Process for polymerizing tetrafunctional long-chain branched polyolefin resins

Abstract

Embodiments of the inventive methods for synthesizing long chain branched copolymers comprise contacting together one or more C2-C14 olefin monomers, at least one diene or polyene, optionally a solvent, and a multi-chain catalyst. The multi-chain catalyst comprises a plurality of polymerization sites and produces at least two polymer chains of the C2-C14 olefin monomer, each polymer chain polymerizing at one of the polymerization sites. The invention relates to a method for synthesizing a long-chain branched polymer by linking the two polymer chains to the diene or polyene, the joining of the two polymer chains being carried out in a synergistic manner during the polymerization.

Description

[0001] This application is a divisional application of the Chinese patent application No. 2019800700724 (Application date: 2019 / 9 / 27, Invention name: Method for polymerizing tetrafunctional long-chain branched polyolefin resin).

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Patent Application No. 62 / 738,621, filed September 28, 2018, the entire disclosure of which is hereby incorporated by reference. Technical Field

[0004] Embodiments of the present disclosure generally relate to polymer compositions having long-chain branches and methods of synthesizing the same. Background Art

[0005] Olefin polymers such as polyethylene and polypropylene are produced by various catalyst systems. The selection of such catalyst systems used in the polymerization process of olefin polymers is an important factor contributing to the characteristics and properties of such olefin polymers.

[0006] Polyethylene and polypropylene are manufactured for use in a variety of articles. Polyethylene and polypropylene polymerization processes can differ in many ways to produce a variety of resulting polyethylene resins with different physical properties that make each resin suitable for different applications. The amount of short-chain branching in a polyolefin affects the physical properties of the polyolefin. The effect of branching on the properties of polyethylene depends on the length and amount of the branches. Short branches primarily affect mechanical and thermal properties. As the frequency of short-chain branches increases, the ability of the polymer to form lamellar crystals decreases, and mechanical and thermal properties decrease. Small amounts of long-chain branching can significantly alter the handling properties of the polymer.

[0007] To form long-chain branching, the vinyl group or terminal double bond of a polymer chain is incorporated into a new polymer chain. Reincorporation of vinyl-terminated polymers and introduction of a diene comonomer are two mechanisms for incorporating vinyl groups from a polymer chain into a second polymer chain. Additionally, long-chain branching is initiated by free radicals. Controlling the amount of branching is difficult in all three mechanisms. When free radicals or dienes are used to initiate long-chain branching, the branching can become excessive, causing gelation and reactor fouling. The reincorporation mechanism does not produce much branching, and branching can only occur after the polymer chain has been generated, further limiting the amount of branching that can occur. Summary of the Invention

[0008] Embodiments of the present disclosure include methods for synthesizing long chain branched copolymers. The methods include making one or more C2-C 14An olefin monomer, at least one diene or polyene, optionally a solvent and a multi-chain catalyst are contacted together. The multi-chain catalyst comprises multiple polymerization sites and produces the C2-C 14 At least two polymer chains of olefin monomers, each polymer chain polymerized at one of the polymerization sites. The method synthesizes the long-chain branched polymer by linking the two polymer chains with the diene or polyene, wherein the joining of the two polymer chains occurs in a concerted manner during the polymerization.

[0009] Various embodiments of the process comprise polymerization that occurs in a solution polymerization reactor or a particle formation polymerization reactor, such as a slurry reactor or a gas phase reactor, wherein a molecular or solid supported catalyst is delivered to or formed in the reaction medium, wherein the reactor system is batch or continuous or hybrid, such as semi-batch, wherein the reactor residence time distribution is narrow, such as in a non-backmixed reactor, or wide, such as in a backmixed reactor and in series and loop reactors. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a graphical depiction of the molecular weight of a polymer as the number of branching methine groups per 1000 carbons increases.

[0011] Figure 2 is a graphical model for the predicted dependence of the molecular weight distribution (MWD) curve on the level of branching.

[0012] Figure 3 is a graphical model for the predicted dependence of relative peak molecular weight on the level of branching.

[0013] Figure 4 is a graphical depiction of the predicted dependence of the molecular weight distribution (MWD) curve on the level of trifunctional diene branching.

[0014] Figure 5 is a graphical depiction of the predicted dependence of the relative peak molecular weight (MW) on the level of trifunctional diene branching.

[0015] Figure 6 is the branching versus peak molecular weight (M p ) is a graphical depiction of the effect of the model predictions on branching per polymer molecule for conventional diene branching (solid line) and "ladder branching" (dashed line).

[0016] Figure 7 is the branching weight average molecular weight (M w ) is a graphical depiction of the effect of the model predictions on branching per polymer molecule for conventional diene branching (solid line) and "ladder branching" (dashed line).

[0017] Figure 8is the branching peak weight average molecular weight (M p ) relative to conventional diene branching (solid line) (relative to B c ) and “ladder-branched” polymers (dashed line) (relative to R c ) of M p Graphical depiction of the impact of branching on the model predictions for each linear segment.

[0018] Figure 9 is the branched weight average molecular weight (M w ) relative to conventional diene branching (relative to B c ) (solid line) and “ladder-branched” polymers (dashed line) (relative to R c ) is a graphical depiction of the model-predicted impact of branching on each linear segment.

[0019] Figure 10 is a graphical depiction of the MWD slope used to calculate the shape metrics G(79 / 29) and G(96 / 08), where S(X) is the slope at X% of the MWD height. G(A / B) = (S(A) - S(B)) / S(A).

[0020] Figure 11 is a measure of the molecular weight distribution (MWD) shape G(79 / 29) compared to conventional and "ladder-branched" model predictions along with the relative peak MW (M p / M po ) is a graphical depiction of the changes in branching levels depicted.

[0021] Figure 12 is the MWD shape measure G(79 / 29) compared to the conventional and “trapezoidal branched” model predictions along with the relative weight-average MW (M w / M wo ) is a graphical depiction of the changes in branching levels depicted.

[0022] Figure 13 is the MWD shape measure G(98 / 08) compared to the conventional and "trapezoidal branching" model predictions along with the relative peak MW (M p / M po ) is a graphical depiction of the changes in branching levels depicted.

[0023] Figure 14 is the MWD shape measure G(98 / 08) compared to the conventional and "trapezoidal branched" model predictions along with the relative weight-average MW (M w / M wo ) is a graphical depiction of the changes in branching levels depicted.

[0024] Figure 15 is a graphical depiction of the MWD curve showing how the point of maximum slope is used to define the high MWD tail area measure.

[0025] Figure 16 is the relative weight average molecular weight (M) of conventional and "ladder-branched" p / M po ) Model predicted MWD area measure A for variations in branching level depicted 高 .

[0026] Figure 17 is the relative peak molecular weight (M) of conventional and “ladder-branched” w / M wo ) Model predicted MWD area measure A for variations in branching level depicted 高 .

[0027] Figure 18 is the relative peak molecular weight (M) of conventional and “ladder-branched” p / M po ) Model predicted MWD area measure A for variations in branching level depicted 尾部 .

[0028] Figure 19 is the relative weight average molecular weight (M) of conventional and "ladder-branched" w / M wo ) Model predicted MWD area measure A for variations in branching level depicted 尾部 .

[0029] Figure 20 is the absolute molecular weight distribution (MWD) graph of the GPC measurement of example series 2.4 as reported in Table 2.

[0030] Figure 21 is a conventional molecular weight distribution curve measured by conventional gel permeation chromatography (GPC).

[0031] Figure 22 is the absolute molecular weight distribution curve measured by GPC triple light scattering detector (also known as absolute GPC).

[0032] Figure 23 is a graph of extensional viscosity as a function of time in seconds for a "ladder-branched" polymer resin.

[0033] Figure 24 is a graph of melt strength (cN) versus viscosity (mm / s) for a "ladder-branched" polymer resin.

[0034] Figure 25 is the conventional molecular weight distribution curve for unbranched ethylene polymers and "ladder-branched" polymer resins as measured by GPC.

[0035] Figure 26 The absolute molecular weight distribution curves of unbranched ethylene polymers and "ladder-branched" polymer resins are measured by GPC triple light scattering detector.

[0036] Figure 27 is a graph of the extensional viscosity of a "ladder-branched" polymer resin as a function of time in seconds.

[0037] Figure 28 is a graph of melt strength (cN) versus viscosity (mm / s) for a "ladder-branched" polymer resin.

[0038] Figure 29 are absolute molecular weight distribution curves measured by a GPC triple light scattering detector for two comparative examples without diene and four samples with varying diene amounts.

[0039] Figure 30A is a graph comparing the absolute molecular weight distributions of conventional branched polymer samples with varying amounts of diene.

[0040] Figure 30B is a graph comparing conventional molecular weight distributions of conventional branched polymer samples with varying amounts of diene.

[0041] Figure 31 is a graph of the rheological ratio of various polymer resins and "ladder-branched" polymer resins as a function of average g'.

[0042] Figure 32 is a graph of the rheological ratio as a function of the polydispersity index (PDI) for various polymer resins and "ladder-branched" polymer resins.

[0043] Figure 33 is a graph of melt strength (hundredths of Newtons, cN) as a function of melt index (Log I2) for polymers produced with single-chain and dual-chain catalysts, with additional lines depicting linear polyethylene, tubular low density polyethylene, and autoclave low density polyethylene. DETAILED DESCRIPTION

[0044] Specific embodiments of the methods for synthesizing polymers and polymers synthesized by the methods of the present disclosure will now be described. It should be understood that the methods for synthesizing polymers disclosed herein can be embodied in different forms and should not be construed as being limited to the specific embodiments set forth herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the subject matter to those skilled in the art.

[0045] definition

[0046] The term "polymer" refers to a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. Thus, the general term polymer encompasses the term "homopolymer," typically used to refer to polymers prepared from only one type of monomer, and "copolymer," which refers to polymers prepared from two or more different monomers. As used herein, the term "interpolymer" refers to a polymer prepared by polymerizing at least two different types of monomers. Thus, the general term interpolymer encompasses copolymers as well as polymers prepared from two or more different types of monomers, such as terpolymers.

[0047] "Polyethylene" or "ethylene-based polymer" shall mean a polymer comprising greater than 50% by weight of units derived from ethylene monomer. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include: low density polyethylene (LDPE); linear low density polyethylene (LLDPE); ultra low density polyethylene (ULDPE); very low density polyethylene (VLDPE); single-site catalyzed linear low density polyethylene, which includes both linear low density resins and substantially linear low density resins (m-LLDPE); medium density polyethylene (MDPE); and high density polyethylene (HDPE).

[0048] The embodiments of the present disclosure comprise the addition of C2 monomers, optionally at least one or more C3-C 12 A method for synthesizing a long-chain branched polymer from an alpha-olefin comonomer, at least one diene, a multi-chain catalyst, and optionally a solvent, wherein the multi-chain catalyst comprises a molecule having multiple polymerization sites to produce at least two copolymer chains, each copolymer chain copolymerizing at one of the polymerization sites; and synthesizing the long-chain branched polymer by linking the two copolymer chains with the diene, the linking of the two copolymer chains being coordinated with the copolymerization.

[0049] The method for synthesizing polymers according to the present disclosure is different from conventional long-chain branching. The term "long-chain branching" refers to a branch having more than 100 carbon atoms. "Branch" refers to a portion of a polymer extending from a tertiary carbon atom or a quaternary carbon atom. When a branch extends from a tertiary carbon atom, there are two other branches, and the two other branches can be polymer chains together, and the branches extend from the polymer chain. Conventionally, long-chain branching (LCB) may occur naturally during polymerization, as shown in Scheme 1. This can occur by vinyl end-capping of the polymer chain and reinsertion of macromolecular vinyl groups that produce trifunctional long-chain branches. Depending on the degree of branching, a variety of methods can determine LCB (such as nuclear magnetic resonance (NMR)) or distinguish the effect of LCB in a polymer. For example, the effect of LCB in shear flow was observed in the Gurp-Palmen analysis, and the increase in shear viscosity and the intensity of shear-thinning behavior at low angular frequencies can also be attributed to LCB. In extensional flow, the influence of LCB is usually identified in the degree of hardening or melt strength and the maximum deformation achieved. Achieving high levels of natural LCBs in polymers is difficult due to the limited concentration of vinyl terminated polymer (maximum one per polymer chain) and the need to achieve high ethylene conversions to ensure LCB formation. To ensure high conversions, the ethylene concentration in the reactor is low, thus enabling a large amount of vinyl terminated polymer to be reinserted into the second polymer chain.

[0050] Scheme 1: Naturally occurring long-chain branching: chain transfer events leading to vinyl-terminated polymers

[0051]

[0052] In Scheme 1, "Cat" is the catalyst and "P" is the polymer chain.

[0053] Long chain branches formed by naturally occurring branching processes are minimal. One way to enhance LCBs is by adding α,ω-dienes to the polymerization system, whether in a free radical, heterogeneous or homogeneous process. Typically, the diene is added to the polymer chain in a similar manner to the α-olefin, but leaves behind pendant vinyl groups that can be reinserted into the polymer chain to form the LCB, as illustrated in Scheme 2. Generally, the diene length is not important as long as it can link two polymer chains together. In principle, the concentration of pendant vinyl groups can be controlled by the amount of diene added to the reactor. Therefore, the extent of LCB can be controlled by the concentration of pendant vinyl groups.

[0054] Scheme 2: Long-chain branching via diene incorporation

[0055]

[0056] In Scheme 2, "Cat" is the catalyst; "P" is the polymer chain; and the diene in this example is 1,5-hexadiene.

[0057] The conventional method of incorporating dienes into polymer synthesis systems suffers from the basic defect of gel formation or reactor fouling. The kinetic model discussed in the following paragraphs can provide a good prediction result for realizing a better understanding of gel formation. For example, longer polymer chains have more inserted olefins, thereby have more inserted dienes, thereby have more side vinyl groups, which means that longer polymer chains will be more likely to be reinserted into the catalyst to form LCB. Therefore, longer polymer chains are preferentially reinserted into tetrafunctional branches, which are even larger polymer molecules and cause gel problems. As indicated in Scheme 2, tetrafunctional LCB has short chain segments (the number of carbon atoms between the two double bonds of the diene) that bridge two long chains on each side of the short chain segments. For polyethylene in a semi-batch reactor at constant pressure, the weight average molecular weight (M) that varies with branching w ) and number average molecular weight (M n ) is shown in the simulation Figure 1 middle. son Figure 1 In, M n Only with M w becomes infinite and increases slightly. w At amounts greater than 200,000 grams per mole (g / mol), the polymer gels, coagulation occurs, or reactor fouling occurs.

