Crosslinkable polymer compositions with propylene-based polymer and reversible crosslinker

Abstract

Embodiments are directed to a crosslinkable polymer composition. In embodiments, the crosslinkable polymer composition includes a propylene-based polymer, a free radical initiator, and bis(4-phenacryloyloxyphenyl) disulfide (BiPheS phenylacrylate). In other embodiments, the crosslinkable polymer composition includes a propylene-based polymer, a freed radical initiator, a coagent, and bis(4-methacryloyloxyphenyl) disulfide (BiPheS methacrylate). Further embodiments are directed to crosslinked compositions formed from the crosslinkable polymer compositions and reprocessing the crosslinked compositions.

Description

[0001] 86143-WO-PCT / DOW 86143 WO CROSSLINKABLE POLYMER COMPOSITIONS WITH PROPYLENE- BASED POLYMER AND REVERSIBLE CROSSLINKER CROSS-REFERENCE TO RELATED APPLICATIONS [1] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 669,770 filed July 11, 2024, the contents of which are incorporated in their entirety herein. TECHNICAL FIELD [2] Embodiments of the present disclosure generally relate to crosslinkable polymer compositions and specifically relate to crosslinkable polymer compositions with propylene- based polymer and reversible crosslinker. BACKGROUND [3] Crosslinked olefin-based polymers, and crosslinked propylene-based polymers in particular, are desirable in a myriad of applications because of their mechanical properties, heat stability, and chemical resistance. Unfortunately, using conventional processes, such as radical processes, to crosslink propylene-based polymers made lead to difficulties, such as chain scission that occurs in the presence of radicals. Moreover, crosslinked propylene-based polymer, also known as thermoset polymer, may be unable to be reprocessed and / or recycled due to the presence of the permanent crosslinked network within the propylene-based polymer. Thus, the use of crosslinked propylene-based polymer carriers concomitant environmental and sustainability concerns. [4] Accordingly, there is a need for improved crosslinked propylene-based polymers that can be reprocessed and / or recycled. SUMMARY [5] The embodiments of the present disclosure meet this need by utilizing a reversible crosslinker, specifically, bis(4-phenacryloyloxyphenyl) disulfide (BiPheS phenylacrylate), or a reversible crosslinker, specifically, bis(4-methacryloyloxyphenyl) disulfide (BiPheS methacrylate), in combination with a coagent. These resulted in crosslinkable polymer compositions that may be crosslinked to produce a crosslinked composition that gives a substantial network response upon crosslinking (e.g., storage modulus (E') at 180 °C greater 86143-WO-PCT / DOW 86143 WO than or equal to 0.01 MPa) and recovers its storage modulus after successive compressive molding cycles (e.g., E' at 180 °C of 2ndmold greater than or about equal to E' at 180 °C of 1stmold), thereby providing a reprocessable and / or recyclable crosslinked propylene-based polymer. [6] In one embodiment, a crosslinkable polymer composition comprises: a propylene- based polymer; a free radical initiator; and bis(4-phenacryloyloxyphenyl) disulfide (BiPheS phenylacrylate). [7] In another embodiment, a crosslinked composition comprises: a propylene-based polymer; and bis(4-phenacryloyloxyphenyl) disulfide (BiPheS phenylacrylate). [8] In one embodiment, a process comprises: heating a first article to a reprocessing temperature, the first article comprising a crosslinked composition; forming, at the reprocessing temperature, the first article into a re-processable propylene-based polymer composition; shaping, at the reprocessing temperature, the re-processable propylene-based composition into a re-processed pre-form; cooling the re-processed pre-form to below the reprocessing temperature; and forming a second article. The crosslinked composition comprises: a propylene-based polymer; and bis(4-phenacryloyloxyphenyl) disulfide (BiPheS phenylacrylate). The second article comprises a re-crosslinked composition. The re- crosslinked composition comprises: the propylene-based polymer; and the BiPheS phenylacrylate. The second article is different from the first article. [9] In another embodiment, a crosslinkable polymer composition comprises: a propylene-based polymer; a free radical initiator; a coagent; and bis(4- methacryloyloxyphenyl) disulfide (BiPheS methacrylate).

[0010] In one embodiment, a crosslinked composition comprises: a propylene-based polymer; a coagent; and bis(4-methacryloyloxyphenyl) disulfide (BiPheS methacrylate).

[0011] In another embodiment, a process comprises: a process comprises: heating a first article to a reprocessing temperature, the first article comprising a crosslinked composition; forming, at the reprocessing temperature, the first article into a re-processable propylene- based polymer composition; shaping, at the reprocessing temperature, the re-processable propylene-based composition into a re-processed pre-form; cooling the re-processed pre-form to below the reprocessing temperature; and forming a second article. The crosslinked composition comprises: a propylene-based polymer; a coagent; and bis(4- 86143-WO-PCT / DOW 86143 WO methacryloyloxyphenyl) disulfide (BiPheS methacrylate). The second article comprises a re- crosslinked composition. The re-crosslinked composition comprises: the propylene-based polymer; the coagent; and the BiPheS methacrylate. The second article is different from the first article.

[0012] Additional features and advantages will be set forth in the detailed description, which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows and the claims.

[0013] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. DETAILED DESCRIPTION

[0014] Specific embodiments of the present application will now be described. The disclosure may be embodied in different forms and should not be construed as limited to the embodiments set forth in this disclosure. Rather, these 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.

[0015] DEFINITIONS

[0016] Unless stated to the contrary, implicit from the context, or customary in the art, all test methods are current as of the filing date of this disclosure.

[0017] The amount of a component (e.g., propylene-based polymer, BiPheS phenylacrylate, BiPheS methacrylate, coagent, and free-radical initiator) in a crosslinkable polymer composition or a crosslinked composition is provided herein in weight percent (wt%), based on a total weight of the crosslinkable polymer composition or the crosslinked composition, unless otherwise noted.

[0018] Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood 86143-WO-PCT / DOW 86143 WO that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0019] The terms "comprising", "including", "having”, and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term, "consisting essentially of” excludes from the scope of any succeeding recitation any other component, step or procedure, excepting those that are not essential to operability. The term "consisting of” excludes any component, step or procedure, not specifically delineated or listed.

[0020] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percentages are based on weight.

[0021] The term “composition,” as used herein, refers to a mixture of materials which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0022] The term "propylene-based polymer," as used herein, refers to a polymer that contains more than 50 mole percent polymerized propylene monomer (based on the total amount of polymerizable monomers) and, optionally, may contain at least one comonomer. Propylene-based polymer includes propylene homopolymer, and propylene copolymer (meaning units derived from propylene and one or more comonomers). The terms "propylene-based polymer" and "polypropylene" may be used interchangeably.

[0023] The term “polymer,” as used herein, refers to a compound prepared by polymerizing monomers, whether of the same or a different type, that in polymerized form provide the multiple and / or repeating “units” or “mer units” that make up a polymer. The generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term copolymer, usually employed to refer to polymers prepared from at least two types of monomers. It also embraces all forms of copolymer, e.g., random, block, etc. The term “propylene / α-olefin polymer” is indicative of copolymer as described above prepared from polymerizing propylene respectively and one or more additional, polymerizable α-olefin monomer. It is noted that although a polymer is 86143-WO-PCT / DOW 86143 WO often referred to as being “made of” one or more specified monomers, “based on” a specified monomer or monomer type, “containing” a specified monomer content, or the like, in this context, the term “monomer” is understood to be referring to the polymerized remnant of the specified monomer and not to the unpolymerized species. In general, polymers herein are referred to as being based on “units” that are the polymerized form of a corresponding monomer.

[0024] "Crystalline" refers to a polymer or polymer block that possesses a first order transition or crystalline melting point (Tm) as determined by differential scanning calorimetry (DSC) or equivalent technique. The term may be used interchangeably with the term "semicrystalline".

[0025] The term "crystallizable" refers to a monomer that can polymerize such that the resulting polymer is crystalline. Crystalline ethylene polymers typically have, but are not limited to, densities of 0.89 g / cc to 0.97 g / cc and melting points of 75°C to 140°C. Crystalline propylene polymers may have, but are not limited to, densities of 0.88 g / cc to 0.91 g / cc and melting points of 100 °C to 170°C.

[0026] "Amorphous" refers to a polymer lacking a crystalline melting point as determined by differential scanning calorimetry (DSC) or equivalent technique.

[0027] "Isotactic" is defined as polymer repeat units having at least 70 percent isotactic pentads as determined by 13C-NMR analysis. "Highly isotactic" is defined as polymers having at least 90 percent isotactic pentads.

[0028] “Impact modified propylene-based copolymer” and the like terms mean a propylene based polymer composition that has been impact-modified such that the composition's impact strength at room temperature or below is maintained or increased as compared to said given composition's impact strength at the same temperature without the added impact modifier.

[0029] "Block copolymer" or “segmented copolymer” refers to a polymer comprising two or more chemically distinct regions or segments (referred to as "blocks") joined in a linear manner, that is, a polymer comprising chemically differentiated units that are joined (covalently bonded) end-to-end with respect to polymerized functionality (e.g., polymerized propylenic functionality), rather than in pendent or grafted fashion. Block copolymers comprise sequences ("blocks") of the same monomer unit, covalently bound to sequences of unlike type. The blocks can be connected in a variety of ways, such as A—B in diblock and 86143-WO-PCT / DOW 86143 WO A—B—A triblock structures, where A represents one block and B represents a different block. In a multi-block copolymer, A and B can be connected in a number of different ways and be repeated multiply. It may further comprise additional blocks of different type. Multi- block copolymers may be linear multi-block, multi block star polymers (in which all blocks bond to the same atom or chemical moiety) or comb-like polymers where the B blocks are attached at one end to an A backbone. The block copolymers can be linear or branched. With respect to the block copolymers, the blocks may differ in the amount of comonomer incorporated therein. The blocks may also differ in the type of comonomer, density, the amount of crystallinity, the crystallite size attributable to a polymer of such composition, the type or degree of tacticity (isotactic or syndiotactic), regio-regularity or regio-irregularity, the amount of branching, including long chain branching or hyper-branching, the homogeneity, or any other chemical or physical property. The block copolymers are characterized by unique distributions of polymer polydispersity (PDI or Mw / Mn), block length distribution, and / or block number distribution, e.g., due to the effect of the shuttling agent(s) in combination with the catalyst(s).

[0030] The term “block composite” (BC) refers to polymers comprising an ethylene based polymer (EP) having an ethylene content of from 10 mol% to 90 mol%, an alpha-olefin based polymer (AOP) having an alpha-olefin content of greater than 90 mol%, and a block copolymer having an ethylene block (EB) and an alpha-olefin block (AOB), wherein the ethylene block of the block copolymer is the same composition as the ethylene based polymer of the block composite and the alpha-olefin block of the block copolymer is the same composition as the alpha-olefin based polymer of the block composite. The compositional split between the amount of ethylene based polymer and alpha-olefin based polymer will be essentially the same as that between the corresponding blocks in the block copolymer. In certain embodiments, the alpha-olefin is propylene. In further embodiments, the AOB and EB may be an iPP-EP diblock copolymer.

[0031] The term “crystalline block composite” (CBC) refers to polymers comprising a crystalline ethylene based polymer (CEP) having an ethylene content of greater than 90 mol%, a crystalline alpha-olefin based polymer (CAOP) having an alpha-olefin content of greater than 90 mol%, and a block copolymer having a crystalline ethylene block (CEB) and a crystalline alpha-olefin block (CAOB), wherein the CEB of the block copolymer is the same composition as the CEP of the crystalline block composite and the CAOB of the block 86143-WO-PCT / DOW 86143 WO copolymer is the same composition as the CAOP of the crystalline block composite. The compositional split between the amount of CEP and CAOP will be essentially the same as that between the corresponding blocks in the block copolymer. In exemplary embodiments, the alpha-olefin is propylene. In further embodiments, the CAOB and the CEB may be an iPP-EP (isotactic polypropylene and ethylene-propylene) diblock copolymer.

