Attorney Docket No.10850-070WO1 CLAIMS What is claimed is: 1. A method comprising: (a) reacting a lignin comprising a 1,3 diol with carbon dioxide, a first catalyst, and an activating agent, in a first solvent to provide a lignin-monomer comprising a six-atom cyclic carbonate; (b) reacting the lignin-monomer comprising a six-atom cyclic carbonate with a second catalyst, initiator, or combination thereof, in a second solvent to provide a polycarbonate. 2. A method comprising: reacting a lignin comprising a 1,3 diol with carbon dioxide, a first catalyst, and an activating agent, in a first solvent to provide a lignin-monomer comprising a six-atom cyclic carbonate. 3. A method comprising reacting a lignin monomer comprising a six-atom cyclic carbonate with a second catalyst, initiator, or combination thereof, in a second solvent to provide a polycarbonate. 4. The method of any of claims 1-3, wherein the lignin is reacted with carbon dioxide and the first catalyst to form a first intermediate, and the first intermediate is combined with an activating agent. 5. The method of any of claims 1-3, wherein the first catalyst comprises a cerium catalyst, a tin catalyst, an organometallic catalyst, a tertiary amine catalyst, or a combination thereof. 6. The method of any of claims 1-3, wherein the first catalyst comprises CeO2, CeO2-ZrO, Bu2Sn(OCH3)2, AgOAc, ZnI2/NEt3, 1,8-diazabicyclo(5.4.0)undec-7- ene or a combination thereof. 7. The method of any of claims 1-3, wherein the first catalyst comprises 1,8- diazabicyclo(5.4.0)undec-7-ene. Attorney Docket No.10850-070WO1 8. The method of any one of claims 1-3, wherein the lignin has a weight average molecular weight (Mw) from 10,000-25,000 g/mol, 25,000-50,000 g/mol, 10,000-50,000 g/mol, 1,000-10,000 g/mol, from 1,000-5,000 g/mol, from 1,000-2,000 g/mol, from 1,000-3,000 g/mol, from 1,000-4,000 g/mol, from 2,000-5,000 g/mol, from 2,000-4,000 g/mol, from 2,000-3,000 g/mol, from 3,000-5,000 g/mol, or from 4,000-5,000 g/mol. 9. The method of any of claims 1-3, wherein the activating reagent comprises a dihalide, alkyl halide, sulfonyl halide, acid chloride, or a combination thereof. 10. The method of any of claims 1-3, wherein the activating reagent comprises a sulfonyl halide and a tertiary amine base. 11. The method of any of claim 1-3, wherein the activating reagent comprises methane sulfonyl chloride, trifluoromethanesulfonyl chloride, or toluenesulfonyl chloride. 12. The method of any of claim 1-3, wherein the first solvent has a dielectric constant (ε) (at 20°C) of the solvent is at least 25, at least 30, or at least 35. 13. The method of any of claims 1-3, wherein the first solvent comprises dimethylacetamide, dimethylformamide, acetonitrile, dimethylsulfoxide, or a combination thereof. 14. The method of any of claims 1-3 wherein the lignin monomer is reacted with a second catalyst comprising an organometallic compound, Lewis acid, Bronsted acid, amine, or combination thereof, in a second solvent. 15. The method of any of claims 1-3, wherein the lignin monomer is reacted with an aminidine, guanidine, tertiary amine, or combination thereof. 16. The method of any of claims 1-3, wherein the lignin monomer is reacted with 1,5,7-triazabicyclo[4.4.0]dec-5-ene. 17. The method of any of claims 1-3, wherein the lignin monomer is reacted with an alcohol, a carboxylic acid, or a combination thereof. Attorney Docket No.10850-070WO1 18. The method of any of claims 1-3, wherein the lignin monomer is reacted with a Bronsted acid. 19. The method of any of claims 1-3, wherein the lignin monomer is reacted with a Lewis acid. 20. The method of any of claims 1-3, wherein the second solvent has a dielectric constant (ε) (at 20°C) that is no greater than 25, no greater than 20, no greater than 15, no greater than 10, or no greater than 5. 21. The method of any of claims 1-3, wherein the second solvent comprises dichloromethane, toluene, ethyl acetate, n-butyl acetate, glyme, methylethylketone, acetone, or a combination thereof. 22. The method of any of claims 1-3, wherein the polycarbonate has a weight average molecular weight (as measured by GPC) that is from 50-500 kDa, from 100-500 kDa, from 100-300 kDa, from 200-300 kDa, from 150-200 kDa, from 150-175 kDa, from 175-200 kDa, from 150-250 kDa, from 200-250 kDa, from 200-225 kDa, from 200-250 kDa, or from 225-250 kDa. 23. The method of any of claims 1-3, wherein the polycarbonate has a polydispersity from 1-2, from 1-1.5, 1-1.25, from 1.25-1.5, from 1.5-1.75, or from 1.75-2. 