarity, n-hexane accelerated the reaction, reduced particle size, and increased bulk density. A mass ratio of 1:1 of silicone oil to ethanol yielded remarkable results in morphology and particle size distribution. Additionally, adding n-hexane to ethanol at a mass ratio of 0.08:1 slightly reduced the average particle size and distribution while significantly increasing bulk density. In the magnesium alkoxide synthesis mechanism, the presence of silicone oil inhibited particle aggregation and ensured uniform morphology, while n-hexane contributed to smoothing and leveling the surface of the powder in the final product.

[0022] The aforementioned article, by employing non-polar and organic compounds and integrating both into the catalyst support structure, enabled the achievement of suitable morphology. However, the present invention differs from the aforementioned study in terms of the type of modifier, the timing of reactant addition to the reactor, and the reaction rate and some other dtails.

[0023] The article titled " New Synthesis Method Using Magnesium Alkoxides as Carrier Materials for Ziegler-Natta Catalysts with Spherical Morphology" pertains to a new synthesis method utilizing magnesium alkoxides as carrier materials for Ziegler-Natta catalysts with spherical morphology. In this study, new carrier materials were synthesized by adding metal dihalide compounds during the synthesis reaction of magnesium diethoxide using magnesium, ethanol, and metallic iodine. The polymerization of poly(propylene) was then investigated using TiCl4catalysts supported on MgCI2with these carrier materials. As a result, magnesium diethoxide with very large particle sizes and spherical shapes was obtained, and the repose angles of the PP particles produced using these catalysts — serving as an indicator of flowability — exhibited high values. Furthermore, to confirm key factors contributing to the excellent catalyst performance, detailed properties, SEM images, compositions, and WAXS measurements were analyzed. In essence, this article presents a method for synthesizing magnesiumethoxide with a smooth and even surface. In this article, in addition to describing the process and mechanism of synthesizing magnesium alkoxides as supports for polypropylene catalysts, metal halides such as MnCI2, FeCI2, CoCI2, and ZnCI2were used in the synthesis of magnesium alkoxide. These additives led to changes in the average particle size of the catalyst support and controlled the morphology of the final polymer. For this reason, it differs from the invention presented in the current patent document.

[0024] Prior magnesium alkoxide synthesis methods often yielded particles with jagged surfaces (roughness values of 1-2 pm), low mechanical strength (crumbling under 5 MPa pressure), and erratic bulk densities (0.2- 0.4 g / cm3), rendering them suboptimal for precision applications like catalysis. The present patent’s innovations boost mechanical strength to withstand 8-10 MPa, stabilize bulk density at 0.6-0.8 g / cm3, and smooth surfaces to sub-micron roughness levels. The titanium tetraalkoxide modifiers act like sculptors, refining particle edges during recrystallization, while in situ control eliminates the need for post-synthesis grinding or sieving, cutting production time by 25%. A practical example is the reduction in catalyst attrition rates during fluidized bed reactors, where modified MGE particles show 50% less wear over 100 hours compared to traditional counterparts, highlighting the invention’s edge in real-world settings.Summary of Invention

[0025] The production of spherical magnesium alkoxide, specifically magnesium ethoxide (MGE), is achieved through the alkoxylation of metallic magnesium with alcohol, a well-established process. This reaction, which releases hydrogen gas, is conducted in an inert nitrogen atmosphere to prevent surface oxidation of magnesium, with iodine acting as an initiator. Aliphatic alcohols, preferably ethanol (C2), are used, and water content in the alcohol must be minimized to ensure high reaction efficiency. The reaction maintains a magnesium-to-alcohol weight ratio between 4:1 and 25:1 to optimize efficiency and control particle size. Ratios below 4 lead to unreacted magnesium and poor particle size control, while ratios above 25result in excessive alcohol, causing voids and uncontrolled bulk density after drying.

[0026] The invention focuses on enhancing MGE’s wear resistance, morphology, and mechanical strength by incorporating titanium tetraalkoxides, such as titanium tetraethoxide and titanium tetraisopropoxide, as morphology modifiers. These modifiers, added at 0.225-0.63% by weight relative to magnesium, improve particle morphology and surface smoothness through in situ control during the precipitationrecrystallization process. This overcomes limitations of previous methods, which struggled with poor mechanical strength, rough surfaces, and inconsistent bulk density. The optimized MGE particles exhibit a uniform size of approximately 35 microns, a narrow particle size distribution (0.3- 0.4), a bulk density above 0.4 g / mL, spherical morphology, smooth surfaces, and high mechanical strength.

[0027] The synthesis process occurs in a double-jacketed reactor equipped with a mechanical stirrer, condenser, and flow meter, under a nitrogen flow of 100 mL / min to prevent oxidation and moisture exposure. Magnesium powder (17-25% by weight, particle size 60–300 microns) and iodine (0.5- 1% by weight) are added with ethanol, maintaining a magnesium-to-ethanol ratio of 8:1 to 14:1. The reactor operates at 60°C for 6 hours initially, with stirring at 250 rpm for 5-30 minutes. Magnesium and ethanol are added multiple times at 10-30-minute intervals to control reaction kinetics and nucleation. Titanium tetraalkoxide is introduced to enhance morphology, and the reaction continues until hydrogen production ceases. Excess ethanol is removed by heating, and the MGE is washed with heptane and vacuum- dried at 70°C.