[0058] The term "gel" or "gelled" refers to a solid composed of at least two components: the first is a three-dimensionally crosslinked polymer, and the second is a medium in which the polymer is not completely dissolved. When the polymer gels and is not completely dissolved, the reactor may become contaminated with the polymer gel.

[0059] The term "ladder-branched" polymer refers to the tetrafunctional long chain branched polymers disclosed in this application, and the term or "ladder-branching mechanism" refers to how the "ladder-branched" polymer is formed.

[0060] In one or more embodiments of the present disclosure, the method for synthesizing long-chain branched polymers achieves long-chain branching and avoids gel formation or reactor fouling. Without being intended to be bound by theory, it is believed that by making two olefins of a diene react in a consistent manner across two proximal polymer chains to avoid reactor fouling. For example and as shown in Scheme 3, one olefin in a diene reacts before a second olefin, and the second olefin reacts before too many ethylene molecules are added to the polymer chain, thereby removing the proximity of the second olefin to the reaction site. Before inserting many ethylene monomers, the reaction of the first olefin in a polymer and the reaction of the second olefin in the diene with adjacent polymer chains are referred to as the synergistic addition of diene to the proximal polymer chain.

[0061] Scheme 3: Description of the diene incorporation in a concerted manner (P is the polymer chain), also known as the "ladder branching" mechanism.

[0062]

[0063] A polymer chain is a linear segment of a polymer, or more specifically a copolymer, optionally joined at one or more ends by a branched junction. For example, a tetrafunctional branched junction joins the ends of four polymer chains, as opposed to a trifunctional branched junction, which joins the ends of three polymer chains as shown in Scheme 1.

[0064] Combinations of multi-chain catalysts and dienes affect the amount and type of branching. Embodiments of the present disclosure relate to controlling polymer properties such as: 1) using multiple diene species, 2) using multiple multi-chain catalyst species, or 3) a combination of polymerization environments comprising multiple reactor zones or gradient zones.

[0065] Although the use of multiple catalysts, including single chain catalysts, can allow conventional branching. The use of multiple diene species also includes those dienes that do not produce branches or do not result in "conventional" LCBs. The method of synthesizing polymers according to the present disclosure is different from conventional long chain branching. The term "long chain branching" refers to branches with more than 100 carbon atoms. The term "branch" refers to a portion of a polymer that extends from a tertiary carbon atom or a quaternary carbon atom. When a branch extends from a tertiary carbon atom, there are two other branches, and the two other branches together can be the polymer chain from which the branch extends. Long chain branching (LCB) may occur naturally during the polymerization process, as shown in Scheme 1. This can occur by end-capping of the polymer chain and reinsertion of macrovinyl groups that produce trifunctional long chain branches.

[0066] In one or more embodiments, the method for polymerizing long-chain branched polymers comprises a catalyst having at least two active sites in close proximity (multi-chain catalyst). In order to make the two active sites close together, the distance between the two active sites can be less than In some embodiments, the two active sites comprise arrive arrive or approximately In various embodiments, the method for polymerizing long-chain branched polymers comprises a multi-chain catalyst. In one or more embodiments, the multi-chain catalyst may comprise at least one metal center, wherein the two active sites are on the same metal center. In some embodiments, the multi-chain catalyst may comprise a metal-ligand complex, wherein the two active sites (two polymer chains) are on the same metal center.

[0067] According to the X-ray crystal structure (AD Bond, Chem. Comm. 2002, 1664), 1,9-decadiene has The distance between the terminal carbons of 1,9-decadiene. Although there is data that 1,9-decadiene forms a ladder between two polymer chains via a "ladder branching" mechanism, it is believed that α,ω-dienes with more than 10 carbon atoms can also form ladders via a "ladder branching" mechanism. Without intending to be bound by theory, the question of whether α,ω-dienes with more than 10 carbon atoms can form ladders can be determined by the distance between the two polymer chains. For example, when the two polymer chains are on different metal atoms of the catalyst (e.g., bimetallic, heterogeneous), the α,ω-dienes can contain additional methylene units (same C-C bond length and angle) to extend this structure to 1,15-hexadecadiene. Without intending to be bound by theory, it is speculated that this 16-carbon analogue still has the potential to form ladders via a "ladder branching" mechanism. In this way, dienes, 1,11-dodecene (with a distance between the terminal carbons of ), 1,13-tetradecene (the distance between the terminal carbons is ), 1,15-hexadecadiene (the distance between the terminal carbons is In some embodiments, when the double-chain catalyst in the "ladder branching" mechanism is a bimetallic catalyst, the diene is less than or equal to

[0068] It is well known that modern computational techniques can reproduce known experimental crystal structures with high accuracy, which can be used as a method to estimate the distances between the chains of the catalyst. For heterogeneous systems, the surface concentration of the metal can be estimated, usually in metal atoms per square nanometer (M / nm 2 ) to measure metal. This surface coverage provides an estimate of the metal available on the surface and, if the metal is uniformly dispersed, can be converted to MM distances, which reflect the distances between polymer chains. For extended surfaces, 1 metal / nm 2 The distance between metal atoms is is just within the expected critical value. Under this condition, it can be determined that 0.3 metal / nm 2 The coverage rate below.

[0069] Examples of catalysts having at least two active sites, wherein the active sites are in close proximity, include, but are not limited to, bimetallic transition metal catalysts; heterogeneous catalysts; dianionic activators having two associated active catalysts; transition metal catalysts having more than one attached growing polymer chain; and Group IV olefin polymerization catalysts comprising a monoanionic group, a bidentate monoanionic group, a tridentate monoanionic group, or a monodentate, bidentate, or tridentate monoanionic group with an external donor.

[0070] The catalysts in Table 1 are illustrative examples of the previously described catalyst classes and specific catalysts contemplated. The examples in Table 1 are not intended to be limiting; rather, the examples are merely illustrative and specific examples of the previously mentioned catalyst classes.

[0071] Table 1: Catalysts with more than one active site in close proximity

[0072]

[0073]

[0074] While not intending to be bound by theory, as explained in this section, the mechanism describes how a dual-chain catalyst can produce a unique bridged molecular architecture when polymerizing a diene comonomer under desired conditions. The term "diene" refers to a monomer or molecule having two olefins. A graphical depiction of the kinetics is shown in Scheme 4, where the catalyst center produces two polyolefin chains. Scheme 4 shows how a combination of diene bridging and chain transfer produces a diene "ladder-branched" polymer structure. The term diene "ladder-branched" polymer refers to long-chain branching in which short chains or ladders containing one to twelve carbon atoms connect the two long chains together. As shown, a metal-ligand catalyst having at least two polymer chain sites grows two separate polymer chains. One of the olefins in the diene is incorporated into one of the catalyst's sites, and it is believed that due to the close proximity of the growth sites, the second olefin of the diene is then rapidly incorporated into the second polymer chain, thereby forming a bridge or ladder. This continuous addition of diene is referred to as "concerted" diene addition, as distinguished from catalysts without two proximal chains, where diene addition results in a concentration of vinyl-containing polymer in the reactor that reacts at a later time. The term "cascade" refers to the incorporation of the diene into two separate polymer chains, thereby linking the chains together. The first polymer chain and the second polymer chain continue to grow until the polymer is transferred to another catalyst, the polymer is released from the catalyst, the catalyst mold, or another diene is added.

[0075] dynamics

[0076] Scheme 4. Illustration of the “ladder branching” dynamics including the resulting molecular architecture. Metal-ligand catalysts by LM + Jointly expressed.

[0077]

[0078] Without intending to be bound by theory, it is believed that when diene bridging reactions are the only source of branching, the molecular weight distribution associated with these proposed kinetics is inherently stable at high branching levels. The molecular weight distribution (MWD) is calculated by dividing the weight average molecular weight by the number average molecular weight (MWD). w / M n The inherent stability of MWD means that even at high branching levels, the weight average molecular weight (M w ) increases only modestly, in contrast to conventional diene comonomer branching technology, where M w and M w / M n It becomes infinite at moderate tetrafunctional branching levels.

[0079] A mathematical model was derived for the purpose of showing how a process for synthesizing polyethylene produces long chain branched polymers having a diene "ladder branched" molecular architecture. The mathematical model will also be used to establish claim metrics and scope. A mathematical model of the branching architecture as described in this disclosure can be derived from the kinetic description of the proposed branching mechanism. This model is based on several assumptions that facilitate mathematical simplification, but these assumptions are not intended to limit the scope of this disclosure. The assumptions follow from the common industrial use of non-reactive additions to copolymers and additional assumptions that are specific to the assumed diene branching mechanism. The general assumptions made include: (1) growth is much faster than chain transfer, so the average chain length is much longer than one monomer length; (2) only a single pure catalyst species is active; (3) the catalyst center produces many chains during its lifetime, and so the chain lifetime is a small fraction of the reaction or residence time; and (4) when there is negligible composition drift, copolymerization can be approximated by a homopolymerization model.

[0080] Dynamics of the "ladder branching" theory of dienes

[0081] In addition to the four commonly made assumptions, the kinetics of the diene "ladder branching" theory are based on four additional assumptions. The first is that the catalyst center simultaneously generates two chains with identical kinetics and statistics. Second, a ladder is formed when a diene bridges two polymer chains of increasing length. Third, a branch point is formed whenever two unbridged chains are bridged by a diene. Finally, unbridged diene reactions are neglected because the MWD is unaffected.

[0082] The kinetic description of the proposed diene "ladder branching" mechanism requires the deployment of nomenclature that describes how each reaction affects the molecular architecture. Some of the nomenclature elements below represent small molecules (M, A, D), while others represent molecular architectures (P n,m 、S n 、D n ). Dynamics will show how named elements interact to form molecular architecture.

[0083] Dynamics Nomenclature

[0084] M: monomer or comonomer; A: chain transfer agent type; D: diene branching type; n, m: indices reflecting the number of monomer repeating units in the subtype; P n,m : a catalyst having two non-bridged propagation polymers having n and m monomer repeat units; D n : an inactive polymer molecule with n monomer repeating units; S n : a catalyst that produces bridged polymer molecules with n monomer repeat units; Kc: a kinetic chain is defined as a linear segment produced by chain transfer; Rg: a step is defined as a bridge between chain segments; Br: a branch is produced when two previously unbridged molecules are bridged.

[0085] The branching kinetic equations are written below using the nomenclature and the assumptions introduced above. Each reaction will be briefly described and the kinetic schemes and rate laws should be understood by anyone skilled in the art of polymerization kinetics.

[0086] Table 2: Kinetics of the diene "ladder branching" theory (n ≥ 1, m ≥ 1)

[0087]

[0088] The result of the growth is that the chain size increases in increments of one repeating unit. Write the growth for each of the two molecules that increase in length starting from the catalyst center. For example, P n,m The first index on is the left chain on the catalyst, and the second index is the right chain on the catalyst. n ) length, the rate of growth is modeled as 2-fold because there are two chain positions (left and right) at each center that are equally available for reaction.

[0089] Like propagation, chain transfer is written separately for the left and right positions on the catalyst. n,m ) chain transfer produces inactive polymer molecules (D n or D m ) and vacancies (P 0,m or P n,0When the growing bridging molecule (S n ) participates in chain transfer, generating unbridged species (P n,0 or P 0,n ), and since all n repeat units remain bonded to the catalyst, no inactive polymer is produced. Assuming that the vacancies (P 0,m and P n,0 ) restarts very quickly and participates in propagation. Since each diene has two polymerizable groups and each catalyst center has two sites (left and right) for diene incorporation, the rate expression for diene bridging includes a factor of 4.

[0090] Only when the unbridged type (P n,m ) reacts effectively with a diene, the diene bridging results in the formation of tetrafunctional branches (br). Tetrafunctional branches are short segments where four polymer chains can emanate from each side of the short segment, with two polymer chains emanating from each side of the short segment. For dienes, tetrafunctional branches are the expected type of LCB. When any catalyst center is effectively incorporated into a diene (regardless of whether it has a bridging (S) n ) or unbridged (P n,m ) molecules), a ladder (rg) is produced. Diene reactions that do not lead to bridging, such as intrachain cyclization and pendant vinyl formation, are ignored and considered non-productive for these kinetics.

[0091] The creation of a kinetic model requires the derivation of a series of population equilibria for each type of polymer species involved. These population equilibria are derived as a function of chain length (n, m) and represent the kinetic rates of change of the various polymer subspecies. The population equilibria given below are given assuming a mass action rate law, where P n,m 、S n and D n The symbol represents the molar concentration of the subspecies with n≥1 and m≥1. The kinetic model can be extended to include other chain transfer reactions, such as by hydrogen (k trh ) and β-hydride elimination (k b ),Ω=k tra A+k trh H2+k b .

[0092]

[0093] In equations (1), (2), and (3):

[0094] Ω = k tra A (4)

[0095] Ψ = k dD (5)

[0096] Φ = k p M (6)

[0097]

[0098] Other important population balances can be derived from equations (1) to (8), such as for the left side (L n ) and right side (R n ). Due to the symmetry imposed when defining the kinetic scheme, the left and right distributions of the growing polymer subspecies are equal.

[0099]

[0100] Molecular properties such as the formation rates of kinetic chains (kc), branches (br), and ladders (rg) are expressed below using mass action rate laws derived from the kinetic scheme. Shorthand notations are used to define the concentration of catalyst and unbridged molecules (ξ 0,0 ) and the concentration of catalyst and bridging polymer molecules (μ0). The total catalyst concentration is therefore ξ 0,0 +μ0.

[0101]

[0102] The first step in rendering a usable model is to convert the relevant polymer subspecies rates Setting α to zero imposes a "steady-state assumption" on the distribution of growing polymer species. This is a very common assumption in addition polymerization models when the lifetime of the growing chain is only a small fraction of the time period of interest. In most non-living industrial polymerizations of this type, chain lifetimes are typically much less than a second, while reactor residence times are at least several minutes. Applying the "steady-state" assumption and summing the liveness rates for all exponentials yields the following relationship.

