Chemical recycling of plastics

Abstract

Provided herein are new materials and methods for producing degradable polymers. Use of a molybdenum catalyst or Niobium catalyst in metathesis polymerization to produce a polymer is disclosed along with monomers for use in such polymerization reactions. The reaction may be an ADMET, ROMP, a metathesis ring-closure or an olefin exchange reaction.

Description

[0001] Chemical Recycling of Plastics

[0002] BACKGROUND

[0003] The problem of disposal of waste plastics has become a serious problem all over the world thousands of tons of waste plastics are generated every day. Disposal methods such as landfilling pose problems such as groundwater pollution and land use patterns, while plastic incineration causes air pollution and harms the health of animals and plants. As people become more aware of the cleanliness of public spaces and the segregation of waste, India is now able to collect waste plastic separately from other waste. In particular, there are no effective recycling or disposal options for polyethylene and polypropylene multi-layer plastic films that contain metal. Various efforts have been made in the past to process waste plastics to produce hydrocarbon fuels.

[0004] DETAILED DESCRIPTION

[0005] Overview

[0006] Described herein are methods and materials for rendering a plastic, e.g., polyethylene, recyclable by inserting precisely placed in-chain functional groups in the polymer backbone. Functional groups exemplified herein include carbonate, urea, thiourea, acid anhydride, phosphonic acid and the sodium salt of phosphonic acid. These functional groups possess strong dipole moments, which in addition to rendering the modified polyethylene chemically recyclable, will also induce strong interactions between polymer chains, thereby yielding strong materials.

[0007] As an example, the carbonate group can be incorporated precisely in the backbone of polyethylene at varying degrees of concentration. Varying concentration is achieved during the synthesis of appropriate precision alpha omega diene monomers. These monomers place the in-chain functional group exactly in the middle of the diene monomer, with polyethylene segments extending towards the terminal diene units. When the material made from such polymers is ready for disposal, it will be chemically disassembled by exposing to high temperature water. Steam would be an obvious choice, as the process would be amenable to scale up to industrial utility.

[0008] This chemical approach would apply to all the functional groups mentioned above as well as any that also might be chemically recyclable via exposure to external stimuli such as high temperature water.

[0009] These new polymers can be transformed into fibers by both wet spinning and melt spinning. They can also be converted to membranes by casting or melt pressing or other standard methods of membrane formation.

[0010] They can also be formed into objects by melt pressing or molding operations.

[0011] Various embodiments may be understood more readily by reference to the following detailed description. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described.

[0012] Definitions

[0013] As used herein, the term “bulk” refers to a bulk polymerization carried out in the absence of any solvent or dispersant.

[0014] As used herein, the term “standard temperature and pressure” generally refers to 20° C. and 1 atmosphere. Standard temperature and pressure may also be referred to as “ambient conditions.” Unless indicated otherwise, parts are by weight, temperature is in ° C., and pressure is at or near atmospheric. The terms “elevated temperatures” or “high-temperatures” generally refer to temperatures of at least 100° C.

[0015] The term “mol percent” or “mole percent” generally refers to the percentage that the moles of a particular component are of the total moles that are in a mixture. The sum of the mole fractions for each component in a solution is equal to 1 . As used herein, the term “metathesis” generally refers to a reaction involving exchange of substituents between olefins, in other words, transalkylidenation.

[0016] It is to be understood that this disclosure is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims.

[0017] All numeric values are herein assumed to be modified by the term “about,” whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term “about” may include numbers that are rounded to the nearest significant figure.

[0018] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit (unless the context clearly dictates otherwise), between the upper and lower limit of that range, and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0019] All publications and patents cited in this specification are herein incorporated by reference as if each individual publication or patent were specifically and individually indicated to be incorporated by reference and are incorporated herein by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. The citation of any publication is for its disclosure prior to the filing date and should not be construed as an admission that the present disclosure is not entitled to antedate such publication by prior disclosure. Further, the dates of publication provided could be different from the actual publication dates that may need to be independently confirmed. Unless otherwise indicated, the present disclosure is not limited to particular materials, reagents, reaction materials, manufacturing processes, or the like, as such can vary. It is also to be understood that the terminology used herein is for purposes of describing particular embodiments only and is not intended to be limiting. It is also possible in the present disclosure that steps can be executed in different sequence where this is logically possible.