[0032] The block composite and crystalline block composite (“the composites”) may be differentiated from conventional, random copolymers, physical blends of polymers, and block copolymers prepared via sequential monomer addition. The composites may be differentiated from random copolymers by characteristics such as higher melting temperatures for a comparable amount of comonomer, BCI, CBCI, and microstructure index; from a physical blend by characteristics such as BCI, CBCI, microstructure index, better tensile strength, improved fracture strength, finer morphology, improved optics, and / or greater impact strength at lower temperature; and from block copolymers prepared by sequential monomer addition by molecular weight distribution, rheology, shear thinning, rheology ratio, and in that there is block polydispersity. For example, the composites include block copolymers having distinct regions or segments (referred to as “blocks”) joined in a linear manner. The blocks differ, e.g., in the type of crystallinity such as polyethylene (PE) versus polypropylene (PP). The block copolymers can be linear or branched. When produced in a continuous process, the composites may possess PDI from 1.7 to 15 (e.g., from 1.8 to 10, from 1.8 to 5, and / or from 1.8 to 3.5). When produced in a batch or semi-batch process, the composites may possess PDI from 1.0 to 2.9 (e.g., from 1.3 to 2.5, from 1.4 to 2.0, and / or from 1.4 to 1.8). Exemplary composites are described in, e.g., U.S. Patent Nos. 8,716,400, 8,802,774, and 8,822,598, which are incorporated herein by reference with respect to, for example, processes to make them and methods of analyzing them.

[0033] The composites include the block copolymers possessing a most probable distribution of block lengths. The block copolymers may contain 2 or 3 blocks or segments. In a process for making the polymers of the composites, chain shuttling is used as a way to prolong the lifetime of a polymer chain such that a substantial fraction of the polymer chains exit at least the first reactor of a multiple reactor series or the first reactor zone in a multiple zoned reactor operating substantially under plug flow conditions in the form of polymer terminated with a chain shuttling agent, and the polymer chain experiences different polymerization conditions in the next reactor or polymerization zone. Different 86143-WO-PCT / DOW 86143 WO polymerization conditions in the respective reactors or zones include the use of different monomers, comonomers, or monomer / comonomer(s) ratio, different polymerization temperatures, pressures or partial pressures of various monomers, different catalysts, differing monomer gradients, or any other difference leading to formation of a distinguishable polymer segment. Thus, at least a portion of the polymer comprises two, three, or more, preferably two or three, differentiated polymer segments arranged intramolecularly.

[0034] The composites are prepared, e.g., by a process comprising contacting an addition polymerizable monomer or mixture of monomers under addition polymerization conditions with a composition comprising at least one addition polymerization catalyst, a cocatalyst, and a chain shuttling agent. The process is characterized by formation of at least some of the growing polymer chains under differentiated process conditions in two or more reactors operating under steady state polymerization conditions or in two or more zones of a reactor operating under plug flow polymerization conditions. Suitable processes useful in producing the composites may be found in, e.g. example, U.S. Patent Nos. 8,053,529, 8,686,087, and 8,716,400. The polymerization may be carried out as a continuous polymerization, e.g., a continuous-solution polymerization, in which catalyst components, monomers, and optionally solvent, adjuvants, scavengers, and / or polymerization aids are continuously supplied to one or more reactors or zones and polymer product continuously removed therefrom. Within the scope of the terms “continuous” and “continuously” as used in this context are those processes in which there are intermittent additions of reactants and removal of products at small regular or irregular intervals, so that, over time, the overall process is substantially continuous. Further, a chain shuttling agent(s) may be added at any point during the polymerization including in a first reactor or zone, at the exit or slightly before the exit of the first reactor, between the first reactor or zone and a second or any subsequent reactor or zone, or even solely to the second or any subsequent reactor or zone. Exemplary chain shuttling agents, catalysts, and cocatalysts are those disclosed in, e.g., U.S. Patent No. 7,951,882. For example, chain shuttling agents that are dialkyl zinc compounds may be used.

[0036] The catalyst may be prepared as a homogeneous composition by addition of the requisite metal complex or multiple complexes to a solvent in which the polymerization will be conducted or in a diluent compatible with the ultimate reaction mixture. The desired cocatalyst or activator and, optionally, the shuttling agent may be combined with the catalyst 86143-WO-PCT / DOW 86143 WO composition either prior to, simultaneously with, or after combination of the catalyst with the monomers to be polymerized and any additional reaction diluent.

[0037] Due to the difference in monomers, temperatures, pressures, or other differences in polymerization conditions between at least two of the reactors or zones connected in series, polymer segments of differing composition such as comonomer content, crystallinity, density, tacticity, regio-regularity, or other chemical or physical difference, within the same molecule are formed in the different reactors or zones. The size of each segment or block is determined by continuous polymer reaction conditions, and preferably is a most probable distribution of polymer sizes. Each reactor in the series can be operated under high pressure, solution, slurry, or gas phase polymerization conditions.

[0038] EMBODIMENTS

[0039] Embodiments of the present disclosure are directed to crosslinkable polymer composition comprising a propylene-based polymer and either BiPheS phenylacrylate or BiPheS methacrylate with a coagent. The crosslinked compositions may be formed from a crosslinkable polymer composition comprising the propylene-based polymer, either BiPheS phenylacrylate or BiPheS methacrylate with a coagent, and a radical initiator. That is, the crosslinked composition may be the reaction product of crosslinking the crosslinkable polymer composition.

[0040] Propylene-based Polymer

[0041] Propylene-based polymer imparts desirable mechanical properties, heat stability, and chemical resistance to the crosslinkable polymer compositions described herein.

[0042] Nonlimiting examples of suitable propylene-based polymer may include polypropylene homopolymer, polypropylene-based elastomer, polypropylene-based block copolymer, propylene-based impact copolymer, and combinations thereof.

[0043] In embodiments, the propylene-based polymer comprises polypropylene homopolymer.

[0044] In embodiments, the propylene-based polymer comprises polypropylene-based elastomer. “Propylene-based elastomer” comprise at least one copolymer with at least about 50 weight percent of units derived from propylene and at least about 4 weight percent of units derived from a comonomer other than propylene. Suitable propylene-based elastomers are taught in US Patent Nos. 6,906,160; 6,919,407; 6,927,256; 6,960,535; 7,250,470; 7,250,471; 86143-WO-PCT / DOW 86143 WO and 7,344,775, each of which are incorporated by reference in their entireties. In embodiments, the propylene-based elastomer may comprise propylene-ethylene elastomer.

[0045] In embodiments, the propylene-based polymer may comprise a melt flow rate (MFR) from 0.1 g / 10 min to 50 g / 10 min, from 0.1 g / 10 min to 25 g / 10 min, from 0.1 g / 10 min to 10 g / 10 min, from 0.1 g / 10 min to 5 g / 10 min, from 1 g / 10 min to 50 g / 10 min, from 1 g / 10 min to 25 g / 10 min, from 1 g / 10 min to 10 g / 10 min, from 1 g / 10 min to 5 g / 10 min, from 10 g / 10 min to 50 g / 10 min, from 10 g / 10 min to 25 g / 10 min, or even from 25 g / 10 min to 50 g / 10 min, , or any and all sub-ranges formed from any of these endpoints.

[0046] In certain embodiments, the propylene-based polymer may comprise from 0.5 wt% to 20 wt% (e.g., from 0.5 wt% to 15 wt%, from 0.5 wt% to 10 wt%, from 0.5 wt% to 6 wt%, from 1.5 wt% to 3 wt, etc.) of a composite component comprising a block composite. In exemplary embodiments, the block composite may have a total ethylene content that is from 25 wt% to 70 wt% (e.g., from 25 wt% to 60 wt%, from 25 wt% to 55 wt%, and from 30 wt% to 50 wt%) based on the total weight of the block composite. The remainder of the total weight of the block composite may be accounted for by units derived from at least one C3- 10 alpha-olefin. For example, the remainder of the total weight of the block composite may be accounted for by units derived from propylene.

[0047] In exemplary embodiments, the block composite refers to polymers comprising an ethylene based polymer (EP) (soft copolymer) having an ethylene content of from 10 mol% to 90 mol%, an alpha-olefin based polymer (AOP) (hard copolymer) having an alpha-olefin content of greater than 90 mol%, and a block copolymer having an ethylene block / segment (EB) and an alpha-olefin block / segment (AOB), wherein the ethylene block of the block copolymer is the same composition as the ethylene based polymer of the block composite and the alpha-olefin block of the block copolymer is the same composition as the alpha-olefin based polymer of the block composite. The compositional split between the amount of ethylene based polymer and alpha-olefin based polymer will be essentially the same as that between the corresponding blocks in the block copolymer.

[0048] In further embodiments, the block composite refers to polymers comprising an EP having an ethylene content that is greater than 10 wt% and less than 95 wt%, an AOP having a propylene content that is greater than 90 wt% and up to 100 wt%, and a block copolymer (e.g., a diblock) having an EB (i.e., soft block) and an AOB (i.e., hard block), wherein the 86143-WO-PCT / DOW 86143 WO AOB of the block copolymer is the same composition as the AOP of the block composite and the EB of the block copolymer is the same composition as the EP of the block composite. The compositional split between the amount of EP and AOP will be essentially the same as that between the corresponding blocks in the block copolymer.

[0049] In exemplary embodiments, the hard blocks refer to highly crystalline blocks of polymerized alpha-olefin units (e.g., propylene). In the hard blocks, the monomer (i.e., propylene) may be present in an amount greater than 90 wt%. The remainder of the hard block may be the comonomer (e.g., ethylene) in an amount of less than 10 wt%. In exemplary embodiments, the hard blocks comprise all or substantially all propylene units, such as an iPP (isotactic) homopolymer block or an iPP copolymer block with less than 10 wt% of ethylene. In exemplary embodiments, the soft blocks refer to amorphous, substantially amorphous, or elastomeric blocks of polymerized ethylene units. In the soft blocks, the monomer (i.e., ethylene) may be present in an amount of greater than 20 wt% and equal to or less than 100 wt% (e.g., from 40 wt% to 99 wt%, from 45 wt% to 90 wt%, and / or from 50 wt% to 80 wt%). The remainder of the soft block may be the comonomer (e.g., propylene).

[0050] According to an exemplary embodiment, the block composite includes a block copolymer having 30-70 wt% hard block and 30-70 wt% soft block. In other words, the block composite includes a block copolymer having 30-70 wt% hard block and 30-70 wt% soft block based on the weight of the block copolymer.

[0051] According to an exemplary embodiment, the block copolymer of the block composite has the formula (EP)-(iPP), in which EP represents the soft block of polymerized ethylene and propylene monomeric units (e.g., 50-80 wt% of ethylene and remainder propylene) and iPP represents a hard block of isotactic propylene homopolymer or isotactic propylene copolymer (e.g., less than 10 wt% of ethylene and remainder propylene).

[0052] The block composites may include from 0.5 wt% to 95.0 wt% EP, from 0.5 to 95.0 wt% iPP, and from 5.0 wt% to 99.0 wt% of the block copolymer. Weight percents are based on total weight of block composite. The sum of the weight percents of EP, iPP, and the block copolymer equals 100%. An exemplary measurement of the relative amount of the block copolymer is referred to as the Block Composite Index (BCI), as further discussed below. The BCI for the block composite is greater than 0 and less than 1.0. 86143-WO-PCT / DOW 86143 WO

[0053] In some embodiments, the block composites may have a microstructure index greater than 1 and equal to or less than 20. The microstructure index is an estimation using solvent gradient interaction chromatography (SGIC) separation to differentiate between block copolymers from random copolymers. In particular, microstructure index estimation relies on differentiating between two fractions, i.e., a higher random copolymer content fraction and a higher block copolymer content fraction, of which the random copolymer and the block copolymer have essentially the same chemical composition. The early eluting fraction (i.e., the first fraction) correlates to random copolymers and the late eluting component (i.e., the second fraction) correlates to block copolymers. The calculation of the microstructure index is discussed below.