[0103] 2Ψξ 0,0 =Ωμ0, so

[0104] The “steady-state hypothesis” arises from the simple branching metric (B c , B n , R c ), which will be useful in molecular architecture models. In this particular case, transient properties are convenient and relevant because they are applicable to a variety of reactors, such as steady-state, well-mixed reactors or batch reactors with negligible drift in temperature or composition. When the chain transfer (Ω) and diene bridging rate (Ψ) parameters do not vary spatially or temporally, the transient branching measure (B c, B n , R c ) is equal to their cumulative average.

[0105] transient tetrafunctional branching of each kinetic chain,

[0106] transient tetrafunctional branching per polymer molecule,

[0107] The instantaneous step of each kinetic chain,

[0108] Moments used to predict the mean MWD

[0109] Models describing the moments of the chain length distribution of polymer species can often be derived from population equilibria generated by kinetic schemes. Moment-based models can be used to predict molecular weight averages and polydispersity indices, but generally do not describe smaller nuances in MWD, such as bimodality, peak MW, and tailing. Moment methods require the definition of moments for the chain length distribution of various polymer subspecies, such as the moments described below. Bulk polymer moments (λ i ) reflects bulk polymer properties, and the solution of models of bulk moments usually requires the solution of various living polymer moments.

[0110] Active polymer MWD moment:

[0111] Bulk polymer MWD moment:

[0112] Any skilled polymer reaction engineer will recognize the derivation of the moment model (Eqs. (20) and (21)) from a series of population equilibria. The rates of change of the dominant bulk polymer moments (λ0, λ1, λ2) are given below, where negligible terms are removed after imposing the assumption that the kinetic chains are long, and therefore Φ>>Ω.

[0113]

[0114] The evaluation of the rate of change of these bulk moments requires a number of active polymer subspecies moments. Due to the "steady-state assumption", these active polymer moments are algebraic and are given below. When predicting higher bulk moments such as λ3, additional active moments are required.

[0115]

[0116] After algebraic simplification of the moment ratios, the instantaneous number and weight average chain length (DPn, DPw) are provided below. Of course, the average molecular weight (M n , M w) is equal to the average chain length multiplied by the apparent monomer repeat unit weight in grams per mole.

[0117]

[0118] By some substitutions, such as the average linear kinetic chain length DP no Equal to Φ / Ω, further simplifying the expression of the model. Moreover, the model can be expressed as the instantaneous branching measure B c 、B n and R c The following is a function of the diene "ladder branch" (B c ) and the number of branches per polymer molecule (B n ) in terms of the model. It was previously shown that for this system, the number of branches per polymer molecule is equal to the number of steps (B) per kinetic chain. n =R c ).

[0119]

[0120] In defining the number-average and weight-average linear kinetic chain quantities as M no and M wo After that, the number average molecular weight and weight average molecular weight (M n , M w ) can also be predicted for each kinetic chain (B c ) of the diene "ladder branches" or branches per polymer molecule (B n ) function.

[0121]

[0122] The unexpected prediction arising from the moment model (Eqs. (20) and (21)) is that at high levels of diene branching, the maximum polydispersity is about 4. Of course, this prediction is for an ideal copolymerization and a single symmetric catalyst system, and any non-ideal situation is likely to increase the polydispersity.

[0123] Model of the complete MWD curve

[0124] Sometimes, the population equilibrium of the molecular weight distribution curve can be solved. Explicit algebraic solutions are usually only available when the reaction rate does not vary in space or time, as assumed in this case. The solution begins with the definition of another distribution quantity Vn derived from Pn,m. Through simplifications due to symmetry, the population equilibrium of Vn is derived by summing the population equilibrium of Pn,m.

[0125]

[0126] Due to the long chain assumption, all subspecies distributions can be considered as continuous rather than discrete functions. When the differential terms are replaced by derivatives, the discrete steady-state polymer species population equilibrium can be closely approximated by differential equations in the continuous variable n. For example, the steady-state population equilibrium of Sn contains the differential term Sn–Sn-1, which is replaced by the derivative as shown in Equation (31).

[0127]

[0128] Similar substitutions yield the following series of ordinary differential equations (ODEs), which can be integrated to yield the chain length distributions for various defined active subspecies distributions L(n), S(n), and V(n). The model is outlined below as an initial value problem, where the chain length distribution function is assumed to start at n = 0. The lower limit n = 0 on the distribution function was chosen only for mathematical simplicity and ultimately does not significantly affect the model predictions when high polymers are formed.

[0129]

[0130] Transient inactive polymer chain length distribution and L n is proportional, as is evident from the species rate Therefore, through L n , the solution of the above differential equations gives the instantaneous inactive polymer distribution X n , and the continuous distribution X(n) is similarly proportional to L(n).

[0131] Transient inactive polymer distribution,

[0132] Solution of the complete MWD curve

[0133] The distribution function for increasing polymer chain length can be solved numerically or analytically by those familiar with the integration of ordinary differential equations. Although algebraically complex, the analytical solution is presented here because it is fully consistent with the moment model (Eqs. (20) and (21)) while also predicting subtle differences in the MWD, such as peak position multimodality and tailing.

[0134] Using Mathematica TM The software package is used to develop analytical solutions to the system of ordinary differential equations that describe the growing polymer distribution functions L(n), S(n), and V(n). The analytical solution of L(n) is used to describe the instantaneous inactive polymer distribution X(n) by normalizing the integral of L(n).

[0135]

[0136] The explicit analytical solution of X(n) can be obtained using Mathematica TM The analytical solution of X(n) is described below as parameter B n and DP no function, and the solution can be obtained by substituting R c =B n =B c / (1-B c ) in R c or B n Aspects of restatement. (36)

[0137] According to Mathematica TM Given the definition of RootSum, the chain length distribution function X(n) is evaluated as follows. The following polynomial has three roots, called x1, x2, and x3. Two of the three roots of the polynomial are in B n The range of possible values ​​for is complex.

[0138] 0=1+B n +(3+5 B n +2 B n 2 )x+3(1+B n )x 2 +x 3 (37)

[0139] The roots x1, x2 and x3 are used for the instantaneous inactive chain length distribution function X(n).

[0140]

[0141] The moments of X(n) are evaluated to obtain the instantaneous number and the weighted average chain length (DP n , DP w ) or molecular weight (M n , M w The average chain lengths and weights resulting from the continuous distribution X(n) are equal to the moment model predictions given previously for long-chain aggregates and discrete distributions, and are denoted by B in the following. c and B n Expression, where R c =B n .

[0142]

[0143] Those skilled in the art of polymer reaction engineering are familiar with the use of predicted bulk polymer MWD models to create simulated size exclusion chromatography (SEC) curves. These simulations are useful in correlating kinetics and how formulations are expected to affect SEC measurements. The primary calibration result of a SEC measurement is a table or graph of dw / dLog(M) versus Log(M), where M is the species molecular weight or size, and dw / dLog(M) indicates the relative amount of polymer corresponding to M. It is recognized that the molecular weight of the polymer can be determined by n 2 A table or graph of X(n) versus Log(M) to simulate this SEC result, where n is expected 2 X(n) is proportional to dw / dLog(M).

[0144] Figure 2 A series of simulated SEC curves are shown, where the level of diene "ladder branching" (B c , B n , R c ) is changing. Figure 2 The independent variables in are scaled by linear molecular weight or chain length, making the plots universal and independent of the starting molecular weight. Figure 2 The zero differentiation case in is well known as the "most probable" MWD (PJ Flory, J. Am. Chem. Soc. 1936, 58, 1877) and is the expected MWD for a linear addition copolymerization performed under ideal homogeneous conditions.

[0145] A more detailed analysis of peak MW values ​​has been performed using a range of differentiation levels applied to the MWD model. Figure 3 A general plot of relative peak MW versus functional branching level is shown. Figure 3 This indicates a poorly differentiated region with peak MW insensitivity (0 <R c <0.15) and higher branching solutions (R c ≥0.15), where the peak MW increases steadily with the level of branching.

[0146] Mechanism and model of alternating trifunctional diene "ladder branching"

[0147] There are alternative mechanisms that could explain the branching and MWD trends observed with dual-chain catalysts when dienes are incorporated under the desired conditions. n increases with diene addition, it has been found that some catalyst-diene combinations lead to M w increases, and also indicates that as the diene level increases, M n There is little or no measurable increase. Constant M nOne explanation is that a single β-hydride elimination (or chain transfer to hydrogen) may tend to occur immediately after the diene is inserted into both growing chains. This scenario would result in the generation of a trifunctional branch through the diene and the bridging growing species (S) would be eliminated from the kinetics in a pure form. n ).

[0148] The kinetic scheme was modified to account for this alternative mechanism by replacing the following reaction with "diene bridging".

[0149]

[0150] Using the same sequence of assumptions as before, any polymer reaction engineer familiar with the art of modeling and kinetics can re-derive the moment and MWD functional models for these alternative kinetics. For this trifunctional branching mechanism, the resulting instantaneous inactive chain length distribution function X(n) is given below:

[0151]

[0152] In equation (41), replace B c is defined as the branch point of each kinetic chain and DP no is defined as the average linear chain length without diene. The kinetic scheme assumes that the linear (kinetic) chain length actually decreases with diene incorporation due to diene-induced beta hydride elimination. Therefore, a good alternating indicator of branching is B n , which is defined as the number of branch points per polymer molecule, where B c =B n / (1+B n ). The function X(n) can be easily expressed using B n Rewrite.

[0153] The integral of X(n) gives the instantaneous number and weight-average chain length (DP n , DP w ) or molecular weight (M n , M w ) results. The average chain length and weight obtained from the continuous distribution X(n) are equal to the moment model predictions assuming long chain aggregation. The integral of X(n) determines the DP n and M n Regarding the branching level (B c or B n The integration of X(n) also shows how the polydispersity is expected to vary with the level of branching when the diene is assumed to produce trifunctional branches.

[0154]

[0155] The above polydispersity (M w / Mn ) versus trifunctional branching level shows no instability or divergence at any branching level. Most surprisingly, at high branching levels, the polydispersity is predicted to stabilize at 4. Of course, this prediction is for an ideal copolymerization and symmetric catalyst system, where any non-idealities are expected to increase polydispersity.

[0156] The chain length distribution function can again be used to construct a predicted MWD curve. Figure 4 is a series of simulated SEC curves, where the level of trifunctional branching (B c or B n ) is changing. Figure 4 The independent variables in are scaled by linear molecular weight or chain length, making the plots universal and independent of the starting molecular weight. Figure 4 The zero differentiation case in is well known as the "most probable" MWD and is expected for linear addition copolymerizations performed under ideal homogeneous conditions. Figure 5 is a relative peak MW graph of trifunctional diene branching, which shows that the MWD peak is at 0.2 n <0.9 or 0.17 c The sensitivity to branching level is greatest at intermediate branching levels within the approximate range of <0.5.

[0157] Conventional branching model

[0158] The purpose of this section is to compare various conventional diene branching and random polymer couplings with the "ladder branching" model. This comparison demonstrates the inherent instability of conventional diene branching and random polymer coupling, as opposed to "ladder branching." The molecular architectures generated by diene "ladder branching" differ from (a) conventional diene continuous stirred tank reactor (CSTR) branching models, (b) conventional diene semi-batch branching models, (c) polymer CSTR coupling models, and (d) polymer batch coupling models.

[0159] a) Conventional diene CSTR branching model Ver Strate-1980 (G. Ver Strate, C. Cozewith, W.W. Graessley, Journal of Applied Polymer Science (J.App.Polym.Sci.) 1980, 25, 59), Guzman-2010 (J.D. Guzman, DJ Arriola, T. Karjala, J. Gaubert, B.W.S. Kolthammer, Journal of the American Institute of Chemical Engineers (AIChE) 2010, 56, 1325):

[0160]

[0161] ​​b) Conventional diene semi-batch branching model, Cozewith-1979 (C. Cozewith, W. W. Graessley, G. VerStrate, Chem. Eng. Sci. 1979, 34, 245) and d) polymer batch coupling model, Cozewith-1979, Flory-1953 (P. J. Flory, Principles of Polymer Chemistry, Cornell University Press, 1953), Tobita-1995 (H. Tobita, J. Polym. Sci. B 1995, 33, 1191):

[0162]

[0163] c) Polymer CSTR coupling model:

[0164]

[0165] Characterization of tetrafunctional long-chain branched polyolefins

[0166] Depending on the degree of branching, various methods can be used to determine the LCB (such as nuclear magnetic resonance (NMR)) or to distinguish the role of the LCB in the polymer. For example, the role of the LCB in shear flow is observed in the van Gurp-Perlman analysis, and the increase in shear viscosity and the intensity of shear thinning behavior at low angular frequencies can also be attributed to the LCB. In extensional flow, the influence of the LCB is usually identified in the degree of hardening or melt strength and the maximum deformation achieved. Other plots, such as the Mark-Houwink plot of the expanded molecular weight distribution (MWD) and the g' vis The graph provides additional information about LCBs. Achieving high levels of natural LCBs in polymers is difficult due to the limited concentration of vinyl terminated polymer (maximum one per polymer chain) and the need to operate to high conversion to ensure LCB formation. To ensure high conversion, the ethylene concentration in the reactor is low, thus enabling the reinsertion of large amounts of vinyl terminated polymer into the second polymer chain.

[0167] The conventional method that diene is incorporated into polymer synthesis system suffers from the basic defect of gel formation or reactor fouling under high branching level.The kinetic model discussed in previous paragraph can provide and realize the good prediction result of better understanding gel formation.For example, the polymer chain that longer polymer chain has more lateral vinyl in proportion and contains more lateral vinyl will more likely reinsert in catalyst to form LCB.Therefore, larger polymer chain preferentially reinserts and forms tetrafunctional branch, and described tetrafunctional branch is even bigger polymer molecule, and causes gel problem or instability when LCB level reaches threshold value.For the ethylene polymer in semi-batch reactor under constant pressure, the weight average molecular weight (MW) that changes with conventional tetrafunctional branch w ) and number average molecular weight (M n ) is shown in the simulation Figure 1 middle. son Figure 1 In, M n Only with M w becomes infinite and increases slightly. In this example, as M w Increased to amounts greater than 200,000 grams per mole (g / mol), the polymer molecular weight distribution (MWD) becomes unstable and gel formation begins. MWD is determined by the weight average molecular weight, M w Divide by the number average molecular weight M n (M w / M n )definition.

