阅读说明：本技术 制备溶解的催化剂络合物的方法、溶解的催化剂调配物和催化烯烃聚合的方法 (Method for preparing dissolved catalyst complex, dissolved catalyst formulation and method for catalyzing olefin polymerization ) 是由 D·吉罗内特 C·鲍彻-雅各布斯 于 2019-09-26 设计创作，主要内容包括：本发明人已发现一种方法,所述方法包括通过将含第8族到第11族过渡金属的催化剂与表面活性剂合并来形成水溶性催化剂前体。所述表面活性剂的特征在于存在疏水链段和亲水链段。据信,所述表面活性剂通过简单配体取代来替代所述催化剂前体结构上的不稳定配体。所述前体随后在聚合条件下与一种或多种单烯属不饱和单体接触以形成聚合物。(The present inventors have discovered a process comprising forming a water-soluble catalyst precursor by combining a group 8 to group 11 transition metal-containing catalyst with a surfactant. The surfactant is characterized by the presence of a hydrophobic segment and a hydrophilic segment. It is believed that the surfactant replaces the labile ligands on the catalyst precursor structure by simple ligand substitution. The precursor is then contacted under polymerization conditions with one or more monoethylenically unsaturated monomers to form a polymer.)

1. A method, comprising:

combining a group 8 to group 11 organosoluble transition metal catalyst precursor with a surfactant in an aqueous solution to form a water-soluble catalyst precursor, wherein the organosoluble catalyst precursor comprises a chelating ligand and a labile ligand.

2. The method of claim 1, wherein the surfactant is complexed with the organosoluble catalyst by ligand substitution of the labile ligand.

3. The method of any preceding claim, wherein the surfactant comprises a polyethylene glycol moiety and a hydrocarbon moiety, and optionally comprises an anionic moiety.

4. The method of claim 3, wherein the anionic moiety is selected from the group consisting of: sulfate, sulfonate, phosphate, phosphonate, carboxylate, and combinations thereof.

5. The method of any preceding claim, wherein the organosoluble catalyst precursor is an aromatic palladium phosphine sulfonate catalyst.

6. The method of any preceding claim, wherein the group 8 to group 11 transition metal organosoluble catalyst precursor has the formula:

wherein M is a group 8 to group 11 transition metal, R₁Is H or alkyl having 1 to 4 carbon atoms, Ar is a substituted or unsubstituted aromatic group, R is a hydrocarbyl group having 1 to 12 carbon atoms, n is the number of occurrences of R and is 0, 1 or 2, and L is a labile ligand.

7. The method of claim 6, wherein M is Pd, L is DMSO, n is 0, and Ar is an aromatic ring substituted with an alkoxy group, wherein the alkoxy group has 1 to 5 carbon atoms.

8. An aqueous solution comprising a water-soluble group 8 transition metal salt of a phosphine sulfonic acid catalyst precursor having the formula:

wherein M is a group 8 to group 11 transition metal, R₁Is H or an alkyl group having 1 to 4 carbon atoms, Ar is a substituted or unsubstituted aromatic group, R is a hydrocarbon group having 1 to 12 carbon atoms, n is the number of occurrences of R and is 0, 1 or 2, and L is a surfactant.

9. The catalyst precursor of claim 8, wherein M is Pd, n is 0, Ar is an aromatic ring substituted with an alkoxy group, wherein the alkoxy group has 1 to 5 carbon atoms, and L is a hydrophilic segment comprising a polyalkylene glycol, a hydrocarbon-based hydrophobic segment, and an anionic moiety.

10. The method of any one of claims 1-7, further comprising contacting one or more monoethylenically unsaturated monomers with the water-soluble catalyst precursor under polymerization conditions to form a polyolefin.

11. The method of claim 10, wherein the pH of the aqueous solution is from about 2 to about 6.

12. The method of any one of claims 10-11, wherein the concentration of the surfactant in the aqueous solution is about 3 to 100 grams per liter, or the concentration of the catalyst precursor in the aqueous solution is about 0.0.01 to 21 μmol per liter, or both.

13. The method of any one of claims 10-12, wherein the monoethylenically unsaturated monomer is selected from the group consisting of: ethylene, propylene, octene, or combinations thereof.

