AMINE-BORANE ADDUCTS IN THE SYNTHESIS OF POLYESTER AND ITS COPOLYMERS USING CYCLIC ESTERS AND COMPOSITIONS THEREOF CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims benefit of US Provisional Application No. 63/309,740 filed on February 14, 2022. US Provisional Application No.63/309,740 is incorporated herein by reference. A claim of priority is made. BACKGROUND [0002] Over the past two decades, organocatalysis has emerged as a powerful alternative to metal-based catalysis for the ring-opening polymerization (ROP) of cyclic esters, paving the way for the synthesis of metal-free aliphatic polyesters aimed at biomedical and microelectronic applications. However, among the organocatalysts described so far, one common feature is their lack of versatility. For instance, organocatalysts that would work for Caprolactone would necessarily not be appropriate for cyclic ethers or even lactides. On the other hand, boron-based ate complexes which also enter in the category of organocatalysts have shown exceptional versatility by enabling the synthesis of miscellaneous oxygenated polymers, including polyethers, polyesters, polycarbonates, polythiocarbonates, polyurethanes, etc. One of the alkyl boron used in these ate complexes, triethyl boron (TEB), is a mild Lewis acid which is oxyphilic and of non-metallic character. When utilized in combination with an oxyanion or a Lewis base, TEB-based Lewis pairs demonstrate reversible interaction and an extraordinary degree of tunability with respect to their reactivity. Unlike classical Lewis pairs which form stable Lewis adducts or frustrated Lewis pairs which have not found yet an opportunity for application in polymer chemistry, such TEB-based Lewis pairs were indeed shown to bring about the “living” (co)polymerizations of the following (co)monomers: epoxides / CO2, epoxides / COS, epoxides / anhydrides, epoxides / isocyanates. There is no study or report on the “living” /controlled ROP of lactones and lactides in the presence of TEB-based ate complexes. SUMMARY [0003] In general, embodiments of the present disclosure describe a process for polymerizing at least one polymerizable compound, comprising reacting a borane and amine to form an amine-borane adduct. The process further comprises contacting the adduct with a composition comprising at least one polymerizable cyclic compound and initiating a ring opening polymerization sufficient to form a polymer. [0004] Embodiments of the present disclosure further describe a polymer of at least one cyclic compound comprising: where An represents an anion selected from halides, carboxylates and alkoxides (mono- or difunctional, polyfunctional); R1 and R2 represent a hydrogen atom, a linear or branched C1- C20 alkyl being saturated or unsaturated; a linear or branched C1-C20 alkyl containing one or more atoms selected from oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom and halogen atom; C1-C20 alkyl bearing one or more aromatic rings; R1, R2, R3, R4 and R5 may be the same or different; where n ranges from 0-5000 , m ranges from 0-5000 and y ranges from 1-1000. BRIEF DESCRIPTION OF DRAWINGS [0005] This written disclosure describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to illustrative embodiments that are depicted in the figures, in which: [0006] FIG. 1A shows the flowchart of the process of synthesizing polyester and its copolymers using Amine-Borane adduct.

[0007] FIG. IB shows the MALDI-TOF MS spectra of the polymerized caprolactone

(PCL) according to some embodiments.

[0008] FIG. 2 shows the ¹ H NMR spectrum of the PCL in CDCh (Table 2, entry 9).

[0009] FIG. 3 shows the ¹³ C NMR spectrum of the PCL in CDCh (Table 2, entry 12).

[0010] FIG. 4 shows the ¹ H NMR Spectrum of the Block Copolymer PPO-b-PCL in

CDCh (entry 1, Table S3).

[0011] FIG. 5 shows the ¹³ C NMR Spectrum of the Block Copolymer PPO-b-PCL in CDCh (entry 1, Table S3).

[0012] FIG. 6 shows the COSY NMR spectra of P(PO-co-VL) copolymer (Entry

4, Table S2).

[0013] FIG. 7 shows the ³ H- ¹³ C HSQC NMR spectra of P(PO-co- VL) copolymer (Entry

4, Table S2).

[0014] FIG. 8 shows the DOSY NMR spectrum of the PVL-b-PPO sample (Table 3, entry 25).

[0015] FIG. 9 shows the SEC curves of the polymer PVL-Z?-PPO in THE (Entry 4, Table

S3).

[0016] FIG. 10 shows the ³ H NMR spectrum of the diblock polymer PVL-b-PPO (Entry 4, Table S3).

[0017] FIG. 11 shows the ³ H NMR spectrum of the obtained PPO-Z?-PCL in CDCh

(Entry 1, Table S3).

[0018] FIG. 12 shows the ¹³ C NMR spectrum of the obtained PPO-Z?-PCL in CDCh (Entry 1, Table S3).

[0019] FIG. 13 shows the ³ H NMR spectrum of the obtained PPO-Z?-PVL in CDCh

(Entry 2, Table S3).

[0020] FIG. 14 shows the ¹³ C NMR spectra of the obtained PPO-Z?-PVL in CDCh (Entry

2, Table S3).

[0021] FIG. 15 shows the ¹ H NMR spectra of the obtained PPO-Z?-PLLA in CDCh (Entry

3, Table S3).