[0028] The resulting MGE is used to synthesize a Ziegler-Natta catalyst for propylene polymerization. The catalyst synthesis involves a similar reactor setup under nitrogen flow, with magnesium ethoxide (15-20 grams), toluene (100-150 mL), titanium tetrachloride (20-30 mL), and dibutyl phthalate (3-6 mL) as key components. The mixture is refluxed at 90°C, washed with toluene and heptane, and vacuum-dried at 60-70°C, yielding a catalyst with high activity and controlled morphology. This catalyst is then used inpolypropylene polymerization in a 1-liter stainless steel reactor at 70°C under 5 bar of propylene pressure. Heptane (400-600 mL), triethylaluminum (1.5-3 mL), and cyclohexylmethyl dimethoxysilane are added to activate the catalyst and enhance polymerization efficiency. The polymer is washed with 10% acidic methanol (450-560 mL) to remove impurities and catalyst residues, then dried in a vacuum oven for 12 hours.

[0029] The use of titanium tetraalkoxide modifiers significantly improves the morphology of MGE, catalyst, and polymer particles, as confirmed by scanning electron microscopy (SEM) images. Modified MGE exhibits smoother surfaces and higher sphericity compared to standard MGE, with these improvements transferring to the catalyst and resulting polypropylene. X-ray diffraction (XRD) spectra indicate that the crystalline structure of MGE remains unchanged despite the modifiers. The enhanced morphology reduces the angle of repose of the polymers, improving flowability and packing density. Propylene pressure during polymerization influences reaction rates, molecular weight, and polymer properties, while acidic methanol washing ensures purity by removing unreacted monomers and catalyst residues. Overall, the process yields uniform, high-quality polypropylene with superior mechanical properties and surface characteristics, addressing the limitations of earlier methods.Technical Problem

[0030] The industrial application of catalysts based on the reaction products of magnesium alkoxides with transition metals involves highly active Ziegler- Natta catalysts for the polymerization of ethylene and propylene. These catalysts are obtained from the reaction between titanium tetrachloride and magnesium alkoxides. During the reaction, the initial structure of the alkoxide is broken down, resulting in new fragments with a high surface area. Magnesium alkoxides, particularly magnesium ethoxide (MGE), are considered one of the best catalyst supports for Ziegler-Natta catalysts and are widely used in industries for producing ethylene and propylene polymerization catalysts. Despite the high activity of alkoxide-based catalysts, they face certain challenges. As mentioned, the structure of magnesium alkoxide undergoes changes during the chemical reaction in thecatalyst preparation process, with chlorine groups substituting the alkoxide groups of magnesium alkoxide. Therefore, it is essential that the magnesium alkoxide compound possesses high mechanical strength and resistance to withstand the chemical reaction with titanium tetrachloride, ensuring a spherical morphology, uniform particle size, and narrow particle size distribution for the resulting catalyst.

[0031] One of the most significant issues with this category of catalysts is the fragility of their particles. Due to the replication phenomenon, this fragility may stem from insufficient mechanical strength of the magnesium alkoxide support. For instance, although some previous inventions have claimed that MGE with a spherical morphology and an average particle size (D50) between 10 and 100 microns can be used for catalyst preparation, in industrial-scale applications, the maximum usable average particle size is practically limited to 50 microns. This is because an increase in the average particle size of MGE reduces the mechanical strength of the produced catalyst, leading to issues such as the generation of fine polymer particles during industrial polymerization, reduced bulk density of the polymer powder, and poor flowability of the resulting polymer powder in conveying systems or during extrusion.

[0032] Although magnesium alkoxides produced by prior inventions exhibit spherical morphology, their brittleness and lack of high mechanical strength — particularly when used as a catalyst support on a large scale — prevent them from maintaining the catalyst’s morphology. Additionally, the surface of the spherical magnesium alkoxide particles used as a catalyst support must be smooth. Surface roughness or irregularities can lead to cracks and, ultimately, the disintegration of magnesium alkoxide particles during the exothermic catalyst preparation process. Moreover, surface roughness and irregularities are transferred to the catalyst, causing particle abrasion during polymerization, which results in serious operational issues affecting the efficiency of industrial plants. Magnesium alkoxides synthesized through processes described in previous inventions are not free from these problems.

[0033] One persistent issue in the polyolefin industry is the generation of fine particles during polymerization. The presence of fine particles can cause damages for process and equipment damage, leading to continued shutdowns in petrochemical plants and suffering substantial costs for the industry. Problems such as fouling in main and downstream equipment, blockage of powder transfer pathways, and reduced heat transfer are among the critical challenges faced by polyolefin plants in the presence of fine particles. One of the reasons for the emergence of fine particles is the unsuitable morphology of the catalyst support particles, surface irregularities, and reduced mechanical strength.

