polymers

Abstract

New polymers are disclosed, having well-defined structures and hydrophilic carbonate and / or ester repeating units. The polymers can be employed as degradable polyol alternatives in a variety of applications, including liquid formulations, emulsifiers and surfactants

Description

POLYMERSINTRODUCTION

[0001] The present invention relates to polymers and liquid formulations comprising the polymers (e.g., polymers in liquid formulations, PLFs).BACKGROUND OF THE INVENTION

[0002] Hydrophilic polymers are an important area of polymer science with outstanding fields of applications, e.g., in drug delivery, self-assembly, surface modification, catalysis and formulations.1The study of the structure-property relationships and properties on their dissolved state of hydrophilic polymers can be fundamental for Polymers in Liquid Formulations (PLF).2

[0003] PLFs are usually low molar mass polymers, hydroxyl end-capped, often term ‘polyols’, which are commercially applied as low viscosity prepolymers for resins, in polyurethane manufacture and coatings, adhesives, sealant applications and as surfactants in liquid formulations. Additionally, surfactants can be applied as thickeners, emulsifiers and binders for home and personal care applications.34Amphiphilic block copolymers, which are synthesised by hydrophilic monomers by copolymerization with hydrophobic blocks, can be seen also as a particular class of surfactants able to modify the surface properties of the liquid in which they are introduced (usually aqueous media).5

[0004] However, the majority of these macromolecules are based on non-degradable synthetic methodologies, and recently, there is an increase demand on re-designing these materials use in formulations.6

[0005] The present invention was devised with the foregoing in mind.SUMMARY OF THE INVENTION

[0006] According to a first aspect of the present invention there is provided a polymer comprising a repeating unit of formula I defined herein.

[0007] In many instances, J is O.

[0008] According to a second aspect of the present invention there is provided a use of a polymer of the first aspect as a thickening agent, a binding agent, a stabilizing agent, a surfactant, a filmforming agent, a viscosity-modifying agent, an adhesion promoter or an encapsulation agent.

[0009] According to a third aspect of the present invention there is provided a liquid formulation comprising a polymer of the first aspect.DETAILED DESCRIPTION OF THE INVENTION

[0010] Throughout the entirety of the description and claims of this specification, where subject matter is described herein using the term “comprise” (or “comprises” or “comprising”), the same subject matter instead described using the term “consist of’ (or “consists of’ or “consisting of’) or “consist essentially of’ (or “consists essentially of’ or “consisting essentially of’) is also contemplated. For example, in terms of repeating units, the polymer of the first aspect may consist of, or consist essentially of, repeating units of formula I. It will be understood that the polymer of the first aspect may contain more than one repeating unit of formula I. For example, the polymer may comprise, consist of, or consist essentially of a first repeating unit of formula I and a second repeating unit of formula I, where the first and second repeating units of formula I are different. For example, X2may be different in the first and second repeating units of formula I (e.g., the polymer may be formed from one epoxide and two different cyclic anhydrides). Alternatively, R1may be different in the first and second repeating units of formula I (e.g., the polymer may be formed from one cyclic anhydride and two different epoxides).

[0011] Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0012] Features described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention is not restricted to the details of any of the specific embodiments recited herein. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0013] The term "(m-nC)" or"(m-nC) group" used alone or as a prefix, refers to any group having m to n carbon atoms.

[0014] The term “alkyl” as used herein refers to straight or branched chain alkyl moieties, typically having 1, 2, 3, 4, 5 or 6 carbon atoms. This term includes reference to groups such as methyl, ethyl, propyl (n-propyl or isopropyl), butyl (n-butyl, sec-butyl or tert-butyl), pentyl, hexyl and the like. Most suitably, an alkyl may have 1, 2, 3 or 4 carbon atoms.

[0015] The term “alkenyl” as used herein refers to straight or branched chain alkenyl moieties, typically having 1, 2, 3, 4, 5 or 6 carbon atoms. The term includes reference to alkenyl moieties containing 1, 2 or 3 carbon-carbon double bonds (C=C). This term includes reference to groups such as ethenyl (vinyl), propenyl (allyl), butenyl, pentenyl and hexenyl, as well as both the cis and trans isomers thereof.