[0022] FIG. 16 shows the ¹³ C NMR spectra of the obtained PPO-b-PLLA in CDCh (Entry 3, Table S3). [0023] FIG.17(A) shows the ¹³ C NMR spectra stack of P(PO-co-VL) copolymer (Entry 4, Table S2). [0024] FIG.17B) shows the ¹³ C NMR spectra of PPO-b-PVL block polymers (Entry 2, Table S3). [0025] FIG.17(C) shows the ¹³ C NMR spectra of homopolymer PVL (Entry 14, Table 1). [0026] Fig. 18 shows the ¹ H NMR spectrum of the obtained PLLA-b-PPC-b-PLLA in CDCl ₃ (Table 3, entry 22). [0027] FIG. 19 shows the GPC trace of the polymer PLLA-b-PPC-b-PLLA (Table 3, entry 23). DETAILED DESCRIPTION [0028] The present disclosure is an effort to advance an easy access to a whole range of oxygenated polymers by TEB-based ate complexes for the synthesis of polyesters through anionic ring-opening polymerization (AROP) of cyclic esters, and of their block or random copolymers by TEB/onium salts system. Furthermore, the TEB-based ate complexes were not nucleophilic enough to promote the polymerization of lactones which was very slow (only 5% conversion of caprolactone over 24 h) despite the addition of (thio)ureas to activate the monomer. To fine-tune and increase the nucleophilic character of growing ate complexes in order to achieve the “controlled” AROP of cyclic esters, various amines have been used. For the polymerization of different cyclic esters, the amines and (thio)ureas were chosen and varied to match their reactivities for successful control of ring opening polymerization. [0029] The present disclosure relates to the use of amine-borane adduct in the synthesis of polyester and its copolymers through (co)polymerization of cyclic esters and with other oxygenated monomers. Triethylborane (TEB) and in general trialkylborane (TAB), especially represent an exceptional Lewis acid owing to its easy commercial availability, mild Lewis acidity, oxyphilic and especially its non-metallic character. Recently, TEB has emerged as a powerful Lewis acid to carry out polymerizations combined with an organic Lewis base (LB) or initiator. Such systems that enter in the category of organocatalyst/metal-free initiators have made a huge success in the homopolymerization of epoxides and their copolymerizations with other monomers, such as oxetanes with carbon dioxide (CO ₂ ). These processes exhibit high activity, controlled/ “living” character and afford polymers or copolymers containing polyethers, polycarbonates, polythiocarbonates or polyesters. In addition, due to the easy availability and non-metallic character of TEB, the polymerizations could be performed under metal-free conditions; multi-step synthesis of catalyst and post-purification removal of catalyst residues like in the cases of organometallic catalysts can thus be avoided. Besides the successful synthesis of various polyethers, polycarbonates, polythiocarbonates, polyesters and polyurethanes, miscellaneous random- and sequential copolymerizations of above-mentioned monomers could be carried out in the presence TEB-based ate complexes acting as initiators. However, there are limited reports on the “living” /controlled ring opening polymerization (ROP) of cyclic esters in the presence of TEB-based ate complexes. In addition, the described systems are not versatile enough for polymerization of other oxygenated monomers such as copolymerization of epoxides with CO ₂ or other heteroallene monomers. [0030] The embodiments of the present disclosure describe the synthesis of polyesters through anionic ring-opening polymerization (AROP) of cyclic esters, and of their block or random copolymers by TEB/onium salts system, which provides access to a large range of oxygenated polymers by TEB based ate complexes. The onium salts may be polymeric or macromolecular alkoxide, carbonate, carboxylic onium salts, the polymers can be polyether, polyester, polycarbonate, polyethercarbonate. Embodiments of the present disclosure also describe a polymerization process wherein the onium salt is selected from tetrabutylammonium chloride (TBACl), Bis(triphenylphosphoranylidene)-ammonium chloride (PPNCl), 1,4- dihydroxymethylbenzene/P4-t-bu (DHMB/P4-t-Bu), tetrabutylammonium butanolate (TBABO), tetraoctylammonium chloride (TOACl), Bis(triphenylphosphoranylidene)- ammonium acetate (PPNAc), hydroxymethylbenzene/P4-t-Bu (HMB/P4-t-Bu), tetrabutylammonium succinate (TBAS). [0031] In the present disclosure, various amines have been used to fine-tune and increase the nucleophilic character of growing ate complexes to achieve the “controlled” AROP of cyclic esters. Furthermore, certain embodiments of the present disclosure describe the polymerization of different cyclic esters, wherein the amines and (thio)ureas were chosen and varied to match their reactivities for successful control of ring opening polymerization. As shown in Scheme 1, this process of the present disclosure was compatible with (homo)copolymerization of other oxygenated monomers and afforded yet other embodiments of the present disclosure, which are poly(ether-ester), poly(carbonate-ester) diblock, triblock or random copolymers.

Scheme 1: An- represents an anion selected from halides, carboxylates and alkoxides; Ct ⁺ represents a cation selected from tetraalkylammoniums, tetraalkylphosphoniums, phosphazeniums; R ₁ , R ₂ , R ₃ , R ₄ and R ₅ independently represent a hydrogen atom, a linear or branched C ₁ -C ₂₀ alkyl being saturated or unsaturated; a linear or branched C ₁ -C ₂₀ alkyl containing one or more atoms selected from oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom and halogen atom; C ₁ -C ₂₀ alkyl bearing one or more aromatic rings; R ₁ , R ₂ , R ₃ , R ₄ and R ₅ may be the same or different. CHEMICAL STRUCTURES AND ABBREVIATIONS USED IN THE EMBODIMENTS OF THE PRESENT DISCLOSURE: [0032] [0033]

Chemical structures and abbreviations of representative cyclic esters:

[0034]

Chemical structures and abbreviations of representative trialkylborane (LA):

[0035]

Chemical structures and abbreviations of primary and secondary amines (AM): [0036]

Chemical structures and abbreviations of (thio)ureas (HBD):

[0037]

Chemical structures and abbreviations of representative initiators (I):

[0038] Processes of synthesizing polyester and its copolymers using Amine-Borane adduct are described herein. The embodiments of the present disclosure describe a process for polymerizing at least one polymerizable compound, comprising at least one cyclic compound, in the presence of an adduct of borane with an amine as the initiator. FIG. 1(A) is a flowchart of the process of synthesizing polyester and its copolymers using Amine-Borane adduct. As shown in FIG. 1(A), the process may comprise reacting 101 the borane and amine to form the amine-borane adduct and contacting 102 the adduct with a composition comprising at least one polymerizable cyclic compound. The process further comprises initiating 103 the ring opening polymerization of the cyclic compounds sufficient to form polymers. [0039] Certain embodiments of the present disclosure describe an anionic ring opening polymerization. Table 1 summarizes anionic ring opening polymerization (AROP) of caprolactone using TEB-Ate complex. The polymerization is carried out using t-BuP ₄ H ⁺ /BnO- as initiator in the presence of amine-borane adduct. [0040] Certain embodiments of the present disclosure describe polymerization of cyclic esters in the presence of (thio)ureas using t-BuP ₄ H ⁺ /BnO- as initiator in the presence of amine- borane adduct. The present disclosure describes the polymerization process according to one or more embodiments wherein the cyclic ester is selected from, but is not limited to, lactide (LA), trimethylene carbonate (TMC), γ-butyrolactone (γ-BL), β-butyrolactone (β-BL), €- Caprolactone (€-CL), δ-valerolactone (δ-VL), δ-hexalactone (δ-HL), ω-pentadecalactone (PDL). Scheme 2 shows the “controlled” AROP of cyclic esters initiated by Phosphazenium alkoxide in the presence of (thio)urea and amine.