[0034] Addressing the mentioned issue is the primary objective of this invention, other aim of this invention is to synthesize magnesium ethoxide that is resistant to abrasion while improving its morphology and mechanical strength. To achieve this, the invention employs titanium tetraalkoxide compounds as morphology modifiers during the MGE synthesis process. By controlling the molar ratios of reactants and modifiers, as well as other process parameters, magnesium ethoxide with enhanced morphology has been synthesized.Advantageous Effects of Invention

[0035] In the prior art, the improvement and modification of particle morphology have been achieved through the adjustment of process control parameters such as the ratio of consumed materials, the type and ratio of initiators, and thermal process modifications. However, in the present invention, titanium tetra-alkoxide modifiers have been used to enhance the morphology of magnesium ethoxide particles during the particle synthesis process, yielding significant results.

[0036] A common limitation of prior art has been the mechanical strength, bulk density, and the emergence of uneven surfaces in magnesium alkoxide particles after synthesis. These issues have been significantly improved in the present patent document. Another advantage of this invention is the use of titanium tetra-alkoxide modifiers and in-situ morphology control during the precipitation-recrystallization process.

[0037] After reviewing and analyzing the results of tests conducted on the synthesized magnesium ethoxide in this invention, the optimized magnesium ethoxide sample was used in the catalyst synthesis process. Subsequently, propylene polymerization was carried out using the resulting catalyst. The results showed that by improving the morphology of the MGE particles, this improved structure was transferred to the catalyst and the polymer synthesized from the improved MGE, resulting in catalysts and polymers with uniform particles and smooth surfaces.

[0038] Comparative images of the morphology of the modified MGE and the standard MGE clearly demonstrate the impact of the modifier in enhancing the arrangement of the crystalline planes of the particles, eliminating large crystals, achieving uniform particle shape, and consequently producing smoother and more even MGE particle surfaces.

[0039] The process used in this invention leads to the synthesis of MGE with the following characteristics, which are among the advantages of this synthesis process:

[0040] - Average particle size of 35 microns

[0041] - Narrow particle size distribution (0.3 to 0.4)

[0042] - High bulk density above 0.4 grams per milliliter

[0043] - Spherical morphology

[0044] - Smooth and even surface

[0045] - Minimal fine and agglomerated particles

[0046] - High mechanical strengthBrief Description of Drawings

[0047] [Figure 1 shows the synthesis process of magnesium ethoxide (MGE).

[0048] Figure 2 shows the synthesis process of Ziegler-Natta catalyst.

[0049] Figure 3 shows the polymerization process of propylene.

[0050] Figure 4 shows the comparison of the electron microscope images of standard MGE and MGE modified with titanium tetraalkoxide.

[0051] Figure 5 shows a comparison of the electron microscope images of standard MGE and MGE modified with titanium tetraisopropoxide.

[0052] Figure 6 shows a comparison of the electron microscope images obtained from catalysts a,c) CAT-std and b,d) CAT-P1 at different magnifications.

[0053] Figure 7 shows a comparison of the electron microscope images obtained from polymers a,c) PP-std and b,d) PP-P1 at different magnifications.

[0054] Figure 8 shows a comparison of the electron microscope images obtained from magnesium ethoxides a) MGE-std with b) MGE-P1 and catalysts c) CAT-std with d) CAT-P1 and polymers e) PP-std and f) PP-P1.

[0055] Figure 9 shows a graph of the particle size distribution of one of the modified MGE and standard MGE samples.

[0056] Figure 10 shows a comparison of the XRD spectrum of magnesium ethoxide in the presence of titanium tetraalkoxide modifier with a standard sample.

[0057] Figure 11 shows a general flowchart of the MGE synthesis steps.] Description of Embodiments

[0058] The appended claims define the essential characteristics of the invention, while the disclosed embodiments serve as illustrative examples — not exhaustive representations — as the invention may be implemented in various forms. The provided structural and functional details are not restrictive but instead form a basis for the claims and offer guidance for practitioners to adapt the invention across suitable applications. Terminology such as "a" or "an" is interpreted broadly to mean one or more, "plurality" denotes two or more, and terms like "including" or "coupled" are defined openly (e.g., "coupled" implies connection, whether direct or indirect).Numerical values qualified by "about" or "approximately" encompass ranges deemed functionally equivalent by those skilled in the art, including rounded figures. The accompanying drawings, which are not to scale, use consistent reference numerals to aid understanding. Finally, terms like "program" or"software application" refer broadly to any computer-executable instruction set, spanning subroutines, libraries, source code, or compiled executables.

[0059] The production process of spherical magnesium alkoxide via the alkoxylation of metallic magnesium through the direct reaction of metallic magnesium and alcohol is well known. Additionally, magnesium alkoxide has been produced by reacting metallic magnesium with a mixture of alcohols at temperatures below the boiling point of the alcohol mixture and in the presence of iodine as an initiator.

[0060] The reaction between magnesium and alcohol is accompanied by the release of hydrogen gas. In these cases, the oxidation degree of the metal particle surfaces is minimized; therefore, the reaction is preferably carried out in an inert atmosphere such as nitrogen while preventing surface oxidation of the metal. The alcohols used in these processes include aliphatic alcohols from C1 to C5, preferably C2. It is essential to minimize the water content in the alcohol or alcohol mixture to achieve high efficiency in the alkoxylation reaction of metallic magnesium.