[0168] For the purposes of this disclosure, polymer gel is narrowly defined as the polymer fraction that phase separates due to its high level of branching and / or high molecular weight. Polymer gels can be observed in solution or in the melt and tend to interfere with properties such as optical clarity and film and fiber performance. Polyethylene interpolymer gels can be measured by the insolubility of the polymer in hot xylene. Gel content is generally correlated with and therefore estimated by GPC polymer recovery. When polymer gel is formed, it may deposit in the reactor and cause fouling.

[0169] Figure 7 and Figure 8The difference in the MWD curves expected from conventionally branched and "ladder-branched" polymers is shown. By studying MWD data and comparing it to MWD models, a series of metrics have been developed to describe MWD properties. Each of the MWD descriptive metrics presented here is independent of the average MW and focuses on the high MW portion of the MWD. ​​The MWD metric is derived from a scaled MWD curve (dW / dlogM) where the major or highest peak in the MWD is defined as having a unity value. If more than one peak has the same height, then the highest MW peak is the major peak. The independent variable in the MWD curve is Log(M), which is the logarithm to base 10 of M. The metric will be defined and presented as a function of M w / M wo and M p / M po And changes, which can be used Figure 6 、 Figure 7 、 Figure 8 and Figure 9 , which translates to branches per molecule or segment. Those skilled in the art of GPC data interpretation will understand these measurements and will be able to calculate them from GPC data.

[0170] A series of GPC shape measures G(A / B) are calculated from the slopes at defined points on the right hand side of the MWD curve, where S(A) and S(B) are the first occurrence of these slopes at the height of the main peak A% and B% to the right of the main peak. If the MWD is "most likely", points A and B are chosen as a pair with nearly identical slopes. A plot of these points and their slopes for the most likely MWD is shown in Figure 10 These slope pairs S(A) and S(B) are used together to calculate a function similar to a second-order derivative, G(A / B), which will be shown to be a useful measure for distinguishing "trapezoidal branched" MWD from conventional or randomly branched MWD. ​​The values ​​of G(79 / 29) and G(96 / 08) describe the change in slope of the right-hand side (RHS) of the MWD and are defined below in terms of the high MW slope:

[0171] G(79 / 29) = (S(79) - S(29)) / S(79) (48)

[0172] G(96 / 08) = (S(96) - S(8)) / S(96) (49)

[0173] The shape metrics G(79 / 29) and G(96 / 08) were tested on the MWD model for tetrafunctional "ladder branching" and conventional diene branching, with the results plotted on Figure 11 、 Figure 12 、 Figure 13 、 Figure 14These figures indicate that conventional branching produces G(79 / 29) and G(96 / 08) values ​​that increase steadily with MW in response to branching. However, when applied to "trapezoidal branching," these shape metrics decrease at low branching levels (low MW). w / M wo ) and then approaches zero at moderate to high branching levels. This is not surprising, as the high MW portion of the "trapezoidal branched" MWD resembles the most likely MWD.

[0174] Figure 11 、 Figure 12 、 Figure 13 and Figure 14 The G(79 / 29) and G(96 / 08) metrics are depicted to have similar responses to branching, however, the G(96 / 08) metric is expected to be more sensitive to the high MW tail produced by conventional diene branching. The term "high MW tail" or "high molecular weight tail" refers to the high molecular weight fraction as shown by conventional GPC and absolute GPC. Depending on the catalyst-diene pairing and the experimental conditions, a "ladder-branched" system can be expected to have some conventional branching, resulting in shape metric values ​​higher than those expected for pure "ladder-branched".

[0175] MWD area measurement

[0176] Visual inspection of the "ladder-branched" MWD shows that there is a lack of the characteristic high MW tail typically found in branched polymers. Figure 16 and Figure 17 The "ladder-branched" MWD data show the lack of tails characteristic of many experiments, but also indicate that some tail formation is possible depending on the polymerization conditions and diene / catalyst pairing.

[0177] Polydispersity index (M w / M n 、M z / M w The polydispersity index (M) is a known measure of tailing, but is not preferred due to its sensitivity to low MWD artifacts. Therefore, a more focused version of the polydispersity index was used to develop a criterion that performs integration only on the high MW portion of the MWD. w / M n and M z / M w The measurement successfully distinguishes diene "ladder branching" from conventional branching and is very sensitive to high MW baseline selection and baseline noise.

[0178] and calculate the MWD dispersion index (M w / M n 、M z / M wCompared to the higher moments required for MWD, the area under the MWD curve is relatively insensitive to baseline problems. Therefore, it was decided to develop a metric that includes the unweighted integral of the MWD. ​​These MWD area metrics A 高 and A 尾部 It is calculated based on the area of ​​the GPC curve defined on the right hand side of the MWD curve. 高 and A 尾部 ) is derived from the scaled MWD curve (dW / logM), where the main or highest peak in the MWD is defined as having a unity value. If more than one peak has the same height, the highest MW peak is the main peak. The independent variable in the MWD curve is Log(M), which is the base 10 logarithm of M. Both MWD area measures are based on the point of maximum slope of the high MW portion of the MWD. ​​The quantities and limits required to evaluate the area measures are listed below and are shown for the most likely MWD. Figure 15 middle.

[0179] S 最大 = the first instance of the maximum downward slope of the RHS (higher MW side) of the main peak (absolute value of the slope) of the scaled MWD

[0180] H smax = Height of scaled MWD at point of maximum slope

[0181] pt1=S 最大 LogM value

[0182] pt2 = LogM value, where S 最大 Tangent intersects the x-axis

[0183] The MWD area metric is defined below, where A 高 It is simply the area of ​​the MWD region that falls after the point of maximum slope. The second area measure A 尾部 It is depicted in Figure 15 The small high MW area in the 高 Evaluate by subtracting the area of ​​the triangle.

[0184]

[0185] A 尾部 =A 高 - 1 / 2(H smax ) 2 / S 最大 (51)

[0186] The area measure A was tested on the MWD model for both “ladder branching” and conventional diene branching. 高 and A 尾部 , where the results are plotted on Figure 16 、 Figure 17 、 Figure 18 ,and Figure 19 The figure shows that A 高 or A 尾部 The defined high MW area increases dramatically with increasing levels of conventional branching. However, the "trapezoidal branching" model predicts that the high MW area measure (A 高 or A 尾部 ) is almost unaffected by the level of “ladder branching”. The most likely MWD A 高 and A 尾部 The values ​​are about 0.07 and 0.015, respectively. Example MWD data will show that linear polymers without dienes tend to have slightly higher A values ​​due to non-ideal aspects of polymerization. 高 and A 尾部 The example data also shows various highly branched "ladder-branched" polymers in which there is essentially no high MW tail exceeding that expected from the most likely MWD. ​​The high MW area measurement can also be diagnostic of the slight level of high MW tail formation that "ladder-branched" polymers can exhibit when accompanied by a certain degree of conventional branching. Measurement A 尾部 Affected less by linear MWD non-idealities than A 高 However, in theory, A 高 and A 尾部 Measurements likewise indicated the formation of a high MW tail.

[0187] Tetrafunctional long-chain branched polyolefin

[0188] As depicted in Scheme 4, polymers produced by "ladder branching" are encompassed by the present disclosure.

[0189] In an embodiment, the ethylene-based polymers of the present disclosure comprise a melt viscosity ratio or rheological ratio (V R) of at least 10 at 190°C. 0.1 / V 100 ), where V 0.1 is the viscosity of the ethylene-based polymer at 190°C at an angular frequency of 0.1 rad / s, and V 100 is the viscosity of the ethylene-based polymer at 190° C. at an angular frequency of 100 rad / s. In one or more embodiments, the melt viscosity ratio is at least 14, at least 20, at least 25, or at least 30. In some embodiments, the melt viscosity ratio is greater than 50, at least 60, or greater than 100. In some embodiments, the melt viscosity ratio is from 14 to 200.

[0190] The “rheological ratio” and “melt viscosity ratio” are given by V at 190°C. 0.1 / V 100 Definition, where V 0.1is the viscosity of the ethylene-based polymer at 190°C at an angular frequency of 0.1 rad / s, and V 100 It is the viscosity of the ethylene polymer at 190°C and an angular frequency of 100 rad / s.

[0191] In one or more embodiments, the ethylene polymers of the present disclosure have an average g', and the average g' is less than 0.86, wherein the average g' is the intrinsic viscosity ratio measured by gel permeation chromatography using a triple detector. In some embodiments, the ethylene polymers of the present disclosure have an average g' of 0.64 to 0.86. All individual values ​​and subranges encompassed by "0.64 to 0.86" are disclosed herein as separate embodiments; for example, the average g' of the ethylene polymers can be in the range of 0.64 to 0.75, 0.68 to 0.79, or 0.65 to 0.83. In one or more embodiments, the average g' is 0.65 to 0.84, 0.66 to 0.82, or 0.66 to 0.80.

[0192] In some embodiments, the ethylene polymer has a G(79 / 29) value of less than or equal to 0.035, as determined from a gel permeation chromatography curve having a peak height, a slope M79 at 79% of the peak height, and a slope M29 at 29% of the peak height, wherein the G(79 / 29) value is equal to (M79-M29) / M79. All individual values ​​and subranges encompassed by "less than or equal to 0.035" are disclosed herein as separate embodiments; for example, "less than or equal to 0.035" includes greater than 0.0 to 0.035, 0.010 to 0.034, and includes negative values. In one or more embodiments, the ethylene polymer of the present disclosure may have a G(79 / 29) value of less than or equal to 0.030, as determined from a gel permeation chromatography curve.

[0193] In one or more embodiments, the melt viscosity ratio of the ethylene-based polymers of the present disclosure may be greater than ten times the elastic modulus, where the melt viscosity ratio (V 0.1 / V 100 ) is the viscosity V of the ethylene polymer at 190°C at an angular frequency of 0.1 rad / s 0.1 and the viscosity V of the ethylene polymer at 190°C at an angular frequency of 100 rad / s 100 is determined, and the elastic coefficient m is [((tan(δ 0.1 )-tan(δ 100 ))*1000) / (0.1-100))], where tan(δ 0.1 ) is the tangent of the phase angle at 0.1 rad / s, and tan(δ 100) is the tangent of the phase angle at 100 rad / s.

[0194] In one or more embodiments, the ethylene-based polymer may have an elastic modulus m less than or equal to 8 seconds / radian at 190° C., where m is [((tan(δ 0.1 )-tan(δ 100 ))*1000) / (0.1-100))]. In other embodiments, the ethylene-based polymer may have an elastic modulus m less than or equal to 4 seconds / radian at 190°C.

[0195] In various embodiments, the melt strength of the ethylene-based polymers of the present disclosure can be greater than 6 cN (Rheotens apparatus, 190° C., 2.4 mm / s 2 , from the die outlet to the wheel center is 120mm, and the extrusion rate is 38.2s -1 , the capillary die length is 30 mm, the diameter is 2 mm and the entrance angle is 180°). In some embodiments, the melt strength of the ethylene-based polymer can be greater than 10 cN.

[0196] In an embodiment, the ethylene-based polymer may have a molecular weight tail, the molecular weight tail being measured by the MWD area A. 尾部 Quantify, and A 尾部 Less than or equal to 0.04. All individual values ​​and subranges encompassed by "less than or equal to 0.04" are disclosed herein as separate embodiments. For example, in some embodiments, the ethylene polymers of the present disclosure have an A of 尾部 Greater than 0 and less than or equal to 0.03 as determined by gel permeation chromatography using triple detection.

[0197] In an embodiment, the M of the ethylene polymer w The M of the ethylene-based polymer may be less than or equal to 800,000 Daltons as measured by gel permeation chromatography using triple detection. w May be less than or equal to 400,000 Daltons.

[0198] In various embodiments, the M of the ethylene polymer p / M p0 Can be greater than 1.20, where M p is the peak molecular weight of the ethylene polymer as determined by conventional gel permeation chromatography, and M p0 It is the initial peak molecular weight of the ethylene polymer without polyene comonomer.

[0199] In various embodiments, the M of the ethylene polymer w / M w0 Greater than 1.20, where Mw M is the weight average molecular weight of the ethylene polymer, as determined from the GPC curve of the ethylene polymer obtained by gel permeation chromatography. w0 is the initial weight average molecular weight of the comparative ethylene polymer as determined by gel permeation chromatography. The comparative ethylene polymer is obtained by mixing ethylene monomer with all C3 to C16 carbon atoms present in the ethylene polymer under defined polymerization conditions in the absence of at least one polyene comonomer. 14 The reaction product of the polymerization of comonomers, if any.

[0200] As discussed previously, each M w0 and M p0 is a measure of polymer resin in the absence of diene added to the reactor during polymerization. Each subsequent addition of diene produces polymer resin from which the measure M can be determined. w or M p The amount of diene introduced into the reactor is small compared to the other reactants in the reactor. Therefore, the addition of diene does not affect the total amount of comonomer, ethylene and solvent in the reactor.

[0201] In various embodiments, the ethylene-based polymer has a gpcBR branching index of 0.1 to 3.0. All individual values ​​and subranges encompassed by "0.10 to 3.00" are disclosed herein as separate embodiments; for example, the ethylene-based polymer can comprise a gpcBR branching index of 0.10 to 2.00, 0.10 to 1.00, 0.15 to 0.65, 0.20 to 0.75, or 0.10 to 0.95.

[0202] The long-chain branched polymerization method described in the preceding paragraph is used to polymerize olefins, primarily ethylene and propylene. In some embodiments, only a single type of olefin or α-olefin is present in the polymerization scheme, resulting in a homopolymer that is essentially a diene comonomer with a small amount of incorporated diene comonomer. However, additional α-olefins can be incorporated into the polymerization procedure. Additional α-olefin comonomers typically have no more than 20 carbon atoms. For example, the α-olefin comonomer can have 3 to 10 carbon atoms or 3 to 8 carbon atoms. Exemplary α-olefin comonomers include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 4-methyl-1-pentene, and ethylidene norbornene. For example, the one or more α-olefin comonomers can be selected from the group consisting of propylene, 1-butene, 1-hexene, and 1-octene; or in an alternative embodiment, selected from the group consisting of 1-hexene and 1-octene.