14. The method of any one of claims 10-13, wherein the catalyst exhibits no decay in activity for at least 1.5 hours from the start of polymerization and/or exhibits less than 36% loss in activity after 6 hours from the start of polymerization.

Technical Field

The present invention relates to olefin polymerization using a surfactant-solubilized catalyst.

Background

Catalytic polymerization and emulsion polymerization processes of olefins are used for the preparation of polymers. The early transition metal catalysts typically used in olefin polymerization are extremely sensitive to water, which means that the catalysts are unstable in the presence of water, and thus these catalysts are not suitable for emulsion polymerization processes. The incompatibility of early transition metal catalysts is also a technical challenge for aqueous processes. There is interest in the industry to develop catalysts that can directly synthesize semi-crystalline polyolefin latexes in an aqueous environment.

Late transition metal catalyzed olefin polymerization processes offer unique opportunities because these metals are less oxophilic than their early transition metal counterparts and are therefore more stable in the presence of water. Although late transition metal catalysts have significant water stability, the productivity of these catalysts in water is lower than in organic solvents. This low activity may be attributed to the rapid deactivation of the catalyst by water. Attempts have been made to improve catalyst stability by encapsulating the procatalyst in nanoscale hydrophobic droplets (miniemulsions) or polymer-based micelles that are stabilized by a large amount or surfactant. See, e.g., Soula, r.; novat, c.; tomov, a.; spatz, r.; claverie, j.; drujon, x.; bolt, j.; saudemont, T. "Catalytic Polymerization of Ethylene in Emulsion" (Macromolecules) 2001, 34(7), 2022-2026, Macromolecules. Basero, A.; kolb, l.; wehrmann, p.; bauers, f.;-Schnetmann, i.; monteil, v.; thomann, r.; chowdry, m.; mecking, s. "catalytic ethylene polymerization in aqueous emulsion: customization of catalysts and Synthesis of Very Small Latex Particles (Catalytic Ethylene Polymerization in Aqueous emulsions: Catalyst Taiiling and Synthesis of Very Small Latex Particles.) "(Polymer Mater Sci Eng) 2004, 90, 740-. Racking, s.; claverie, J. "Transition Metal Catalyzed Polymerization in Aqueous Systems (Transition Metal Catalyzed Polymerization in Aqueous Systems.)" (see later)Transition Metal Polymerization Catalysis (Late Transition Metal Catalysis); boffa, l.s., Kacker, s., Rieger b., Striegler, s.eds; Wiley-VCH, 2003; page 231-. Bauers, f.m.; mecking, S. "Aqueous latex of High Molecular Mass Polyethylene by Catalytic Polymerization" (High Molecular Mass Polyethylene Aqueous latex.) applied in International Edition 2001, 40(16), 3020-. Soula, r.; saillard, b.; spatz, r.; claverie, j.; laleuro, m.f.; monnet, C. "Catalytic Copolymerization of Ethylene with Polar and non-Polar alpha-Olefins in Emulsion (Catalytic Copolymerization of Ethylene and Polar and Nonpolara alpha-Olefins in Emulsion.)" 2002. Bauers, f.m.; zuideveld, m.a.; thomann, r.; mecking, S. "Catalytic Polymerization in Emulsion" ("macromolecular Polymerization in Emulsion.)" 