[0054] The block composites may have a weight average molecular weight (Mw) from 10,000 g / mol to 2,500,00 g / mol, from 35,000 g / mol to 1,000,000 g / mol, from 50,000 g / mol to 300,000 g / mol, and / or from 50,000 g / mol to 200,000 g / mol. For example, the Mw may be from 20 kg / mol to 1,000 kg / mol, from 50 kg / mol to 500 kg / mol, and / or from 80 kg / mol to 200 kg / mol. The molecular weight distribution (Mw / Mn) or polydispersity of the block composites may be less than 5, between 1 and 5, and / or between 1.5 and 4. Weight average molecular weight (Mw) and number average molecular weight (Mn) are well known in polymer art and can be determined by methods known to a person of ordinary skill in the art.

[0055] The melt flow rate (MFR) of the block composites may be from 0.1 g / 10 min to 1,000 g / 10 min measured in accordance with ASTM D-1238 (230°C; 2.16 kg). For example, the melt flow rate of the block composites may be from 1 g / 10 min to 50 g / 10 min, from 1 g / 10 min to 25 g / 10 min, from 3 g / 10 min to 15 g / 10 min, and / or from 5 g / 10 min to 10 g / 10 min.

[0056] The density of the block composites may be between 0.850 and 0.900 g / cc. In exemplary embodiments, the density of the block composites is from 0.860 to 0.895, from 0.865 to 0.895, and / or from 0.865 to 0.890 g / cc. Density is measured in accordance with ASTM D792.

[0057] The block composites may have a second peak Tm of greater than 90°C ( e.g., greater than 100°C). According to an exemplary embodiment, the block composites exhibit a second peak Tm in a range from 100°C to 150°C). 86143-WO-PCT / DOW 86143 WO

[0058] In certain embodiments, the propylene-based polymer may comprise from 0.5 wt% to 20 wt% (e.g., from 0.5 wt% to 15 wt%, from 0.5 wt% to 10 wt%, from 0.5 wt% to 6 wt%, from 1.5 wt% to 3 wt, etc.) of a composite component comprising a crystalline block composite. In exemplary embodiments, the crystalline block composite may have a total ethylene content that is from 40 wt% to 70 wt% based on the total weight of the crystalline block composite. The remainder of the total weight of the crystalline block composite may be accounted for by units derived from at least one C3-10 alpha-olefin. For example, the remainder of the total weight of the crystalline block composite may be accounted for by units derived from propylene.

[0059] The crystalline block composite (CBC) refers to polymers having a crystalline ethylene based polymer (CEP), a crystalline alpha-olefin based polymer (CAOP), and a block copolymer comprising a crystalline ethylene block / segment (CEB) and a crystalline alpha- olefin block / segment (CAOB), wherein the CEB of the block copolymer is the same composition as the CEP of the crystalline block composite and the CAOB of the block copolymer is the same composition as the CAOP of the crystalline block composite. Additionally, the compositional split between the amount of CEP and CAOP will be essentially the same as that between the corresponding blocks in the block copolymer.

[0060] The crystalline block composite (CBC) includes the crystalline ethylene based polymer (CEP), the crystalline alpha-olefin based polymer (CAOP), and the block copolymer having the crystalline ethylene block (CEB) and the crystalline alpha-olefin block (CAOB), where the CEB is the same composition as the CEP and the CAOB is the same composition as the CAOP. In the crystalline block composite, the alpha-olefin is at least one selected from the group of C3-10 α olefins (e.g., may be propylene and / or butylene). The CAOP and the CAOB may have an alpha-olefin content that is greater than 90 mol%. The CEP and CEB comprise greater than 90 mol% of units derived from ethylene (i.e., ethylene content), and any remainder may be at least one of selected from the group of C3-10 α –olefins as a comonomer (in an amount less than 10 mol%, less than 7 mol%, less than 5 mol%, less than 3 mol%, etc.).

[0061] In exemplary embodiments, the CAOP and CAOB include propylene, e.g., greater than 90 mol% units derived from propylene and any remainder may be ethylene and / or at least one of selected from the group of C4-10 α –olefins as a comonomer (in an amount less than 10 mol%, less than 7 mol%, less than 5 mol%, less than 4 mol%, less than 4 mol%, etc.). 86143-WO-PCT / DOW 86143 WO The CEP and CEB include ethylene, e.g., greater than 90 mol% units derived from ethylene and any remainder may be propylene and / or at least one of selected from the group of C4-10 α –olefins as a comonomer (in an amount less than 10 mol%, less than 7 mol%, less than 5 mol%, less than 4 mol%, less than 4 mol%, etc.). The compositional split between the amount of CEP and CAOP will be essentially the same as that between the corresponding blocks in the block copolymer. The CEB and the CAOB may be referred to as hard (crystalline) segments / blocks.

[0062] In exemplary embodiments, the CAOB refers to highly crystalline blocks of polymerized alpha olefin units in which units derived from the monomer that is one of C3- 10 α olefins are present in an amount greater than 90 mol%, greater than 93 mol%, greater than 95 mol%, and / or greater than 96 mol%. In other words, the comonomer content in the CAOB is less than 10 mol%, less than 7 mol%, less than 5 mol%, and / or less than 4 mol%. A CAOB with propylene crystallinity may have corresponding melting points that are 80°C and above, 100°C and above, 115°C and above, and / or 120°C and above. In some embodiments, the CAOB comprises all or substantially all propylene units. CEB refers to blocks of polymerized ethylene units in which the comonomer content (such as propylene) is 10 mol% or less, between 0 mol% and 10 mol%, between 0 mol% and 7 mol%, and / or between 0 mol% and 5 mol%. Said in another way, the CEB is derived from at least 90 mol% ethylene, greater than 90 mol% ethylene, greater than 93 mol% ethylene, and / or greater than 95 mol% ethylene. Such CEBs have corresponding melting points that may be 75°C and above, 90°C and above, and / or 100°C and above.

[0063] In an exemplary embodiment, the CAOB may refer to highly crystalline blocks of polymerized alpha olefin units in which the monomer that is one of C3-10 α olefins is present in an amount of at least 88 wt% and / or at least 90 wt%. In other words, the comonomer content in the CAOBs is less than 10 wt%. CEB may refer to blocks of polymerized ethylene units in which the comonomer content (such as propylene) is 10 wt% or less.

[0064] The crystalline block composite may include from 0.5 wt% to 95.0 wt% CEP, from 0.5 wt% to 95.0 wt% CAOP, and from 5.0 wt% to 99.0 wt% of the crystalline block copolymer. For example, the crystalline block composite may include from 5.0 wt% to 80.0 wt% CEP, from 5.0 wt% to 80.0 wt% CAOP, and from 20.0 wt% to 90.0 wt% of the crystalline block copolymer. Weight percents are based on total weight of crystalline block composite. The sum of the weight percents of CEP, CAOP, and the crystalline block 86143-WO-PCT / DOW 86143 WO copolymer equals 100%. An exemplary measurement of the relative amount of the crystalline block copolymer is referred to as the Crystalline Block Composite Index (CBCI). The CBCI for the crystalline block composite is greater than 0 and less than 1.0. For example, the CBCI is from 0.20 to 0.99, from 0.30 to 0.99, from 0.40 to 0.99, from 0.40 to 0.90, from 0.40 to 0.85, and / or from 0.50 to 0.80.

[0065] The crystalline block composite may have, a Tm greater than 90°C (e.g., for both a first peak and a second peak), a Tm greater than 100 °C (e.g., for both a first peak and a second peak), and / or greater than 120 °C (e.g., for at least one of a first peak and a second peak). For example, the Tm is in the range of from 100 °C to 250 °C, from 110 °C to 220 °C, and / or from 115 °C to 220 °C. According to an exemplary embodiment, the crystalline block composite exhibits a second peak Tm in a range from 100 °C to 130 °C (e.g., 100 °C to 120 °C, 100 °C to 110 °C, etc.) and a first peak Tm in a range from 110 °C to 150 °C (e.g., 110 °C to 140 °C, 115 °C to 130 °C, 115 °C to 125 °C, etc.), in which the second peak Tm is less than the first peak Tm.

[0066] The crystalline block composite may have a weight average molecular weight (Mw) from 10,000 g / mol to 2,500,000 g / mol, from 35000 g / mol to 1,000,000 g / mol, from 50,000 g / mol to 300,000 g / mol, and / or from 50,000 g / mol to 200,000 g / mol. For example, the Mw may be from 20 kg / mol to 1000 kg / mol, from 50 kg / mol to 500 kg / mol, and / or from 80 kg / mol to 125 kg / mol. The molecular weight distribution (Mw / Mn) or polydispersity of the crystalline block composites may be less than 5, between 1 and 5, and / or between 1.5 and 4. Weight average molecular weight (Mw) and number average molecular weight (Mn) are well known in polymer art and can be determined by methods known to a person of ordinary skill in the art.

[0067] The MFR (melt flow rate) of the crystalline block composites may be from 0.1 to 1000 dg / min (230°C / 2.16 kg), from 1 to 500 g / 10 min (230°C / 2.16 kg), from 3 to 30 g / 10 min (230°C / 2.16 kg), and / or from 5 to 11 g / 10 min (230°C / 2.16 kg).

[0068] In accordance with ASTM D792, the density of the crystalline block composite may be between 0.850 and 0.920 g / cc (e.g., from 0.860 g / cc to 0.915 g / cc, from 0.875 g / cc to 0.910 g / cc, and / or from 0.890 g / cc to 0.910 g / cc).

[0069] In embodiments, the propylene-based polymer comprises impact modified propylene-based copolymer. 86143-WO-PCT / DOW 86143 WO

[0070] In embodiments, the propylene-based polymer may comprise post consumer recycle polypropylene.

[0071] The crosslinkable polymer composition and the resulting crosslinked composition may comprise a minimum amount of propylene-based polymer (e.g., greater than or equal to 70 wt%) to ensure the crosslinked composition has desirable mechanical properties, heat stability, and chemical resistance. The amount of propylene-based polymer may be limited (e.g., less than or equal to 99 wt% or 98.5 wt%) to ensure that enough reversible crosslinker and, in some embodiments, coagent, is present to ensure a substantial network response upon crosslinking and reprocessability and / or recyclability of the crosslinked composition. Accordingly, in embodiments including BiPheS phenylacrylate, the crosslinkable polymer composition and the resulting crosslinked composition may comprise from 70 wt% to 99 wt% of the propylene-based polymer. In embodiments including BiPheS methacrylate, the crosslinkable polymer composition and the resulting crosslinked composition may comprise from 70 wt% to 98.5 wt% of the propylene-based polymer. In embodiments, the amount of propylene-based polymer in the crosslinkable polymer composition and the resulting crosslinked composition may be greater than or equal to 70 wt%, greater than or equal to 75 wt%, greater than or equal to 80 wt%, greater than or equal to 85 wt%, or even greater than or equal to 90 wt%. In embodiments, the amount of propylene-based polymer in the crosslinkable polymer composition and the resulting crosslinked composition may be less than or equal to 99 wt%, less than or equal to 98.5 wt%, less than or equal to 97 wt%, less than or equal to 95 wt%, less than or equal to 93 wt%, or even less than or equal to 91 wt%. In embodiments, the amount of propylene-based polymer in the crosslinkable polymer composition and the resulting crosslinked composition may be from 70 wt% to 99 wt%, from 70 wt% to 98.5 wt%, from 70 wt% to 97 wt%, from 70 wt% to 95 wt%, from 70 wt% to 93 wt%, from 70 wt% to 91 wt%, from 75 wt% to 99 wt%, from 75 wt% to 98.5 wt%, from 75 wt% to 97 wt%, from 75 wt% to 95 wt%, from 75 wt% to 93 wt%, from 75 wt% to 91 wt%, from 80 wt% to 99 wt%, from 80 wt% to 98.5 wt%, from 80 wt% to 97 wt%, from 80 wt% to 95 wt%, from 80 wt% to 93 wt%, from 80 wt% to 91 wt%, from 85 wt% to 99 wt%, from 85 wt% to 98.5 wt%, from 85 wt% to 97 wt%, from 85 wt% to 95 wt%, from 85 wt% to 93 wt%, from 85 wt% to 91 wt%, from 90 wt% to 99 wt%, from 90 wt% to 98.5 wt%, from 90 wt% to 97 wt%, from 90 wt% to 95 wt%, from 90 wt% to 93 wt%, or even from 90 wt% to 91 wt%, or any and all sub-ranges formed from any of these endpoints. 86143-WO-PCT / DOW 86143 WO

[0072] Reversible Crosslinker

[0073] As described in further detail below, reversible crosslinker, such as BiPheS phenylacrylate or BiPheS methacrylate with a coagent, ensures a substantial network response upon crosslinking and imparts reprocessability and / or recyclability to the crosslinked composition.