Scheme 2: “Controlled” AROP of cyclic esters initiated by phosphazenium alkoxide in the presence of (thio)urea and amine. [0041] In the present disclosure, it was found that in the presence of TEB-based ate complexes used as initiators, the polymerization of lactones is very slow (no polymerization of CL was observed over 24 h). Therefore, various amines and (thio)ureas were used alone or together along with TEB-based initiating species and eventually achieved the control of the AROP of the above mentioned cyclic esters. It was found that the role of amines and of (thio)ureas used as additives is not the same: amines preferentially activate the monomer whereas (thio)ureas give rise to distinct TEB-based active species in the presence of TEB-based initiators. In both cases, the ROP of the tested cyclic esters was only moderately increased (only 4% and 5% conversion of CL achieved over 24 h when BuA and TU were respectively added). However, when used together, a synergistic effect was observed, as illustrated by the fast and yet controlled polymerization of all three cyclic esters (CL, VL, LLA) (see the results in Table 2). Table 2A shows the comparative results of the synergistic effect of the Amine and Thiourea. In the case of LLA (L-Lactide), the presence of amines was even found to be unnecessary. As shown in Scheme 2, the three cyclic esters, CL, VL and LLA were polymerized in the presence of phosphazenium t-Bu-P ₄ H ⁺ benzoxide/TEB serving as TEB- based initiators with or without addition of amines and (thio)ureas used alone or synergistically. As a demonstration of the versatility of these TEB-based systems, PO and VL were randomly copolymerized; PO, CL, VL and LLA were also sequentially copolymerized affording an array of statistical, diblock and triblock copolymers.

[0042] Table 2 summarizes the ring opening polymerization of various cyclic esters in the presence of (thio)ureas using t-BuP4H ⁺ /BnO" as initiator in the presence of amine-borane adduct. Table 2 A shows the comparative results of the synergistic effect of amine and Thiourea. Although only CL is shown in Table 2A as a model monomer, other cyclic esters were impacted similarly by this synergy.

Table 2. Ring-opening polymerization of cyclic esters in the presence of (thio)ureas using t-BuP ₄ H ⁺ /noO- as a The polymerizations were carried out at 25 °C in toluene for CL and VL and in THF for lactide. [M] _o = 1.0 mol L ^-1 . ^b Determined by ¹ H NMR from the crude polymerization mixtures. ^c Theoretical molar mass = Mass(monomer) x (M/I) x Conversion+108. ^d Determined by SEC (in THF) at 35 °C using polystyrene standard and modified by correction factors of 0.56 for PCL, 0.57 for PVL, 0.58 for PLLA. ^e The polymerization was conducted at 50°C. ^f TEB-BuA adduct were added into the reaction mixture. Table 2A: Comparative results showing the synergistic effect of Amine and Thiourea

Ring-opening polymerization of cyclic esters in the presence of amine and thiourea using t-BuP ₄ H ⁺ /BnO- as initiator. ^a a The polymerizations were carried out at 25 °C in THF for CL. ^b Determined by ¹ H NMR from the crude polymerization mixtures. ^c Theoretical molar mass = Mass(monomer) x (M/I) x Conversion+108. ^d Determined by SEC (in THF) at 35°C using polystyrene standard and modified by correction factors of 0.56 for PCL.

[0043] Yet other embodiments of the present disclosure describe sequential polymerization of epoxides (or epoxides and carbon dioxide) and cyclic esters for polyester- containing block polymers. Table 3 summarizes the sequential polymerization of epoxides (or epoxides and carbon dioxide) and cyclic esters for polyester-containing block polymers.

Table 3. Sequential polymerization of epoxides (or epoxides and carbon dioxide) and cyclic esters for polyester- containing block a The polymerization was performed in toluene with sequential addition of monomer, TEB; and cyclic esters. ^b Determined by ¹ H NMR spectra of crude polymerization mixtures. ^c Determined by SEC at 35°C using THF as the solvent and using polystyrene standard without a correction factor. ^d The solvent is THF. ^e Polymerizations were carried out in 50 mL Parr reactor under 10 bar CO2 with stirring at 40 °C first. ^f TEB (3.0 equiv.) were added in the second polymerization.