2003, 204, F7-F8 for chemical and physical macromolecules (macromolecules. chem. Phys.) ". Wehrmann, p.; meking, S. "Aqueous Dispersions of Polypropylene and Poly (1-Butene) with Variable microstructure Formed from Neutral Nickel (II) Complexes (Aqueous Dispersions of Polypropylene and Poly (1-Butene) with Variable microstructure" "macromolecules 2006, 39(18), 5963-. Claverie, j.p.; soula, r. "Catalytic polymerization in Aqueous Medium" (advance in Polymer Science (Oxford.) ") 2003 april, p. 619-. Racking, s.; hell, a.; bauers, F.M. "Aqueous Catalytic Polymerization of olefins (Aqueous Catalytic Polymerization of olefins.)" applied chemistry International edition 2002, 41(4), 544-. Asua, J.M. "Miniemulsion Polymerization." Advance in Polymer science 2002, 27(7), 1283-1346, and Boucher-Jacobs, C.; rabnawaz, m.; katz, j.s.; even, r.; guironnet, "encapsulation of catalysts for Ethylene Polymerization in Aqueous media in Block Copolymer Micelles for the Polymerization of Ethylene in Aqueous media" (natural-communications (d.nat.)) 2018, 9(1), 841. Alternatively, use has been proposedAmine-terminated polyethylene glycol (PEG) or sulfonated arylphosphines as water-soluble complexes of hydrophilic ligands as catalyst precursors. See, e.g., Zhang, d.; guironnet, d.;-Schnetmann, i.; mecking, S. "Water soluble Complex [ (kappa 2-P, O-phosphinosulfonate) PdMe (L)]And its catalytic properties (Water-Soluble Complexes [ (kappa 2-P, O-Phosphonesulfonato) PdMe (L)]and the tea Catalytic Properties 2009, 28(14), 4072-. Godin, a.; mecking, S. "Aqueous Dispersions of heterogeneous Polyolefin Particles (Aqueous Dispersions of Multiphase polyolefins Particles.)" "macromolecules" 2016, 49(21), 8296-. Godin, a.;-Schnetmann, i.; mecking, S. "Nanocrystal Formation in Aqueous intercalation Polymerization" (Nanocrystal Formation in Aqueous intercalation Polymerization.) "macromolecules 2016, 49(23), 8825-. Korthals, Brigitte, i.; mecking, S. "having Water-soluble ligand L [ (salicylaldimine-K2N, O) NiMe (L)]Nickel (II) -Methyl Complexes of (a) and their catalytic properties in aqueous dispersion systems (Nickel (II) -Methyl Complexes with Water-solid Ligands L [ (Saliclylaldiminato-K2N, O) NiMe (L))]and the same Catalytic Properties in Disperse Aqueous Systems. "" organometallic 2007, No.26, 1311-. Yu, s. -m.; berkefeld, a.;-Schnetmann, i.; muller, G.; meking, S. "Synthesis of Aqueous Polyethylene dispersions with Electron Deficient Neutral Nickel (II) catalyst with Alkylimine Ligands (Synthesis of Aqueous Polyethylene dispersions with Electron depletion Nuclear-purification Neutral Nickel (II) Catalysts with Alkylimine Ligands)" 2007, 40(3), 421-428. Yu, s. -m.; mecking, S. "Variable Crystallinity Polyethylene Nanoparticles (Variable crystalline Polyethylene Nanoparticles.)" macromolecules 2009, 42(11), 3669-.Sauca, s.n.; asua, J.M. "Catalytic Polymerization of Ethylene in Aqueous Media" (J.M.) "J.M.2011, 168(3), 1319-1330, from Chemical Engineering journal. Berkefeld, a.; mecking, S. "study of the mechanism of catalyzing the Growth of Polyethylene chains in the Presence of water (mechanical students of Catalytic Polyethylene Chain Growth in the Presence of Water.)" (applied chemistry International edition 2006, 45(36), 6044-. Hristov, i.h.; DeKock, r.l.; anderson, g.d.w.;-Schnetmann, i.; racking, s.; ziegler, T. "side reactions of late transition metal complexes in emulsion polymerization which may occur due to water (1.): water Complexation and Hydrolysis of Growing chains (positional Side Reactions to Water in Emulsion Polymerization by Metal complexes.1.Water Complexation and Hydrolysis of the Growing Chain.) "(Inorganic Chemistry) 2005, 44(22), 7806. 7818. However, these techniques have been hampered by low catalyst productivity in water, high encapsulation costs, and/or high costs of water-soluble labile ligands.