[0074] In embodiments, the crosslinkable polymer composition and the resulting crosslinked composition may comprise BiPheS phenylacrylate. BiPheS phenylacrylate has Structure 1 shown below:

[0075] As mentioned hereinabove, conventional processes, such as radical processes, to crosslink propylene-based polymers made lead to difficulties, such as chain scission that occurs in the presence of radicals. Crosslinking of propylene-based polymers may be established by increasing the grafting yield while reducing chain scission if tertiary radicals propagate to and are stabilized by a vinyl crosslinker prior to chain scission. As shown in Structure 1, BiPheS phenylacrylate includes a phenyl ring adjacent to the vinyl group, which may increase reactivity toward a tertiary carbon radical by stronger stabilization energy via resonance, thereby preventing chain scission.

[0076] In other embodiments, the crosslinkable polymer composition and the resulting crosslinked composition may comprise BiPheS methacrylate. BiPheS methacrylate has Structure 2 shown below: STRUCTURE 2 86143-WO-PCT / DOW 86143 WO

[0077] Compared to BiPheS phenylacrylate, which bears a styrene-like substructure for resonance stabilization, as described herein, BiPheS methacrylate has less resonance stabilization and, therefore, has lower reactivity toward a tertiary radical. As such, a coagent may be added to help improve reactive toward a tertiary radical, thereby preventing chain scission.

[0078] The crosslinkable polymer composition and the resulting crosslinked composition may comprise a minimum amount of BiPheS phenylacrylate or BiPheS methacrylate (e.g., greater than or equal to 1 wt%) to ensure a substantial network response upon crosslinking and impart reprocessability and / or recyclability to the crosslinked composition. The amount of BiPheS phenylacrylate or BiPheS methacrylate may be limited (e.g., less than or equal to 20 wt%) to prevent undesirable aggregation or homopolymerization of the reversible crosslinker rather than contributing to the network structure, which may lead to undesirable properties. Accordingly, in embodiments, the crosslinkable polymer composition and the resulting crosslinked composition may comprise from 1 wt% to 20 wt% of the BiPheS phenylacrylate or the BiPheS methacrylate. In embodiments, the amount of the BiPheS phenylacrylate or the BiPheS methacrylate in the crosslinkable polymer composition and the resulting crosslinked composition may be greater than or equal to 1 wt%, greater than or equal to 1.5 wt%, greater than or equal to 2 wt%, greater than or equal to 2.5 wt%, greater than or equal to 3 wt%, or even greater than or equal to 3.5 wt%. In embodiments, the amount of the BiPheS phenylacrylate or the BiPheS methacrylate in the crosslinkable polymer composition and the resulting crosslinked composition may be less than or equal to 20 wt%, less than or equal to 15 wt%, less than or equal to 10 wt%, less than or equal to 9 wt%, less than or equal to 8 wt%, less than or equal to 7 wt%, less than or equal to 6 wt%, less than or equal to 5 wt%, or even less than or equal to 4 wt%. In embodiments, the amount of the amount of the BiPheS phenylacrylate or the BiPheS methacrylate in the crosslinkable polymer composition and the resulting crosslinked composition may be from 1 wt% to 20 wt%, from 1 wt% to 15 wt%, from 1 wt% to 10 wt%, from 1 wt% to 9 wt%, from 1 wt% to 8 wt%, from 1 wt% to 7 wt%, from 1 wt% to 6 wt%, from 1 wt% to 5 wt%, from 1 wt% to 4 wt%, from 1.5 wt% to 20 wt%, from 1.5 wt% to 15 wt%, from 1.5 wt% to 10 wt%, from 1.5 wt% to 9 wt%, from 1.5 wt% to 8 wt%, from 1.5 wt% to 7 wt%, from 1.5 wt% to 6 wt%, 86143-WO-PCT / DOW 86143 WO from 1.5 wt% to 5 wt%, from 1.5 wt% to 4 wt%, from 2 wt% to 20 wt%, from 2 wt% to 15 wt%, from 2 wt% to 10 wt%, from 2 wt% to 9 wt%, from 2 wt% to 8 wt%, from 2 wt% to 7 wt%, from 2 wt% to 6 wt%, from 2 wt% to 5 wt%, from 2 wt% to 4 wt%, from 2.5 wt% to 20 wt%, from 2.5 wt% to 15 wt%, from 2.5 wt% to 10 wt%, from 2.5 wt% to 9 wt%, from 2.5 wt% to 8 wt%, from 2.5 wt% to 7 wt%, from 2.5 wt% to 6 wt%, from 2.5 wt% to 5 wt%, from 2.5 wt% to 4 wt%, from 3 wt% to 20 wt%, from 3 wt% to 15 wt%, from 3 wt% to 10 wt%, from 3 wt% to 9 wt%, from 3 wt% to 8 wt%, from 3 wt% to 7 wt%, from 3 wt% to 6 wt%, from 3 wt% to 5 wt%, from 3 wt% to 4 wt%, from 3.5 wt% to 20 wt%, from 3.5 wt% to 15 wt%, from 3.5 wt% to 10 wt%, from 3.5 wt% to 9 wt%, from 3.5 wt% to 8 wt%, from 3.5 wt% to 7 wt%, from 3.5 wt% to 6 wt%, from 3.5 wt% to 5 wt%, from 3.5 wt% to 4 wt%, or any and all sub-ranges formed from any of these endpoints.

[0079] Coagent

[0080] As described herein, BiPheS methacrylate has relatively low resonance stabilization and a relatively low reactivity toward a tertiary radical. As such, a coagent may be added to help improve reactive toward a tertiary radical, thereby preventing chain scission.

[0081] In embodiments, the coagent may comprise styrene; divinyl benzene; 1,1,1- trimethylolpropane trimethacrylate; pentaerythrityl tetramethacrylate (PETM); trimethylolpropanetiacrylate (TMPTA); pentaerythritol tetraacrylate (PETA); pentaerythritol tetrallyl ether; diallyl maleate; triallyl cyanurate; diallyl itaconate; triallylisocyanurate (TAIC); or a combination thereof. In embodiments, the coagent may comprise styrene, pentaerythritol tetraacrylate (PETA), or a combination thereof.

[0082] Coagents, like styrene and divinyl benzene, may be included to propagate tertiary radicals and provide resonance stabilization to prevent chain scission. Coagents, like 1,1,1- trimethylolpropane trimethacrylate; PETM; TMPTA; PETA; pentaerythritol tetrallyl ether; diallyl maleate; triallyl cyanurate; diallyl itaconate; and TAIC, may be included to increase crosslink density by establishing permanent crosslinks alongside dynamic crosslinks provided by BiPheS methacrylate and other coagents, like styrene and divinyl benzene.

[0083] The crosslinkable polymer composition and the resulting crosslinked composition may comprise a minimum amount of coagent (e.g., greater than or equal to 0.5 wt%) to prevent chain scission and / or increase crosslink density. The amount of the coagent may be limited (e.g., less than or equal to 15 wt%) to ensure a sufficient amount of propylene-based 86143-WO-PCT / DOW 86143 WO polymer is present to achieve desired results. Accordingly, in embodiments, the crosslinkable polymer composition and the resulting crosslinked composition may comprise from 0.5 wt% to 15 wt% of the coagent. In embodiments, the amount of the coagent in the crosslinkable polymer composition and the resulting crosslinked composition may be greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 3 wt%, greater than or equal to 4 wt%, or even greater than or equal to 5 wt%. In embodiments, the amount of the coagent in the crosslinkable polymer composition and the resulting crosslinked composition may be less than or equal to 15 wt%, less than or equal to 10 wt%, less than or equal to 9 wt%, less than or equal to 8 wt%, less than or equal to 7 wt%, or even less than or equal to 6 wt%. In embodiments, the amount of the coagent in the crosslinkable polymer composition and the resulting crosslinked composition may be from 0.5 wt% to 15 wt%, from 0.5 wt% to 10 wt%, from 0.5 wt% to 9 wt%, from 0.5 wt% to 8 wt%, from 0.5 wt% to 7 wt%, from 0.5 wt% to 6 wt%, from 1 wt% to 15 wt%, from 1 wt% to 10 wt%, from 1 wt% to 9 wt%, from 1 wt% to 8 wt%, from 1 wt% to 7 wt%, from 1 wt% to 6 wt%, from 2 wt% to 15 wt%, from 2 wt% to 10 wt%, from 2 wt% to 9 wt%, from 2 wt% to 8 wt%, from 2 wt% to 7 wt%, from 2 wt% to 6 wt%, from 3 wt% to 15 wt%, from 3 wt% to 10 wt%, from 3 wt% to 9 wt%, from 3 wt% to 8 wt%, from 3 wt% to 7 wt%, from 3 wt% to 6 wt%, from 4 wt% to 15 wt%, from 4 wt% to 10 wt%, from 4 wt% to 9 wt%, from 4 wt% to 8 wt%, from 4 wt% to 7 wt%, from 4 wt% to 6 wt%, from 5 wt% to 15 wt%, from 5 wt% to 10 wt%, from 5 wt% to 9 wt%, from 5 wt% to 8 wt%, from 5 wt% to 7 wt%, or even from 5 wt% to 6 wt%, or any and all sub-ranges formed from any of these endpoints.

[0084] Free Radical Initiator

[0085] Free radical initiator enables crosslinking of the crosslinkable polymer composition, thereby forming the crosslinked composition. The free radical initiator decomposes whereby forming free radicals and the reaction of primary radicals with polymer composition.

[0086] In embodiments, the free radical initiator may comprise an organic peroxide. Nonlimiting examples of suitable organic peroxide include bis(1,1-dimethylethyl) peroxide; bis(1,1-dimethylpropyl) peroxide; 2,5-dimethyl-2,5-bis(1,1-dimethylethylperoxy) hexane; 2,5-dimethyl-2,5-bis(1,1-dimethylethylperoxy) hexyne; 4,4-bis(1,1-dimethylethylperoxy) valeric acid; butyl ester; 1,1-bis(1,1-dimethylethylperoxy)-3,3,5-trimethylcyclohexane; benzoyl peroxide; tert-butyl peroxybenzoate; di-tert-amyl peroxide (“DTAP”), bis(α-t-butyl- peroxyisopropyl) benzene (“BIBP”); isopropylcymyl t-butyl peroxide; t- 86143-WO-PCT / DOW 86143 WO butylcumylperoxide; di-t-butyl peroxide; 2,5-bis(t-butylperoxy)-2,5-dimethylhexane; 2,5- bis(tbutylperoxy)-2,5-dimethylhexyne-3,1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane; isopropylcumyl cumylperoxide; butyl 4,4-di(tert-butylperoxy) valerate; di(isopropylcumyl) peroxide; dicumyl peroxide, and combinations thereof. In embodiments, the free radical initiator may comprise dicumyl peroxide.