[0044] The embodiments of the present disclosure also describe representative polyester- containing random copolymers through (ter)polymerization of cyclic esters with epoxides, and with epoxides and carbon dioxide. Scheme 3 shows the statistical and block polymerization of cyclic esters and epoxides. As shown in Scheme 3, embodiments of the present disclosure also describe that TEB-based ate complexes successfully used in the synthesis of several oxygenated polymers, require additional activation by (thio)ureas and amines for lactones, and by (thio)ureas alone for lactides, inducing in both cases a fast polymerization and producing well-defined polyester samples free of epimerization. Therefore, it appears that TEB-based ate complexes, by their versatility, provide an opportunity to copolymerize either randomly or sequentially more than one family of monomers (Scheme 3). To further demonstrate the versatility of TEB-based ate complexes, the embodiments of the present disclosure describe TEB-based initiation systems were used to synthesize block copolymers made of poly(propylene oxide) blocks and polyester blocks. For example, after obtaining the first ester PVL block through ROP of VL as described in the previous section, PO along with 3 more eq. of TEB were added to sequentially ROP of PO: a PVL-b-PPO diblock copolymer with PVL as first block was obtained with a well-defined structure (Scheme 3B, FIG.9, FIG.10). Likewise, starting from polyether blocks which were successfully grown using tetrabutylammonium chloride as initiator, poly(propylene oxide)-b-polylactone and poly(propylene oxide)-b- polylactide block copolymers were synthesized (Scheme 3C). Tetrabutylammonium chloride (TBACl) was added to TEB before initiating the polymerization of PO. After complete AROP of PO in the presence 2 eq. TEB with respect to TBACl, lactones and lactide monomers were then sequentially polymerized after introducing in the reaction medium either an amine and/or a urea (Table 4) under optimized conditions as previously shown (TEB/XyDA/UPh=2/0.5/3/1). In all cases (Table 4), narrow, unimodal SEC traces were detected, and a clear shift of traces with respect to the traces of the PPO precursor was observed, indicating the formation of the expected diblock copolymers. In addition to the characteristic peaks due to PPO and polyester blocks in NMR spectra (FIGS. 11-16), the diffusion- ordered (DOSY) NMR spectrum exhibits same diffusion coefficients for the two block segments, confirming the diblock nature of the copolymers formed, PPO-b-PVL, PPO-b-PCL and PPO-b-PLLA. Similar to the preparation of PVL-b-PPO diblock copolymer, sequential additions of PO and the use of more TEB afforded PPO-b-PVL-b-PPO triblock copolymer. The embodiments of the present disclosure, therefore, also describe triblock polymers of the cyclic esters and epoxides. The embodiments of the present disclosure also describe triblock polymers of the cyclic esters with epoxides and carbon dioxide. The embodiments of the present disclosure also describe triblock polymers of the different cyclic esters.

Scheme 3: Statistical and block polymerization of cyclic esters and epoxides

Table 4 summarizes representative polyester-containing random copolymers through (ter)polymerization of cyclic esters with epoxides, and epoxides, carbon dioxide.

Table 4. Representative polyester-containing random copolymers through (ter)polymerization of cyclic estere with epoxides, and epoxides, carbon dioxide. ^{a a} Polymerizations were carried out at 60°C over a period of 12 hours. ^b Yield = weight of polymer obtained/theoretical weight of an alternating polymer at full conversion* 100%. ^c Determined by GPC with THF as eluent and calibrated by polystyrene standard. ^d at room temperature. [0045] The embodiments of the present disclosure are obtained by anionic ring opening polymerization as mentioned above. Scheme 4 represents the proposed mechanism of AROP of cyclic esters initiated by t-BuP ₄ H ⁺ /BnO- in the presence of amine and urea. Scheme 4. Proposed mechanism of AROP of cyclic esters initiated by [t-BuP ₄ H ⁺ ][BnO-]/TEB in the presence of amine and urea. ¹¹ B NMR characterization (pure TEB δ= 73.5 ppm; TEB-BuA δ= -3.9 ppm; [t-BuP ₄ H ⁺ ][BnO- ]/TEB δ= 0.9 ppm; [t-BuP4H ⁺ ][BnO-]/TEB/BuA/CL δ= 0.8 ppm; [t-BuP4H ⁺ ][BnO-]/TEB/UPh/CL δ= 1.3 ppm; [t- BuP ₄ H ⁺ ][BnO-]/TEB/BuA/UPh/CL δ= 0.8; -3.9 ppm) was performed in THF-d ₈ . Certain embodiments of the present disclosure describe the polymerization of cyclic esters carried out in the presence of TEB/onium salts system. The AROP of caprolactone (CL) proceeded very fast when initiated by [t-BuP ₄ H ⁺ ][BnO-] that was obtained by deprotonation of BnOH by a superbase t-BuP ₄ . The produced polyester exhibited, as expected, a broad polydispersity due to the occurrence of transesterification reactions (entry 1, Table S1). Upon adding one equivalent of TEB, an ate complex made from the above mentioned alkoxide initiator [t-BuP ₄ H ⁺ ][BnO-] and TEB was formed which totally quenched polymer growth: no monomer conversion was detected even after 24 hrs (entry 2, Table S1) and only a modest conversion of 1% was observed after 48hrs (entry 3, Table S1). In contrast, in the case of epoxides, adding TEB in excess to the alkoxide did not boost the polymerization neither at room temperature nor at 50 ^o C (entry 4 and 5, Table S1), indicating that the ate complex formed upon addition of TEB was not nucleophilic enough to ring-open CL. Upon reducing the amount of TEB and using a ratio of 0.8 