There remains a need for a higher activity catalyst useful in aqueous catalytic polymerization of olefins (e.g., ethylene) in emulsion. It is also desirable to have a catalyst with high productivity in water. There is also a need for a process for the direct synthesis of semi-crystalline polyolefin latexes that is simple to operate and cost effective.

Disclosure of Invention

The present inventors have discovered a process comprising forming a water-soluble catalyst precursor by combining a group 8 to group 11 transition metal-containing catalyst with a surfactant. The surfactant is characterized by the presence of a hydrophobic segment and a hydrophilic segment. It is believed that the surfactant replaces the labile ligands on the catalyst precursor structure by simple ligand substitution. The precursor is then contacted under polymerization conditions with one or more monoethylenically unsaturated monomers to form a polymer. This process provides unexpectedly high yields and productivity for polyethylene latex synthesis.

Thus, according to one embodiment, this is a method of preparing a formulation comprising combining a group 8 to group 11 transition metal organosoluble catalyst precursor with a surfactant in an aqueous solution and forming a water-soluble catalyst precursor, wherein the organosoluble catalyst precursor comprises a chelating ligand and a labile ligand. The present invention is also the aforementioned method wherein the labile ligand undergoes ligand substitution with a surfactant. According to another embodiment, the present invention is a water-soluble catalyst precursor prepared by the foregoing method and preferably having the structure:

wherein M is a group 8 to group 11 transition metal, and is preferably Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt and Au, and is most preferably Pd, R₁Is H or an alkyl group having 1 to 4 carbon atoms, but is preferably methyl, Ar is a substituted or unsubstituted aromatic group, preferably having 1 to 3 aromatic rings, and preferably at least one of the aromatic rings has an alkoxy substitution, wherein the alkoxy group has 1 to 5, preferably 1 to 3, and most preferably 1 carbon atom, R is a hydrocarbon group having 1 to 12 carbon atoms, preferably an aromatic ring or an alkyl group having 1 to 5 carbon atoms, n is the number of occurrences of R and is 0, 1 or 2, preferably 0. In the procatalyst used to form the dissolved procatalyst, L is any known ligand, but is preferably dimethyl sulfoxide (DMSO) or N (Me)₂C₆H₁₃(R¹ ₃) Wherein R is¹Is a hydrocarbon group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms.

Detailed Description

The catalysts of the present disclosure are late transition metal-containing catalysts. The late transition metal is a group 8 to group 11 transition metal, and comprises Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt and Au. The group 8 to group 11 transition metal-containing catalyst precursor comprises a complex of a transition metal and a ligand comprisingChelating ligands (such as phosphine sulfonates and nitrogen-containing compounds) and labile ligands (such as dimethyl sulfoxide). In one embodiment, the ligand comprises an aromatic ring and one or more halogens. In one embodiment, the ligand is a nitrogen-containing compound. In one embodiment, the ligand is pyridine. In one embodiment, the ligand is-NR₃Wherein each R is the same or different and is a straight or branched alkyl group having 1 to 10 carbon atoms. In one embodiment, -NR₃is-N (CH)₃)₂(C₅H₁₁). In one embodiment, the ligand is a base. In one embodiment, the ligand is a Lewis base. In one embodiment, the ligand is an amine, pyridine, or phosphine. In one embodiment, the ligand is a ketone, ether, phosphine oxide, sulfoxide, alcohol, or olefin.

The group 8 to group 11 transition metal-containing catalyst may be any group 8 to group 11 transition metal-containing catalyst that can undergo ethylene polymerization without the need for an additional chemical activator.

One preferred catalyst precursor has the following structure:

wherein M is a group 8 to group 11 transition metal, and is preferably Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt and Au, and is most preferably Pd, R₁Is H or an alkyl group having 1 to 4 carbon atoms, but is preferably methyl, Ar is a substituted or unsubstituted aromatic group, preferably having 1 to 3 aromatic rings, and preferably at least one of the aromatic rings has an alkoxy substitution, wherein the alkoxy group has 1 to 5, preferably 1 to 3, and most preferably 1 carbon atom, R is a hydrocarbon group having 1 to 12 carbon atoms, preferably an aromatic ring or an alkyl group having 1 to 5 carbon atoms, n is the number of occurrences of R and is 0, 1 or 2, preferably 0. In the procatalyst used to form the dissolved procatalyst, L is any known labile ligand, but is preferably dimethyl sulfoxide (DMSO) or N (Me)₂C₆H₁₃(R¹ ₃) Wherein R is¹Is a hydrocarbon group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms.

According to a preferred embodiment, the catalyst precursor has the following structure

In the present invention, it is believed that labile ligands L or X as shown in the above structures are substituted with a surfactant. This can be achieved by ligand substitution. For example, the catalyst precursor may be added to an aqueous solution of a surfactant. Preferably, the solution is heated and/or stirred. If heated, the solution is heated to a temperature in the range above ambient temperature (e.g., 20℃.) but below 90℃. DMSO is preferably used as labile ligand.