[0087] The crosslinkable polymer composition may comprise a minimum amount of free radical initiator (e.g., greater than or equal to 0.5 wt%) to initiate crosslinking of the crosslinkable polymer composition. The amount of the free radical initiator may be limited (e.g., less than or equal to 10 wt%) to prevent formation of permanent crosslinks incapable of dynamic chemistry. Accordingly, in embodiments, the crosslinkable polymer composition may comprise from 0.5 wt% to 10 wt% free radical initiator. In embodiments, the amount of the free radical initiator in the crosslinkable polymer composition may be greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, or even greater than or equal to 3 wt. In embodiments, the amount of the free radical initiator in the crosslinkable polymer composition may be less than or equal to 10 wt%, less than or equal to 8 wt%, less than or equal to 6 wt%, or even less than or equal to 4 wt%. In embodiments, the amount of the free radical initiator in the crosslinkable polymer composition may be from 0.5 wt% to 10 wt%, from 0.5 wt% to 8 wt%, from 0.5 wt% to 6 wt%, from 0.5 wt% to 4 wt%, from 1 wt% to 10 wt%, from 1 wt% to 8 wt%, from 1 wt% to 6 wt%, from 1 wt% to 4 wt%, from 2 wt% to 10 wt%, from 2 wt% to 8 wt%, from 2 wt% to 6 wt%, from 2 wt% to 4 wt%, from 3 wt% to 10 wt%, from 3 wt% to 8 wt%, from 0.5 wt% to 6 wt%, or even from 3 wt% to 4 wt%, or any and all sub-ranges formed from any of these endpoints.

[0088] Blend Component

[0089] In embodiments, the crosslinkable polymer composition and / or the crosslinked composition includes a blend component. Nonlimiting examples of suitable blend component include ethylene vinyl acetate (EVA), polyolefins (e.g., polypropylene other than the propylene-based polymer crosslinked with reversible crosslinker and polyethylene), polymers (e.g., polystyrene, ABS, SBS and the like) and combinations thereof. Non-limiting examples of suitable polyolefins include polyethylene; polypropylene; polybutylene (e.g., polybutene-1); polypentene-1; polyhexene-1; polyoctene-1; polydecene-1; poly-3- methylbutene-1; poly-4-methylpentene-l; polyisoprene; polybutadiene; poly-1,5-hexadiene; 86143-WO-PCT / DOW 86143 WO interpolymers derived from olefins; interpolymers derived from olefins and other polymers such as polyvinyl chloride, polystyrene, and polyurethane; and combinations thereof.

[0090] In an embodiment, the polyolefin is a homopolymer such as polyethylene, polypropylene, polybutylene, polypentene-1, poly-3-methylbutene-1, poly-4-methylpentene- 1, polyisoprene, polybutadiene, poly-1,5-hexadiene, polyhexene-1, polyoctene-1 and polydecene-1.

[0091] Nonlimiting example of suitable polypropylene as a blend component (other than the propylene-based polymer that is crosslinked with reversible crosslinker) include low density polypropylene (LDPP), high density polypropylene (HDPP), high-melt strength polypropylene (HMS-PP) and combination thereof. Nonlimiting examples of polyethylene include ultra low density polyethylene (ULDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), high molecular weight high density polyethylene (HMW-HDPE), ultra high molecular weight polyethylene (UHMW-PE) and combinations thereof. In an embodiment, the blend component is a high-melt strength polypropylene (HMS-PP), a low density polyethylene (LDPE) or a combination thereof.

[0092] Additives

[0093] The crosslinkable composition and / or the crosslinked composition may contain one or more optional additives. Nonlimiting examples of suitable additives include grafting initiators, cross-linking catalysts, blowing agent, blowing agent activators (e.g., zinc oxide, zinc stearate and the like), coagents (e.g., triallyl cyanurate), plasticizers, processing oils, processing aids, carbon black, colorants or pigments, stability control agents, nucleating agents, fillers, antioxidants, acid scavengers, ultraviolet (UV) stabilizers, flame retardants, lubricants, processing aids, extrusion aids, and combinations thereof. When present, the total amount of additive can be from greater than 0% to 80%, or from 0.001% to 70%, or from 0.01% to 60 %, or from 0.1 % to 50 %, or from 0.1 % to 40%, or from 0.1% to 20%, or from 0.1 % to 10 %, or from 0.1% to 5% of the total weight of the composition.

[0094] In embodiments, the crosslinkable composition and / or the crosslinked composition includes an antioxidant. Non-limiting examples of suitable antioxidants include aromatic or hindered amines such as alkyl diphenylamines, phenyl-a-naphthylamine, alkyl or aralkyl substituted phenyl-a-naphthylamine, alkylated p-phenylene diamines, tetramethyl- 86143-WO-PCT / DOW 86143 WO diaminodiphenylamine and the like; phenols such as 2,6-di-t-butyl-4-methylphenol; 1,3,5- trimethyl-2,4,6-tris(3',5,-di-t-butyl-4,-hydroxybenzyl)benzene; tetrakis[(methylene(3,5 -di-t- buty1-4-hydroxyhydrocinnamate)]methane (e.g., IRGANOX™ 1010, from Ciba Geigy, NewYork); acryloyl modified phenols; octadecyl-3,5- di-t-butyl-4-hydroxycinnamate (e.g., IRGANOX 1076, commercially available from Ciba Geigy); phosphites and phosphonites; hydroxylamines; benzofuranone derivatives; and combinations thereof. When used, the amount of the antioxidant in the composition can be from greater than 0 to 5%, or from 0.0001 to 2.5%, or from 0.001 to 1%, or from 0.001 to 0.5% of the total weight of the composition.

[0095] In embodiments, the crosslinkable composition and / or the crosslinked composition includes a UV stabilizer. Non-limiting examples of suitable UV stabilizers include benzophenones, benzotriazoles, aryl esters, oxanilides, acrylic esters, formamidines, carbon black, hindered amines, nickel quenchers, hindered amines, phenolic antioxidants, metallic salts, zinc compounds and combinations thereof. When used, the amount of the UV stabilizer can be from greater than 0 to 5%, or from 0.01 % to 3 %, or from 0.1 % to 2 %, or from 0.1% to 1% of the total weight of the composition.

[0096] In embodiments, the crosslinkable composition and / or the crosslinked composition includes a colorant or a pigment. Non-limiting examples of suitable colorants or pigments include inorganic pigments such as metal oxides such as iron oxide, zinc oxide, and titanium dioxide, mixed metal oxides, carbon black, organic pigments such as anthraquinones, anthanthrones, azo and monoazo compounds, arylamides, benzimidazolones, BONA lakes, diketopyrrolo-pyrroles, dioxazines, disazo compounds, diarylide compounds, flavanthrones, indanthrones, isoindolinones, isoindolines, metal complexes, monoazo salts, naphthols, b- naphthols, naphthol AS, naphthol lakes, perylenes, perinones, phthalocyanines, pyranthrones, quinacridones, and quinophthalones, and combinations thereof. When used, the amount of the colorant or pigment in the composition can be from greater than 0 to 10%, or from 0.1% to 5 %, or from 0.25% to 2% of the total weight of the composition.

[0097] In embodiments, the crosslinkable composition and / or the crosslinked composition includes a filler. Nonlimiting examples of suitable fillers include talc, calcium carbonate, chalk, calcium sulfate, clay, kaolin, silica, glass, fumed silica, mica, wollastonite, feldspar, aluminum silicate, calcium silicate, alumina, hydrated alumina such as alumina trihydrate, glass microsphere, ceramic microsphere, thermoplastic microsphere, barite, wood flour, glass fibers, carbon fibers, marble dust, cement dust, magnesium oxide, magnesium 86143-WO-PCT / DOW 86143 WO hydroxide, antimony oxide, zinc oxide, barium sulfate, titanium dioxide, titanates and combinations thereof.

[0098] In embodiments, the filler is barium sulfate, talc, calcium carbonate, silica, glass, glass fiber, alumina, titanium dioxide, or a mixture thereof. In a further embodiment, the filler is talc, calcium carbonate, barium sulfate, glass fiber or a mixture thereof. When used, the amount of the filler in the composition can be from greater than 0 to 80%, or from 0.1 to 60%, or from 0.5 to 40%, or from 1 to 30%, or from 10 to 40% of the total weight of the composition.

[0099] In embodiments, the crosslinkable composition and / or the crosslinked composition includes a lubricant. Nonlimiting examples of suitable lubricants include fatty alcohols and their dicarboxylic acid esters, fatty acid esters of short chain alcohols, fatty acids, fatty acid amides, metal soaps, oligomeric fatty acid esters, fatty acid esters of long-chain alcohols, montan waxes, polyethylene waxes, polypropylene waxes, natural and synthetic paraffin waxes, fluoropolymers and combinations thereof. When used, the amount of the lubricant in the composition can be from greater than 0% to 5%, or from 0.1 to 4%, or from 0.1% to 3% of the total weight of the composition.

[0100] In embodiments, the crosslinkable composition and / or the crosslinked composition includes an antistatic agent. Non-limiting examples of suitable antistatic agents include conductive fillers (e.g., carbon black, metal particles and other conductive particles), fatty acid esters (e.g., glycerol monostearate), ethoxylated alkylamines, diethanolamides, ethoxylated alcohols, alkylsulfonates, alkylphosphates, quaternary ammonium salts, alkylbetaines and combinations thereof. Where used, the amount of the antistatic agent in the composition can be from greater than 0 % to 5 %, or from 0.01 to 3 %, or from 0.1 to 2 % of the total weight of the composition.

[0101] In embodiments, the crosslinkable composition and / or the crosslinked composition includes a blowing agent. A "blowing agent" is a substance that is capable of producing a cellular structure in the composition via a foaming process. The blowing agent is used for foaming the crosslinked composition. Nonlimiting examples of suitable blowing agent include an inorganic physical blowing agent, such as air, argon, nitrogen, carbon dioxide, argon, helium, oxygen, and neon, and an organic physical blowing agent, such as an aliphatic hydrocarbon, e.g., propane, n- butane, isobutane, n-pentane, isopentane, and n-hexane, an 86143-WO-PCT / DOW 86143 WO alicyclic hydrocarbon, e.g., cyclohexane and cyclopentane, a halogenated hydrocarbon, e.g., chlorofluoromethane, trifluoromethane, 1,1-difluoroethane, 1,1,1,2-tetrafluoroethane, methyl chloride, ethyl chloride, and methylene chloride, and a dialkyl ether, e.g., dimethyl ether, diethyl ether, and methyl ethyl ether.

[0102] Non-limiting examples of suitable organic blowing agents include aliphatic hydrocarbons having 1-6 carbon atoms, aliphatic alcohols having 1-3 carbon atoms, and fully and partially halogenated aliphatic hydrocarbons having 1-4 carbon atoms. Non-limiting examples of suitable aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n- pentane, isopentane, neopentane, and the like. Non-limiting examples of suitable aliphatic alcohols include methanol, ethanol, n-propanol, and isopropanol. Non- limiting examples of suitable fully and partially halogenated aliphatic hydrocarbons include fluorocarbons, chlorocarbons, and chlorofluorocarbons. Non-limiting examples of suitable fluorocarbons include methyl fluoride, perfluoromethane, ethyl fluoride, 1,1-difluoroethane (HFC152a), 1,1,1- trifluoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane, difluoromethane, perfluoroethane, 2,2-difluoropropane, 1,1,1- trifluoropropane, perfluoropropane, dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane. Non-limiting examples of suitable partially halogenated chlorocarbons and chlorofluorocarbons include methyl chloride, methylene chloride, ethyl chloride, 1,1,1-trichloroethane, 1,1-dichloro- 1-fluoroethane (HCFC-141b), l-chloro- l,ldifluoroethane (HCFC-142b), l,l-dichloro-2,2,2- trifluoroethane (HCFC-123) and l-chloro- l,2,2,2-tetrafluoroethane(HCFC-124). Non-limiting examples of suitable fully halogenated chlorofluorocarbons include trichloromonofluoromethane (OPOI 1}, dichlorodifluoromethane (CFO-12}, trichlorotrifluoroethane (CFO-113), 1,1,1- trifluoroethane, pentafluoroethane, dichlorotetrafluoroethane (CFO-114), chloroheptafluoropropane, and dichlorohexafluoropropane. Non-limiting examples of suitable chemical blowing agents include azodicarbonamide, azodiisobutyro- nitrile, benezenesulfonhydrazide, 4,4-oxybenzene sulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, barium azodicarboxylate, N,N'- dimethyl-N,N'- dinitrosoterephthalamide, and trihydrazino triazine.