[0016] The term “alkylidene” as used herein refers to straight or branched chain alkylidene moieties. Most suitably, alkylidene is methylidene.

[0017] The term “alkynyl” as used herein refers to straight or branched chain alkynyl moieties, typically having 1, 2, 3, 4, 5 or 6 carbon atoms. The term includes reference to alkynyl moieties containing 1, 2 or 3 carbon-carbon triple bonds (C≡C). This term includes reference to groups such as ethynyl, propynyl, butynyl, pentynyl and hexynyl.

[0018] The term “alkoxy” as used herein refers to -O-alkyl, wherein alkyl is a straight or branched chain and comprises 1, 2, 3, 4, 5 or 6 carbon atoms. In one class of embodiments, alkoxy has 1, 2, 3 or 4 carbon atoms. This term includes reference to groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, pentoxy, hexoxy and the like.

[0019] The term "aryl" or “aromatic” as used herein means an aromatic ring system comprising 6, 7, 8, 9 or 10 ring carbon atoms. Aryl is often phenyl but may be a polycyclic ring system, having two or more rings, at least one of which is aromatic. This term includes reference to groups such as phenyl, naphthyl and the like.

[0020] The term “carbocyclyl”, “carbocyclic” or “carbocycle” means a non-aromatic saturated or partially saturated monocyclic, or bridged bicyclic, ring system(s).

[0021] The term "halogen" or “halo” as used herein refers to F, Cl, Br or I. In a particular, halogen may be F or Cl, of which Cl is more common.

[0022] The term “substituted” as used herein in reference to a moiety means that one or more, especially up to 5. Preferably, “substituted” as used herein in reference to a moiety means that 1, 2 or 3, of the hydrogen atoms in said moiety are replaced independently of each other by the corresponding number of the described substituents. Even more preferred, “substituted” as used herein in reference to a moiety means that 1 or 2, of the hydrogen atoms in said moiety are replaced independently of each other by the corresponding number of the described substituents. The term “optionally substituted” as used herein means substituted or unsubstituted.

[0023] It will, of course, be understood that substituents are only at positions where they are chemically possible, the person skilled in the art being able to decide (either experimentally or theoretically) without inappropriate effort whether a particular substitution is possible.

[0024] In a first aspect, the invention provides a polymer comprising a repeating unit of formulawhereinX is:i) a group X1of structure:ii) a group X2of structure:0 Oin which L1is a linker separating the two carbonyl groups by a distance of 3-4 bond lengths; n is a number 0 to 100 (e.g., 0 to 5);J is O, (2-22C)alkylene or CRaRb;Raand Rbare each independently H or (1 -10C)alkyl;R1is H, (1 -22C)alkyl, (2-22C)alkenyl, SO3’, SO3H, R2or Y;R2is a group:. OR-X)R3each R3is independently H or Y; andY is a group of structure:O O AAin which L2is a linker separating the two carbonyl groups by a distance of 3-4 bond lengths.

[0025] Through rigorous investigation, the inventors have developed the polymers of the first aspect, having well-defined structures and hydrophilic carbonate and / or ester repeating units. The polymers can be employed as degradable polyol alternatives in a variety of applications, including liquid formulations, emulsifiers and surfactants.

[0026] X may be a group X1. In such instances, a carbonate linkage is formed between adjacent repeating units of formula I. The polymer may therefore comprise poly(carbonate) moieties and / or be a poly(carbonate). A repeating unit of formula I in which X is X1can be formed by ring-opening copolymerisation of CO2and an epoxide.

[0027] The polymer may comprise more than one X1-containing repeating unit of formula I. For example, the polymer may comprise two different X1-containing repeating units of formula I. The repeating units of formula I may be arranged in any order, e.g., alternating, randomly or as blocks.

[0028] X may be a group X2. In such instances, an ester linkage is formed between adjacent repeating units of formula I. The polymer may therefore comprise poly(ester) moieties and / or be a poly(ester). A repeating unit of formula I in which X is X2can be formed by ring-opening copolymerisation of a cyclic anhydride and an epoxide.

[0029] The polymer may comprise more than one X2-containing repeating unit of formula I. For example, the polymer may comprise two different X2-containing repeating units of formula I. The repeating units of formula I may be arranged in any order, e.g., alternating, randomly or as blocks.