Surfactants are a class characterized by hydrophobic and hydrophilic segments. Examples of hydrophobic segments include C8-C20 straight or branched chain alkyl groups, C8-C15 alkylbenzene residues, naphthalene, alkylnaphthalene, tristyrylphenol, or other water-insoluble hydrocarbons. Alternatively, it may be perfluoroalkyl or polysiloxane. According to a preferred embodiment, the hydrophilic segment comprises a polymer having repeating units- [ -O- (CH)₂)n-]The polyalkylene glycol of (a) wherein n is 2, 3 or 4, but preferably 2, to form a polyethylene glycol, and preferably at least 5, more preferably at least 10, but preferably not more than 40, more preferably not more than 20 repeating units are present. The hydrophobic segment is preferably a hydrocarbon group having at least 6, more preferably at least 8, most preferably at least 10 and preferably not more than 30, more preferably not more than 16 carbon atoms. According to a preferred embodiment, the surfactant further comprises an anionic group, such as phosphate, sulfate, sulfonate, phosphonate, carboxylate or a combination thereof. Commercially available surfactants useful in The present invention include Tergitol from Dow Chemical Company^TM15S-20 and Rhodofac from Solvay^TMAnd RS-610. Preferably, the surfactant is characterized by the absence of any amine functional groups. Another type of surfactant that can be used is a surfactant having a structure of 1An alkylated sulfate of 0to 20 carbon atoms. One example is sodium dodecyl sulfate.

The amount of surfactant relative to the catalyst is preferably at least 0.02 grams surfactant per micromolar catalyst, preferably greater than 0.04 grams surfactant per micromolar catalyst, and most preferably greater than 0.15 grams surfactant per micromolar catalyst. In other words, the amount of surfactant in the solution is at least 3 or at least 4 or at least 5 grams per liter, and preferably no more than 100 or no more than 50 grams per liter.

The concentration of the dissolved catalyst precursor in the solution is preferably 0.01 to 21. mu. mol/liter.

The stabilized catalyst is useful for catalyzing the polymerization of olefins. In one embodiment, the catalyzed olefin polymerization is conducted by contacting a stabilization catalyst with a monoethylenically unsaturated monomer under polymerization conditions to form a polyolefin. In one embodiment, the monomer is ethylene. In other embodiments, the monoethylenically unsaturated monomers are ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and other mono-olefins having from 2 to 8 carbon atoms. In some embodiments, more than one different monoethylenically unsaturated monomer may be used in the polymerization, such as ethylene and propylene or ethylene and octene. In some embodiments, one, two, or three monoethylenically unsaturated monomers may be used to form the polyolefin. The polyolefin may be, for example, a homopolymer, copolymer, or terpolymer. The lower molecular weight monomer (e.g., ethylene) is typically in gaseous form and is contacted with the catalyst in solution in a pressurized reactor, and at least some of the monomer is subsequently dissolved in solution. Suitable pressures are preferably from 30 to 160 bar. Suitable reaction temperatures are generally in the range from 60 to 100 ℃. It may be advantageous to stir or mix the reaction solution.

Applicants have found that dissolved catalysts surprisingly have the highest activity at lower pH. Thus, according to one embodiment, the pH is less than 7 or less than 5.

The methods and catalysts described herein are further illustrated by the following non-limiting examples.

Examples of the invention

The following materials were used.

Example 1 preparation of Pd catalyst precursor

The Pd catalyst precursor was prepared according to the catalyst synthesis route shown below:

methods for preparing catalyst precursors are described in "Insertion Polymerization of acrylates", Guironnet et al, proces of the american chemical society (j.am.chem.soc.) 2009, 131(2) 422-.

These initial catalyst precursors are soluble in organic solvents.

All manipulations of the metal complexes were carried out under an inert atmosphere using a glove box or Schlenk technique (Schlenk technique). The solvent was dried and degassed. Deionized water was degassed with argon prior to use. The aqueous surfactant solution is prepared in advance and degassed before use. Unless otherwise stated, reagents obtained from commercial suppliers were used without any purification.

EXAMPLE 2 preparation of Water-soluble surfactant-stabilized Pd catalyst

The water-soluble surfactant-dissolved catalyst was synthesized by a simple ligand exchange reaction shown below. Using three surfactants, i.e. SDS, Tergitol^TM15-S-20 and Rhodafac^TMAnd RS-610. The 1-Pd-DMSO complex was used as an organic catalyst precursor. It is hypothesized that weak coordination of the DMSO ligand improves the yield of this ligand exchange.