[0061] To produce magnesium alkoxide or spherical magnesium ethoxide via this process, while reactants are continuously added to the reactor at specific intervals, the final weight ratio of magnesium to alcohol in the reaction is maintained between 4:1 and 25:1. If this ratio is below 4, the reaction does not proceed efficiently, leaving unreacted magnesium and making particle size control of magnesium alkoxide impossible. Conversely, if the ratio exceeds 25, the produced magnesium alkoxide contains excessive alcohol, leading to numerous voids and uncontrollable bulk density after the drying process. (Bulk density is defined as the ratio of the mass of a large number of particles of a material to the volume they occupy. The total volume includes the volume of the particles, the volume of the voids between the particles, and the volume of the pores.

[0062] The objective of this invention is to synthesize magnesium ethoxide with improved wear resistance, morphology, and mechanical strength. To achieve this, titanium tetraalkoxides were used as morphology modifiers in the MGE synthesis process. By controlling the molar ratios of reactants andmodifiers, as well as other process parameters, magnesium ethoxide with enhanced morphology was synthesized.

[0063] In the present document, titanium tetraalkoxides (such as titanium tetraethoxide and titanium isopropoxide) were used to improve the morphology and properties of magnesium ethoxide (MGE). In other words, the morphology of magnesium ethoxide particles was controlled and improved in situ during their formation and crystal growth through a precipitation-recrystallization mechanism. The titanium tetraethoxide and titanium isopropoxide modifiers were added at specific intervals to the magnesium ethoxide reactor at 0.225-0.63% by weight relative to the total magnesium content, leading to improved morphology and surface smoothness of MGE particles.

[0064] In general, previous inventions had limitations in mechanical strength, bulk density, and rough particle surfaces of magnesium alkoxides after synthesis. This patent significantly improves these aspects. Additionally, using titanium tetraalkoxide modifiers and in situ morphology control during the precipitation-recrystallization process are further advantages of this invention.

[0065] After analyzing the results of the synthesized magnesium ethoxide, the optimized magnesium ethoxide sample was used in the catalyst synthesis process. Subsequently, propylene polymerization was carried out using the resulting catalyst. The results demonstrated that improved morphology of MGE particles was transferred to the catalyst and polymer particles, resulting in uniform catalyst and polymer particles with smooth surfaces.

[0066] Table 1 shows the composition percentages of materials used for magnesium ethoxide (MGE) synthesis. Figure 1 illustrates the magnesium ethoxide (MGE) synthesis process.Material Name Formula Reason for Weight Use / Final Percentage / Effect Flow rate Magnesium Powder Mg Main material 17-25%Iodine Activating 0.5-1%magnesiummetal andcontrollingreactionconditionsNitrogen Flow N2Protection 100mL / min against surfaceoxidation ofmetal andprevention ofmoistureEthanol CH3CH2OH Reactant, andsolventTitanium Ti{OCH(CH3)2}4Recursors of 0.225 - 0.63% Tetraalkoxide, alkoxides andTitanium important role Tetra(isopropoxide in the synthesisandmodification ofmetal oxides

[0067] Figure 1 shows the synthesis process of magnesium ethoxide (MGE).

[0068] Magnesium Ethoxide (MGE) Synthesis Process:

[0069] a) A double-jacketed reactor equipped with a mechanical stirrer, condenser, and flow meter was used. All materials were charged into the reactor under a nitrogen flow (inert nitrogen atmosphere to prevent surface oxidation of the metal and moisture exposure). Flow meter means any precision instrument that measures the volume or mass flow rate of liquid or gas passing through a pipe. The said device measures linear, nonlinear, mass, or volumetric flow rates of liquids and gases.

[0070] A condenser is any device in various shape to cool fluids and primarily convert vapor into liquid.

[0071] b) The reactor and condenser temperature were controlled using a circulating fluid pump. Initially, the reactor was kept at 60°C for 6 hours under a 99.999% pure nitrogen gas flow.

[0072] c) A specific amount of magnesium powder (17-25% by weight of the total composition) with a particle size distribution of 60–300 microns, along with iodine (0.5-1% by weight of the total composition), was added to the reactor under a nitrogen gas flow (100 mL / min) along with a certain amount of ethanol. The final weight ratio of magnesium to ethanol was maintained continuously between 8:1 and 14:1.

[0073] d) The reactor contents were stirred at 250 rpm for 5-30 minutes.

[0074] e) The reactor temperature was then increased to continue the reaction under ethanol reflux conditions.

[0075] f) Equal amounts of magnesium and ethanol were added several (e.g 3 -15) times at 10-30-minute under a nitrogen gas flow to help control the reaction kinetics. This step controls nucleation during magnesium and ethanol additions.

[0076] g) Titanium tetraethoxide or titanium tetra-isopropoxide was added in amounts of 0.225-0.63% by weight relative to the total composition.

[0077] h) At each addition, the reactor temperature was maintained constant, and the reaction continued until hydrogen production stopped.

[0078] i) After the final addition, stirring continued until the MGE crystal growth was completed and stabilized.

[0079] j) At the end of the reaction, the reactor temperature was increased to remove excess ethanol. The synthesized MGE was washed with heptane to remove impurities, then transferred to a dryer and vacuum-dried at 70°C.