[0103] Crosslinked Composition

[0104] The crosslinkable polymer compositions as described herein, including an propylene-based polymer and either BiPheS phenylacrylate or BiPheS methacrylate with a 86143-WO-PCT / DOW 86143 WO coagent, may be melt blended at a temperature from 100 °C to 250 °C, from 120 °C to 200 °C, from 120 °C to 180 °C, or from 120 °C to 160 °C to trigger a crosslinking reaction and form the crosslinked composition.

[0105] In embodiments, the propylene-based polymer of the crosslinked composition may form a polymer backbone and the BiPheS phenylacrylate or BiPheS methacrylate along with a coagent may be grafted onto the polymer backbone. The crosslinked composition may include disulfide linkages formed from the BiPheS phenylacrylate or BiPheS methacrylate by way of the crosslinking reaction, the disulfide linkages formed from BiPheS phenylacrylate shown in Structure 3 below and the disulfide linkage formed from BiPheS methacrylate shown in Structure 4 below.

[0106] The term (and structure) “Pm” in Structures 3 and 4 above refers to the chain of polymerized propylene (and optional comonomer(s)) for the propylene-based polymer.

[0107] The properties of the crosslinked composition may be evaluated at an elevated temperature greater than the melting temperature of the propylene-based polymer (e.g., 180 °C). Properties of the crosslinked composition at the elevated temperature may be more indicative of crosslinking as the propylene-based polymer will have already melted at the elevated temperature. Properties evaluated at a relatively lower temperature less than the melting temperature of the propylene-based polymer (e.g., 100 °C) may capture both the propylene-based polymer and the crosslinking. 86143-WO-PCT / DOW 86143 WO

[0108] The crosslinked composition may provide a substantial network response upon crosslinking (e.g., E' at 180 °C greater than or equal to 0.01 MPa). In embodiments, the crosslinked composition may comprise E' at 180 °C greater than or equal to 0.01 MPa, greater than or equal to 0.05 MPa, greater than or equal to 0.1 MPa, greater than or equal 0.2 MPa, greater than or equal to 0.3 MPa, or even greater than 0.4 MPa.

[0109] Damping ratio (tan δ) at 180 °C is similarly indicative of crosslinking, with a relatively larger presence of crosslinks corresponding to a relatively lower tan δ at 180 °C (e.g., less than 0.50). In embodiments, the crosslinked composition may comprise tan δ at 180 °C less than 0.50, less than 0.45, less than 0.40, less than 0.35, or even less than 0.30.

[0110] In embodiments, the crosslinked composition may comprise E' at 100 °C greater than or equal to 1, greater than or equal to 5, greater than or equal to 10, greater than or equal to 25, greater than or equal to 50, greater than or equal to 100, or even greater than or equal to 150.

[0111] In embodiments, the crosslinked composition may comprise tan δ at 100 °C less than 0.25, less than 0.23, less than 0.21, less than 0.19, less than 0.17, or even less than 0.15.

[0112] In embodiments, the propylene-based polymer may comprise a virgin propylene- based polymer. “Virgin propylene-based polymer,” as used herein, is a propylene-based polymer that has not been subjected to crosslinking reaction. That is, “virgin propylene- based polymer” refers to the propylene-based polymer that is present in the crosslinkable polymer composition and the resulting crosslinked composition prior to the propylene-based polymer being crosslinked with the BiPheS phenylacrylate or the BiPheS methacrylate with the coagent. The virgin propylene-based polymer is the propylene -based polymer prior to crosslinking, the crosslinked composition containing the same propylene -based polymer that was virgin, but is now crosslinked with the BiPheS phenylacrylate or the BiPheS methacrylate with the coagent. In this way, the virgin propylene-based polymer may serve as a baseline to evaluate properties of the crosslinked composition.

[0113] In embodiments, the crosslinked composition may comprise E' at 180 °C that is greater than the E' for the virgin propylene-based polymer at 180 °C, due to the increased crosslinking. Similarly, in embodiments, the crosslinked composition may comprise tan δ at 180 °C that is less than the tan δ value of the virgin propylene-based polymer at 180 °C. 86143-WO-PCT / DOW 86143 WO

[0114] In embodiments, the crosslinked composition may comprise E' at 100 °C that is about equal to the E' for the virgin propylene-based polymer at 100 °C, due to the change in crystallinity after dynamic crosslinking and processing compared to the virgin polymers. E' at 100 °C of the crosslinked composition may be slightly smaller (decrease in crystallinity will decrease E' below the melt transition despite enhancement from crosslinking) or slightly larger (crystallinity is marginally affected and crosslinking enhances E') as compared to the virgin propylene-based polymer. In embodiments, the crosslinked composition may comprise tan δ at 100 °C that is less than the tan δ value of the virgin propylene-based polymer at 100 °C.

[0115] Reprocessability and / or Recyclability

[0116] The dynamic crosslinker BiPheS phenylacrylate or BiPheS methacrylate enables a cyclic “reprocessing” for fabrication of new polymeric articles or molds. The aromatic disulfide bonds of BiPheS phenylacrylate and BiPheS methacrylate are mostly associative in nature and, thus, crosslinked compositions containing them retain their crosslinked nature at the reprocessing temperature. More specifically, when the crosslinked propylene-based polymer composition is heated to the reprocessing temperature, a relatively small amount of the disulfide linkages break, or otherwise cleave, into sulfur radicals. The sulfur radicals interchange with still-existing disulfide linkages to simultaneously “swap in” the radical to become a new partner and eject one of the old partners as a new radical. The new radical can then interact with other linkages for further bond exchange, enabling reprocessing. This may be referred to as a “[2+1] radical mediated mechanism.”

[0117] The cleaving and interchange that occurs at the reprocessing temperature enables the previously-crosslinked propylene-based polymer composition to flow at the reprocessing temperature, forming a reprocessable propylene-based composition. Heating to the reprocessing temperature enables link interchange and polymer chain flow, allowing the propylene-based composition to be reshaped readily. At the reprocessing temperature, the reprocessable propylene-based polymer composition is flowable, enabling shaping and / or fabrication of the now flowable re-processable propylene composition (with BiPheS phenylacrylate or BiPheS methacrylate with coagent) into a new pre-form or article. Upon cooling to below the reprocessing temperature, the disulfide linkages essentially become static, the network is re-established, and the re-crosslinked propylene-based composition is formed in the new article configuration with a return to the high viscosity (no flow at room 86143-WO-PCT / DOW 86143 WO temperature) and resistance to mechanical deformation indicative of the crosslinked network. When the newly-formed article of the reprocessable propylene-based polymer composition is cooled below the reprocessing temperature, the disulfide linkages in the re-processable propylene-based polymer composition are fully reestablished and the propylene-based polymer (with BiPheS phenylacrylate or BiPheS methacrylate with coagent) becomes a recrosslinked propylene-based polymer composition in the shape of the newly-fabricated article. Below the reprocessing temperature, the network disulfide linkages are stable, and the recrosslinked propylene-based polymer composition exhibits the high viscosity and resistance to mechanical deformation indicative of a crosslinked network. This cycle of crosslink / reprocess / re-crosslink and fabrication into a new article can be repeated.

[0118] Bounded by no particular theory, the number of “reprocessing” cycles that are possible with the present crosslinked propylene-based composition (before competitive thermal and oxidative permanent crosslinking occurs and prevents further reprocessing), can be determined by calculating the ratio of the melt viscosity of the crosslinked propylene- based polymer composition before and after a reprocessing cycle. For the crosslinked propylene-based polymer composition to be re-processable, the ratio of the Mooney viscosity after reprocessing to the Mooney viscosity before reprocessing is from 0.5 to 5, or from 0.7 to 3 or from 0.9 to 2 or from 0.95 to 1.2.

[0119] Other metrics for monitoring the number of “reprocessing” cycles that are possible with the BiPheS phenylacrylate or BiPheS methacrylate dynamic crosslinkers before competitive oxidative permanent crosslinking occurs include visual observation. Formed film that is mechanically deformed is heated to the reprocessing temperature and is visually inspected to determine whether the mechanically deformed film heals to form a stable film. This metric of re-processability is noted in Table 2 below.

[0120] In embodiments, a process may comprise heating a first article to a reprocessing temperature; forming, at the reprocessing temperature, the first article into a re-processable propylene-based polymer composition; shaping, at the reprocessing temperature, the re- processable propylene-based composition into a re-processed pre-form; cooling the re- processed pre-form to below the reprocessing temperature; and forming a second article, the second article comprising a re-crosslinked composition. The second article may be different from the first article. 86143-WO-PCT / DOW 86143 WO

[0121] In embodiments, the reprocessing temperature may be from 100 °C to 250 °C, thereby breaking disulfide linkages of the cross-linked composition and forming the reprocessable propylene-based polymer composition. In embodiments, the reprocessing temperature may be from 100 °C to 250 °C, from 100 °C to 225 °C, from 100 °C to 200 °C, from 100 °C to 175 °C, from 130 °C to 250 °C, from 130 °C to 225 °C, from 130 °C to 200 °C, from 130 °C to 175 °C, from 160 °C to 250 °C, from 160 °C to 225 °C, from 160 °C to 200 °C, from 160 °C to 175 °C, from 190 °C to 250 °C, from 190 °C to 225 °C, or even from 190 °C to 200 °C, from 100 °C to 175 °C, or any and all sub-ranges formed from any of these endpoints.

[0122] In embodiments, the shaping step is a procedure selected from the group consisting of injection molding, extrusion molding, thermoforming, slushmolding, over molding, insert molding, blow molding, cast molding, tentering, compression molding, and combinations thereof.

[0123] In embodiments, the crosslinked composition recovers its storage modulus after successive molding cycles (e.g., E' at 180 °C of 2ndmold greater than or about equal to E' at 180 °C of 1stmold) thereby providing a reprocessable and / or recyclable crosslinked propylene-based polymer. The crosslinked composition of the second article and of successive articles may have the same or similar E' at 180 °C, tan δ at 180 °C, E' at 100 °C, and / or tan δ at 100 °C as described hereinabove with respect to the crosslinked composition.

[0124] Nonlimiting examples of suitable articles (first article and second article) for the present crosslinked / re-crosslinked propylene-based polymer (with BiPheS phenylacrylate or BiPheS methacrylate) composition include elastic film; elastic fiber; soft touch good, such as tooth brush handles and appliance handles; gaskets and profiles; adhesives (including hot melt adhesives and pressure sensitive adhesives); footwear (including shoe soles and shoe liners); auto interior parts and profiles; foam articles (both open cell foam and closed cell foam); impact modifiers for other thermoplastic polymers such as high density polyethylene, isotactic polypropylene, or other olefin polymers; coated fabrics; hoses; tubing; weather stripping; cap liners; flooring; and combinations thereof.

[0125] TEST METHODS

[0126] Density 86143-WO-PCT / DOW 86143 WO

[0127] Density was measured in accordance with ASTM D792, with results reported in g / cm3at 25 °C.

[0128] Melt Flow Rate

[0129] MFR (for propylene-based polymers) was measured in accordance with ASTM D 1238, Condition 230 °C / 2.16 kg with results reported in grams per 10 minutes (g / 10 min).

[0130] Dynamic Mechanical Analysis (DMA)

[0131] DMA experiments were conducted using a TA Instruments RSA-G2 Solid Analyzer to measure the storage modulus (E'), loss modulus (E''), and damping ratio (tan δ) of crosslink networks as a function of temperature and recycling under a nitrogen atmosphere. DMA was operated in tension mode at a frequency of 1 Hz with a 0.03% oscillatory strain. Data was collected from 70 °C to 200 °C with a heating rate of 3 °C / minute.