to the initiator -thus leaving some benzoxide uncomplexed ([t- BuP ₄ H ⁺ ][BnO-]/[TEB]=1/0.8)- the polymerization proceeded uncontrolled; the polydispersity index (Đ = 1.42) was narrower than that without TEB (entry 6, Table S1), but scrambling transesterification reactions could not be efficiently curbed with a ratio of 0.8 between the growing chains and TEB. Considering that ate complexes made of [t-BuP ₄ H ⁺ ][BnO-] alkoxide and TEB are not active enough towards CL, several amines were used hoping that they can either modify the nucleophilic character of the growing ate complex or activate the monomer through hydrogen bonding. The addition of one equivalent of butyl amine (BuA) to the [t- BuP ₄ H ⁺ ][BnO-]/TEB ate complex triggered the polymerization of CL, though at a slow pace (28% conversion after 192 h), generating a PCL sample with a narrow polydispersity index (Đ=1.09) and controlled molar mass (entry 7, Table S1). ^a The reactions were run in toluene ([M]0 = 1.0 mol L-1). ^b Determined by 1H NMR in CDCl3. ^c Theoretical molar mass = 114 × (M/I) × Conversion + 108. ^d Determined by SEC (in THF) at 35 ^o C using polystyrene standard and a correction factor of 0.56. ^e TEB-BuA adduct were added into the reaction mixture. [0046] ¹¹ B NMR was performed to verify the hypothesis that the primary amine when mixed with Boron-based ate complexes can weaken the BnO-/TEB Lewis pair and thus activate it. ¹¹ B was used as a probe to understand the exact role played by these amines. It was determined that the amines did not disrupt the Lewis pair made of oxy-anion (BnO-) and TEB (4) but they activate cyclic esters through hydrogen-bonded interaction with the monomer carbonyl, allowing a rather slow but well controlled ROP of CL, VL, and LLA to occur (route A, Scheme 4). Besides BuA, other amines used included, but are not limited to, isobutylamine (IBuA), isopropylamine (IPA), cyclohexanamine (CyHA), 1,3-xylenediamine (XyDA), ethylenediamine (EtDA), diethylamine (DEA), diisobutylamine (DIBA), diisopropylamine (DIPA) and triethylamine (TEA). These amines were used in association with [t-BuP ₄ H ⁺ ][BnO- ]/TEB and their impact on the rate of polymerization was evaluated (entries 10-19, Table S1). Based on the obtained results, the various amines used can be ranked in the following order for their ability to activate CL through hydrogen-bonding and thus for their influence on the rate of polymerization: normal primary amines > isopropyl amine and isobutyl amine > secondary amines. XyDA demonstrated the highest impact on the rate of polymerization and on the control of CL ROP.89% conversion of CL could be reached at room temperature in 120 hours, and the polymers generated exhibited molar masses very close to the theoretical value and a narrow polydispersity (1.06). [0047] The controlled ROP of cyclic esters is described in the present disclosure, with respect to the use of (thio)ureas in yet other embodiments. In the presence of alkoxides (mono- or difunctional, polyfunctional), the latter compounds get deprotonated and appear to activate both the hydroxyl-terminated chain end and the monomer. The present disclosure also demonstrates that the boron-based ate complexes and (thio)ureas are perfectly compatible and that their combination produces novel reactive species (5) that are distinct from the initial ate complexes (3). Thus, four hydrogen-bonding donor (HBD) (thio)ureas were tested as activators in the AROP of cyclic esters carried out in the presence of the complex [t-BuP ₄ H ⁺ ][BnO-]/TEB, which include, but are not limited to, 1,3-diisopropylthiourea(TU), 1,3-diphenylthiourea (TUPh), 1,3-diethylurea (UEt) and 1,3-diphenylurea (UPh). As evidenced by ¹¹ B NMR, these reactive species are more nucleophilic than their parent boron-based ate complex, but unlike the latter species, are able to bring about the “living”/controlled ROP of cyclic esters. The propagation proceeds at a moderate rate in the presence of these boron-based urea anions (5) or thioimidolate but is free of intramolecular/transesterification reactions (route B, Scheme 4). The present disclosure also describes embodiments wherein a synergistic effect is observed when alkoxide/urea/TEB systems are associated with amines. The said synergy likely entails monomer activation by both amine and urea through hydrogen bonding with the monomer carbonyl (6 and 6’, TEB complexed and uncomplexed urea anions), bringing about a rather fast ROP of cyclic esters (route C, Scheme 4, entry 4 in Table 1). Yet the corresponding sample with rather broader dispersity (D = 1.18) also indicates that transesterification occurred after addition of BuA, due to the presence of the species 6’. The latter species which is found in experiments corresponding to entries 1 and 2 of Table 1 are obviously responsible for transesterification reactions. In other words, the species when associated with t-BuP ₄ H ⁺ cations do not bring about a “living’/controlled polymerization of cyclic esters. Upon adding an excess of TEB (entry 6, Table 1), there was a favored formation of the species 6 at the expense of species 6’ and eventually a rather fast and yet controlled ROP of cyclic esters was achievable. ¹ H NMR characterizations give similar results, where only urea disrupts the ate complex 3 into 5, with two group of peaks appearing at 0.82, 0.28 ppm and 0.73, 0.15 ppm corresponding to methyl and methylene protons of TEB, revealing the existence of two different species 6 and 6’ after addition of both urea and amine into the ate complex 3.