[0020] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a support” includes a plurality of supports. In this specification and in the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings unless a contrary intention is apparent.

[0021] Various embodiments are directed to methods of performing metathesis chemistry at temperatures of at least 100° C. and above the melting temperature of the polymer that may employ catalysts in bulk conditions (without solvent).

[0022] Description of a non-limiting set of Embodiments

[0023] According to one embodiment, provided is a method of metathesis polymerization to produce a polymer that involves forming a polymerization mixture by combining a catalyst (e.g. a molybdenum catalyst or niobium catalyst), and one or more monomers selected from at least one cyclic monomer comprising an alkene, at least one linear monomer comprising an a,co-dieneyl-monomer, and combinations thereof; and heating the polymerization mixture to a temperature of 100° C or greater, or 120° C or greater. In a specific example, the molybdenum catalyst comprises a catalyst selected from

[0024]

[0025] , and

[0026] In another example, the niobium catalyst comprises a catalyst selected from

[0027] ; and / or In a further example, the at least one linear monomer comprises a monomer selected from the group consisting of:

[0028] The catalyst and the monomer may be combined at a ratio of 1 :250-750 catalyst: monomer.

[0029] In a more specific example of the method of metathesis polymerization, the heating step comprises heating the polymerization mixture to a temperature greater than the melting point of the polymer in bulk conditions to form a molten polymerization mixture; and further comprising performing intensive mixing on the molten polymerization mixture to produce the polymer.

[0030] The polymerization mixture may further comprise a solvent having a boiling point in excess of the polymerization temperature at the polymerization pressure.

[0031] In certain examples, the monomer may include a general functional group selected from alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, and amides.

[0032] Alternatively, the monomer may include a more specific functional group selected from carbonate, sulfite, urea, thiourea, acid anhydride, phosphonic acid, and halogen salt of phosphonic acid.

[0033] According to a further embodiment, provided is a method of metathesis ringclosure that involves combining at least one acyclic non-conjugated diene with a catalyst, the catalyst optionally being a molybdenum catalyst or niobium catalyst to form a reaction mixture; and heating the reaction mixture to a temperature above 100° C, or 120° C or greater, or about 100° C to about 140° C. The non-conjugated diene may include a functional group selected from alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, and amides. Preferably, the non-conjugated diene includes a functional group selected from carbonate, sulfite, urea, thiourea, acid anhydride, phosphonic acid, and halogen salt of phosphonic acid. The polymerization mixture may further comprise a solvent having a boiling point in excess of the polymerization temperature at the polymerization pressure.

[0034] In a specific example, the molybdenum catalyst comprises a catalyst selected from

[0035] , and

[0036] In another specific example, the niobium catalyst comprises a catalyst selected from

[0037]

[0038] In yet another embodiment, provided is a method of metathesis olefin exchange that involves combining at least one alkene with a catalyst, the catalyst optionally being a molybdenum catalyst or niobium catalyst, to form a reaction mixture; and heating the reaction mixture to a temperature above 100° C, or 120° C. or greater. The alkene may include a functional group selected from alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, and amides. In a specific example, the molybdenum catalyst comprises a catalyst selected from The niobium catalyst comprises a catalyst selected from

[0039] In a more specific example, wherein the method of metathesis olefin exchange produces a polymer, and the heating step comprises heating the polymerization mixture to a temperature greater than the melting point of the polymer in bulk conditions to form a molten polymerization mixture; and the method may further involve performing intensive mixing on the molten polymerization mixture to produce the polymer.

[0040] Any of the reaction mixtures described herein may further comprises a quinone, such as quinone is benzoquinone. Also, alternative catalysts that may be used in the methods described herein may include:

[0041] Structure C is an example according to various embodiments, illustrating a schematic chemical structure of a ruthenium catalyst that may be used for high temperature metathesis chemistry. Given certain selections of the functional groups (Ri , R2, R3, R4, Rs, Re, R7, Rs, R9, R10, R11 , R12, R13, R14, R15, and Rie), Structure C includes or encompasses both Structure A and Structure B.