24. A lignin monomer prepared according to the process of any of claims 2-13. 25. A lignin monomer, having the formula: , wherein Ar1 and Ar2 are independently an aromatic ring in a lignin structural moiety. 26. The lignin monomer according to claim 24 or 25, wherein the monomer has a weight average molecular weight (Mw) from 10,000-25,000 g/mol, 25,000- Attorney Docket No.10850-070WO1 50,000 g/mol, 10,000-50,000 g/mol, 1,000-10,000 g/mol, from 1,000-5,000 g/mol, from 1,000-2,000 g/mol, from 1,000-3,000 g/mol, from 1,000-4,000 g/mol, from 2,000-5,000 g/mol, from 2,000-4,000 g/mol, from 2,000-3,000 g/mol, from 3,000-5,000 g/mol, or from 4,000-5,000 g/mol. 27. A polycarbonate prepared according to a process of any of claims 1 or 3-23. 28. A lignin-based polycarbonate, comprising units having the formula: , wherein Ar1 and Ar2 are independently an aromatic ring in a lignin structural moiety. 29. The polycarbonate of claim 28, wherein the polycarbonate has a weight average molecular weight (as measured by GPC) that is from 50-500 kDa, from 100-500 kDa, from 100-300 kDa, from 200-300 kDa, from 150-200 kDa, from 150-175 kDa, from 175-200 kDa, from 150-250 kDa, from 200-250 kDa, from 200-225 kDa, from 200-250 kDa, or from 225-250 kDa. 30. The polycarbonate of claim 28 or 29, wherein the polycarbonate has a polydispersity from 1-2, from 1-1.5, 1-1.25, from 1.25-1.5, from 1.5-1.75, or from 1.75-2. 31. A method of recycling a lignin-based polycarbonate, comprising combining a lignin-based polycarbonate with a recycling catalyst in a recycling solvent. 32. The method according to claim 31, wherein the recycling catalyst comprises cerium catalyst like CeO2 or CeO2-ZrO (mixite) oxide catalysts, a tin catalyst such as Bu2Sn(OCH3)2, an organometallic catalyst such as copper-based catalysts, magnesium-based catalysts, aluminum-based catalysts, silver- based catalysts, for example, AgOAc, zinc-based catalysts, such as ZnI2/NEt3, cobalt-based catalysts, chromium-based catalysts, iron-based Attorney Docket No.10850-070WO1 catalysts, nickel-based catalysts, titanium-based catalysts, hafnium-based catalysts, and zirconium-based catalysts, a tertiary amine catalyst such as 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU), or any combination thereof. 33. The method according to claim 32, wherein the recycling solvent dimethylacetamide, dimethylformamide, acetonitrile, dimethylsulfoxide, or a combination thereof. |
Attorney Docket No.10850-070WO1 [0071] The skilled person understands that additional reactive intermediates may be formed, for instance a carbonic acid may be installed on the primary alcohol group. The various intermediates are in chemical equilibrium, which may be driven towards the carbonic acid with an excess of carbon dioxide. Unless specified to the contrary, the depiction of one exemplary chemical intermediate does not exclude the presence of other intermediates. [0072] In still further aspects, the intermediate product (I) can be further reacted with an activating reagent comprising at least one reactive leaving group to give an activated intermediate. In some aspects, the activating reagent can include a dihalide, aryl or alkyl halide, sulfonyl halide, acid chloride, or any combination thereof, optionally in combination with a base. In certain implementations the activating reagent is a sulfonyl halide like methane sulfonyl chloride, trifluoromethanesulfonyl chloride, or toluenesulfonyl (“tosyl”) chloride. (“TsCl”) and a tertiary amine, for example triethylamine or diethylisopropylamine. [0073] In still further aspects, the intermediate product is reacted with the activating reagent at a temperature from 0 °C to about 35 °C, including exemplary values of about 1 °C, about 2 °C, about 3 °C, about 4 °C, about 5 °C, about 6 °C, about 7 °C, about 8 °C, about 9 °C, about 10 °C, about 11 °C, about 12 °C, about 13 °C, about 14 °C, about 15 °C, about 16 °C, about 17 °C, about °C, about 18 °C, about 19 °C, about 20 °C, about 21 °C, about 22 °C, about 23 °C, about 24 °C, Attorney Docket No.10850-070WO1 about 25 °C, about 26 °C, about 27 °C, about 28 °C, about 