[0203] Long chain branched polymers, such as homopolymers and / or interpolymers (including copolymers) of ethylene and optionally one or more comonomers such as α-olefins, can include at least 50 weight percent of units derived from ethylene. All individual values ​​and subranges encompassed by "at least 50 weight percent" are disclosed herein as separate embodiments; for example, ethylene-based polymers, homopolymers and / or interpolymers (including copolymers) of ethylene and optionally one or more comonomers such as α-olefins can include: at least 60 weight percent of units derived from ethylene; at least 70 weight percent of units derived from ethylene; at least 80 weight percent of units derived from ethylene; or 50 to 100 weight percent of units derived from ethylene; or 80 to 100 weight percent of units derived from ethylene.

[0204] In some embodiments of the ethylene polymer, the ethylene polymer comprises an additional α-olefin. The amount of the additional α-olefin in the ethylene polymer is less than or equal to 50 mole percent (mol%); in other embodiments, the amount of the additional α-olefin comprises at least 0.01 mol% to 25 mol%; and in other embodiments, the amount of the additional α-olefin comprises at least 0.1 mol% to 10 mol%. In some embodiments, the additional α-olefin is 1-octene.

[0205] In some embodiments, the long-chain branched polymer can include at least 50 mole percent of units derived from ethylene. All individual values ​​and subranges from at least 90 mole percent are included herein and disclosed as separate embodiments herein. For example, the ethylene polymer can include at least 93 mole percent of units derived from ethylene; at least 96 mole percent of units; at least 97 mole percent of units derived from ethylene; or in the alternative, 90 to 100 mole percent of units derived from ethylene; 90 to 99.5 mole percent of units derived from ethylene; or 97 to 99.5 mole percent of units derived from ethylene.

[0206] In some embodiments of the long chain branched polymers, the amount of additional α-olefin is less than 50%; other embodiments comprise at least 1 mole percent (mol%) to 20 mol%; and in yet other embodiments, the amount of additional α-olefin comprises at least 5 mol% to 10 mol%. In some embodiments, the additional α-olefin is 1-octene.

[0207] Any conventional polymerization method can be used to produce the long-chain branched polymer. Such conventional polymerization methods include, but are not limited to, solution polymerization, gas phase polymerization, slurry phase polymerization, and combinations thereof using one or more conventional reactors, such as loop reactors, isothermal reactors, fluidized bed gas phase reactors, stirred tank reactors, batch reactors in parallel or in series, or any combination thereof.

[0208] In one embodiment, can in dual reactor system for example monocyclic reactor system, produce ethylene polymer via solution polymerization, wherein ethylene and optionally one or more alpha-olefins are polymerized in the presence of catalyst system as described herein and optionally one or more cocatalysts.In another embodiment, can in dual reactor system (for example, dual cyclic reactor system), produce ethylene polymer by solution polymerization, wherein ethylene and optionally one or more alpha-olefins are polymerized in the presence of the disclosure and catalyst system as described herein and optionally one or more other catalysts.Catalyst system as described herein can optionally be used in the first reactor or the second reactor in combination with one or more other catalysts.In one embodiment, can in dual reactor system (for example, dual cyclic reactor system), produce ethylene polymer by solution polymerization, wherein ethylene and optionally one or more alpha-olefins are polymerized in the presence of catalyst system as described herein in these two reactors.

[0209] In another embodiment, the long chain branched polymer can be produced via solution polymerization in a single reactor system, such as a single loop reactor system, wherein ethylene and optionally one or more α-olefins are polymerized in the presence of a catalyst system as described herein and optionally one or more cocatalysts as described in the preceding paragraphs. In some embodiments, the long chain branched polymerization process for producing the long chain branched polymer comprises polymerizing ethylene and at least one additional α-olefin in the presence of a catalyst system.

[0210] The long-chain branched polymer can further include one or more additives. Such additives include, but are not limited to, antistatic agents, color enhancers, dyes, lubricants, pigments, primary antioxidants, secondary antioxidants, processing aids, UV stabilizers and combinations thereof. The ethylene polymer can contain any amount of additives. By the weight of the ethylene polymer and one or more additives, the ethylene polymer can include about 0 percent to about 10 percent of the gross weight of such additives. The ethylene polymer can further include a filler, which can include, but are not limited to, organic or inorganic fillers. By the combined weight of the ethylene polymer and all additives or fillers, the long-chain branched polymer can contain about 0 to about 20 weight percent fillers, such as calcium carbonate, talcum powder or Mg (OH) 2. The ethylene polymer can further be blended with one or more polymers to form a blend.

[0211] In some embodiments, the long chain polymerization process for producing a long chain branched polymer may comprise polymerizing ethylene and at least one additional α-olefin in the presence of a catalyst having two polymer production sites. The density of the long chain branched polymer produced by this catalyst having two polymer production sites may be, for example, 0.850 g / cm2 according to ASTM D792 (incorporated herein by reference in its entirety). 3 to 0.960g / cm 3 、0.880g / cm 3 to 0.920g / cm 3 、0.880g / cm 3 to 0.910g / cm 3 or 0.880g / cm 3 to 0.900g / cm 3 .

[0212] In another embodiment, the long chain branched polymer produced by the long chain polymerization process may have a melt flow ratio (MFR) of 5 to 100. 10 / I2), wherein the melt index I2 is measured at 190°C and a 2.16 kg load according to ASTM D1238 (incorporated herein by reference in its entirety), and the melt index I is measured at 190°C and a 10 kg load according to ASTM D1238 10 In other embodiments, the melt flow ratio (I 10 / I2) is 5 to 50, and in other embodiments, the melt flow ratio is 5 to 25, and in other embodiments, the melt flow ratio is 5 to 9.

[0213] In some embodiments, the long chain branched polymer produced by the long chain polymerization process has a molecular weight distribution (MWD) of 1 to 20, where MWD is defined as M w / Mn , M w is the weight average molecular weight and Mn is the number average molecular weight. In other embodiments, the polymer obtained from the catalyst system has an MWD of 1 to 10. Another embodiment comprises an MWD of 1 to 3; and other embodiments comprise an MWD of 1.5 to 2.5.

[0214] Parallel Polymerization Reactor (PPR)

[0215] Small-scale solution polymerization examples were performed in 15 mL vials using a total liquid volume of 5 mL, a constant ethylene pressure of 150 psig, and a polymerization temperature of 120°C. The 5 mL liquid volume consisted of 0.84 mL of a comonomer mixture containing 500 nmol of MMAO-3A, ​​catalyst, and a toluene solution containing an activator, with sufficient Isopar-E added to reach the 5 mL liquid volume. H was added to the reaction mixture by simultaneously pre-pressurizing the empty reaction vial with 20 ± 3 psig of hydrogen (H) at 80°C, allowing any given diene experiment to be performed at the same H loading. All liquid volumes were distributed at room temperature and added volumetrically relative to the 5 mL total volume. Finally, the catalyst was added to the reaction mixture as a 5 mM toluene solution, which was separately activated with 1.5 equivalents of cocatalyst A (di(tetradecyl)methylammonium tetrakis(pentafluorophenyl)borate). The comonomer solution was primarily composed of 1-octene, with a minor volume fraction (0-6%) of diene species. The polymerization run was continued for a period not exceeding about 30 minutes and was quenched by the addition of CO and then depressurization of the vial.

[0216] Gel Permeation Chromatography (conventional GPC)

[0217] The chromatographic system consists of a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5) and a 4-capillary viscometer (DV) connected to a Precision Detectors (now Agilent Technologies) 2-angle laser scattering (LS) detector model 2040. For all absolute light scattering measurements, a 15-degree angle was used for measurement. The autosampler oven chamber was set to 160 degrees Celsius, and the column chamber was set to 150 degrees Celsius. The columns used were 4 Agilent "Mixed A" 30cm 20-micron linear mixed bed columns. The chromatographic solvent used was 1,2,4-trichlorobenzene and contained 200ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 microliters, and the flow rate was 1.0 ml / min.

[0218] The GPC column set was calibrated using at least 20 polystyrene standards with narrow molecular weight distributions ranging from 580 to 8,400,000 molecular weights and arranged in 6 "cocktail" mixtures with at least ten times the molecular weights separated. The standards were purchased from Agilent Technologies. For molecular weights equal to or greater than 1,000,000, 0.025 g of polystyrene standards were prepared in 50 ml of solvent, and for molecular weights less than 1,000,000, 0.05 g of polystyrene standards were prepared in 50 ml of solvent. The polystyrene standards were dissolved and gently stirred at 80 degrees Celsius for 30 minutes. Equation 52 was used to convert the polystyrene standard peak molecular weight into polyethylene molecular weight (as described by Williams and Ward in Polymer Science Magazine, Polym. Let., 6,621 (1968)):

[0219] M 聚乙烯 =A×(M 聚苯乙烯 ) B (52)

[0220] Where M is the molecular weight, the value of A is 0.4315, and B equals 1.0.

[0221] A polynomial between order 3 and 5 was used to fit the corresponding polyethylene equivalent calibration points. Minor adjustments to A (approximately 0.415 to 0.44) were made to correct for column resolution and band broadening effects, resulting in the NIST standard NBS 1475 at 52,000 Mw.

[0222] Plate counts were performed on the GPC column set using eicosane (prepared as 0.04 g in 50 mL of TCB and dissolved under slow stirring for 20 minutes). Plate counts (Equation 53) and symmetry (Equation 54) were measured with a 200 μL injection according to the following equations:

[0223]

[0224] where RV is the retention volume in milliliters, peak width is in milliliters, peak maximum is the maximum height of the peak, and 1 / 2 height is the peak maximum 1 / 2 height.

[0225]

[0226] Wherein RV is the retention volume in milliliters and peak width is in milliliters, peak maximum is the maximum position of the peak, tenth height is 1 / 10 the height of the peak maximum, and wherein post-peak refers to the tail of the peak with a retention volume later than the peak maximum, and wherein front-peak refers to the front of the peak with a retention volume earlier than the peak maximum. The plate count of the chromatographic system should be greater than 24,000 and the symmetry should be between 0.98 and 1.22.

[0227] The samples were prepared semi-automatically using the PolymerChar "Instrument Control" software, with a target sample weight of 2 mg / ml and solvent (containing 200 ppm BHT) added to a septum-capped vial previously sparged with nitrogen using a PolymerChar high-temperature autosampler. The samples were dissolved at 160 degrees Celsius for 2 hours with "low speed" shaking.

[0228] Based on the GPC results using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR spectrometer according to Equations 55-57, the TM M was determined using the software, the baseline-subtracted IR chromatogram at each equally spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve at point (i). n(GPC) 、M w(GPC) and M z(GPC) Calculation.

[0229]

[0230] To monitor deviations over time, a flow rate marker (decane) was introduced into each sample via a micropump controlled by the PolymerChar GPC-IR system. This flow rate marker (FM) was used to linearly correct the pump flow rate for each sample (Flow Rate (Nominal)) by comparing the RV of the corresponding decane peak within the sample (RV(FM Sample)) to the retention volume of the decane peak within the narrow standard calibration (RV(FM Calibration)). It was then assumed that any changes in the decane marker peak time were related to a linear change in flow rate (Flow Rate (Effective)) throughout the run. To facilitate the highest accuracy in the measurement of the RV of the flow marker peak, the peak of the flow marker concentration chromatogram was fit to a quadratic equation using a least squares fitting routine. The first derivative of the quadratic equation was then used to solve for the true peak position. After calibrating the system based on the flow marker peak, the effective flow rate (relative to the narrow standard calibration) was calculated as Equation 58. By PolymerCharGPCOne TMThe software completes the processing of the flow marker peaks.An acceptable flow rate correction is such that the effective flow rate should be within + / - 2% of the nominal flow rate.

[0231] Flow rate (effective) = flow rate (nominal) * (RV (calibrated FM) / RV (FM sample)) (58)

[0232] Triple Detector GPC (TDGPC) (Absolute GPC)

[0233] The chromatography system, run conditions, column setup, column calibration, and calculation of conventional molecular weight moments and distributions were performed according to the methods described in Gel Permeation Chromatography (GPC).

[0234] To determine the offset of the viscometer and light scattering detectors relative to the IR5 detector, a systematic approach for determining multi-detector offset was performed in a manner consistent with that published by Balke, Mourey et al. (Mourey and Balke, Chromatography Polym., Chapter 12, (1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, Chromatography Polym., Chapter 13 (1992)) using the PolymerChar GPCOne TM The software optimizes the w / M n >3) with triple detector logarithmic (MW and IV) results from the narrow standards column calibration curve.

[0235] Absolute molecular weight data were obtained using the PolymerChar GPC One in a manner consistent with that published by Zimm (Zimm, BH, J. Chem. Phys., 16, 1099 (1948)) and Kratochvil (Kratochvil, P., Classical Light Scattering from Polymer Solutions, Elsevier, Oxford, New York (1987)). TM The total injected concentration used to determine the molecular weight is obtained from the mass detector area and the mass detector constant, which is derived from a suitable linear polyethylene homopolymer or one of the polyethylene standards of known weight average molecular weight. The calculated molecular weight (using GPCOne TM) are obtained using the light scattering constant from one or more polyethylene standards mentioned below and a refractive index concentration coefficient dn / dc 0.104. Typically, the mass detector response (IR5) and the light scattering constant (using GPCOne TM Viscometer calibration (using GPCOne TM The viscometer constant (determined) can be accomplished using the methods described by the manufacturer, or alternatively, by using the published values ​​of suitable linear standards such as Standard Reference Material (SRM) 1475a (available from the National Institute of Standards and Technology, NIST). TM The specific viscosity area (DV) and injected mass of the calibration standards are related to their intrinsic viscosity. The chromatographic concentration is assumed to be low enough to eliminate the effect of the second viral coefficient (concentration effect on molecular weight).

[0236] Absolute weight average molecular weight (M w(Abs) ) is calculated by dividing the light scattering (LS) integral chromatogram (determined by the light scattering constant) by the mass recovered from the mass constant and the mass detector (IR5) area (using GPCOne TM The molecular weight and intrinsic viscosity responses are at the end of the chromatogram where the signal-to-noise ratio is low (using GPCOne TM ) linear extrapolation. According to equations 59-60, the other corresponding moments M are calculated as follows n(Abs) and M z(Abs) :

[0237]

[0238] g' ave value

[0239] g' is defined as the viscosity of the branched polymer divided by the viscosity of the linear polymer at the same MW:

[0240]

[0241] g' ave Or the average g' is the weight average of g' (BH Zimm, WH Stockmayer, Journal of Chemical Physics 1949, 17, 1301).