[0042] The following lists provide some examples of the functional groups that may be employed in Structure C. The functional groups listed are merely examples; other functional groups may be employed. Referring to Structure C, functional groups R1 , R2, Rs, F , RS, Re, R7, Rs, R9, R10, R11 , R12, R13, and R14 may be the same or different and may each be independently selected from hydrogen (H), a linear Ci-Ce hydrocarbon, a branched C3-C6 hydrocarbon, and a cyclic C3-C6 hydrocarbon. Still referring to Structure C, functional groups R15 and R16 may be the same or different and may each be any negative ligand. For example, functional groups R15 and R16 may be the same or different and may each be independently selected from Cl— (chloro), CN— (cyano), Br — (bromo), O — (oxo), OH — (hydroxo), CO3 — (carbonate), CH3COO — (acetato), SCN — (thiocyanato), SO4 — (sulphato), C2O4 — (oxalato), and NO2 — (nitrito). In this context, “independently selected” means that each group may be chosen from the list of options with out respect to the selection made from the list for any other groups, allowing the functional groups to be the same or different.

[0043] According to another embodiment, provided is a method that involves disassembling a polymer made by the methods described herein. The disassembling may involve subjecting the polymer to high temperature water, optionally, wherein the high temperature water is 100 degrees Celsius or higher. The use of catalysts and monomers described herein provide for a plastic that is degradable and / or recyclable.

[0044] Acyclic Diene Metathesis Polymerization (ADMET) Polymerization or Copolymerization

[0045] According to various embodiments, the high-temperature metathesis polymerization may be an ADMET polymerization or copolymerization, where one or more non-conjugated acyclic diene has a boiling point in excess of 100° C. and a melting point (Tm) below the polymerization temperature.

[0046] The polymerization temperature may be in a range having a lower limit and / or an upper limit. The range may include or exclude the lower limit and / or the upper limit. The lower limit and / or upper limit can be selected from about 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, and 200° C. For example, according to certain embodiments, the polymerization temperature may be in a range of from about 20° C. to about 200° C., or any combination of lower limits and upper limits described. The catalyst concentration may be in a range having a lower limit and / or an upper limit. The range may include or exclude the lower limit and / or the upper limit. The lower limit and / or upper limit can be selected from about 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, and 1 mol percent. For example, according to certain embodiments, the catalyst concentration may be in a range of from about 0.3 to about 1 mol percent, or any combination of lower limits and upper limits described.

[0047] The reaction time may be in a range having a lower limit and / or an upper limit. The range may include or exclude the lower limit and / or the upper limit. The lower limit and / or upper limit can be selected from about 0.5, 1 , 1 .5, 2, 2.5, 3, 3.5, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 hrs. For example, according to certain embodiments, the reaction time may be of from about 0.5 to about 100 hrs, or any combination of lower limits and upper limits described.

[0048] According to various embodiments, the polymerization or copolymerization may be carried out in the melt in bulk. The polymerization or copolymerization may employ a molybdenum or niobium catalyst as described herein or an equivalent thereof. The polymerization may be carried out at a temperature higher than the melting point of the polymer in the absence of solvent. The acyclic diene may be a functionalized diene or an unfunctionalized diene, where any functionalization does not inhibit or poison the catalyst. If functionalization occurs too close to the terminal olefin (less than 3 methylene spacers) coordination of the functional group with the catalyst could occur simultaneously or preferentially with respect to the olefin. This will limit catalyst / olefin reactivity and therefore polymer molecular weight / reaction progress. A functionalized diene may be functionalized with one or more functional groups. The functional groups may be, separately or in combination, alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, amides, or any other functional group. In an alternative embodiment, the functional groups may be, separately or in combination, carbonate, sulfite, urea, thiourea, acid anhydride, phosphonic acid, and halogen salt of phosphonic acid.

[0049] Hydrogenation may be performed in any suitable manner. For example, an unsaturated polymer may be combined with 3 equiv of p-toluenesulfonyl hydrazine (TSH) and tripropylamine (TPA) dissolved in o-xylene or 1 ,1 ,2,2-tetrachloroethane. After a bubbler is attached, the reaction mixture may be refluxed until nitrogen is no longer being evolved from the reaction vessel. After addition of more TSH and TPA, the mixture may be refluxed until no more nitrogen is released. The solvent may be removed, and the polymer may be analyzed via 13C and 1 H NMR to determine whether complete saturation was achieved.