29 °C, about 30 °C, about 31 °C, about 32 °C, about 33 °C, and about 34 °C. In some implementations, the intermediate product is reacted with the activating reagent at a temperature from 0- 25°C., from 0-20°C., from 0-15°C, from 0-10°C, from 10-30°C, from 10-25°C, from 10-20°C, from 15-25°C, from 20-50°C, from 20-30°C, from 30-50°C, or from 25- 35°C. [0074] In still further aspects, the intermediate product is reacted with the activating reagent for about 12 h to about 24 h, including exemplary values of about 13 h, about 14 h, about 15 h, about 16 h, about 17 h, about 18 h, about 19 h, about 20 h, about 21 h, about 22 h, and about 23 h. In some implementations, the intermediate product is reacted with the activating reagent for a time that is from 6-48 h, from 12-48 h, from 18-48 h, from 24-48h, from 6-12 h, from 6-18 h, from 12-24 h, or from 18-36 h. [0075] The exemplary reaction between the intermediate product (I) and the activating reagent is shown in Scheme (2). In this example, the intermediate product (I) is reacted with TsCl/NEt 3 to form an additional intermediate product (II) that then forms a lignin-based monomer unit (III) comprising a carbonate group. In certain aspects, the carbonate group is a cyclic carbonate group, for example a six-atom cyclic carbonate or a five-atom cyclic carbonate. In preferred implementations, the carbonate is a six-atom cyclic carbonate. [0076] In certain implementations the reaction is carried out in a solvent selected from dimethylacetamide, dimethylformamide, acetonitrile, dimethylsulfoxide, or a combination thereof. In certain implementations, the dielectric constant (ε) (at 20°C) of the solvent is at least 25, at least 30, or at least 35. It has been found that the use of a solvent with similar dielectric constant to the cyclic carbonate (64) drives the equilibrium towards the cyclic carbonate monomer. In certain implementations, the reaction is carried out in a non-protic solvent (for example, a solvent other than water, alkyl alcohols, or carboxylic acids) as these solvents can compete with formation of the cyclic monomer. [0077] Attorney Docket No.10850-070WO1 [0078] As disclosed herein are lignin derived cyclic six-atom carbonates having the formula: , wherein Ar 1 and Ar 2 are as defined above. The cyclic carbonate may be obtained according to the processes disclosed herein. [0079] In some aspects, the lignin-based monomer unit (III) comprising a six-atom carbonate group is polymerized to form a polycarbonate. In such exemplary and unlimiting aspects, the step of polymerizing comprises a ring opening polymerization (ROP). Attorney Docket No.10850-070WO1 [0080] In certain aspects, the ring opening polymerization can be performed in the presence of the second catalyst, and initiator, or a combination thereof. As used herein, the second catalyst is a compound that is not ultimately incorporated into the polycarbonate system. An initiator, on the other hand, is typically incorporated at the carboxyl terminus of the polycarbonate. [0081] In certain implementations, the second catalyst includes an organometallic compound, for example catalysts comprising a metal including Al, Sb, Sn, Mg, Ca, Fe, Zn, Zr, or Ln, a Lewis acid, e.g., a compound having the formula MXn wherein M is a metal, X is a ligand, and n is a number from 1-6 selected to satisfy valence. In some cases, M is Al, Mg, Ca, B, Fe, Sc, Y, Sr, Ba, Co, Cr, Ir, Ga, Ti, V, Ce, Sm, Zr, Zn, Sn, or Yb, X can be chosen from OTs, OTf, OMs, OAC, Cl, Br, F, or I, and n is equal to the oxidation state of M. It is understood that any other known in the art Lewis acids can also be used a Bronsted acid (for example a sulfonic acid, phosphonic acid, or carboxylic acid), or an amine, for example a guanidine, amidine, or tertiary amine. The second catalyst can include Sb 2 O 3, Sb 2 O 5, antimony acetate, dodecylbenzenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, toluenesulfonic acid, diphenyl phosphate, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 1,2,3-tricyclohexylguanidine, 1,2,3-triisopropylguanidine, or any combination thereof. In still further aspects, the catalyst can be present in any amount. In still further aspects, the second catalyst comprises 1,5,7- triazabicyclo[4.4.0]dec-5-ene (TBD). [0082] In still further aspects, the ring