[0242] Dynamic mechanical spectroscopy (or small-angle oscillatory shear)

[0243] Complex viscosity (η*), modulus (G', G"), tan δ and phase angle (δ) were obtained by dynamic oscillation frequency sweep testing at 190°C in the frequency range of 0.1 to 100 rad / s. The strain level was set in the linear viscoelastic range, as identified by a strain sweep test at 190°C with 100 rad / s. The tests were performed on a TA Instruments strain controlled rheometer ARES-G2 using stainless steel parallel plates with a diameter of 25 mm. 3.3 mm thick samples were extruded and then trimmed in two steps before the actual testing. In the first step, the sample was melted for 2.5 minutes, extruded to a 3 mm gap and trimmed. After an additional soaking time of 2.5 minutes at 190°C, the sample was extruded to a 2 mm gap and the excess material was trimmed. The method has an additional built-in five minute delay to allow the system to reach thermal equilibrium. The tests were performed under a nitrogen atmosphere.

[0244] gpcBR Branching Index by Triple Detector GPC (TDGPC)

[0245] The gpcBR branching index is determined by first calibrating the light scattering, viscosity, and concentration detectors as previously described. The baseline is then subtracted from the light scattering, viscometer, and concentration chromatograms. The integration windows are then set to ensure that all low molecular weight retention volume ranges are integrated into the light scattering and viscometer chromatograms, which indicate the presence of polymer detectable from the refractive index chromatogram. Linear polyethylene standards are then used to establish polyethylene and polystyrene Markhoven constants. After obtaining the constants, these two values ​​are used to construct two linear reference conventional calibration values ​​for polyethylene molecular weight and polyethylene intrinsic viscosity as a function of elution volume, as shown in Equations (62) and (63):

[0246]

[0247] The gpcBR branching index is a robust method for characterizing long chain branching, as described in Yau, Wallace W., "Examples of Using 3D-GPC–TREF for Poly-olefin Characterization," Macromol. Symp., 2007, 257, 29-45. The index avoids the "layer-by-layer" TDGPC calculations traditionally used to determine g' values ​​and branching frequency calculations, in favor of the entire polymer detector area. From the TDGPC data, the peak area method can be used to obtain the absolute weight average molecular weight (M) of the sample bulk using a light scattering (LS) detector. w, abs). The method described avoids the "layer-by-layer" ratio of the light scattering detector signal to the concentration detector signal, as required in conventional g' determination. In the case of TDGPC, the sample intrinsic viscosity can also be obtained independently using equation (64). In this case, the area calculation provides higher accuracy because, as the overall sample area, it is less sensitive to detector noise and changes caused by the TDGPC settings on the baseline and integration limits. More importantly, the peak area calculation is not affected by detector volume offset. Similarly, the sample intrinsic viscosity (IV) is obtained with high accuracy by the area method in equation (64):

[0248]

[0249] In Equation (64), DPi represents the differential pressure signal monitored directly from the online viscometer. To determine the gpcBR branching index, the molecular weight of the sample is determined using the light scattering elution area of ​​the sample polymer. The viscosity detector elution area of ​​the sample polymer is used to determine the intrinsic viscosity (IV or [η]) of the sample. First, the molecular weight and intrinsic viscosity of a linear polyethylene standard sample (such as SRM1475a) or equivalent are determined using a conventional calibration ("cc") for both molecular weight and intrinsic viscosity as a function of elution volume:

[0250]

[0251] Equation (66) was used to determine the gpcBR branching index:

[0252]

[0253] where [η] is the measured intrinsic viscosity, [η] cc is the intrinsic viscosity from conventional calibration (or conv GPC), Mw is the measured weight average molecular weight, and M w,cc The weight average molecular weight determined by light scattering (LS) is often referred to as the "absolute weight average molecular weight" or "M w (abs)". From the M using a conventional GPC molecular weight calibration curve ("conventional calibration"). w,cc Often referred to as "polymer chain backbone molecular weight," "normal weight average molecular weight," and "M w (conv)”.

[0254] All statistical values ​​with "cc or conv" subscripts were determined using their corresponding elution volumes, corresponding conventional calibrations described previously, and concentrations (Ci). Non-subscripted values ​​are based on measurements of mass detector, LALLS, and viscometer areas. Iteratively adjusted K PEThe values ​​of α and Log K are adjusted until the gpcBR measurement value for the linear reference sample is zero. For example, in this particular case, the final values ​​for α and Log K used to determine gpcBR are 0.725 and -3.355 for polyethylene, and 0.722 and -3.993 for polystyrene, respectively. Once the K and α values ​​are determined using the procedure discussed,

[0255] Previously, the procedure was repeated using the branched samples. The branched samples were analyzed using the final Markhoven constant as the best "cc" calibration value.

[0256] The interpretation of gpcBR is straightforward. For linear polymers, gpcBR will be close to zero because the values ​​measured by LS and viscometry will be close to conventional calibration standards. For branched polymers, gpcBR will be higher than zero, especially at higher levels of long-chain branching, because the measured polymer molecular weight will be higher than the calculated M. w,cc , and calculate the IV cc will be higher than the measured IV of the polymer. In effect, the gpcBR value represents the fractional IV change due to the molecular size contraction effect caused by polymer branching. A gpcBR value of 0.5 or 2.0 would mean an IV at levels of 50% and 200%, respectively, relative to the molecular size contraction effect of an equivalent weight of a linear polymer molecule. For these specific examples, the advantage of using gpcBR is its greater precision compared to traditional "g' index" and branching frequency calculations. All parameters used in the gpcBR index determination achieve high precision and are not adversely affected by the low TDGPC detector response from the concentration detector under high molecular weight conditions. Errors in detector volume alignment also do not affect the accuracy of the gpcBR index determination.

[0257] Batch Reactor Polymerization Procedure

[0258] Batch reactor polymerization was carried out in a 2L Parr TM The reactor is heated by an electric heating mantle and cooled by an internal winding cooling coil containing cooling water. TMThe TG process computer controls and monitors the reactor and heating / cooling system. The bottom of the reactor is equipped with a dump valve that empties the reactor contents into a stainless steel dump pot. The dump pot is pre-filled with a catalyst kill solution (typically 5 mL of an Irgafos / Irganox / toluene mixture). The dump pot is discharged into a 30-gallon blowdown tank, and both the pot and the tank are purged with nitrogen. All solvents used for polymerization or catalyst replenishment are run through solvent purification columns to remove any impurities that may affect polymerization. 1-Octene and Isopar E are passed through two columns, the first column containing A2 alumina and the second column containing Q5. Ethylene is passed through two columns, the first column containing A204 alumina and molecular sieves, the second column contains the Q5 reactant. The N2 used for transfer passes through the column containing A204 alumina, A single column of molecular sieves and Q5.

[0259] The reactor is first loaded with a jet tank containing IsoparE solvent and / or 1-octene, according to the reactor load. The jet tank is filled to the load set point by using a laboratory scale on which a jet tank is installed. After adding the liquid feed, the reactor is heated to the polymerization temperature set point. If ethylene is used, it is added to the reactor to maintain the reaction pressure set point when ethylene is in temperature of reaction. The addition of ethylene is monitored by a micro-motion flowmeter (Micro Motion). For some experiments, the standard condition at 150°C is 585g IsoparE containing 13g ethylene, 15g 1-octene, 240psi hydrogen, and the standard condition at 150°C is 555g IsoparE containing 15g ethylene, 45g 1-octene, 200psi hydrogen.

[0260] The procatalyst and activator were mixed with an appropriate amount of purified toluene to achieve the desired molarity. The procatalyst and activator were handled in an inert glove box, drawn into a syringe, and pressure-transferred into a catalyst injection tank. The syringe was rinsed three times with 5 mL of toluene. A timer was started immediately after the catalyst addition. If ethylene was used, it was added via a Camile to maintain the reaction pressure set point in the reactor. The polymerization reaction was run for 10 minutes, after which the agitator was stopped and the bottom dump valve was opened to empty the reactor contents into a dump pot. The contents of the dump pot were poured into a tray and placed in a laboratory fume hood, where the solvent was evaporated overnight. The tray containing the remaining polymer was transferred to a vacuum oven, where it was heated to 140°C under vacuum to remove any residual solvent. After the tray cooled to ambient temperature, the polymer yield was weighed to measure efficiency and submitted for polymer testing.

[0261] Examples

[0262] Tetrafunctional branching in the presence of various multichain catalysts and various dienes

[0263] The results of the small-scale polymerizations are summarized in Tables 3 to 7 (the experiments were conducted in parallel polymerization reactors, PPRs). The polymer results reported in Tables 3 to 7 were produced by polymerizing ethylene, octene, and diene species in the presence of multi-chain catalysts and single-chain catalyst controls. The polymer results in each of Tables 3 to 7 are the product of various catalysts and diene species. The results in Table 3 are based on polymer products of 3-methyl-1,4-pentadiene, ethylene and octene in the presence of Comparative Catalyst C1 (Comp. Cat. C1"), Catalyst 1 ("Cat. 1") and Catalyst 2 ("Cat. 2"). The results in Table 4 are based on polymer products of 1,4-pentadiene, ethylene and octene in the presence of Catalyst 2 and Catalyst 4 ("Cat. 4"). The results in Table 5 are based on polymer products of 1,5-hexadiene, ethylene and octene in the presence of Comparative Catalyst C1, Catalyst 3 ("Cat. 3"), Catalyst 5 ("Cat. 5") and Catalyst 6 ("Cat. 6"). The results in Table 6 are based on polymer products of 1,7-octadiene, Polymer products of ethylene and octene. The results in Table 7 are polymer products based on 1,9-decadiene, ethylene and octene in the presence of Catalyst 3, Catalyst 5, Catalyst 6 and Catalyst 2 (Figueroa, R.; Froese, RD; He, Y.; Klosin, J.; Theriault, CN; Abboud, KA, Organometallics, 2011, 30, 1695-1709, Froese, RD; Jazdzewski, BA; Klosin, J.; Kuhlman, RL; Theriault, CN; Welsh, DM; Abboud, KA, Organometallics, 2011, 30, 251-262)

[0264]

[0265] The addition of the single-chain catalyst in Series 3.C (Comparative Catalyst C1) increased the amount of α-olefins as indicated by the twofold and higher octene levels in the polymer when compared to the other catalysts. When the single-chain catalyst in Series 3.C (Comparative Catalyst C1) was used, the various levels of added diene had no significant effect on the polymer MWD. ​​However, the addition of diene to the dual-chain catalysts in Tables 3 to 7 increased the MWD with increasing diene levels. w and M pThe values ​​are higher and there is usually no evidence of the formation of a high molecular weight tail.

[0266] In each of the examples containing diene, the amount of diene introduced into the reactor was small compared to the other reactants in the reactor. Therefore, the addition of diene did not affect the amount of comonomer, ethylene, and solvent added to the reactor.

[0267] Example 1 - Tetrafunctional Branching via 3-Methyl-1,4-Pentadiene

[0268] Table 3: Small scale polymerization (PPR) with 3-methyl-1,4-pentadiene as the diene species.

[0269]

[0270] Example 2 - Tetrafunctional Branching via 1,4-Pentadiene

[0271] Table 4: Small scale polymerization (PPR) with 1,4-pentadiene as the diene species.

[0272]

[0273] Table 4: continued

[0274]

[0275] Figure 20 The peak weight average molecular weight shift is shown with increasing diene content. Figure 20 The series P2.4.1–P2.4.4 are plotted as dWdLogM as a function of LogM, which is the GPC plot, as reported in Table 4. As the diene volume percentage increases, the peak in the GPC plot shifts to the right.

[0276] Example 3 - Tetrafunctional Branching via 1,5-Hexadiene

[0277] Table 5: Small scale polymerization (PPR) with 1,5-hexadiene as the diene species.

[0278]

[0279] Example 4 - Tetrafunctional Branching via 1,7-Octadiene

[0280] Table 6: Small scale polymerization (PPR) with 1,7-octadiene as the diene species.

[0281]

[0282] Example 5 - Tetrafunctional Branching via 1,9-Decadiene

[0283] Table 7: Small scale polymerization (PPR) with 1,9-decadiene as the diene species.

[0284]

[0285] Branching example in a batch reactor

[0286] The molecular weight distribution (MWD) curves and DSC of the two branched examples were studied and compared with the linear samples.

[0287] Batch Reactor Example 1

[0288] In Tables 8 to 12, the polymer characteristics of the comparative linear polymer sample (1C) are compared with the branched polymer from the batch reactor. The polymerization reaction took place at a temperature of 150°C with 555 g of ISOPAR-E TM The reaction mixture was neutralized under a hydrogen pressure (ΔH2) of 200 psi. Ethylene pressure was maintained constant at 150 psi in the presence of 0.3 μmole of catalyst 8, 0.36 μmole of cocatalyst A (di(tetradecyl)methylammonium tetrakis(pentafluorophenyl)borate), and 10 μmole of MMAO-3A.

[0289] Table 8: Polymer properties of Example 1 and comparative batch reactor polymers.

[0290]

[0291] Table 8: Continued

[0292]

[0293] Figure 21 The following are typical molecular weight distribution curves for the polymers in series 8.C (linear) and 8.1 (branched), as determined by GPC. The shape of the curve for the branched polymer (series 8.1) is altered compared to the linear polymer. Additionally, the peak of the molecular weight curve is shifted to the right.

[0294] Figure 22 are the absolute molecular weight distribution curves for the polymers in series 8.C (linear) and 8.1 (branched), as determined by GPC.

[0295] Figure 23 This is the extensional viscosity fixture for the branched samples in Series 8.1.

[0296] Table 9: Dynamic mechanical spectra of branched sample 8.1 at 190°C

[0297]

[0298] The dynamic mechanical spectrum of branched Example 8.1 was measured and the results are reported in Table 9. The viscosity at 0.1 rad / s was calculated to be 27,457 Pa s and the viscosity at 100 rad / s was measured to be 974 Pa s, providing a rheological ratio (V 0.1 / V 100 ).

[0299] The elastic coefficient m is [((tan(δ 0.1 )-tan(δ 100 ))*1000) / (0.1-100))]. tan(δ 0.1 ) is the tangent of the phase angle at 0.1 rad / s and tan(δ 100 ) is the tangent of the phase angle at 100 rad / s. 0.1 ) is 1.6, and the tan(δ 100 ) is 0.8, which results in an elasticity factor of 7.9 at 190°C.