[0048] One or more embodiments of the present disclosure describe a polymer of at least one cyclic compound, comprising, but not limited to,

OR

Where An represents an anion selected from halides, carboxylates and alkoxides (mono- or difunctional, polyfunctional); R ₁ and R ₂ represent a hydrogen atom, a linear or branched C ₁ - C ₂₀ alkyl being saturated or unsaturated; a linear or branched C ₁ -C ₂₀ alkyl containing one or more atoms selected from oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom and halogen atom; C1-C20 alkyl bearing one or more aromatic rings; R ₁ , R ₂ , R ₃ , R ₄ and R ₅ may be the same or different; where n ranges from 0-5000, m ranges from 0-5000 and y ranges from 1-1000. The molecular weight of the polymer ranges from 10,000 g.mol ^-1 to 1,000,000 g.mol ^-1 . [0049] The other main advantage of using urea anions as Lewis base in combination with TEB as Lewis acid is that the Lewis pair formed can not only serve to polymerize cyclic esters but also an epoxide such as PO. As such, the (thio)urea anions can only catalyze the ROP of cyclic esters but are helpless for epoxides. However, when associated with amines, urea anions/TEB Lewis pairs demonstrate enough adaptability and adjustability of their reactivity to allow the successful (co)polymerization of both cyclic esters and epoxides. Examples Example 1: Synthesis of TEB-BuA adduct [0050] In a flame-dried Schlenk flask, BuA (1.095 g, 15 mmol) was mixed with a 1.0 M solution of TEB in THF (10 mL, 10 mmol) at −78 °C. The mixture was gradually warmed to room temperature and stirred for 2 h. Then the volatiles were removed from mixture under vacuum. A clear oil solution of TEB-BuA adduct was obtained as also confirmed by NMR. ¹ H NMR (400MHZ, CDCl ₃ ), δ (ppm), 2.78 (CH ₃ CH ₂ CH ₂ CH ₂ NH ₂ ), 2.64 (CH ₃ CH ₂ CH ₂ CH2NH ₂ ), 1.52 (CH ₃ CH ₂ CH2CH ₂ NH ₂ ), 1.38 (CH ₃ CH2CH ₂ CH ₂ NH ₂ ), 0.95 (CH ₃ CH ₂ CH ₂ CH ₂ NH ₂ ), 0.70 (B(CH ₂ CH3) ₃ ), 0.15(B(CH2CH ₃ ) ₃ ). ¹¹ B NMR (128 MHz, THF- d ₈ ) δ (ppm), -3.92. Example 2: Controlled Anionic Ring Opening Polymerization of Caprolactone in the Presence of TEB and Amine [0051] In an argon-filled glove box, benzyl alcohol (BnOH, 5.2 μL, 0.05 mmol, 1.0 equiv.) and t-BuP ₄ (62.5 μL, 0.05 mmol, 1.0 equiv.) were added into the Schlenk tube by micro syringe. After 5 min of stirring, TEB (1M in THF, 50 μL, 0.05 mmol, 1.0 equiv.), 1,3- xylenediamine (XyDA) (3.4 mg. 0.025 mmol, 0.5 equiv.), toluene (4.5 mL), ε-caprolactone (CL) ([CL] ₀ = 1.0 mol L ⁻¹ , 0.57g, 5 mmol, 100 equiv.) were sequentially added to the solution to initiate the polymerization. The mixture was stirred at 25 °C and monitored by ¹ H NMR spectroscopy. An excess of acetic acid was added to neutralize the catalyst. The polymer was obtained by precipitation from CH ₂ Cl ₂ in cold methanol and dried under vacuum. Yield: 75%; Conversion: 89%; ¹ H NMR (400MHZ, CDCl ₃ ), δ (ppm), 1.38 (m, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 1.65−1.68 (m, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 2.31 (t,(−OCOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 3.66 (t, −CH ₂ CH ₂ OH), 4.06 (t, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 5.12 (s, PhCH ₂ O−), 7.32−7.40 (m, 5H, aromatic). (Entry 19, Table S1). FIG.1(B) shows the MALDI-TOF MS spectra of the polymerized caprolactone (PCL). FIG.2 shows the ¹ H NMR spectrum of the PCL in CDCl ₃ (Table 2, entry 9). FIG.3 shows the ¹³ C NMR spectrum of the PCL in CDCl ₃ . (Table 2, entry 12). Example 3: Block Copolymer Synthesis of PPO-b-PCL through Sequential Anionic Ring Opening Polymerization [0052] In an argon-filled glove box, TBACl (27.7 mg, 0.1 mmol, 1.0 equiv.), TEB (1M in THF, 200 μL, 0.2 mmol, 2.0 equiv.), toluene (9.0 mL), and PO (0.58 g, 10 mmol, 100 equiv.) were sequentially added to the Schlenk tube. The solution was stirring overnight at room temperature. After few solutions of the first segment were taken for NMR and SEC, XyDA (6.8 mg. 0.05 mmol, 1.0 equiv.), UPh (63.6 mg. 0.3 mmol, 3.0 equiv.), and CL ([CL] ₀ = 1.0 mol L-1, 1.14 g, 10 mmol, 100 equiv.) were added to the solution to block the polymerization. The mixture was stirred at room temperature and monitored by ¹ H NMR spectroscopy. An excess of acetic acid was added to neutralize the catalyst. The polymer was obtained by precipitation from CH ₂ Cl ₂ in cold methanol and isolated poly(propylene oxide)-block- poly(caprolactone) (PPO-b-PCL) diblock copolymers were dried under vacuum. Yield: 90%; ¹ H NMR (400MHZ, CDCl ₃ ), δ (ppm), 1.13, 1.38, 1.65-1.68, 2.31, 3.41-3.55, 4.06. FIG. 4 shows the ¹ H NMR Spectrum of the Block Copolymer PPO-b-PCL in CDCl _3. FIG. 5 shows the ¹³ C NMR Spectrum of the Block Copolymer PPO-b-PCL in CDCl _3. Example 4: Random Polymerization for the Synthesis of statistical copolymer of P(PO-co-VL) through Sequential Anionic Ring Opening Polymerization [0053] In an argon-filled glove box, benzyl alcohol (BnOH, 5.2 μL, 0.05 mmol, 1.0 equiv.) and t-BuP ₄ (62.5 μL, 0.05 mmol, 1.0 equiv.) were added into the Schlenk tube by micro syringe. After 5 min of stirring, TEB (1M in THF, 100 μL, 0.1 mmol, 2.0 equiv.), ethylenediamine (EtDA) (0.025 mmol, 0.5 equiv.), THF (1.0 mL), δ-valerolactone (VL) (2.5 mmol, 50 equiv.) and PO (0.58 g, 10 mmol, 100 equiv.) were sequentially added to the solution to initiate the polymerization. The mixture was stirred at 50 °C and monitored by ¹ H NMR spectroscopy. An excess of acetic acid was added to neutralize the catalyst. The polymer was obtained by precipitation from CH ₂ Cl ₂ in cold methanol and dried under high vacuum. Yield: 76%; ¹ H NMR (400MHZ, CDCl ₃ ), δ (ppm), 1.11(d, (−OCH ₂ CH(CH ₃ )O−) _n ), 1.21 (d, (−OCH ₂ CH(CH ₃ )OCOCH ₂ CH ₂ CH ₂ CH ₂ O−))157−166 (m (−OCOCH ₂ CH ₂ CH ₂ CH ₂ O−) _n ) 2.32 (t, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 3.39-3.52 (t, (−OCH ₂ CH(CH ₃ )O−) _n and (−OCOCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₃ ) O−)), 4.08 (t, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 5.04 (m, (−OCH2CH(CH3)OCOCH2CH2CH2CH2O−)) (Table S2). Table S2 shows the statistical copolymerization of VL and PO by TEB-EtDA. FIG.6 shows the ¹ COSY NMR spectra of P(PO-co-VL) copolymer (Entry 4, Table S2). FIG.7 shows the ¹ C HSQC NMR spectra of P(PO-co-VL) copolymer (Entry 4, Table S2). Example 5: Block Polymer Synthesis of PVL-b-PPO through Sequential Anionic Ring Opening Polymerization [0054] In an argon-filled glove box, BnOH (5.2 μL, 0.05 mmol, 1.0 equiv.) and t-BuP ₄ (62.5 μL, 0.05 mmol, 1.0 equiv.) were added into the Schlenk tube by micro syringe. After 5 min of stirring, TEB (1M in THF, 100 μL, 0.1mmol, 2.0 equiv.), butylamine (0.1 mmol, 2.0 equiv.), toluene (4.5 mL), δ-Valerolactone ([VL] ₀ = 1.0 mol L ⁻¹ , 5 mmol, 100 equiv.) were sequentially added to the solution to initiate the polymerization. The mixture was stirred at room temperature and monitored by ¹ H NMR spectroscopy. After a period of time, TEB (0.3 mmol, 3.0 equiv.) and PO (0.58 g, 10 mmol, 100 equiv.) was added to the reaction solution. The mixture was stirred at room temperature and monitored by NMR spectroscopy. An excess of acetic acid was added to neutralize the catalyst. The polymer was obtained by precipitation from CH ₂ Cl ₂ in cold methanol and isolated poly(valerolactone)-block- poly(propylene oxide) (PVL-b-PPO). Yield: 91%; ¹ H NMR (400MHZ, CDCl ₃ ), δ (ppm), 1.13, 1.68−1.70, 2.34, 3.41-3.55, 4.08. FIG.8 shows the DOSY NMR spectrum of the PVL-b-PPO sample (Table 3, entry 25). Table S3 shows the sequential block copolymerization of epoxides and cyclic esters for polyester containing block polymers. FIG.9 shows the SEC curves of the polymer PVL-b-PPO in THF (Entry 4, Table S3). FIG.10 shows the ¹ H NMR spectrum of the deblock polymer PVL-b-PPO (Entry 4, Table S3).