opening polymerization is performed in the presence of an initiator. It is understood that any known in the art of ROP initiators that are suitable for the desired application can be utilized. In certain aspects, the initiators can comprise one or more alcohols or carboxylic acids, (for instance a phenol, benzyl alcohol), or any combination thereof. [0083] In some aspects and as disclosed herein, the catalyst and the initiator can be the same or different. [0084] In still further aspects, any of the disclosed herein, the ROP reaction can be performed at a temperature range from about 10°C to about 180°C, including exemplary values of about 20°C, about 30°C, about 40°C, about 50 °C, Attorney Docket No.10850-070WO1 about 60°C, about 70°C, about 80°C, about 90°C, about 100°C, about 110°C, about 120°C, about 130°C, about 140°C, about 150°C, about 160°C, and about 170 °C. In certain implementations, the ROP reaction is performed at room temperature. In certain implementations the ROP reaction can be performed at a temperature of at least about 20°C, at least about 30°C, at least about 40°C, at least about 50 °C, at least about 60°C, at least about 70°C, at least about 80°C, at least about 90°C, at least about 100°C, at least about 110°C, at least about 120°C, at least about 130°C, at least about 140°C, at least about 150°C, at least about 160°C, or at least about 170 °C. In certain implementations, the ROP reaction is performed at a temperature from 10-35°C, from 15-30°C, from 20- 30°C, or from 20-25°C. [0085] In yet further aspects, the ROP reaction is performed for a time that is from about 5 sec to 5 hours, including exemplary values of about 10 sec, about 30 sec, about 1 min, about 10 min, about 30 min, about 1 hour, about 2 hours, about 3 hours, and about 4 hours. In certain implementations, the ROP reaction is performed for a time between 5-600 minutes, from 5-400 minutes, from 5-250 minutes, from 5-100 minutes, from 5-50 minutes, or from 25-50 minutes. In still other aspects, the time period needed to complete the disclosed herein ROP reactions can be any time needed to provide a desirable amount of the product. [0086] In still further aspects, the ROP can be performed in the presence of a solvent. Any known in the art solvents can be used, for example, organic solvents, inorganic solvents, ionic liquids, and the like. In certain implementations, the ROP reaction can be performed in a solvent having a dielectric constant (ε) (at 20°C) that is no greater than 25, no greater than 20, no greater than 15, no greater than 10, or no greater than 5. In certain implementations, the ROP reaction can be performed in a solvent having a dielectric constant (ε) (at 20°C) that is from 0-25, from 0-20, from 0-15, from 1-20, from 1-15, from 1-10, from 1-7.5, from 1-5, or from 5-10. In certain implementations, the second solvent is dichloromethane, toluene, ethyl acetate, n-butyl acetate, glyme, methylethylketone, acetone, or a combination thereof. [0087] Also disclosed herein are lignin derived polycarbonates having the formula: Attorney Docket No.10850-070WO1 , wherein Ar 1 and Ar 2 are as defined above. The lignin derived polycarbonates can be obtained according to the processes disclosed herein. [0088] In still further exemplary aspects, the formation of polycarbonate through ring opening polymerization can occur according to Scheme (3). [0089] It is understood that the polycarbonate can have any desired molecular weight. For example, the molecular weight of the polycarbonate can range from about 1,000 Da to about 200,000 Da, including exemplary values of about 5,000 Da, about 10,000 Da, about 15,000 Da, about 20,000 Da, about 25,000 Da, about 30,000 Da, about 35,000 Da, about 40,000 Da, about 45,000 Da, about 50,000 Da, about 55,000 Da, about 60,000 Da, about 65,000 Da, about 70,000 Da, about 75,000 Da, about 80,000 Da, about 85,000 Da, about 90,000 Da, about 95,000 Da, about 100,000 Da, about 105,000 Da, about 110,000 Da, about 115,000 Da, about 120,000 Da, about 125,000 Da, about 130,000 Da, about 135,000 Da, about 140,000 Da, about 145,000 Da, about 150,000 Da, about 155,000 Da, about 160,000 Da, about 165,000 Da, about 170,000 Da, about 175,000 Da, about 180,000 Da, about 185,000 Da, about 190,000 Da, about 195,000 Da. In some implementations, the