[0300] Table 10: Dynamic mechanical spectra of comparative linear sample 8.C at 190°C

[0301]

[0302] The dynamic mechanical spectrum of Comparative 8.C was measured and the results are reported in Table 10. The shear viscosity at 0.1 rad / s was calculated to be 892 Pa s and the shear viscosity at 100 rad / s was measured to be 526 Pa s, providing a rheological ratio (V 0.1 / V 100 ). Compare the tan(δ 0.1 ) is 53.3 and tan(δ 100 ) is 2.0, which results in an elastic modulus of 513.4 at 190°C.

[0303] The rheology of the linear comparative polymer resin is very low (1.7) when compared to the rheology of the branched example (series 8.1). The increased rheology and low elasticity factor of branched example 1 (series 8.1) indicate nonlinear polymer behavior. Strong shear thinning and elastic behavior are typically indicative of entangled long-chain branched polymers.

[0304] Figure 24 is the melt strength obtained by means of a Rheotens apparatus for branched example 1 (series 8.1).

[0305] Branching Example 2

[0306] In Table 11, branched polyethylene was synthesized in which the diene was 1,9-decadiene. The branched polymer was polymerized at 150° C. in 555 g of Isopar E and a hydrogen pressure (ΔH) of 200 psi. The ethylene pressure was maintained constant at 150 psi in the presence of 0.3 μmole of catalyst 7, 0.36 μmole of cocatalyst A, and 10 μmole of MMAO-3A.

[0307] Table 11: Polymer properties of branched polymers of Example 2 and Comparative Examples.

[0308]

[0309] Figure 25 are typical molecular weight distribution curves for the polymers in series 11.C (linear) and branched Example 2 in 11.1 (branched), as determined by GPC. Figure 26 are the absolute molecular weight distribution curves for the polymers in series 11.C (linear) and 11.1 (branched), as determined using a light scattering triple photodetector. The shape of the curve for the branched polymers (series 11.1) is altered compared to the linear polymers.

[0310] Figure 27 is the extensional viscosity obtained by the extensional viscosity fixture of Branched Example 2 in Series 11.1.

[0311] Table 12: Dynamic mechanical spectra of branched example 2 (series 11.1) at 190°C

[0312]

[0313]

[0314] Comparative dynamic mechanical spectroscopy was measured and the results are reported in Table 12. The shear viscosity at 0.1 rad / s was calculated to be 17,643 Pa s and the shear viscosity at 100 rad / s was measured to be 857 Pa s, providing a rheological ratio (V 0.1 / V 100 tan(δ) of the branched polymer in Example 2 (Series 11.1) 0.1 ) is 2.0, and tan(δ 100 ) is 1.0, which results in an elasticity factor of 10.4 at 190°C.

[0315] Figure 28 is the melt strength obtained by means of a Rheotens apparatus for branched example 2 (series 11.1).

[0316] Branching studies under various conditions

[0317] Tetrafunctional "ladder branching" was studied under various conditions, such as increased ethylene pressure, increased octene monomer, increased starting molecular weight, decreased starting molecular weight, various dienes, increased or decreased diene amount, and various multichain catalysts.

[0318] Example 1: Various dienes and diene amounts

[0319] The examples in Tables 13 to 22 were prepared under the same conditions and polymerized at a temperature of 150° C. in the presence of Catalyst 7. The conditions comprised: 585 g Isopar E; 15 g 1-octene; a hydrogen pressure of 240 psi; an ethylene pressure of 150 psi; 0.3 μmole Catalyst 7; 0.36 μmole Cocatalyst A; and 10 μmole MMAO-3A.

[0320] Table 13. Various dienes tested under the same conditions using catalyst 7.

[0321]

[0322] Table 13: Continued

[0323]

[0324]

[0325] The results in Table 13 indicate that when the diene is present in the polymerization reaction, the molecular weight increases without a high molecular weight tail.

[0326] Example 2: Conditions for producing high molecular weight

[0327] Table 14: Nonadiene tested under conditions that yielded higher linear MW

[0328]

[0329] T = 150 ° C, Isopar E: 585 g, 1-octene: 15 g; ΔH2: 140 psi, ethylene: 150 psi, catalyst 7: 0.3 μmole, cocatalyst A: 0.36 μmole, MMAO-3A: 10 μmole.

[0330] Utilizing these polymerization conditions to produce high molecular weight polymers results in tetrafunctional "ladder branching" which occurs when the diene is incorporated into the polymerization reaction. The polymerization reaction produces a polymer resin having high molecular weight and tetrafunctional "ladder branching."

[0331] Example 3: Conditions for Producing Branched Homopolymers

[0332] Table 15: Examples of high density polyethylene using decadiene and pentadiene

[0333]

[0334]

[0335] T = 160 ° C, Isopar E: 600 g, 1-octene: 0 g; ΔH2: 240 psi, ethylene: 150 psi, catalyst 7: 0.4 μmole, cocatalyst A: 0.48 μmole, MMAO-3A: 10 μmole.

[0336] Incorporating a diene into a polymerization reaction used to prepare a homopolymer (diene-poor) results in an increase in molecular weight (tetrafunctional "ladder branching"). The data reported in Table 15 indicate that the molecular weight of the ethylene-only resin examples increases when two different dienes are incorporated into the polymerization reaction.

[0337] Table 16: Low Density Polyethylene Example Using Pentadiene Over Catalyst 8

[0338]

[0339] T = 150 ° C, Isopar E: 555 g, 1-octene: 45 g; ΔH2: 220 psi, ethylene: 150 psi, catalyst 8: 0.4 μmole, cocatalyst A: 0.48 μmole, MMAO-3A: 10 μmole.

[0340] The results in Table 16 indicate that branching occurs with different catalysts and at different densities. The resins in Table 16 show branching with Catalyst 8 and sufficient octene (7 mol% in the polymer).

[0341] Table 17: Low Density Polyethylene Examples at Higher Linear MW Using Pentadiene and Decadiene over Catalyst 8

[0342]

[0343] T = 150 ° C, Isopar E: 555 g, 1-octene: 45 g; ΔH2: 140 psi, ethylene: 150 psi, catalyst 8: 0.3 μmole, cocatalyst A: 0.36 μmole, MMAO-3A: 10 μmole.

[0344] Based on the results in Table 17, molecular weight increases with the addition of tetrafunctional "ladder-branched" dienes. These examples have higher linear molecular weights. In Examples 5.1 and 5.2, Catalyst 8 produced polymer resins with higher molecular weights when decadiene or pentadiene was present in the polymerization reaction.

[0345] Table 18: Hexene used as comonomer instead of octene and comparison of different catalysts with decadiene

[0346]

[0347] T = 150 ° C, ethylene: 150 psi, MMAO-3A: 10 μmole,

[0348] *Isopar E: 585 g, 1-hexene: 15 g; ΔH2: 240 psi, catalyst 7: 0.3 μmole, cocatalyst A: 0.36 μmole.

[0349] **Isopar E: 555 g, 1-hexene: 45 g; ΔH2: 200 psi, catalyst 8: 0.3 μmole, cocatalyst A: 0.36 μmole.

[0350] The results in Table 18 indicate that molecular weight increases (tetrafunctional "ladder branching") when different α-olefin comonomers are used. The polymer resins in Table 18 were produced from two different catalysts and two different hexene loadings.

[0351] Table 19: Low Density Polyethylene Examples at Higher Linear MW Using Decadiene over Catalyst 7

[0352]

[0353] T = 150 ° C, Isopar E: 555 g, 1-octene: 45 g; ΔH2: 60 psi, ethylene: 150 psi, catalyst 7: 0.3 μmole, cocatalyst A: 0.36 μmole, MMAO-3A: 10 μmole.

[0354] Based on the results in Table 19, diene molecular weight increases with varying octene levels (tetrafunctional "ladder branching"). The examples in Table 19 indicate that tetrafunctional "ladder branching" occurs even with polymers containing 7 mol% octene.

[0355] Table 20: Branching by different dienes (e.g. pentadiene)

[0356]

[0357] T = 150 ° C, Isopar E: 555 g, 1-octene: 45 g; ΔH2: 100 psi, ethylene: 150 psi, catalyst 7: 0.3 μmole, cocatalyst A: 0.36 μmole, MMAO-3A: 10 μmole.

[0358] As demonstrated in Table 20, tetrafunctional "ladder branching" occurs at different octene levels and at higher starting molecular weights. Examples 8.1 and 8.2 indicate that with 7 mol% octene and a starting molecular weight of approximately 83,000 g / mol, tetrafunctional "ladder branching" occurs. w The polymer resin results in branching of both decadiene and pentadiene.

[0359] Table 21: Branching via high octene levels and low linear molecular weight.

[0360]

[0361] T = 150 ° C, Isopar E: 542 g, 1-octene: 58 g; ΔH2: 200 psi, ethylene: 150 psi, catalyst 7: 0.3 μmole, cocatalyst A: 0.36 μmole, MMAO-3A: 10 μmole.

[0362] The results in Table 21 show that at lower density (high octene levels in the polymer) and lower starting molecular weight, molecular weight increases (tetrafunctional "ladder branching"). In Example 9.1, the polymer resin had greater than 9 mol% octene and a starting molecular weight of approximately 43,000 g / mol. w When a diene is incorporated into the polymerization reaction, the molecular weight increases ("ladder branching" occurs).

[0363] Table 22: "Ladder Branching" by Decadiene at Lower Linear Molecular Weights

[0364]

[0365] T = 150 ° C, Isopar E: 555 g, 1-octene: 45 g; ΔH2: 180 psi, ethylene: 150 psi, catalyst 7: 0.3 μmole, cocatalyst A: 0.36 μmole, MMAO-3A: 10 μmole.

[0366] The results in Table 22 indicate that at lower starting molecular weights, molecular weight increases with diene (tetrafunctional "ladder branching") through varying levels of incorporated octene. In Example 22.1, the starting molecular weight of the polymer resin was approximately 51,000 g / mol, and when diene was incorporated into the polymerization reaction, the molecular weight increased to 70,000 g / mol (tetrafunctional "ladder branching" occurred).

[0367] Table 23: Different ethylene pressures and octene added to the reactor

[0368]

[0369] T = 150 ° C, Isopar E: 533 g, 1-octene: 67 g; ΔH2: 240 psi, ethylene: 233 psi, catalyst 7: 0.3 μmole, cocatalyst A: 0.36 μmole, MMAO-3A: 10 μmole.

[0370] From the data in Tables 23 and 24, as the ethylene pressure and the amount of octene in the reactor increased, the molecular weight increased (tetrafunctional "ladder branching" occurred).

[0371] Table 24: Varying ethylene pressure and amount of octene added to the reactor.

[0372]

[0373] T = 150 ° C, Isopar E: 510 g, 1-octene: 90 g; ΔH2: 240 psi, ethylene: 300 psi, catalyst 7: 0.3 μmole, cocatalyst A: 0.36 μmole, MMAO-3A: 10 μmole.

[0374] Example 4: Decadiene Homopolymer Catalyzed by Catalyst 7

[0375] Table 25: No octene was added to the reactor.

[0376]

[0377] Table 25: Continued

[0378]

[0379]

[0380] T = 150 ° C, Isopar E: 600 g, 1-octene: 0 g (except entry 25.C.1 with 0.2 g), ΔH2: 240 psi, ethylene: 150 psi, catalyst 7: 0.4 μmole, cocatalyst A: 0.48 μmole, MMAO-3A: 10 μmole.

[0381] The results summarized in Table 25 indicate that tetrafunctional "ladder branching" occurs when octene is not present in the reactor. The molecular weight of each example in Table 25 increases with increasing amounts of decadiene in the polymerization reaction.

[0382] Table 26: Carbon and proton NMR evaluations of the methine, vinyl, and vinylidene groups (per 1000 carbon atoms) for the examples reported in Table 25.

[0383]

[0384] Example 26.C.1 is the result of a polymerization reaction containing 0.2 octene. Figure 29 is a graph of Log(MW) for Examples 26.C.1, 26.C.2, and 26.1-26.4. As the amount of decadiene increases, the molecular weight peak shifts to the right. Tables 27 through 32 summarize the results of dynamic mechanical spectroscopy for Examples 26.C.1, 26.C.2, and 26.1-26.4. The results in each of Tables 27 through 32 indicate that the elastic modulus m decreases with increasing amounts of tetrafunctional "trapezoidal branching." Additionally, the results in each of Tables 27 through 32 indicate that the rheological ratio increases with increasing amounts of tetrafunctional "trapezoidal branching."

[0385] Figure 29 It is a conventional molecular weight distribution for the series 26.C.1, 26.C.2 and the curves 26.1 to 26.4.

[0386] Table 27: Dynamic mechanical spectra of Example 26.C.1 (linear short chain branched polymer) at 190°C.

[0387]

[0388] Comparative dynamic mechanical spectroscopy was measured and the results are reported in Table 27. The shear viscosity at 0.1 rad / s was calculated to be 762 Pa s and the shear viscosity at 100 rad / s was measured to be 552 Pa s, providing a rheological ratio (V 0.1 / V 100 ). Tan (δ) of the branched polymer in Example 26.C.1 0.1 ) is 192.8, and tan(δ 100 ) is 2.8, which results in an elastic modulus of 1901.6 at 190°C.

[0389] Table 28: Dynamic mechanical spectra of Example 26.C.2 (linear polymer) at 190°C.

[0390]

[0391] The dynamic mechanical spectrum of Comparative Example 26.C.1 was measured and the results are reported in Table 28. The shear viscosity at 0.1 rad / s was calculated to be 662 Pa s and the shear viscosity at 100 rad / s was measured to be 501 Pa s, providing a rheological ratio (V 0.1 / V 100 ). Tan(δ) of the linear polymer in Example 26.C.1 0.1 ) is 401.3 and tan(δ 100 ) is 3.1, which results in an elastic modulus of 3986.2 at 190°C.

[0392] Table 29: Dynamic mechanical spectra of Example 26.1 (tetrafunctional "ladder-branched" polymer) at 190°C.