^a _{The polymerization was performed in toluene with sequential addition of monomer, TEB; and cyclic esters.} ^b Determined by ¹ H NMR spectra of crude polymerization mixtures. ^c Determined by SEC at 35 ^o C using THF as the solvent and using polystyrene standard without a correction factor. ^d The solvent is THF. ^e TEB (3.0 equiv.) were added in the second polymerization. ^f TEB (3.0 equiv.) and PO (100 equiv.) were added after the second polymerization. Example 6: Block Polymer Synthesis of Diblock Copolymers polyether-b-polyester of PPO-b- PCl, PPO-b-PVL, PPO-b-PLLA through Sequential Anionic Ring Opening Polymerization [0055] In an argon-filled glove box, TBACl (27.7 mg, 0.1 mmol, 1.0 equiv.), TEB (1M in THF, 200 μL, 0.2 mmol, 2.0 equiv.), toluene (9.0 mL), and PO (0.58 g, 10 mmol, 100 equiv.) were sequentially added to the Schlenk tube. The solution was stirring overnight at room temperature. After sampling for NMR and SEC for the first block, XyDA (6.8 mg.0.05 mmol, 1.0 equiv.), UPh (63.6 mg. 0.3 mmol, 3.0 equiv.), and CL ([CL] ₀ = 1.0 mol L ⁻¹ , 1.14 g, 10 mmol, 100 equiv.) were added to the solution to initiate second block polymerization. The mixture was stirred at room temperature and monitored by ¹ H NMR spectroscopy. An excess of acetic acid was added to neutralize the catalyst. The polymer was obtained by precipitation from CH ₂ Cl ₂ in cold methanol and isolated poly(propylene oxide)-block-poly(caprolactone) (PPO-b-PCL) diblock copolymers were dried under vacuum. Yield: 90%; ¹ H NMR (400MHZ, CDCl ₃ ), δ (ppm), 1.13(d, (−OCH ₂ CH(CH ₃ )O−) _n ), 1.38 (m, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 1.65−1.68 (m, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 2.31 (t,(−OCOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 3.41-3.55 (t, (−OCH ₂ CH(CH ₃ )O−) _n ), 4.06 (t, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O−) _n ). M _{n(PPO), SEC} = 11.9 kg mol ⁻¹ ; Ð _M = 1.08; M _{n(PPO-b-PCL), SEC} = 34.5 kg mol ⁻¹ ; Ð _M = 1.08 (Entry 1, Table S3). A similar experiment for the synthesis of diblock copolymerization of propylene oxide and valerolactone was carried out to obtain poly(propylene oxide)-block-poly(valerolactone) (PPO- b-PVL). Yield: 91%; ¹ H NMR (400MHZ, CDCl ₃ ), δ (ppm), 1.11(d, (−OCH ₂ CH(CH ₃ )O−) _n ), 1.68−1.70 (m, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 2.34 (t, (−OCOCH ₂ CH ₂ CH ₂ CH ₂ O−) _n ), 3.41- mol ⁻¹ ; Ð _M = 1.04; M _{n(PPO-b-PVL), SEC} = 35.6 kg mol ⁻¹ ; Ð _M = 1.09 (Entry 2, Table S3). A similar experiment for the synthesis of diblock copolymerization of propylene oxide and L-lactide was carried out to obtain poly(propylene oxide)-block-poly(L-lactide) (PPO-b-PLLA). The solvent was THF. Yield: 91%; ¹ H NMR (400MHZ, CDCl ₃ ), δ (ppm), 1.13(d, (−OCH ₂ CH(CH ₃ )O−) _n ), 1.57(m, (−OCOCH(CH ₃ )O−) _n ), 3.41-3.55(t, (−OCH ₂ CH(CH ₃ )O−) _n ), 5.13−5.20(q, (−OCOCH(CH ₃ )O−) _n ). M _{n(PPO), SEC} = 12.4 kg mol ⁻¹ ; Ð _M = 1.05; M _{n(PPO-b-PLLA),SEC} = 31.2 kg mol ⁻¹ ; Ð _M = 1.14 (Entry 3, Table S3). FIG.11 shows the ¹ H NMR spectrum of the obtained PPO-b-PCL in CDCl ₃ (Entry 1, Table S3). FIG. 12 shows the ¹³ C NMR spectrum of the obtained PPO-b-PCL in CDCl ₃ (Entry 1, Table S3). FIG.13 shows the ¹ H NMR spectrum of the obtained PPO-b-PVL in CDCl ₃ (Entry 2, Table S3). FIG.14 shows the ¹³ C NMR spectra of the obtained PPO-b-PVL in CDCl ₃ (Entry 2, Table S3). FIG.15 shows the ¹ H NMR spectra of the obtained PPO-b-PLLA in CDCl ₃ (Entry 3, Table S3). FIG. 16 shows the ¹³ C NMR spectra of the obtained PPO-b-PLLA in CDCl ₃ (Entry 3, Table S3). FIG.17(A) shows the ¹³ C NMR spectra stack of P(PO-co-VL) copolymer (Entry 4, Table S2). FIG.17(B) shows the ¹³ C NMR spectra of PPO-b-PVL block polymers (Entry 2, Table S3). FIG.17(C) shows the ¹³ C NMR spectra of homopolymer PVL (Entry 14, Table 1). Example 7: Block Polymerization for the Synthesis of Triblock Copolymer of PLLA-b-PPC- b-PLLA through Sequential Anionic Ring Opening Polymerization [0056] In a glovebox, the TBAS (0.025 mmol, 1.0 equiv.), PO (200 mmol, 8000 equiv.), TEB (1M in THF, 50 μL, 0.05 mmol, 2.0 equiv.) are added in a Schlenk reactor. In the case a gas is used, the reaction is conducted in a Parr pressure vessel and the CO ₂ is charged outside the glovebox. The reactor is sealed before taking out of the glovebox. The reaction medium was stirred at a designated temperature for a designated period of time. After few solutions of the first segment were taken for NMR and SEC, butylamine (0.05 mmol, 2.0 equiv.) and L-LA (10 mmol, 400 equiv.) were added to the solution to block the polymerization. The mixture was stirred at room temperature and monitored by ¹ H NMR spectroscopy. An excess of acetic acid was added to neutralize the catalyst. The polymer was obtained by precipitation in cold methanol and isolated triblock copolymers (PLLA-b-PPC-b-PLLA). were dried under vacuum. Yield: 53%; ¹ H NMR (500 MHz, CDCl3) δ 