polycarbonate can have a number average molecular weight (as measured by GPC) that is from 50-500 kDa, from 100-500 kDa, from 100-250 kDa, from 100-200 kDa, from 150-200 kDa, from, from 100-150 kDa, from 125-150 kDa, from 100-125 kDa, from 150-175 kDa, from 175-200 kDa. In some implementations, the polycarbonate can have a weight average molecular Attorney Docket No.10850-070WO1 weight (as measured by GPC) that is from 50-500 kDa, from 100-500 kDa, from 100-300 kDa, from 200-300 kDa, from 150-200 kDa, from 150-175 kDa, from 175- 200 kDa, from 150-250 kDa, from 200-250 kDa, from 200-225 kDa, from 200-250 kDa, or from 225-250 kDa. In certain implementations, the polycarbonate can have a polydispersity from 1-2, from 1-1.5, 1-1.25, from 1.25-1.5, from 1.5-1.75, or from 1.75-2. [0090] In still further aspects, the formed polycarbonate is substantially biodegradable. Yet, in other aspects, the formed polycarbonate is fully biodegradable. [0091] The polycarbonate may be recycled to the cyclic carbonate monomer by treatment a recycling catalyst in a recycling solvent. In certain exemplary and non- limiting aspects, the recycling catalyst includes a cerium catalyst like CeO2 or CeO2- ZrO (mixite) oxide catalysts, a tin catalyst such as Bu 2 Sn(OCH 3 ) 2 , an organometallic catalyst such as copper-based catalysts, magnesium-based catalysts, aluminum- based catalysts, silver-based catalysts, for example, AgOAc, zinc-based catalysts, such as ZnI 2 /NEt 3 , cobalt-based catalysts, chromium-based catalysts, iron-based catalysts, nickel-based catalysts, titanium-based catalysts, hafnium-based catalysts, and zirconium-based catalysts, a tertiary amine catalyst such as 1,8- diazabicyclo(5.4.0)undec-7-ene (DBU), or any combination thereof. [0092] In certain implementations the recycling is carried out in a solvent selected from dimethylacetamide, dimethylformamide, acetonitrile, dimethylsulfoxide, or a combination thereof. In certain implementations, the dielectric constant (ε) (at 20°C) of the recycling solvent is at least 25, at least 30, or at least 35. [0093] Also disclosed herein is a method of capturing carbon dioxide, wherein the method comprises: converting carbon dioxide into a polycarbonate material by reaction of a lignin-based material with carbon dioxide; wherein the polycarbonate material is fully biodegradable. In such aspects, the method ensures the cradle-to- cradle formation of fully biodegradable polycarbonate and reduces carbon dioxide emissions. [0094] Also disclosed is a method of recycling a lignin-based material, which comprises: providing a biomass comprising a lignin-based material; and reacting the Attorney Docket No.10850-070WO1 lignin-based material with a stream of carbon dioxide to form a polycarbonate material; wherein the polycarbonate material is fully biodegradable. [0095] It is understood that the polycarbonate is completely degradable by enzyme/bacteria and hydrolysis, which are commonly available in the natural environment. [0096] The polycarbonate exhibits high mechanical strength and thermal properties. In certain implementations, the polycarbonate has a glass transition temperature (Tg) from 30-60°C, from 30-45°C, from 45-60°C, from 30-40°C., from 35-45°C, from 40-50°C, from 45-55°C, or from 50-60°C. [0097] Also disclosed are articles comprising the polycarbonate material formed by the disclosed herein methods. For example, and without limitations, the articles comprising the disclosed herein polycarbonates can comprise components of optical storage devices, automotive parts, packaging, electronics, mirrors and the like. In still further aspects, the articles formed herein can be used in the field of medicine, bioengineering electronics, textile, containers, furniture, automotive, military equipment, coatings, appliances, films, and the like. In certain aspects, the articles prepared from the disclosed biodegradable lignin-based polymers can also comprise packaging, food packaging, disposable cutlery, tableware, film, bags, nets, or any combination thereof. [0098] In still further aspects, disclosed are methods of making the articles, wherein the methods can comprise a step of extrusion, compression molding, injection molding, transfer molding, blow molding, or any combination thereof. EXAMPLES [0099] The following examples are