[0050] According to various other embodiments and examples, hydrogenation has been performed using a 150 mL Parr high-pressure stainless steel reaction vessel equipped with a 50 mL round bottom flask and a Teflon stirring bar / 0.15 g of unsaturated polymers may be dissolved in 20 mL of anhydrous toluene and degassed for 1 hour before adding 15 wt % of Pd / C. The round bottom flask was placed into the bomb and then sealed. The Parr vessel was purged with 500 psi of hydrogen gas three times. The bomb was then charged to 900 psi, and the mixture was stirred for 5 days at 90° C. The resultant polymer was filtered and precipitated into cold methanol to obtain a white solid, which was then filtered, transferred to a vial and dried under high vacuum (3x10-4 mmHg) overnight, yielding 0.13 g (87%) of final polymer.

[0051] According to various embodiments high-temperature metathesis polymerization may be an ADMET polymerization or copolymerization may produce a polymer or a copolymer having a wide range of molecular weights. The polymers or copolymers may have a weight average (Mw) within a range having a lower limit and / or an upper limit. The range may include or exclude the lower limit and / or the upper limit. The lower limit and / or upper limit can be selected from about 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, and 200 kg / mol. For example, according to certain embodiments, the polymers or copolymers may have a weight average (Mw) of from about 35 to about 130 kg / mol, or any combination of lower limits and upper limits described.

[0052] Fling-Opening Metathesis Polymerization (ROMP)

[0053] According to various embodiments, the high-temperature metathesis polymerization may be a ring-opening metathesis polymerization (ROMP) or copolymerization carried out at temperatures in excess of 100° C. A functionalized or unfunctionalized cyclic olefin or alkene may have a boiling point in excess of 100° C. and a Tm below the polymerization temperature. Polymerization or copolymerization may optionally be carried out in the melt in bulk. The polymerization or copolymerization may employ a catalyst as described herein, including, but not limited to, molybdenum catalyst, niobium catalyst, as well as Structure A, Structure B, or Structure C, or an equivalent thereof. The polymerization can be carried out to high molecular weights as long as functional groups on the cyclic olefin or alkene does not inhibit or poison the catalyst. The functional groups of the cyclic olefin or alkene may be, separately or in combination, alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, amides, or any other functional group. In an alternative embodiment, the functional groups may be, separately or in combination, carbonate, sulfite, urea, thiourea, acid anhydride, phosphonic acid, and halogen salt of phosphonic acid.

[0054] Ring-Closure Metathesis

[0055] According to various embodiments, the high-temperature metathesis polymerization may be a ring-closure metathesis can be carried out using the molybdenum or niobium catalysts as described herein, or their equivalent. The ringclosure can be carried out at temperatures in excess of 100° C. where a functionalized or unfunctionalized non-conjugated diene has a boiling point in excess of 100° C. and a Tmbelow the metathesis reaction temperature. The reaction can be carried out in the melt for some dienes and employing a molybdenum or niobium catalysts as described herein, or their equivalent. Functional groups of a functionalized non-conjugated diene can be, separately or in combination, alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, amides, or any other functional group. In an alternative embodiment, the functional groups may be, separately or in combination, carbonate, sulfite, urea, thiourea, acid anhydride, phosphonic acid, and halogen salt of phosphonic acid.

[0056] Olefin-Exchange Metathesis

[0057] According to various embodiments, the high-temperature metathesis chemistry may be olefin-exchange metathesis can be carried out using the molybdenum or niobium catalysts described herein or their equivalent. The exchange reaction can be carried out at temperatures in excess of 100° C. where a functionalized or unfunctionalized ene, diene, triene or polyene has a boiling point in excess of 100° C. and a Tmbelow the metathesis reaction temperature. The exchange can be driven to a single product or a plurality of products depending upon the proportion of reactant olefins, their relative concentration, their symmetry, volatility of an exchange product, or other factor. The functional groups can be, separately or in combination, alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, amides, or any other functional group. In an alternative embodiment, the functional groups may be, separately or in combination, carbonate, sulfite, urea, thiourea, acid anhydride, phosphonic acid, and halogen salt of phosphonic acid.