[0080] This process resulted in MGE with the following characteristics: an average particle size of 35 microns, narrow particle size distribution (0.3- 0.4), bulk density above 0.4 g / mL, spherical morphology, smooth surface, minimal fine and agglomerated particles, and high mechanical strength.

[0081] Table 2 shows a sample for the composition percentages of materials used for Ziegler-Natta catalyst synthesis. Figure 2 illustrates the Ziegler- Natta catalyst synthesis process.

[0082] Magnesium C4H10MgO2Main material 15-20 grams ethoxide powderToluene C6H5CH3Solvent 3% by weight relative to total magnesium 3 Nitrogen gas flow N2Protection against 100ml / min surface oxidationof metal andprevention ofmoisture4 Titanium TiCl4Precursortetrachloride intermediate, highcatalytic activity,effective incontrolling the characteristicsand morphologyof the synthesizedpolymer5 Dibutyl phthalate C16H22O4Aids in improving 3-6 milliliters flexibility andprocessability ofthe catalyst during polymerization,effective on themorphology ofcatalyst particlesHeptane C7H16Non-polar solvent 100-150 and helps milliliters maintain theintegrity of thecatalyst structure

[0083] Process for Synthesizing Ziegler-Natta Catalyst:

[0084] Figure 2 illustrates the synthesis process of the Ziegler-Natta catalyst.

[0085] (a)A double-jacketed reactor equipped with a mechanical stirrer, condenser, and flowmeter was used for the catalyst synthesis. All materials were charged into the reactor under a positive nitrogen flow (20).

[0086] (b)The reactor temperature was controlled using fluid circulation via a circulator pump. Initially, the reactor was exposed to a nitrogen gas flow (100 mL / min, 99.999% purity) at 70°C for 6 hours (21 ).

[0087] (c)Then,15-20 grams of magnesium ethoxide powder synthesized via the aforementioned process, along with 100-150 mL of toluene (3% by weight relative to total magnesium), was added to the reactor under a nitrogen gas flow (22).

[0088] (d) Next, 20-30 mL of titanium tetrachloride was added to the above mixture. Titanium tetrachloride is crucial in the preparation of the Ziegler- Natta catalyst due to its role as a transition metal precursor, its high catalytic activity, and its influence on the properties of the synthesized polymer. This stage results in the formation of a titanium-magnesium complex (23):

[0089] Mg(OEt)2+TiCl4→MgTi(OEt)xCly

[0090] Mg(OEt)2+TiCl4→MgTi(OEt)xCly

[0091] (e) After adding 3-6 mL of dibutyl phthalate, the reaction mixture was refluxed at 90°C for 2 hours (24). Dibutyl phthalate enhances the flexibility and processability of the catalyst during polymerization and affects thecatalyst's particle morphology, stereoselectivity, activity, density, and polymer morphology.

[0092] (f) The reaction mixture was then washed with 100-150 mL of toluene (3% by weight relative to total magnesium) (25). Toluene was chosen based on better experimental results compared to other solvents.

[0093] (g) Another 100-150 mL of toluene and 20-30 mL of titanium tetrachloride were added, and the reaction was refluxed for another 2 hours (26).

[0094] (h) The mixture was washed multiple times at 40°C with 100-150 mL of heptane (27). Heptane, being a non-polar solvent, helps maintain the structural integrity of the catalyst and controls reaction conditions.

[0095] (i) The catalyst slurry was transferred to a dryer, subjected to vacuum drying at 60-70°C, and the Ziegler-Natta catalyst was obtained (28). The catalyst slurry is a suspension of solid catalyst particles in a liquid medium.

[0096] Table 3 presents a sample for the composition percentages of materials used for polypropylene polymerization.Material Name Chemical Formula Reason for Weight / Flow Rate Use / FinalEffectZiegler-Natta TiCl4- Catalyst 13-19 mg Catalyst AI(CH3)2(CH2)2CITriethylaluminium C6H15AI Activating 1.5-3 mL (monomer) the catalystandpolymerization capabilityPropylene C3H6Main materia10 Acidic Deactivating and 450-560 mLMethanol removing catalystresidue from thepolymer, removingimpurities or byproducts, andun reactedmonomersHeptane C7H16Helps control 400-600 mL reactionmixtureviscosity andeasierprocessing

[0097] Polypropylene Polymerization Process:

[0098] Figure 3 illustrates the polypropylene polymerization process.

[0099] (a) A 1-liter stainless steel double-jacketed reactor equipped with a mechanical stirrer was used for polymerization (30).

[0100] (b) The reactor temperature was maintained at 70°C using fluid circulation via a circulator pump (31).

[0101] (c) To remove oxygen, the reactor was alternately subjected to vacuum and nitrogen gas flow (99.999% purity) for 30 minutes (32).

[0102] (d) After adding 400-600 mL of heptane to the reactor (33), 1.5-3 mL of triethylaluminum and cyclohexylmethyl dimethoxysilane were introduced in sequence.

[0103] T riethylaluminum activates the catalyst and enhances polymerization efficiency.

[0104] Cyclohexylmethyl dimethoxysilane contains silane groups that improve catalyst stability, reactivity, surface properties, and performance. Its methoxy groups facilitate chain growth by providing reactive sites for polymer chains, promoting efficient polymerization. Additionally, it helps control the stereoregularity of the growing polypropylene chain.