Surface active agent

EXAMPLE 3 solubility quantification of stabilized catalyst and catalyst precursor

UV titration was developed to use the absorption of aromatic ligands to quantify the fraction of palladium phosphine sulfonate complex dissolved in the aqueous phase. Using water-soluble/Rhodafac^TMThe known water-soluble PEG-amine complex 1-Pd-NH2PEG of (a) draws a calibration curve. The maximum absorbance of the complex was determined to occur at a wavelength λ max of 293 nm. Here, the aqueous solution for determining the calibration value contains a surfactant (Rhodafac)^TM) So that it faithfully represents the aqueous solution used for the synthesis of the water-soluble stabilized catalyst.

The water-soluble stabilized catalyst solution was prepared by adding 0.1mL of 0.02. mu. mol/L1-Pd-DMSO complex in Dichloromethane (DCM) to 10mL of an aqueous Rhodafac heated to 85 deg.C under vigorous stirring^TMSolution (8 g/L). After addition, gases evolved from the solution as the volatile organic solvent flashed off, resulting in a clear solution. After cooling, the UV/Vis absorption spectrum of the solution was determined. Using a calibration curve, the 99% Pd complex was calculated to dissolve in water. Without being bound by theory, it is hypothesized that coordination of the palladium complex to the PEG unit of the surfactant improves solubility.

In a series of control experiments, new UV/Vis absorbance calibration values in the absence of surfactant were determined and the dissolution of 1-Pd-DMSO was repeated. The UV/Vis absorption spectrum of the neat aqueous solution shows that 87% of the palladium complex is dissolved in the aqueous phase. However, this experiment does not provide complete validation for UV titration. Therefore, the experiment was repeated using the corresponding pyridine complex (1-Pd-pyr) instead of the 1-Pd-DMSO complex. Pyridine coordinates significantly more strongly to the metal center than DMSO, and therefore the formation of water-soluble aqueous complexes is expected to be less favorable. See Guironnet, d.; roesle, p.; lu nzi, T.;-Schnetmann, i.; mecking, s. "insertion polymerization of acrylates" journal of american chemists 2009, 131(2), 422-. In fact, only 40% of the pyridine complex was found to be dissolved in the aqueous solution. Furthermore, the resulting aqueous solution is clearly heterogeneous, which highlights the low yield of exchange with 1-Pd-pyr ligand. Taken together, these experiments verifyUV/Vis titration method for quantification of the percentage of complex dissolved in water.

Example 4 ethylene polymerization and preparation of polyethylene latex

The surfactant dissolution method described above was then used to synthesize polyethylene latexes by exposing the aqueous catalyst solution to ethylene. A summary of the polymerization of ethylene using various surfactants is provided in table 1.

Specifically, three different surfactants were used, namely Sodium Dodecyl Sulfate (SDS), an alkyl sulfonated surfactant; tergitol^TMA non-anionic pegylated surfactant; and Rhodafac^TMA phosphorylated pegylated surfactant. As a control, the polymerization was also carried out in the absence of surfactant.

In the absence of surfactant, a polyethylene latex with a broad particle size distribution was formed, and a significant amount of coagulated polyethylene (52% of PE formed) was observed to float on top of the latex. Despite this colloidal instability, the catalyst conversion (TO) rate still reached 850TO h^-1. See table 1. It should be noted that the activity reported here does not contain polymer isolated as coagulum.

The addition of surfactant significantly improved the colloidal stability of the latex as indicated by the lower amount of coagulum formed. See table 1. The activity of the catalyst also depends on the surfactant, among which SDS and Tergitol^TMSpecific Rhodafac production^TMLow activity. The pH of all polymerizations was set to the same (. about.7) so that a small amount of cesium hydroxide was added to neutralize the Rhodafac^TMAnd (3) solution.

The effect of pH on catalyst activity was also investigated. A series of polymerizations were carried out at pH 3 and pH 10 using different surfactants. The results are summarized in table 1.

TABLE 1 ethylene polymerization with various surfactants at various pHs with 1-Pd-DMSO in water^a

^aThe polymerization was carried out at 85 ℃ for 0.5h (h) at a catalyst loading of 20. mu. mol in 100mL of water.