for the purpose of illustration of the invention only and are not intended to limit the scope of the present invention in any manner whatsoever. Example 1 – Synthesis of cyclic carbonate monomer from lignin and CO2 Attorney Docket No.10850-070WO1 [00100] Three grams of lignin was placed into a dry three-neck round bottom flask furnished with two dropping funnels, and a magnetic stirrer. Anhydrous dimethylformamide (DMF) (0.1 mol L -1 , 135 mL) was added to the sealed flask and stirred until it formed a homogeneous dark brown solution. The system was purged of air by continuous argon gas flow to create a closed inert atmosphere. Then, a carbon dioxide (CO 2 ) gas-filled balloon was inserted into the system to replace the argon gas with CO 2 . The reaction mixture was saturated with CO 2 for 10 minutes and 2.02 mL of DBU (13.5 mmol) was added dropwise into the CO2-infused saturated solution of lignin in DMF. The reaction mixture became viscous after the addition. After being stirred for 2 hours at room temperature, the flask was placed in an ice bath to cool down the temperature to 0 °C. Subsequently, CO2-saturated 1.88 mL triethylamine (TEA) (13.5 mmol) was added gradually to the solution followed by the slow addition of CO 2 -saturated TsCl (2.57g, 13.5 mmol) solution in DMF. Both the TEA and TsCl solutions were added in a dropwise manner using the attached dropping funnels. Afterward, the reaction mixture was allowed to come to room temperature and stirred for an additional 24 hours. The crude product was washed several times with deionized water, DCM, and brine solution. The organic layer was collected and passed through the anhydrous MgSO4 to eliminate the trapped water. Lastly, a dark brown sticky product was obtained after evaporating the organic layer using a rotary evaporator. The total yield was 1.92 g (64 wt%). Example 2 – Ring Opening Polymerization [00101] The following procedure for the preparation of polymer P-4 is representative of the ring opening polymerization. The cyclic carbonate monomer (410 mg, OH content: 4.5 mmol g -1 , 1 equivalent) was taken in a pressure relief cap- containing 20 mL vial with a magnetic stirrer.1.8 mL (1 mol L -1 ) of anhydrous DCM was added in the vial and continuously flushed with argon gas. A solution of TBD (2.57 mg, 0.018 mmol, 0.01 equivalent) was prepared in anhydrous dichloromethane (DCM) with a concentration of 1 mol L -1 . Then, 18 µL of TBD solution was added in the monomer solution under argon atmosphere. The reaction mixture was stirred at room temperature for 30 minutes. The samples were collected in aliquots to track the polymer formation by 1 H NMR spectroscopy and GPC. Subsequently, the collected reaction solutions were quenched with benzoic acid. After removing the solvent Attorney Docket No.10850-070WO1 under reduced pressure, the crude product was dissolved in the least quantity of DCM and precipitated from diethyl ether. Multiple washes with diethyl ether yielded a light yellowish product. [00102] The reaction time (2, 5, 10, and 30 min) and amount of TBD (0.5, 1.0, 2.0, and 5.0 %) were varied for different polymerization reactions: (Table 1) a monomer: catalyst ratio; b number-average molecular weight; c weight-average molecular weight; d polydispersity index; e 5% decomposition temperature in TGA; f glass transition temperature from DSC. Example 3 – Chemical recycling [00103] The chemical recycling process of P-4 to the cyclic monomer was elaborated as follows. P-4 (250 mg, OH content: 4.5 mmol g -1 , 1 equivalent), DBU (8.56 mg, 0.05 equivalent) and 2.2 mL of acetonitrile (0.5 mol L -1 ) were taken in a 4 mL vial charged with a magnetic stirrer. After attaining a homogeneous brown Attorney Docket No.10850-070WO1 solution, the reaction mixture was placed in an oil bath at 90 °C and stirred for 24 hours. Afterward, the temperature cooled down to room temperature. Rotary evaporation was used to concentrate the crude solution. Subsequently, the product was washed several times with DCM and water. Finally, a dark brown sticky substance was obtained after concentrating the filtered organic layer. The total yield was 190 mg (76 wt %). Additional Embodiments 1. A method comprising: (a) reacting a lignin comprising a 1,3 diol with carbon dioxide, a first catalyst, and an activating agent, in a first solvent to provide a lignin-monomer comprising a six-atom cyclic carbonate; (b) reacting the lignin-monomer comprising a six-atom cyclic carbonate with a second catalyst, initiator, or combination thereof, in a second solvent to provide a polycarbonate. 