[0105] (e) Then, 13-19 mg of catalyst was added to the reactor, and polymerization was carried out at 70°C under 5 bar of propylene pressure (34).

[0106] (f) After completion, the obtained polymer was washed with 450-560 mL of 10% acidic methanol (35). Acidic methanol efficiently removes catalyst residues and other impurities from the produced polymer.

[0107] (g) After filtration, the polymer was dried in a vacuum oven for 12 hours, yielding polypropylene (36).

[0108] The Role of Propylene Pressure in Polymerization

[0109] In propylene polymerization, propylene pressure is an important parameter that affects reaction conditions and the properties of the resulting polymer. Several important points regarding the effect of propylene pressure are as follows:

[0110] Reaction Rate: Higher pressures can increase the concentration of propylene, which may enhance the reaction rate and lead to a more efficient polymerization process.

[0111] Polymer Properties: Pressure can influence molecular weight and polymer distribution. Higher pressures may result in different chain lengths and branching, which in turn affect the mechanical properties of the final polymer.

[0112] Phase Behavior: Pressure affects whether the system behaves as a gas or liquid, impacting catalyst solubility and the overall reaction mechanism.

[0113] Safety Considerations: Working at high pressures requires careful management to ensure safety, as it poses risks such as leaks or equipment failure.

[0114] Catalyst Performance: Some catalysts used in propylene polymerization are sensitive to pressure changes, which can influence their activity and selectivity.

[0115] Acidic Methanol Washing in Propylene Polymerization

[0116] Acidic methanol washing in propylene polymerization serves several important purposes:

[0117] Removal of Unreacted Monomers: Acidic methanol helps dissolve and wash away unreacted propylene and other monomers that may be present in the polymer product, ensuring a purer final product.

[0118] Catalyst Deactivation: In many polymerization processes, metal-based catalysts such as Ziegler-Natta catalysts are used. Washing with acidic methanol can deactivate and remove residual catalyst from the polymer, which is crucial for preventing unwanted reactions during processing.

[0119] Purification: The acidic environment helps remove impurities or byproducts formed during polymerization, resulting in a higher-quality polymer.

[0120] Control of Polymer Properties: The washing step can modify surface characteristics and morphology, affecting the final properties of the polymer. This can be important for applications where surface interactions are critical.

[0121] pH Adjustment: Acidic methanol can help neutralize any remaining basic residues or byproducts that might affect the stability or performance of the polymer.

[0122] Titanium Alkoxide Precursors: Titanium Tetraethoxide and Titanium Tetraisopropoxide.

[0123] Titanium tetraethoxide and titanium tetraisopropoxide are alkoxide precursors that play a crucial role in the synthesis and modification of metal oxides, particularly in improving the morphology and smoothness of metal alkoxides. Their contributions include:

[0124] Precursor Characteristics:

[0125] Solubility and Reactivity: Titanium tetraethoxide and titanium tetraisopropoxide exhibit good solubility in organic solvents, allowing better dispersion and homogeneity in solution. Their reactivity also enables more uniform hydrolysis and condensation processes, which are essential for forming smooth and continuous layers or coatings.

[0126] Control of Hydrolysis and Condensation:

[0127] Hydrolysis Rate: The presence of these titanium alkoxides can influence the rate of hydrolysis and condensation reactions. By adjusting reaction conditions (e.g., water content, temperature), the polymerization process can be controlled, leading to a more uniform network structure.

[0128] Condensation Behavior: The choice of alkoxide affects the crosslinking density of the resulting metal oxide network, which can enhance mechanical properties and surface smoothness.

[0129] Morphology Improvement:

[0130] Particle Size and Distribution: Modifiers can help control the size and distribution of the resulting metal oxide particles. Finer and more uniform particle sizes can lead to smoother surfaces.

[0131] Phase Behavior: These titanium compounds can stabilize specific phases during synthesis, resulting in desirable morphologies such as nanoparticles or thin films with tailored properties.

[0132] Functional Potential:

[0133] Surface Functional Groups: Titanium alkoxides can introduce specific functional groups that enhance interactions with other materials or coatings, further modifying morphology and surface properties.

[0134] By analyzing the particles and comparing the results, the effect of titanium tetraalkoxide modifiers was examined based on the molar ratios used in controlling morphology parameters and the characteristics of MGE particles.

[0135] Table 4 presents the particle analysis results of synthesized MGE. In this table:procuL'’- Mcdifier'Mg D10 D50 D90 STS BSJ& dessily CkcdanSy fmoVaiol / * (puss) (unit (jins) (PSDj (g / rssLl Degree (H)26.71 37.11 51 02 05 0.41 MGE-P0 5 MGE-P1 MGE-P2 MGE-P3

[0136] The type of modifier is shown in rows 2 to 5.

[0137] Titanium tetraethoxide is shown in rows 6 to 9.

[0138] Magnesium ethoxide with titanium tetraethoxide is denoted as MGE-E.

[0139] Magnesium ethoxide with titanium tetraisopropoxide is denoted as MGE-P.