[0132] Differential Scanning Calorimetry (DSC)

[0133] DSC was conducted using a Mettler Toledo DSC822e differential scanning calorimeter to measure thermal properties including peak and endpoint melting temperatures and crystallinities of the virgin polymer and crosslinked compositions (network polymers). The network materials tested for most polymers were samples of the crosslinked 1st-molded samples and reprocessed 2nd-molded sample. A 10 °C / min heating rate and a 40 °C / min cooling rate were adapted for all measurements in a temperature range of 0 °C to 200 °C.

[0134] EXAMPLES

[0135] By way of example, and not limitation, some embodiments of the present disclosure will not be described in detail by the following examples.

[0136] Materials

[0137] Materials used in Comparative Compositions C1-C12 and Example Compositions E1-E10 are provided in Table 1 below. 86143-WO-PCT / DOW 86143 WO

[0138] Table 1

[0139] Synthesis of BiPheS phenylacrylate

[0140] To synthesize BiPheS phenylacrylate, 2-phenylacryloyl chloride (5.00 g, 30.0 mmol) was dissolved in 150 mL dichloromethane (DCM) and was stirred at 0 ℃ in an ice bath. 86143-WO-PCT / DOW 86143 WO bis(4-hydroxyphenyl) disulfide (2.5 g, 10 mmol, supplied by Ambeed, Inc.) and 4- dimethylaminopyridine (DMAP) (20 mg, 0.08 mmol, supplied by Sigma-Aldrich) were added to the mixture, resulting in a milky yellowish solution. Triethylamine (supplied by Sigma- Aldrich) was added dropwise. The solution developed purple hue upon addition and gradually turned back to be milky yellowish. Triethylamine was continually added until the solution was no longer purple. 10% more triethylamine was added dropwise to ensure completion. In total, about 5 mL (36 mmol) triethylamine was added. The mixture returned to room temperature and stirred overnight for 18 hours. 500 mL of 0.1 M K2CO3solution (supplied by Sigma-Aldrich) was poured into the mixture and stirred for 1 hour. 500 mL DCM was then added, and the aqueous phase was removed by a separation funnel. The organic phase was further extracted with DI water twice and dried over magnesium sulfate. Then DCM was then removed by a rotary evaporator. The crude product was purified twice by first dissolving in 15 mL DCM at 40 ℃ and then recrystallized at room temperature for 5 hours and dried in a vacuum oven at 80 °C for 24 hours to yield BiPheS phenylacrylate

[0141] Synthesis of BiPheS methacrylate

[0142] To synthesize BiPheS methacrylate, bis(4-hydroxyphenyl) disulfide (1.00 g, 3.99 mmol, supplied by Ambeed, Inc.) and triethylamine (1.62 g, 16.0 mmol, supplied by Sigma- Aldrich) were added to dry acetonitrile (20 mL, supplied by Fisher Scientific) in a round- bottom flask and stirred under nitrogen flow until dissolution. The solution was then cooled to 0 °C in an ice bath, at which point methacryloyl chloride (1.67 g, 16.0 mmol, supplied by Sigma-Aldrich) was added dropwise under vigorous stirring. The resulting mixture was warmed to 30 °C and allowed to react for 24 hours. After evaporating the solvent under reduced pressure, the precipitates were dissolved in chloroform, washed via liquid-liquid extraction with a 0.10 mol / L potassium carbonate solution (3 x 150 mL) and water (3 x 150 mL), and dried over magnesium sulfate. The organic layer was then filtered and evaporated under reduced pressure, resulting in a yellow-orange solid, which was recrystallized from ethanol to result in light-yellow crystals. The crystals were dried in a vacuum oven at 80 °C for 24 hours to yield BiPheS methacrylate, as shown in Structure 2 above.

[0143] Preparation of crosslinked compositions

[0144] Appropriate masses of starting materials including polymer pellets (polypropylene- based polymer), crosslinker (BiPheS phenylacrylate or BiPheS methacrylate), coagent 86143-WO-PCT / DOW 86143 WO (styrene or PETA) and radical initiator (dicumyl peroxide) were massed separately on an analytical balance (typically, 1 g of polymer, 0.04 g of crosslinker, 0.04 g of coagent, and 0.04 g of radical initiator). Prior to synthesis, the cup of a Dynisco (formerly Atlas) Laboratory Mixing Molder (LMM) was flushed of impurities by loading the polymer of interest, heating to above its melt transition, and mixing for 3-5 minutes. After removing the polymer debris from flushing, the massed polymer pellets and the powder mixture of crosslinker and radical initiator were added via spatula into the cup. The starting materials were added in doses such that they were evenly distributed throughout the cup prior to mixing. Additionally, three steel balls (about 5 mm diameter) were added evenly to the cup to emulate extrusion processes during melt-state mixing. Next, the temperature of the LMM was increased above the melt transition of the polymer, and the starting materials were mixed at this temperature at 120 RPM (maximum rotational speed) for 3-5 minutes to ensure homogenization of the ingredients in the melt state while minimizing radical initiation. For ADSTIF HA802H, D115A, PRO-FAX SD242, and MOPRYLENE®, this mixing temperature was 180 °C. For, VISTAMAXX 8880, VERSIFY 2400, VERSIFY 3401, INTUNE™ D5535, and INTUNE™ D5545, this mixing temperature was 160 °C. Mixing occurs at this temperature for approximately 3 minutes. During mixing, the rotor of the LMM was manually cycled upwards and downwards periodically to facilitate homogenization of the blend.

[0145] After mixing for 3 minutes, mixing is ceased and the homogenized polymer blend was removed from the cup via spatula. The blend was then compression molded into a mm- thick film in a PHI press (Model 0230C-X1) at 180 °C (a temperature at which radical initiation and crosslinker grafting processes can commence) and 10 MPa for 15 minutes to obtain a crosslinked 1st-molded sample. The film was then cut into mm-sized pieces and compression molded at 180 °C and 10 MPa for 10 minutes to obtain a reprocessed 2nd-molded sample. Strips were cut from each sample film for dynamic mechanical analysis (DMA).

[0146] PRO-FAX SD242

[0147] Referring now to Table 2, Comparative Compositions C1 and C2 and Example Compositions E1-E3, crosslinkable compositions containing PRO-FAX SD242 with varying amounts of BiPheS phenylacrylate (crosslinker), BiPheS methacrylate (crosslinker), styrene (coagent), PETA (coagent), and dicumyl peroxide (free radical initiator), were formed. 86143-WO-PCT / DOW 86143 WO

[0148] Referring now to Table 3, the performance criteria of the crosslinked compositions are shown. Processability of crosslinked compositions (network blends) was assessed by film quality after completing the aforementioned standard compression molding procedure and conditions shown in Table 2. Thermomechanical properties of the crosslinked compositions (network blends) were also tested via DMA to assess network response for 1st-molded samples compared to virgin PRO-FAX SD242 material. Hence, performance criteria were based on the virgin PRO-FAX SD242 properties. As noted herein, the performance criteria of the crosslinked compositions, such as tan δ at 180 °C, may be dependent on the properties of the propylene-based polymer being used therein, such as PRO-FAX SD242.

[0002] 86143-WO-PCT / DOW 86143 WO

[0149] Table 2 * For processability: 1 – Network blend is not processable; pieces do not heal to form cohesive film for property testing. 2 – Network blend is partially processable; pieces heal partially and require more time to heal fully. Resulting films are intact to enable property testing. 3 – Network blend is fully processable; pieces heal completely, allowing for exhaustive property testing and recycling. N / A – Sample was not tested due to lack of processability or network response. 86143-WO-PCT / DOW 86143 WO

[0150] Table 3

[0151] In Table 2, a minimum E' at 180 °C of 0.01 MPa is indicative of a network response (crosslinking) over the thermoplastic response of virgin PRO-FAX SD242 with crosslinker, optionally coagent, and free radical initiator. Typically, synthesizing dynamic networks via the described procedures is successful using 4 wt% BiPheS phenylacrylate and 4 wt% free radical initiator (Example Composition E1). Table 2 shows using 4 wt% BiPhes methacrylate, 4 wt% styrene, and 4 wt% free radical initiator (Example Composition E2). Table 2 also shows using 4 wt% BiPhes methacrylate, 4 wt% styrene, 4 wt% PETA, and 4 wt% free radical initiator (Example Composition E3).

[0152] Comparative Compositions C1 and C2 in Table 2 did not produce network material due to lack of crosslinker (Comparative Composition C1) or crosslinker with relatively low reactivity (Comparative Composition C2). Example Compositions E1-E3 gave network responses (E' about 0.01 MPa at 180 °C) and enable full processability (score of 3) assessed through film quality after compression molding. For Example Composition E1, the relatively high reactivity of BiPheS phenylacrylate allowed for a network response without any coagent. For Example Composition E2, styrene coagent helped to achieve an E' at 180 °C similar to that of Example Composition E1. For Example E3, inclusion of styrene and PETA coagents resulted in an E' at 180 °C than Examples Compositions E1 and E2, correlating to the strongest dynamic network response. With aromatic disulfide bonds in crosslinkers, Example Compositions E1-E3 were fully processable (score of 3 for film quality) with processability akin to Comparative Compositions C1 and C2.

[0153] Polymer Evaluation

[0154] Based on the findings of PRO-FAX SD242, the E1 formulation for PRO-FAX SD242 (1 g polymer basis, 4 wt% crosslinker, 4 wt% radical initiator) was translated to ADSTIF HA802H, D115A, MOPRYLENE®, VISTAMAXX™ 8880, VERSIFY™ 2400, VERSIFY™ 86143-WO-PCT / DOW 86143 WO 3401, INTUNE™ D5535, and INTUNE™ D5545. Example Compositions E1 and E5-E10 and Comparative Compositions C3 and C4 and properties thereof are shown in Table 4.

[0155] Sufficient network responses and full recoveries of thermomechanical properties evaluated using DMA after 2 successive compression molding cycles were obtained with this formulation for each of the propylene-based polymers. The performance criteria of the crosslinked compositions are shown in Table 5. “Virgin” or “virgin polymer,” as used in this Polymer Evaluation example, refers to PRO-FAX SD242, ADSTIF HA802H, D115A, MORPRYLENE®, VISTAMAXX™ 8880, VERSIFY™ 2400, VERSIFY™ 3401, INTUNE™ D5535, or INTUNE™ D5545 prior to crosslinking.

[0156] Table 6 shows properties of Comparative Composition C2 and Example Compositions E2 and E3.

[0157] Comparative Compositions C5-C12 in Table 7 include formulations that did not produce reprocessable network materials, as well as virgin polymer formulations without any crosslinker or radical initiator.

[0003] 86143-WO-PCT / DOW 86143 WO

[0158] Table 4 86143-WO-PCT / DOW 86143 WO

[0159] Table 4 cont. 86143-WO-PCT / DOW 86143 WO

[0161] Table 4 cont. 86143-WO-PCT / DOW 86143 WO

[0162] Table 5

[0163] Table 6 86143-WO-PCT / DOW 86143 WO

[0164] Table 7

[0165] Table 7 cont.

[0166] Table 4 exhibits E' and tan δ at 100 °C and 180 °C for Example Compositions E1 and E5-E10 and Comparative Compositions C3 and C4. Table 6 exhibits E' and tan δ at 100 °C and 180 °C for Example Compositions E2 and E3 and Comparative Composition C2.

[0167] E' at 100 °C of the network polymers were about equal (on the same order of magnitude) to the E' at 100 °C of the respective virgin polymers with experimental uncertainty. Depending on the change in crystallinity after dynamic crosslinking and processing compared to the virgin polymers, E' at 100 °C was slightly smaller (decrease in crystallinity will decrease E' below the melt transition despite enhancement from crosslinking) or slightly larger (crystallinity is marginally affected and crosslinking enhances E'). Successive molds at 100 °C for Example Compositions E1 and E5-E10 exhibited E' at 86143-WO-PCT / DOW 86143 WO 100 °C approximately equal (on the same order of magnitude) to the E' at 100 °C of the respective virgin polymers and 1st-molded samples within experimental uncertainty.