2. A method comprising: reacting a lignin comprising a 1,3 diol with carbon dioxide, a first catalyst, and an activating agent, in a first solvent to provide a lignin-monomer comprising a six-atom cyclic carbonate. 3. A method comprising reacting a lignin monomer comprising a six-atom cyclic carbonate with a second catalyst, initiator, or combination thereof, in a second solvent to provide a polycarbonate. 4. The method of any of embodiments 1-3, wherein the lignin is reacted with carbon dioxide and the first catalyst to form a first intermediate, and the first intermediate is combined with an activating agent. 5. The method of any of embodiments 1-4, wherein the first catalyst comprises a cerium catalyst, a tin catalyst, an organometallic catalyst, a tertiary amine catalyst, or a combination thereof. 6. The method of any of embodiments 1-5, wherein the first catalyst comprises CeO2, CeO2-ZrO, Bu2Sn(OCH3)2, AgOAc, ZnI2/NEt3, 1,8- diazabicyclo(5.4.0)undec-7-ene or a combination thereof. Attorney Docket No.10850-070WO1 The method of any of embodiments 1-6, wherein the first catalyst comprises 1,8-diazabicyclo(5.4.0)undec-7-ene. The method of any one of embodiments 1-7, wherein the lignin has a weight average molecular weight (Mw) from 10,000-25,000 g/mol, 25,000-50,000 g/mol, 10,000-50,000 g/mol, 1,000-10,000 g/mol, from 1,000-5,000 g/mol, from 1,000-2,000 g/mol, from 1,000-3,000 g/mol, from 1,000-4,000 g/mol, from 2,000-5,000 g/mol, from 2,000-4,000 g/mol, from 2,000-3,000 g/mol, from 3,000-5,000 g/mol, or from 4,000-5,000 g/mol. The method of any of embodiments 1-8, wherein the activating reagent comprises a dihalide, alkyl halide, sulfonyl halide, acid chloride, or a combination thereof. The method of any of embodiments 1-9, wherein the activating reagent comprises a sulfonyl halide and a tertiary amine base. The method of any of claim 1-10, wherein the activating reagent comprises methane sulfonyl chloride, trifluoromethanesulfonyl chloride, or toluenesulfonyl chloride. The method of any of claim 1-11, wherein the first solvent has a dielectric constant (ε) (at 20°C) of the solvent is at least 25, at least 30, or at least 35. The method of any of embodiments 1-12, wherein the first solvent comprises dimethylacetamide, dimethylformamide, acetonitrile, dimethylsulfoxide, or a combination thereof. The method of any of embodiments 1-13 wherein the lignin monomer is reacted with a second catalyst comprising an organometallic compound, Lewis acid, Bronsted acid, amine, or combination thereof, in a second solvent. The method of any of embodiments 1-14, wherein the lignin monomer is reacted with an aminidine, guanidine, tertiary amine, or combination thereof. The method of any of embodiments 1-15, wherein the lignin monomer is reacted with 1,5,7-triazabicyclo[4.4.0]dec-5-ene. Attorney Docket No.10850-070WO1 The method of any of embodiments 1-16, wherein the lignin monomer is reacted with an alcohol, a carboxylic acid, or a combination thereof. The method of any of embodiments 1-17, wherein the lignin monomer is reacted with a Bronsted acid. The method of any of embodiments 1-18, wherein the lignin monomer is reacted with a Lewis acid. The method of any of embodiments 1-19, wherein the second solvent has a dielectric constant (ε) (at 20°C) that is no greater than 25, no greater than 20, no greater than 15, no greater than 10, or no greater than 5. The method of any of embodiments 1-20, wherein the second solvent comprises dichloromethane, toluene, ethyl acetate, n-butyl acetate, glyme, methylethylketone, acetone, or a combination thereof. The method of any of embodiments 1-21, wherein the polycarbonate has a weight average molecular weight (as measured by GPC) that is from 50-500 kDa, from 100-500 kDa, from 100-300 kDa, from 200-300 kDa, from 150-200 kDa, from 150-175 kDa, from 175-200 kDa, from 150-250 kDa, from 200-250 kDa, from 200-225 kDa, from 200-250 kDa, or from 225-250 kDa. The method of any of embodiments 1-22, wherein the polycarbonate has a polydispersity from 1-2, from 1-1.5, 1-1.25, from 