[0058] Characteristics of the Resultant Polymers

[0059] Methods according to various embodiments produce polymers that lack tacticity, or more formally “stereogenicity”. Stereogenicity refers to the presence of chiral centers along the polymer backbone. Chiral centers can only be present when the functional groups are pendant on the polymer backbone. Various embodiments described above produce polymers with the sulfone group incorporated into the polymer backbone. In other words, the sulfone group is not pendant to the polymer backbone and, therefore, by definition, the polymer lacks tacticity or stereogenicity.

[0060] The techniques, monomers and catalysts described herein may be used to produce functionalized processable, relatively high mw polymers. In addition, such polymers are hydrolyzable after use back to monomer or oligomer materials.

[0061] Mixing

[0062] Different types of mixing may be employed according to various embodiments, which include “extensive mixing” and “intensive mixing.” Extensive mixing may also be referred to as blending, mixing and distributive mixing. Intensive mixing may also be referred to as compounding, dispersion, and dispersive mixing. Extensive mixing is essentially stirring together the ingredients and the result is a mixture of ingredients that can in principle, be separated. On the other hand, intensive mixing involves the more intimate dispersion of the additives into the matrix of the polymer. Intensive mixing may require a physical change in the components. For example, a polymer may need to be in the molten or rubbery state during mixing. The mixing is driven by a mechanical motor, and a stirring paddle attached to the motor via a shaft is submerged into the molten reaction mixture. According to various embodiments, the type of mixing that is happening is intensive mixing, in that at the end of the reaction, no monomer is left, only polymer (or oligomers), the additive, and catalyst. The additive and catalyst can in principle be removed from the resulting polymer.

[0063] Rate and Degree of Polymerization

[0064] The method according to various embodiments, may include heating a polymerization mixture to a temperature greater than the melting point of the polymer, which may be 100° C. or greater, in bulk conditions to form a molten polymerization mixture; and mechanically stirring the molten polymerization mixture. The mechanical stirring may comprising intensive or extensive mixing. According to various embodiments, the polymer has a weight average molecular weight (Mw) of at least about Mw=10,000 Da within about 3 hours. According to various embodiments, a degree of polymerization of from about 10 to about 100 may be achieved in from about 3 to about 24 hours.

[0065] In order to understand how catalyst addition methodology might increase the molecular weight of precision ADMET polymers experiments were conducted using the Grubbs C668 CAAC catalyst. The reactions are provided below:

[0066]

[0067] ADM

[0068] Two polymers possessing in-chain functional groups were remade - the precision ketone polymer and the precision sulfone polymer.

[0069] Catalyst addition for high temperature bulk polymerization typically involves dividing the catalyst into three aliquots, adding the first at the start, followed by addition to the other two aliquots further into the polymerization. Instead, a full amount of catalyst (1 :500 ratio catalyst: monomer) at the start of the reaction. It was observed that the molecular weights of the ketone and sulfone polymers were increased by up to a factor of four in as little as 3 hours by simply altering how catalyst addition is done. Higher molecular weights were achieved at lower reaction times. Number average molecular weights for the ketone polymer were an all-time high, 71 ,000 vs a maximum of 18,000 in previous work. Number average molecular weights for the sulfone polymer were 26,000 vs prior values of 11 ,000 maximum.

[0070] Accordingly, in method embodiments described herein involving addition of catalyst with monomer, the full amount of the catalyst may be added at the start of the reaction.

[0071] All the features disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C § 112, sixth paragraph. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C § 112, sixth paragraph.

[0072] All patents, patent applications, provisional applications, and publications referred to or cited herein, supra or infra, are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

[0073] It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations and are merely set forth for a clear understanding of the principles of this disclosure. It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application. Many variations and modifications may be made to the above-described embodiment(s) of the disclosure without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

Claims

CLAIMSWhat is claimed is:1 . A method of metathesis polymerization to produce a polymer, the method comprising: forming a polymerization mixture by combining a catalyst, the catalyst optionally being a molybdenum catalyst or niobium catalyst, and one or more monomers selected from at least one cyclic monomer comprising an alkene, at least one linear monomer comprising an a,co-dieneyl-monomer, and combinations thereof; heating the polymerization mixture to a temperature of 100° C. or greater; wherein, optionally,(i) the molybdenum catalyst comprises a catalyst selected from, and(ii) the niobium catalyst comprises a catalyst selected from; and / or(iii) the at least one linear monomer comprises a monomer selected from the group consisting of:

2. The method of metathesis polymerization according to claim 1 , wherein the catalyst and the monomer are combined at a ratio of 1 :250-750 catalyst: monomer, and wherein,optionally, the catalyst is added as a full amount at the start of the polymerization reaction.