[0168] At 180 °C, E' of the network polymers of Example Compositions E1 and E5-E10 were substantially larger than the E' at 180 °C of the respective virgin polymers, as the virgin polymers did not possess network characteristics that would give relatively large E' at 160 °C (e.g., > 0.01 MPa) above the melt transitions. Successive molds at 180 °C for each of the Example Compositions E1 and E5-E10 exhibited E' at 160 °C approximately equal (on the same order of magnitude) or slightly larger (from additional crosslink formation during processing) to the E' at 180 °C of the 1st-molded samples within experimental uncertainty.

[0169] Comparative Compositions C3 and C4, compositions including ADSTIF HA802H and VISTAMAXX™ 8880, respectively, did not give a substantial network response upon crosslinking. Regarding ADSTIF HA802H, while not wishing to be bound by theory, the relatively low MI of ADSTIF HA802H (i.e., MI = 2.3 g / 10 min) may result in limited mixing in the batch mixer used. Relatively better mixing of the composition including ADSTIF HA802H would be expected to produce a substantial network response. Regarding VISTAMAXX™ 8880, while not wishing to be bound by theory, the relatively high MI of VISTAMAXX™ 8880 (i.e., MI > 50 g / 10 min), indicating the polymer has a relatively low molecular weight, may require a very high level of crosslinking to give a substantial network response.

[0170] Coinciding with the larger presence of crosslinks in the network materials, tan δ at 100 °C and 180 °C were smaller for the Example Compositions E1 and E5-E10 compared to their virgin counterparts. Additionally, these values were maintained for successively molded samples at both temperatures. The Example Compositions E1 and E5-E10 demonstrate that the polymers not only give substantial dynamic network responses upon crosslinking (≥1 MPa at 100 °C and ≥ 0.1 MPa at 180 °C), but are also reprocessable and recover their E' and tan δ after successive compression molding cycles. Comparative examples that were processable did not achieve substantial network responses.

[0171] Tables 4 and 6 also provide the thermal properties (melting ranges and crystallinities) of the virgin polymers, Example Compositions E1 and E5-E10, and Comparative Compositions C3 and C4 (network formulations) determined by DSC. Reactive crosslinking diminished the order of the crystal structures forming during cooling post- 86143-WO-PCT / DOW 86143 WO process, which decreased the crystallinities as well as melting peaks and endpoints of the network polymers compared to their virgin counterparts.

[0172] While particular embodiments of the present disclosure have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the disclosure. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this disclosure.

Claims

86143-WO-PCT / DOW 86143 WO CLAIMS 1. A crosslinkable polymer composition comprising: a propylene-based polymer; a free radical initiator; and bis(4-phenacryloyloxyphenyl) disulfide (BiPheS phenylacrylate).

2. The crosslinkable polymer composition of claim 1, wherein the propylene-based polymer is selected from the group consisting of polypropylene homopolymer, polypropylene-based elastomer, polypropylene-based block copolymer, propylene-based impact copolymer, and combinations thereof.

3. The crosslinkable polymer composition of any one of the preceding claims, wherein the free radical initiator comprises an organic peroxide.

4. The crosslinkable polymer composition of any one of the preceding claims, wherein the crosslinkable polymer composition comprises: from 70 wt% to 99 wt% of the propylene-based polymer; from 0.5 wt% to 10 wt% of the free radical initiator; and from 1 wt% to 20 wt% of the BiPheS phenylacrylate.

5. A crosslinked composition comprising: a propylene-based polymer; and bis(4-phenacryloyloxyphenyl) disulfide (BiPheS phenylacrylate).

6. The crosslinked composition of claim 5, wherein the crosslinked composition comprises the linkages of Structure 3: STRUCTURE 386143-WO-PCT / DOW 86143 WO 7. The crosslinked composition of claim 5 or claim 6, the crosslinked composition comprising: from 70 wt% to 99 wt% of the propylene-based polymer; and from 1 wt% to 20 wt% of the BiPheS phenylacrylate.

8. The crosslinked composition of any one of claims 5-7, wherein the propylene-based polymer is selected from the group consisting of polypropylene homopolymer, polypropylene- based elastomer, polypropylene-based block copolymer, propylene-based impact copolymer, and combinations thereof.

9. The crosslinked composition of any one of claims 5-8, wherein the crosslinked composition has: a storage modulus (E') at 180 °C greater than or equal to 0.01 MPa; and a damping ratio (tan δ) at 180 °C less than 0.

50.

10. The crosslinked composition of any one of claims 5-9, wherein: the propylene-based polymer is a virgin propylene-based polymer prior to the crosslinked composition being crosslinked; and the crosslinked composition has: E' at 180 °C that is greater than the E' for the virgin propylene-based polymer at 180 °C; and tan δ at 180 °C that is less than the tan δ value of the virgin propylene-based polymer at 180 °C.

11. A process comprising: heating a first article to a reprocessing temperature, the first article comprising a crosslinked composition, wherein the crosslinked composition comprises: a propylene-based polymer; and bis(4-phenacryloyloxyphenyl) disulfide (BiPheS phenylacrylate); forming, at the reprocessing temperature, the first article into a re-processable propylene- based polymer composition;86143-WO-PCT / DOW 86143 WO shaping, at the reprocessing temperature, the re-processable propylene-based composition into a re-processed pre-form; cooling the re-processed pre-form to below the reprocessing temperature; and forming a second article, the second article comprising a re-crosslinked composition, wherein the re-crosslinked composition comprises: the propylene-based polymer; and the BiPheS phenylacrylate; wherein the second article is different from the first article.

12. The process of claim 11, wherein the reprocessing temperature is from 100 °C to 250 °C, thereby breaking disulfide linkages of the cross-linked composition and forming the reprocessable propylene-based polymer composition.

13. The process of claim 11 or claim 12, wherein the crosslinked composition comprises linkages of Structure 3:STRUCTURE 3 14. The process of any one of claims 11-13, wherein the crosslinked composition comprises: from 70 wt% to 99 wt% of the propylene-based polymer; and from 1 wt% to 20 wt% of the BiPheS phenylacrylate.

15. The process of any one of claims 11-14 wherein the propylene-based polymer is selected from the group consisting of polypropylene homopolymer, polypropylene-based elastomer, polypropylene-based block copolymer, propylene-based impact copolymer, and combinations thereof.

16. The process of any one of claims 11-15, wherein the second article comprises: a storage modulus (E') at 180 °C greater than or equal to 0.01 MPa; and86143-WO-PCT / DOW 86143 WO E' at 180 °C of the second article is greater than or about equal to E' at 180 °C of the first article.

17. A crosslinkable polymer comprising: a propylene-based polymer; a free radical initiator; a coagent; and bis(4-methacryloyloxyphenyl) disulfide (BiPheS methacrylate).

18. The crosslinkable polymer composition of claim 17, wherein the coagent comprises styrene; divinyl benzene; 1,1,1-trimethylolpropane trimethacrylate; pentaerythrityl tetramethacrylate (PETM); trimethylolpropanetiacrylate (TMPTA); pentaerythritol tetraacrylate (PETA); pentaerythritol tetrallyl ether; diallyl maleate; triallyl cyanurate; diallyl itaconate; triallylisocyanurate (TAIC); or a combination thereof.

19. The crosslinkable polymer composition of claim 17 or claim 18, wherein the propylene- based polymer is selected from the group consisting of polypropylene homopolymer, polypropylene-based elastomer, polypropylene-based block copolymer, propylene-based impact copolymer, and combinations thereof.

20. The crosslinkable polymer composition of any one of claims 17-19, wherein the free radical initiator comprises an organic peroxide.

21. The crosslinkable polymer composition of any one of claims 17-20, wherein the crosslinkable polymer composition comprises: from 70 wt% to 98.5 wt% of the propylene-based polymer; from 0.5 wt% to 10 wt% of the free radical initiator; from 0.5 wt% to 15 wt% of the coagent; and from 1 wt% to 20 wt% of the BiPheS methacrylate.

22. A crosslinked composition comprising: a propylene-based polymer; a coagent; and86143-WO-PCT / DOW 86143 WO bis(4-methacryloyloxyphenyl) disulfide (BiPheS methacrylate).

23. The crosslinked composition of claim 22, wherein the crosslinked composition comprises the linkages of Structure 4:

24. The crosslinked composition of claim 22 or claim 23, the crosslinked composition comprising: from 70 wt% to 98.5 wt% of the propylene-based polymer; from 0.5 wt% to 15 wt% of the coagent; and from 1 wt% to 20 wt% of the BiPheS methacrylate.

25. The crosslinked composition of any one of claims 22-24, wherein the propylene-based polymer is selected from the group consisting of polypropylene homopolymer, polypropylene- based elastomer, polypropylene-based block copolymer, propylene-based impact copolymer, and combinations thereof.

26. The crosslinked composition of any one of claims 22-25, wherein the coagent comprises styrene; divinyl benzene; 1,1,1-trimethylolpropane trimethacrylate; pentaerythrityl tetramethacrylate (PETM); trimethylolpropanetiacrylate (TMPTA); pentaerythritol tetraacrylate (PETA); pentaerythritol tetrallyl ether; diallyl maleate; triallyl cyanurate; diallyl itaconate; triallylisocyanurate (TAIC); or a combination thereof.

27. The crosslinked composition of any one of claims 22-26, wherein the crosslinked composition has: a storage modulus (E') at 180 °C greater than or equal to 0.01 MPa; and a damping ratio (tan δ) at 180 °C less than 0.50.86143-WO-PCT / DOW 86143 WO 28. The crosslinked composition of any one of claims 22-27, wherein: the propylene-based polymer is a virgin propylene-based polymer prior to the crosslinked composition being crosslinked; and the crosslinked composition has: E' at 180 °C that is greater than the E' for the virgin propylene-based polymer at 180 °C; and tan δ at 180 °C that is less than the tan δ value of the virgin propylene-based polymer at 180 °C.

29. A process comprising: heating a first article to a reprocessing temperature, the first article comprising a crosslinked composition, wherein the crosslinked composition comprises: a propylene-based polymer; a coagent; and bis(4-methacryloyloxyphenyl) disulfide (BiPheS methacrylate); forming, at the reprocessing temperature, the first article into a re-processable propylene- based polymer composition; shaping, at the reprocessing temperature, the re-processable propylene-based composition into a re-processed pre-form; cooling the re-processed pre-form to below the reprocessing temperature; and forming a second article, the second article comprising a re-crosslinked composition, wherein the re-crosslinked composition comprises: the propylene-based polymer; and the coagent; and the BiPheS phenylacrylate; wherein the second article is different from the first article.

30. The process of claim 29, wherein the reprocessing temperature is from 100 °C to 250 °C, thereby breaking disulfide linkages of the cross-linked composition and forming the reprocessable propylene-based polymer composition.86143-WO-PCT / DOW 86143 WO 31. The process of claim 29 or claim 30, wherein the crosslinked composition comprises linkages of Structure 4:

32. The process of any one of claims 29-31, wherein the crosslinked composition comprises: from 70 wt% to 98.5 wt% of the propylene-based polymer; from 0.5 wt% to 15 wt% of the coagent; and from 1 wt% to 20 wt% of the BiPheS methacrylate.

33. The process of any one of claims 29-32 wherein the propylene-based polymer is selected from the group consisting of polypropylene homopolymer, polypropylene-based elastomer, polypropylene-based block copolymer, propylene-based impact copolymer, and combinations thereof.

34. The process of any one of claims 29-33, the coagent comprises styrene; divinyl benzene; 1,1,1-trimethylolpropane trimethacrylate; pentaerythrityl tetramethacrylate (PETM); trimethylolpropanetiacrylate (TMPTA); pentaerythritol tetraacrylate (PETA); pentaerythritol tetrallyl ether; diallyl maleate; triallyl cyanurate; diallyl itaconate; triallylisocyanurate (TAIC); or a combination thereof.

35. The process of any one of claims 29-34, wherein the second article comprises: a storage modulus (E') at 180 °C greater than or equal to 0.01 MPa; and E' at 180 °C of the second article is greater than or about equal to E' at 180 °C of the first article.

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