1.25-1.5, from 1.5-1.75, or from 1.75-2. A lignin monomer prepared according to the process of any of embodiments 2-13. A lignin monomer, having the formula: , Attorney Docket No.10850-070WO1 wherein Ar 1 and Ar 2 are independently an aromatic ring in a lignin structural moiety. The lignin monomer according to claim 24 or 25, wherein the monomer has a weight average molecular weight (Mw) from 10,000-25,000 g/mol, 25,000- 50,000 g/mol, 10,000-50,000 g/mol, 1,000-10,000 g/mol, from 1,000-5,000 g/mol, from 1,000-2,000 g/mol, from 1,000-3,000 g/mol, from 1,000-4,000 g/mol, from 2,000-5,000 g/mol, from 2,000-4,000 g/mol, from 2,000-3,000 g/mol, from 3,000-5,000 g/mol, or from 4,000-5,000 g/mol. A polycarbonate prepared according to a process of any of embodiments 1 or 2-23. A lignin-based polycarbonate, comprising units having the formula: , wherein Ar 1 and Ar 2 are independently an aromatic ring in a lignin structural moiety. The polycarbonate of claim 28, wherein the polycarbonate has a weight average molecular weight (as measured by GPC) that is from 50-500 kDa, from 100-500 kDa, from 100-300 kDa, from 200-300 kDa, from 150-200 kDa, from 150-175 kDa, from 175-200 kDa, from 150-250 kDa, from 200-250 kDa, from 200-225 kDa, from 200-250 kDa, or from 225-250 kDa. The polycarbonate of claim 28 or 29, wherein the polycarbonate has a polydispersity from 1-2, from 1-1.5, 1-1.25, from 1.25-1.5, from 1.5-1.75, or from 1.75-2. A method of recycling a lignin-based polycarbonate, comprising combining a lignin-based polycarbonate with a recycling catalyst in a recycling solvent. Attorney Docket No.10850-070WO1 32. The method according to claim 31, wherein the recycling catalyst comprises cerium catalyst like CeO2 or CeO2-ZrO (mixite) oxide catalysts, a tin catalyst such as Bu 2 Sn(OCH 3 ) 2 , an organometallic catalyst such as copper-based catalysts, magnesium-based catalysts, aluminum-based catalysts, silver- based catalysts, for example, AgOAc, zinc-based catalysts, such as ZnI 2 /NEt 3 , cobalt-based catalysts, chromium-based catalysts, iron-based catalysts, nickel-based catalysts, titanium-based catalysts, hafnium-based catalysts, and zirconium-based catalysts, a tertiary amine catalyst such as 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU), or any combination thereof. 33. The method according to claim 32, wherein the recycling solvent dimethylacetamide, dimethylformamide, acetonitrile, dimethylsulfoxide, or a combination thereof. [00104] The compositions and methods of the appended claims are not limited in scope by the specific compositions and methods described herein, which are intended as illustrations of a few aspects of the claims and any compositions and methods that are functionally equivalent are intended to fall within the scope of the claims. Various modifications of the compositions and methods in addition to those shown and described herein are intended to fall within the scope of the appended claims. Further, while only certain representative compositions and method steps disclosed herein are specifically described, other combinations of the compositions and method steps also are intended to fall within the scope of the appended claims, even if not specifically recited. Thus, a combination of steps, elements, components, or constituents may be explicitly mentioned herein or less, however, other combinations of steps, elements, components, and constituents are included, even though not explicitly stated. The term "comprising" and variations thereof as used herein is used synonymously with the term "including" and variations thereof and are open, non-limiting terms. Although the terms "comprising" and "including" have been used herein to describe various embodiments, the terms "consisting essentially of" and "consisting of" can be used in place of "comprising" and "including" to provide for more specific embodiments of the invention and are also disclosed. Other than in the examples, or where otherwise noted, all numbers expressing quantities of Attorney Docket No.10850-070WO1 ingredients, reaction conditions, and so forth used in the specification and claims are to be understood at the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, to be construed in light of the number of significant digits and ordinary rounding approaches.