3. The method of metathesis polymerization according to claims 1 or 2, wherein the temperature is 120° C. or greater.

4. The method of metathesis polymerization according to any of claims 1 -3, wherein the heating step comprises heating the polymerization mixture to a temperature greater than the melting point of the polymer in bulk conditions to form a molten polymerization mixture; and further comprising performing intensive mixing on the molten polymerization mixture to produce the polymer.

5. The method of metathesis polymerization according to any of claims 1 -4, wherein the polymerization mixture further comprises a solvent having a boiling point in excess of the polymerization temperature at the polymerization pressure.

6. The method of metathesis polymerization according to any of claims 1 -5, wherein the monomer comprises a functional group selected from alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, and amides.

7. The method of metathesis polymerization according to any of claims 1 -5, wherein the monomer comprises a functional group selected from carbonate, sulfite, urea, thiourea, acid anhydride, phosphonic acid, and halogen salt of phosphonic acid.

8. A method of metathesis ring-closure, comprising: combining at least one acyclic non-conjugated diene with a catalyst, the catalyst optionally being a molybdenum catalyst or niobium catalyst to form a reaction mixture; and heating the reaction mixture to a temperature above 100° C.

9. The method of metathesis ring-closure according to claim 8, wherein the nonconjugated diene comprises a functional group selected from alkyl, aryl, alkylaryl,ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, and amides.

10. The method of metathesis ring-closure according to claim 8, wherein the nonconjugated diene comprises a functional group selected from carbonate, sulfite, urea, thiourea, acid anhydride, phosphonic acid, and halogen salt of phosphonic acid.11 . The method of metathesis ring-closure according to claim 8, wherein the temperature is 120° C. or greater.

12. The method of metathesis ring-closure according to claim 8, wherein the polymerization mixture further comprises a solvent having a boiling point in excess of the polymerization temperature at the polymerization pressure.

13. The method of metathesis ring-closure according to claim 8, wherein the molybdenum catalyst comprises a catalyst selected from14. The method of metathesis ring-closure according to claim 8, wherein the niobium catalyst comprises a catalyst selected from15. A method of metathesis olefin exchange, comprising: combining at least one alkene with a catalyst, the catalyst optionally being a molybdenum catalyst or niobium catalyst, to form a reaction mixture; and heating the reaction mixture to a temperature above 100° C.

16. The method of metathesis olefin exchange according to claim 15, wherein the alkene comprises a functional group selected from alkyl, aryl, alkylaryl, ketone, aldehyde, ether, ester, carboxylic acid, alkylsilyl, arylsilyl, alkylarylsilyl, amine, epoxy, sulfone, sulfonic acid ester, and amides.

17. The method of metathesis olefin exchange according to claim 15, wherein the molybdenum catalyst comprises a catalyst selected from, and18. The method of metathesis olefin exchange according to claim 15, wherein the niobium catalyst comprises a catalyst selected from19. The method of metathesis olefin exchange according to claim 15, wherein the temperature is 120° C. or greater.

20. The method of metathesis olefin exchange according to claim 15, wherein the method produces a polymer, and wherein the heating step comprises heating the polymerization mixture to a temperature greater than the melting point of the polymer in bulk conditions to form a molten polymerization mixture; and further comprising performing intensive mixing on the molten polymerization mixture to produce the polymer. 21 . The method of metathesis polymerization according to claim 1 , wherein the reaction mixture further comprises a quinone.

22. The method of metathesis olefin exchange according to claim 21 , wherein the quinone is benzoquinone.

23. The method according to any of claims 1 -22, wherein the catalysts are selected from24. A polymer produced by the method according to any of claims 1 -23.

25. The polymer of claim 24, that is degradable by high temperature water.

26. A method comprising disassembling a polymer according to claims 24 or 25 by subjecting the polymer to high temperature water, optionally, wherein the high temperature water is 100 degrees Celsius or higher.

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