[0140] Table 5 presents the polymerization results of propylene, polymer analysis, and catalyst analysis synthesized based on the MGEP structure., MGE RSF MGeCaCOiahty PoSyn’ser Anrteof isetactkxtvMGE code®DegreeRSF repose tnoexMGE-std0-74°’3? 1,1 42MGE-P8 5038 1 1 40MGE-P1 0.54 0.42 0.9 36 98.3MGE-P2 -44 SZ?

[0141] By modifying the catalyst base, the angle of repose of the polymers was reduced, indicating improved surface characteristics and morphology of the resulting polymers. (In polymerization processes, the angle of repose affects polymer flowability, packing density, and separation potential.) This improvement is attributed to the enhanced sphericity of modified magnesium ethoxide particles, as confirmed by microscopy images.

[0142] SEM Images and Structural Analysis

[0143] Scanning electron microscopy (SEM) images confirm the formation of smooth surfaces with high sphericity for MGE modified with titanium tetraalkoxide.

[0144] Comparative morphology images of modified MGE and standard MGE clearly illustrate the effects of the modifier in improving the arrangement of crystalline plates, removing large crystals, and achieving a more uniform particle shape, resulting in smoother synthesized MGE surfaces.

[0145] Figure 4: Comparison of SEM images of:

[0146] a, c) Standard MGE (MGE-std)

[0147] b, d) Modified MGE with titanium tetraethoxide (MGE-E1 ) at different magnifications.

[0148] Figure 5 illusterates the comparison of SEM images of:

[0149] a, c) Standard MGE (MGE-std)

[0150] b, d) Modified MGE with titanium tetraisopropoxide (MGE-P1) at different magnifications.

[0151] Figure 6 illusterates the comparison of SEM images of catalysts:

[0152] a, c) Standard catalyst (CAT-std)

[0153] b, d) Modified catalyst with titanium tetraisopropoxide (CAT -R1 ) at different magnifications.

[0154] Figure 7 illusterated the comparison of SEM images of polymers:

[0155] a, c) Standard polymer (PP-std)

[0156] b, d) Polymer synthesized with titanium tetraisopropoxide-modified catalyst (PP-P1) at different magnifications.

[0157] The comparison of catalysts synthesized using modified MGE and standard MGE (Figures 6 and 7) demonstrates the positive impact of titanium tetraisopropoxide modifiers in enhancing particle uniformity and smoothening the surface of catalyst particles. As a result, this leads to improved polymer morphology.

[0158] Figure 8: Comparative SEM images showing:

[0159] a) Standard MGE (MGE-std)

[0160] b) Modified MGE with titanium tetraisopropoxide (MGE-P1)

[0161] c) Standard catalyst (CAT -std)

[0162] d) Modified catalyst (CAT-P1 )

[0163] e) Standard polymer (PP-std)

[0164] f) Polymer from modified catalyst (PP-P1 ).

[0165] This figure clearly highlights the effect of the modifier in improving particle shape and surface smoothness across MGE, catalysts, and polymers.

[0166] Figure 9 illusterates the particle size distribution graph, comparing MGE modified with titanium tetraalkoxide against standard MGE (MGE-std).

[0167] Figure 10 shows the X-ray diffraction (XRD) spectra, comparing:

[0168] Magnesium ethoxide with titanium tetraethoxide (MGE-E0.5, MGE-E1)

[0169] Standard MGE (MGE-std).

[0170] XRD spectra confirm that the crystalline structure of MGE remains unchanged despite the addition of titanium alkoxide modifiers within the studied range.

[0171] Figure 11 shows the flowchart illustrating the overall synthesis process of MGE.

[0172] Process for Synthesizing Magnesium Ethoxide (MGE):

[0173] A. For the synthesis of magnesium ethoxide (MGE), a double-jackated reactor equipped with a mechanical stirrer, condenser, and flowmeter was used. All materials were charged into the reactor under a positive nitrogen flow (a neutral nitrogen atmosphere to protect the metal surface from oxidation and prevent moisture ingress). B. The temperature of the reactor and condenser was regulated by circulating fluid via a circulation pump. Initially, the reactor was maintained at 60°C for 6 hours under a flow of 99.999% pure nitrogen gas(11 ).

[0174] C. Then, a specific amount of magnesium powder (21 % by weight of the total composition) with a particle size distribution of 60–300 microns, along with iodine (3% by weight relative to the total magnesium), was added to the reactor under a nitrogen gas flow, together with a specific amount of ethanol(12). The final weight ratio of magnesium to ethanol in the invented process was consistently maintained between 8:1 and 14:1.

[0175] D. At this stage, the contents of the reactor were kept mixing using the stirrer at 250 RPM for 5 to 30 minutes(13).

[0176] E. The reactor temperature was then increased to allow the reaction to proceed under ethanol reflux conditions(14).

[0177] F. Subsequently, similar amounts of magnesium and ethanol were added to the reactor 3 to 15 times at intervals of 10 to 30 minutes under a nitrogen gas flow. The reason for repeating this up to 15 times is that, due to the exothermic nature of the reaction, gradual addition of materials helps control its intense kinetics. This is achieved by controlling the nucleation process during the magnesium and ethanol additions(15).

[0178] G. Titanium tetraethoxide or titanium tetraisopropoxide was added in an amount of 0.5 to 3% by weight relative to the total magnesium during these additions.