5.18, 5.02, 4.29, 4.21, 4.14, 3.57, 3.41, 1.61, 1.36, 1.16, 1.15. Fig. 18 shows the ¹ H NMR spectrum of the obtained PLLA-b-PPC-b-PLLA in CDCl ₃ (Table 3, entry 22). FIG.19 shows the GPC trace of the polymer PLLA-b-PPC-b-PLLA (Table 3, entry 23). [0057] From the foregoing explanation, description and examples, it is apparent that by using amine-borane adduct, the synthesis of polyester and its copolymers through (co)polymerization of cyclic esters and with other oxygenated monomers was successfully advanced, which in turn affords an easy access to a whole range of oxygenated polymers by TEB-based ate complexes. The polymerization was achieved using anionic ring-opening polymerization. As a demonstration of the versatility of these TEB-based systems, PO and VL were randomly copolymerized; PO, CL, VL and LLA were also sequentially copolymerized affording an array of statistical, diblock and triblock copolymers. The present disclosure is successfully employed to copolymerize CO ₂ with various epoxides under metal-free conditions. TEB-based Lewis pairs have been progressively and successfully applied to the homopolymerization and copolymerization of epoxides with various comonomers, including anhydrides, COS, CS ₂ , isocyanates and the likes. [0058] In order to further expand the utilization of these TEB-based Lewis pairs as initiators, the present disclosure demonstrates their ability to multitask by adding cyclic esters to the above list of (co)polymerized monomers. Unlike other initiating systems that were mainly designed for one family of monomers, these TEB-based Lewis pairs can also serve to copolymerize either randomly or sequentially more than one type of monomers, as illustrated in the present disclosure, by the synthesis of polyester-polyether random and block copolymers. [0059] The other main advantage of using urea anions as Lewis base in combination with TEB as Lewis acid is that the Lewis pair formed can not only serve to polymerize cyclic esters but also an epoxide such as PO. As such, the (thio)urea anions can only catalyze the ROP of cyclic esters but are helpless for epoxides. However, when associated with amines, as shown in the present disclosure, urea anions/TEB Lewis pairs demonstrate enough adaptability and adjustability of their reactivity to allow the successful (co)polymerization of both cyclic esters and epoxides. The present disclosure also describes Controlled AROP of cyclic esters initiated by phosphazenium alkoxide in the presence of (thio)urea and amine. [0060] While the disclosure has been described with reference to exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted for elements thereof without departing from the scope of the embodiment(s). In addition, many modifications may be made to adapt a particular situation or material to the teachings of the embodiment(s) without departing from the essential scope thereof. Therefore, it is intended that the disclosure is not limited to the disclosed embodiment(s) but that the disclosure will include all embodiments falling within the scope of the appended claims. Various examples have been described. These and other examples are within the scope of the following claims. [0061] Other embodiments of the present disclosure are possible. Although the description above contains much specificity, these should not be construed as limiting the scope of the disclosure, but as merely providing illustrations of some of the presently preferred embodiments of this disclosure. It is also contemplated that various combinations or sub- combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of this disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form various embodiments. Thus, it is intended that the scope of at least some of the present disclosure should not be limited by the particular disclosed embodiments described above. [0062] Thus, the scope of this disclosure should be determined by the appended claims and their legal equivalents. Therefore, it will be appreciated that the scope of the present disclosure fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more." All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present disclosure, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. [0063] The foregoing description of various preferred embodiments of the disclosure have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise embodiments, and obviously many modifications and variations are possible in light of the above teaching. The example embodiments, as described above, were chosen and described in order to best explain the principles of the disclosure and its practical application to thereby enable others skilled in the art to best utilize the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the claims appended hereto. [0064] Various examples have been described. These and other examples are within the scope of the following claims.