^bPS is the particle size determined by Dynamic Light Scattering (DLS).

^cDetermination by 1H-NMR in Cl2CDCDC12 at 90 DEG C

^dpH adjusted with CsOH.

^epH adjusted with H3PO4 (1M).

It was observed that the activity of the palladium phosphine sulfonate catalyst was lower at higher pH with all three surfactants. Rhodafac was observed at pH 3^TMThe activity is highest in the case of surfactants.

Rhodafac is also known^TMAnd stability of the catalyst in the presence of SDS was tested. See table 2. With both surfactants, the catalyst did not exhibit any activity decay for more than 1.5 hours. In Rhodafac^TMIn the case of (2), only 35% loss of activity was observed after 6 hours of polymerization. Interestingly, good stability but lower activity was observed in the case of SDS, indicating that SDS inhibits the catalyst to a large extent. This inhibition may explain the lower activity previously reported for the same catalyst when carried out in miniemulsion polymerization and in the case of water-soluble precursors. See, Zhang, d.; guironnet, d.;-Schnetmann, i.; mecking, S. "Water soluble Complex [ (kappa 2-P, O-phosphinosulfonate) PdMe (L)]And its catalytic properties "[ organometallic ] 2009, 28(14), 4072-.

Using Rhodafac^TMDynamic Light Scattering (DLS) analysis of the prepared latex showed that the volume of the polyethylene particles formed increased linearly over time, which is in contrast to the absence of new nucleationOr any condensed phase. The ratio between the mass of PE formed in the water and the mass of PE collected as coagulum remains constant over time. Both of these observations indicate that the particles are stable throughout the polymerization process and that the coagulation is caused by the presence of insoluble catalyst fractions that remain active throughout the experiment.

EXAMPLE 5 Effect of surfactant concentration on catalyst Activity

The effect of surfactant concentration on catalyst activity was investigated. See table 3.

TABLE 3 ethylene polymerization with 1-Pd-DMSO and various amounts of RhodafacTM a

^aThe polymerization was carried out at 85 ℃ for 0.5h in 100mL of water with a catalyst loading of 20. mu. mol.

^bDetermined by DLS.

^cAt 90 ℃ C at C1₂CDCDCl₂Middle through¹H-NMR measurement^d7. mu. mol of catalyst were used.

The addition of a larger amount of surfactant resulted in a higher activity and a lower amount of coagulum, consistent with the coagulum caused by the insoluble catalyst. Rather than continuously increasing the surfactant loading to completely dissolve the catalyst and achieve maximum activity, the catalyst loading is decreased. The polymerization containing 7. mu. mol catalyst (33% of the original loading) exhibited 4040TO. h^-1Without the formation of coagulum.

Characteristics of the polyethylene particles

The isolated polyethylene samples prepared in the aqueous emulsion were analyzed by NMR spectroscopy and Differential Scanning Calorimetry (DSC). A broad melting temperature of about 110 ℃ and high crystallinity were observed as determined by DSC. These thermal properties and passage¹The low molecular weight determined by H-NMR was consistent. The presence of olefinic protons in NMR spectra indicates that the ratio of chain transfer rate to propagation rate in water is greater than that of organic solventsMedium to large. In addition, this observation is generally in contrast to the polymerization behavior using nickel salicylaldimine catalysts, which rarely undergo any chain transfer in water. See, Godin, a.;-Schnetmann, i.; mecking, s. "nanocrystal formation in aqueous intercalation polymerization" [ macromolecules ] 2016, 49(23), 8825-.

Transmission Electron Microscopy (TEM) image of latex samples with Tergitol^TMAnd SDS the synthesized particles appeared to coalesce as small round particles. The volume of these subparticles (assumed to be spheres) is well matched to the volume of a single polymer chain (based on its molecular weight). Furthermore, the round particle morphology is consistent with the assumption that the catalyst shuttles between the aqueous phase and the particles. The water solubility of the palladium methyl complex indicates that the corresponding palladium hydride is also water soluble and, therefore, after chain transfer, the catalyst becomes water soluble until it intercalates multiple ethylene units and disintegrates into the PE particles. On the other hand, for Rhodafac^TMThis morphology was not observed. Without being bound by theory, it is speculated that this difference is due to the concomitant Rhodafac^TMBut not with other surfactants.