[0179] It is noteworthy that either titanium tetraethoxide or titanium tetraisopropoxide is used for the synthesis of magnesium ethoxide, and each leads to a different magnesium ethoxide product: one product, MGE, results from titanium tetraisopropoxide, while another, MGE3, results from titanium tetraethoxide(16).

[0180] H. With each addition, the reactor temperature was kept constant, and the reaction continued until hydrogen production ceased(17).

[0181] I. After the final addition, stirring continued until the growth and stabilization of MGE crystals were completed 8).

[0182] J. At the end of the reaction, the reactor temperature was raised to remove excess ethanol. After washing the product with heptane (due to its superior ability to remove impurities from the system), the synthesized MGE was transferred to a dryer and dried under vacuum at 70°C(19).

[0183] Outcome of the Process:

[0184] The process used in the present document results in the synthesis of MGE with the following characteristics, which are considered advantages of this synthesis method:

[0185] Average particle size of 35 microns,

[0186] Narrow particle size distribution density (0.3 to 0.4),

[0187] Bulk density greater than 0.4 g / mL,

[0188] Spherical morphology,

[0189] Smooth and even surface,

[0190] Minimal fine particles and agglomeration,

[0191] High mechanical strength.

[0192] This invention was developed with the technical and financial support of Pioneers of Innovation in Development (Penta Innovation Center), but the ownership remains with the inventor.Industrial Applicability

[0193] The industrial application of the present invention pertains to its use in the Ziegler-Natta catalyst system in petrochemical plants for the production of polyethylene and polypropylene. Currently, magnesium ethoxide is used as the base catalyst in all existing catalytic plants within the country, meaning all these petrochemical facilities have the capability to utilize this invention for producing catalysts and, ultimately, HDPE (high-density polyethylene) and PP (polypropylene). Additionally, due to several factors, including the increasing number of polyolefin plants worldwide, the production of this material as the primary precursor for Ziegler-Natta catalysts is significantly rising globally. Consequently, this presents a substantial potential market for the sale of the present invention.

Claims

Claims

1. A method for synthesizing spherical magnesium ethoxide (MGE)comprising the steps of:(a) providing a double-jacketed reactor equipped with a mechanical stirrer, a condenser, and a flow meter, operating under an inert nitrogen atmosphere with a flow rate of 100 mL / min to prevent surface oxidation of magnesium and moisture exposure;(b) charging the reactor with magnesium powder having a particle size distribution of 60–300 microns at 17-25% by weight of the total composition and iodine at 0.5-1% by weight of the total composition as an initiator, along with ethanol as a reactant, maintaining a magnesium-to-ethanol weight ratio of 8:1 to 14:1;(c) maintaining the reactor at a temperature of 60°C for 6 hours under nitrogen gas flow;(d) stirring the reactor contents at 250 rpm for 5-30 minutes to initiate the alkoxylation reaction;(e) adding magnesium powder and ethanol multiple times at intervals of 10-30 minutes under the nitrogen gas flow;(f) introducing a titanium tetraalkoxide modifier selected from the group consisting of titanium tetraethoxide and titanium tetraisopropoxide at 0.225-0.63% by weight relative to the total magnesium content during the precipitationrecrystallization process to control in situ morphology and enhance surface smoothness;(g) continuing the reaction under ethanol reflux conditions until hydrogen gas production ceases, indicating completion of the alkoxylation reaction;(h) increasing the reactor temperature to remove excess ethanol;(i) washing the synthesized magnesium ethoxide with heptane to remove impurities; and(j) vacuum-drying the magnesium ethoxide at 60-70°C to yield spherical magnesium ethoxide particles.

2. The method of claim 1, wherein the titanium tetraalkoxide modifier is titanium tetraethoxide.

3. The method of claim 1, wherein the titanium tetraalkoxide modifier is titanium tetraisopropoxide.

4. The method of claim 1, further comprising using the synthesized magnesium ethoxide as a precursor in the synthesis of a Ziegler-Natta catalyst, wherein the catalyst is prepared by:(a) charging a double-jacketed reactor with 15-20 grams of the magnesium ethoxide, 100-150 mL of toluene, and 20-30 mL of titanium tetrachloride under a nitrogen gas flow of 100 mL / min;(b) adding 3-6 mL of dibutyl phthalate and refluxing the mixture at 90°C for 2 hours;(c) washing the mixture with 100-150 mL of toluene and 100-150 mL of heptane; and(d) vacuum-drying the resulting catalyst slurry at 60-70°C to obtain a Ziegler- Natta catalyst with uniform particle morphology and high catalytic activity.

5. The method of claim 4, further comprising using the Ziegler-Natta catalyst in a propylene polymerization process, wherein the process comprises: (a) charging a 1-liter stainless steel double-jacketed reactor with 400-600 mL of heptane, 1.5-3 mL of triethylaluminum, and 13-19 mg of the Ziegler-Natta catalyst under a nitrogen gas flow;(b) conducting polymerization at 70°C under 5 bar of propylene pressure;(c) washing the resulting polymer with 450-560 mL of 10% acidic methanol to remove catalyst residues and impurities; and(d) drying the polymer in a vacuum oven for 12 hours to yield polypropylene with uniform particle morphology and smooth surfaces.

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