[0030] In some instances, the polymer comprises a first repeating unit of formula I, in which X is a group X1, and a second repeating unit of formula I, in which X is a group X2. The polymer may therefore comprise poly(carbonate-co-ester) moieties and / or be a poly(carbonate-co-ester). Thefirst and second repeating units of formula I may be arranged in any order, e.g., alternating, randomly or as blocks.

[0031] n may be a number 0 to 80 (e.g., 1-80). Suitably, n is a number 0 to 50 (e.g., 1-50). In some instances, n may be a number 0 to 20 (e.g., 1 to 20).

[0032] n may be a number 0 to 4. Suitably, n is a number 0 to 3.

[0033] In some instances, n is 0. In others, it is 1, 2 or 3.

[0034] In some instances, when n is 0, R1is not H.

[0035] L1is a linker separating the two carbonyl groups of the X2structure by a distance of 3-4 bond lengths. For illustrative purposes, non-limiting examples of L1are depicted below, which have been annotated to show the relevant number of bonds lengths.I IvfWV' s / vw*

[0036] It will be understood thatX2groups can be obtained by ring opening of a 5- to 6-membered cyclic anhydride, in which the linker between the two carbonyls of the anhydride group becomes L1. A variety of 5- to 6-membered cyclic anhydride are readily available and may be used to prepare polymer of the first aspect.

[0037] For example, in L1, the 3-4 bond lengths may be:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C, N and O, with the proviso that at least one (suitably at least two) of the three atoms is C.

[0038] Alternatively, in L1, the 3-4 bond lengths may be:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C and O, with the proviso that at least one (suitably at least two) of the three atoms is C.

[0039] In L1, any of said C atoms participating in said 3-4 bond lengths may be optionally substituted with one or two R4, and any of said N atoms participating in said 3-4 bond lengths may be optionally substituted with one R5, in which:(i) each R4is independently selected from (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R4x-R4y-R4z, and each R5is independently (1-22C)alkyl, wherein R4xis selected from absent, -S- and -(CH2)h-C(O)O-, R4yis -(CH2CH2O)i-, and R4zis selected from H and (1 -10C)alkyl, in which h is 0 or 1 and i is 1-100; and / or(ii) two R4substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

[0040] Suitably, R4and R5may be such that:(i) each R4is independently selected from (1 -15C)alkyl, (2-15C)alkenyl, (2-15C)alkynyl, (1-4C)alkylidene, halo and phenyl, and each R5is independently (1 -4C)alkyl; and / or(ii) two R4substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

[0041] More suitably, R4and R5may be such that:(i) each R4is independently selected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-4C)alkylidene, chloro, bromo and phenyl, and each R5is independently (1 -4C)alkyl; and / or (ii) two R4substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

[0042] In some instances, L1may have a structure L1aor L1b:V2.^_ -^-v3-v4-v5-^-l_1a |_1bin which= represents a single bond or a double bond;V1and V2are both C(R4a)m, in which m is 1 or 2;V3, V4and V5are each independently selected from C(R4a)p, in which p is 1 or 2, N(R5a)q, in which q is 0 or 1, and O, with the proviso that at least one (suitably at least two) of V3, V4and V5is C(R4a)p;each R4ais independently selected from hydrogen, (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R4x-R4y-R4zas defined hereinbefore, and each R5ais independently (1-22C)alkyl; and / ortwo R4asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

[0043] R4aand R5amay have any of those definitions outlined hereinbefore in relation to R4and R5respectively.

[0044] The 3-7 membered carbocyclic ring or 6-membered aromatic ring formed from two R4or R4asubstituents may be substituted with one or more R6, wherein each R6is independently selected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-10C)alkoxy, (1-4C)alkylidene, halo, amino, hydroxy, -B(OH)2and carboxy. Suitably, each R6is independently selected from (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl and chloro.

[0045] L1may have a structure according to any one of the following:

[0046] Polymers in which R1is Y can be obtained by reacting the hydroxylated polymer (i.e., where R1is H, or R1is R2and R3is H) with a 5- to 6-membered cyclic anhydride, in which the linker between the two carbonyls of the anhydride group becomes L2. A variety of 5- to 6-membered cyclic anhydride are readily available.