The inventors have therefore surprisingly found a simple strategy for the preparation of semi-crystalline polyethylene latexes in water. The catalyst precursor dissolves in water by coordinating to the water-soluble surfactant. In addition, the catalyst generally exhibits high activity and high stability, and the activity exceeds 6 hours. The chemical nature of the surfactant and the pH of the aqueous solution were found to play an important role in the polymerization rate. The palladium catalysts studied here perform best at acidic pH under phosphated surfactants. However, the common sulfonated surfactant SDS has been shown to inhibit the catalyst to a large extent.

Thus, the methods described in the present disclosure provide an easy strategy for the in situ synthesis of water-soluble stabilized catalysts active for olefin polymerization.

The disclosure is further illustrated by the following aspects.

In general, the invention can alternatively comprise, consist of, or consist essentially of any suitable component disclosed herein. The present invention can additionally or alternatively be formulated so as to be free or substantially free of any components, materials, ingredients, adjuvants, or species used in the prior art compositions or that are not otherwise necessary to the achievement of the function and/or objectives of the present invention.

The compositions, methods, and articles of manufacture may alternatively comprise, consist of, or consist essentially of any suitable component or step disclosed herein. The compositions, methods, and articles of manufacture can additionally or alternatively be formulated so as to be free or substantially free of any components, materials, ingredients, adjuvants, or species used in the prior art compositions or that are not otherwise necessary to the achievement of the function and/or purpose of the compositions, methods, and articles of manufacture.

All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. "combination" includes blends, mixtures, alloys or reaction products. Moreover, the terms "first," "second," and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a" and "an" herein do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Unless expressly stated otherwise, "or" means "and/or. It is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

Throughout this disclosure, the terms "procatalyst" and "catalyst precursor" are used synonymously.

"alkyl" as used herein refers to a hydrocarbon group having 1 to 20 carbon atoms, preferably 2 to 16 carbon atoms; and "substituted alkyl" includes alkyl further having one or more of the following: hydroxy, (lower alkyl) alkoxy, (lower alkyl) mercapto, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, aryloxy, substituted aryloxy, halogen, trifluoromethyl, cyano, nitro, nitrone, amino, amido, C (O) H, acyl, oxyacyl, carboxy, carbamate, sulfonyl, sulfonamide, or sulfonyl substituents. "lower alkyl" means a hydrocarbon group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms; and "substituted lower alkyl" includes lower alkyl further bearing one or more substituents as described herein. "alkylene" means a divalent hydrocarbon group having 1 to 20 carbon atoms, preferably 2 to 10 carbon atoms; and "substituted alkylene" includes alkylene further bearing one or more substituents as set forth above. "cycloalkylene" refers to a divalent ring-containing group containing 3-8 carbon atoms, and "substituted cycloalkylene" refers to cycloalkylene further bearing one or more substituents as set forth above. "arylene" refers to a divalent aromatic group having 6 to 14 carbon atoms, and "substituted arylene" refers to an arylene group further bearing one or more substituents as set forth above. "polyarylene" refers to a divalent moiety comprising a plurality (i.e., at least two, up to 10) of divalent aromatic groups each having 6 to 14 carbon atoms, wherein the divalent aromatic groups are linked to each other directly or via 1-3 atom linking groups; and "substituted polyarylene" refers to a polyarylene further bearing one or more substituents as set forth above. "heteroarylene" refers to a divalent aromatic group containing one or more heteroatoms (e.g., N, O, P, S or Si) as part of a ring structure and having 3 to 14 carbon atoms; and "substituted arylene" refers to arylene further bearing one or more substituents as set forth above. "Polyheteroarylene" refers to a divalent moiety comprising 2-4 heteroarylenes (each containing at least one heteroatom and 3-14 carbon atoms), wherein the heteroarylenes are linked to each other directly or via a 1-3 atom linking group; and "substituted polyheteroarylene" refers to a polyheteroarylene further bearing one or more substituents as set forth above. "(meth) acrylate" refers collectively to both acrylates and methacrylates.

All references are incorporated herein by reference.

While specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may not be presently foreseen may suggest themselves to applicants or other skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications, variations, improvements, and substantial equivalents.