[0393]

[0394]

[0395] The dynamic mechanical spectrum of Example 26.1 was measured and the results are reported in Table 29. The shear viscosity at 0.1 rad / s was calculated to be 7,410 Pa s and the shear viscosity at 100 rad / s was measured to be 883 Pa s, providing a rheological ratio (V 0.1 / V 100 ). The tan(δ) of the branched polymer in Example 13.1 0.1 ) is 4.3, and tan(δ 100 ) is 1.3, which results in an elastic modulus of 29.8 at 190°C.

[0396] Table 30: Dynamic mechanical spectra of Example 26.2 (tetrafunctional "ladder-branched" polymer) at 190°C.

[0397]

[0398] The dynamic mechanical spectrum of Example 26.2 was measured and the results are reported in Table 30. The shear viscosity at 0.1 rad / s was calculated to be 56,549 Pa s and the shear viscosity at 100 rad / s was measured to be 1,236 Pa s, providing a rheological ratio (V 0.1 / V 100 ). The tan(δ) of the branched polymer in Example 26.2 0.1 ) is 1.2, and tan(δ 100 ) is 0.8, which results in an elasticity factor of 4.2 at 190°C.

[0399] Table 31: Dynamic mechanical spectra of Example 26.3 (tetrafunctional "ladder-branched" polymer) at 190°C.

[0400]

[0401] The dynamic mechanical spectrum of Example 26.3 was measured and the results are reported in Table 31. The shear viscosity at 0.1 rad / s was calculated to be 56,549 Pa s and the shear viscosity at 100 rad / s was measured to be 1,236 Pa s, providing a rheological ratio (V 0.1 / V 100 ). The tan(δ) of the branched polymer in Example 26.3 0.1 ) is 1.2, and tan(δ100 ) is 0.8, which results in an elasticity factor of 4.2 at 190°C.

[0402] Table 32: Dynamic mechanical spectra of Example 26.4 (tetrafunctional "ladder-branched" polymer) at 190°C.

[0403]

[0404]

[0405] The dynamic mechanical spectrum of Example 26.4 was measured and the results are reported in Table 32. The shear viscosity at 0.1 rad / s was calculated to be 909,000 Pa s and the shear viscosity at 100 rad / s was measured to be 3,054 Pa s, providing a rheological ratio (V 0.1 / V 100 ). The tan(δ) of the branched polymer in Example 26.4 0.1 ) is 0.3, and tan(δ 100 ) is 0.3, which results in an elastic modulus of 0.4 at 190°C.

[0406] Guzman-2010 shows and analyzes the MWD and physical properties produced by conventional diene branching in a steady-state CSTR. In a highly mixed one-gallon reactor system, ethylene, 1-octene and 1,9-decadiene were copolymerized using a constrained geometry catalyst (CGC). The specific CGC catalyst used by Guzman is described in detail in U.S. Patent No. 5,965,756 (Structure IX) and U.S. Patent No. 7,553,917 (Example 3). The Guzman-2010 catalyst is designed to grow single chains from the catalyst center. Guzman's data were collected in steady state while operating the CSTR at a pressure of 525 psig and a temperature of 155°C over a range of diene feed concentrations. The various steady-state polymer samples collected by Guzman did not contain measurable levels of gel or insoluble material. However, at the highest diene feed level, some slight internal reactor fouling was observed, and it is expected that higher diene feed levels will lead to gel formation or reactor MWD instability.

[0407] In Table 33, a series of selected data from Guzman is summarized over a range of continuous diene feed levels for otherwise fixed reactor conditions. Throughout the series, ethylene and 1-octene feed concentrations were set at 13.8 wt% and 3.6 wt%, respectively. The catalyst feed rate was continuously adjusted to maintain a constant ethylene conversion of 79% throughout the series, resulting in a constant polymer production rate of 2.2 kg / hr. The polymer density (a measure of copolymer composition) was constant at approximately 0.922 g / cc.

[0408] Table 33: Comparative example of Guzman CSTR results using single chain constrained geometry catalyst and 1,9-decadiene.

[0409]

[0410] A. 1,9-Decadiene feed level, expressed as total mass fraction, in ppm

[0411] B. 1,9-Decadiene incorporation, expressed as polymer mass fraction in ppm.

[0412] The data in Table 33 show how changes in the level of conventional diene branching affect average molecular weight and polydispersity as well as properties such as viscosity, I2 and I 10 The effect of conventional diene branching on molecular weight is shown in Table 33 for both absolute and conventional MWD measurement techniques. While absolute MWD measurement is the preferred method for branched polymers, it is not always available. Therefore, Table 33 also contains molecular weights measured by conventional techniques using a refractive index detector. The results in Table 33 show that, by either measurement technique, as the diene feed is increased from zero to 923 ppm, the weight average molecular weight (M w ) basically increased.

[0413] Although not reported in Guzman, the MWD curves associated with Table 33 were found and plotted for absolute and conventional GPC measurement techniques, respectively. Figure 30A and 30B middle. Figure 30A and 30B The MWD curve data in the Figure 2 show that the expected high M ions produced by conventional diene branching occur. w It is also apparent from the MWD curves that there is no significant shift in peak MW with increasing diene branching.

[0414] Will Figure 30A and 30B The molecular weight distribution data in Table 34 are simplified to describe the evolution of the position and shape of the MWD curve as more diene monomer is fed into the CSTR. The data in Table 34 show these MWD measurements for absolute and conventional MWD measurements of Guzman's polymer samples. The absolute MWD measurement data in Table 34 show that the molecular weight increases by up to 87% when the 1,9-decadiene feed ranges from 0 to 923 ppm. As shown in Table 34, the molecular weight increases by up to 87%. p As indicated, the peak molecular weight change does not significantly alter the molecular weight measurement method, which is inconsistent with the "ladder-branched" polymer results. The shape factors are summarized in Table 34 and are inconsistent with "ladder-branched" polymers because G 79 / 29 and A 尾部 The value ofw increases with the increase of .

[0415] Table 34: Molecular weight data and measurements associated with the examples in Table 33.

[0416]

[0417] Some key parameters of commercial resins are listed in Table 35. Some basic parameters of the materials were determined in solution, gas phase and high pressure reactors.

[0418] Table 35: Physical properties of non-"ladder-branched" polymer compositions

[0419]

[0420] TM Trademark of The Dow Chemical Company

[0421] *Competitor resins were tested as a comparison. Exxon resin is from ExxonMobil. Equistar resin is a LyondellBasell polyethylene product.

[0422] The data summarized in Table 35 are Figure 31 and Figure 32 The data show the difference between "ladder-branched" polymers and LDPE, LLDPE, ULDPE and ethylene resins containing diene monomers. Figure 31 and Figure 32 In the figure, the "ladder-branched" polymers of the present disclosure (ladder-shaped PE in the example) are clustered together, indicating that the "ladder-branched" polymers have unique polymerization properties compared to other ethylene-based resins. Figure 31 As shown in the figure, the rheological ratio of the "ladder-branched" polymer is at least 10 and the average g' is less than 0.86. Figure 31 In FIG, the average g' of the plotted LDPE resins is less than 0.65; the prior art ethylene-diene resins (listed in the legend as prior art ET-diene) do not aggregate together.

[0423] exist Figure 33In the , melt strength (hundredths of Newtons, cN) was measured as a function of melt index (Log I2). Polymers produced by the dual-chain catalyst (as indicated by triangles and circles) were compared to polymers produced by a single-chain catalyst and literature-based curves for autoclave LDPE, tubular LDPE, and linear polyethylene. The melt strength of the polymer produced by the dual-chain catalyst was less than that of the autoclave LDPE, tubular LDPE, and polymer produced by the single-chain catalyst, but significantly greater than that of linear polyethylene. This indicates that the polymer produced by the dual-chain catalyst has entangled long-chain branches.

[0424] It should be apparent to those skilled in the art that various modifications may be made to the described embodiments without departing from the spirit and scope of the claimed subject matter. Therefore, this specification is intended to cover modifications and variations of the described embodiments as long as these modifications and variations are within the scope of the appended claims and their equivalents.

[0425] In summary, the present invention includes but is not limited to the following:

[0426] 1. A method for synthesizing a long-chain branched copolymer, the method comprising:

[0427] Make one or more C2-C 14 contacting together an olefin monomer, at least one diene or polyene, optionally a solvent, and a multi-chain catalyst, wherein the multi-chain catalyst comprises a plurality of polymerization sites;

[0428] Producing the C2-C 14 at least two polymer chains of an olefin monomer, each polymerized at one of the polymerization sites; and

[0429] The long-chain branched polymer is synthesized by linking the two polymer chains to the diene or polyene, the joining of the two polymer chains occurring in a concerted manner during the polymerization.

[0430] 2. A process according to item 1, wherein ethylene is added to an extent that the resulting copolymer contains more than 50 mol% ethylene.

[0431] 3. The process of item 1 or 2, wherein the diene and polyene comonomers are incorporated at a level to achieve at least one bridged junction per 100 copolymer chains.

[0432] 4. The process according to any one of items 1 to 3, wherein the diene is non-conjugated or the polyene has at least two non-conjugated bonds per molecule.

[0433] 5. The method according to any one of the preceding items, wherein the multi-chain catalyst is a heterogeneous catalyst, wherein the surface concentration of metal atoms is greater than or equal to 0.3 metal atoms / square nanometer (metal / nm 2 ).

[0434] 6. The method according to any one of the preceding items, wherein the multi-chain catalyst has two linked transition metals connected by a divalent anion activator, wherein the distance between the metal atoms is less than or equal to

[0435] 7. The method according to any one of the preceding items, wherein the multi-chain catalyst consists of two or more transition metals covalently tethered, wherein the distance between the metal atoms is less than or equal to

[0436] 8. The method according to any of the preceding items, wherein the multi-chain catalyst has two or more polymer chains on the same metal.

[0437] 9. The process according to any of the preceding items, wherein the multi-chain catalyst has a monoanionic ligand, is a Group IV metal (Ti, Zr, Hf), and has two polymer chains on the same metal.

[0438] 10. The method according to any one of the preceding items, wherein the long-chain branched copolymer M w than the M of the polymer synthesized in the absence of the diene or polyene w is at least 20% greater, or wherein the long chain branched copolymer M p than the M of the polymer synthesized in the absence of the diene or polyene p At least 20% larger.

[0439] 11. The process of any of the preceding items, wherein the polydisperse long chain branched polymer has from 0.01 to 0.5 diene junctions per number average copolymer chain or from 0.02 to 1.0 diene junctions per weight average copolymer chain.

[0440] 12. The process according to any of the preceding items, wherein the polymerization occurs in a solution polymerization reactor or a particle formation polymerization reactor, such as a slurry reactor or a gas phase reactor, wherein a molecular or solid supported catalyst is delivered to the reaction medium or formed in the reaction medium, wherein the reactor system is batch or continuous or hybrid, such as semi-batch, wherein the reactor residence time distribution is narrow as in a non-backmixed reactor or wide as in a backmixed reactor and in series and loop reactors.

Claims

1. A method for synthesizing a long-chain branched copolymer, the method comprising: Ethylene and one or more C3-C 14 An α-olefin comonomer, at least one diene, optionally a solvent, and a double-chain catalyst are contacted together, wherein the double-chain catalyst comprises two polymerization sites, wherein The double-chain catalyst comprises a single monoanionic ligand and a single Group IV metal and has two polymer chains on the Group IV metal, and wherein the diene is selected from the group consisting of 2-methyl-1,4-pentadiene, 3-methyl-1,4-pentadiene, 1,3-divinylcyclopentane, 2-methyl-1,5-hexadiene, 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene, 1,8-nonadiene, and 1,9-decadiene; Producing the ethylene and C2-C 14 two polymer chains of an olefin alpha-olefin comonomer, each polymerized at one of the polymerization sites; and The long chain branched copolymer is synthesized by linking the two polymer chains to the diene, wherein the linking of the two polymer chains occurs in a concerted manner during the polymerization, wherein the reactions occur in a concerted manner meaning that one of the dienes reacts before the second olefin, and the second olefin reacts before the addition of an ethylene molecule to the polymer chain, thereby removing the second olefin from close proximity to the reaction site.

2. A process according to claim 1 wherein ethylene is added to such an extent that the resulting copolymer contains more than 50 mol% ethylene.

3. The process of claim 1 wherein the diene comonomer is incorporated at a level to achieve at least one bridged junction per 100 copolymer chains as determined by NMR spectroscopy.

4. The method according to any one of claims 1 to 3, wherein the double-chain catalyst is a heterogeneous catalyst in which the surface concentration of metal atoms is greater than or equal to 0.3 metal atoms / nm2.

5. The method according to any one of claims 1 to 3, wherein the long-chain branched copolymer M w than the M of the polymer synthesized without the diene w is at least 20% greater, or wherein the long chain branched copolymer M p than the M of the polymer synthesized without the diene p At least 20% larger.

6. The method of any one of claims 1 to 3, wherein the long chain branched polymer has 0.01 to 0.5 diene junctions per number average copolymer chain or 0.02 to 1.0 diene junctions per weight average copolymer chain.

7. The process of any one of claims 1 to 3, wherein the polymerization occurs in a solution polymerization reactor or a particle formation polymerization reactor, including a slurry reactor or a gas phase reactor, wherein a molecular or solid supported catalyst is delivered to or formed in the reaction medium, wherein the reactor system is batch or continuous or hybrid, such as semi-batch, wherein the reactor residence time distribution is narrow as in a non-backmixed reactor or wide as in backmixed reactors and series and loop reactors.

8. The method according to any one of claims 1 to 3, wherein: The double-chain catalyst has the following structure: wherein L is a monoanionic ligand, P is a growing polymer chain, and M is selected from Ti, Zr, and Hf; or The double-chain catalyst has the following structure: wherein X and L together form a bidentate monoanionic ligand, P is a growing polymer chain, and M is selected from Ti, Zr, and Hf.

9. The method according to claim 8, wherein the double-stranded catalyst is selected from:

10. The method of any one of claims 1 to 3, wherein the long chain branched copolymer has a melt viscosity ratio (V ) of at least 10 at 190°C. 0.1 / V 100 ), where V 0.1 is the viscosity of the ethylene-based polymer at 190°C at an angular frequency of 0.1 rad / s, and V 100 It is the viscosity of the ethylene polymer at 190°C and an angular frequency of 100 rad / s.

11. The method of any one of claims 1 to 3, wherein the long chain branched copolymer has an average g' of 0.64 to 0.86, wherein the average g' is an intrinsic viscosity ratio determined by gel permeation chromatography using a triple detector.

Images