[0047] For example, in L2, the 3-4 bond lengths may be:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C, N and O, with the proviso that at least one (suitably at least two) of the three atoms is C.

[0048] Alternatively, in L2, the 3-4 bond lengths may be:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C and O, with the proviso that at least one (suitably at least two) of the three atoms is C.

[0049] In L2, any of said C atoms participating in said 3-4 bond lengths may be optionally substituted with one or two R7, and any of said N atoms participating in said 3-4 bond lengths may be optionally substituted with one R8, in which:(i) each R7is independently selected from (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R7x-R7y-R7z, and each R8is independently (1-22C)alkyl, wherein R7xis selected from absent, -S- and -(CH2)j-C(O)O-, R7yis -(CH2CH2O)k-, and R7zis selected from H and (1 -10C)alkyl, in which j is 0 or 1 and k is 1-100; and / or(ii) two R7substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

[0050] Suitably, R7and R8may be such that:(i) each R7is independently selected from (1 -15C)alkyl, (2-15C)alkenyl, (2-15C)alkynyl, (1-4C)alkylidene, halo and phenyl, and each R8is independently (1 -4C)alkyl; and / or(ii) two R7substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

[0051] More suitably, R7and R8may be such that:(i) each R7is independently selected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-4C)alkylidene, chloro, bromo and phenyl, and each R8is independently (1 -4C)alkyl; and / or (ii) two R7substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

[0052] In some instances, L2may have a structure L2aor L2b:_^W1_W2|. -^-w3-w4-w5-^-|_2a |_2bin which= represents a single bond or a double bond;W1and W2are both C(R7a)x, in which x is 1 or 2;W3, W4and W5are each independently selected from C(R7a)y, in which y is 1 or 2, N(R8a)z, in which z is 0 or 1, and O, with the proviso that at least one (suitably at least two) of W3, W4and W5is C(R7a)y;each R7ais independently selected from hydrogen, (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R7x-R7y-R7zas defined hereinbefore, and each R8ais independently (1-22C)alkyl; and / ortwo R7asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

[0053] R7aand R8amay have any of those definitions outlined hereinbefore in relation to R7and R8respectively.

[0054] The 3-7 membered carbocyclic ring or 6-membered aromatic ring formed from two R7or R7asubstituents may be substituted with one or more R9, wherein each R9is independentlyselected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-10C)alkoxy, (1-4C)alkylidene, halo, amino, hydroxy, -B(OH)2and carboxy. Suitably, each R9is independently selected from (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl and chloro.

[0055] L2may have a structure according to any one of the following:CH2COO-(CH2CH20)1-1OOH S-(CH2CH2O)1-10OHANC|

[0056] J is most suitably O. Therefore, the repeating unit of formula I most suitably has a structure according to formula la:ooR1(la)wherein X, n and R1are as defined hereinbefore.

[0057] In some instances, R1is H, (1-22C)alkyl, (2-22C)alkenyl.

[0058] In some instances, R1is R2or Y.

[0059] In some instances, R1is H, (1-22C)alkyl, (2-22C)alkenyl or R2, and R3is H.

[0060] In some instances, R1is H, (1-22C)alkyl, (2-22C)alkenyl or Y, and R3is H.

[0061] In some instances, R1is H or R2, and R3is H.

[0062] In some instances, R1is R2or Y, and R3is Y.

[0063] In situations where R1is R2, each oxygen atom in R2may be bound to its own Y group, or both oxygen atoms in R2may be coordinated to a single Y group, e.g.:

[0064] The polymer of the first aspect may be linear.

[0065] The polymer of the first aspect may be crosslinked.

[0066] Crosslinked polymers of the first aspect may comprise a crosslinking moiety of formula III:whereinJ, R1and n have any of the definitions outlined hereinbefore in relation to formula I;1and each represent a point of attachment to a polymeric chain comprising a repeating unit of formula I; andL3is a linker separating the two carbonyl groupsAC=O by a distance of 3-4 bond lengths and the two carbonyl groupsBC=O by a distance of 3-4 bond lengths.

[0067] In many instances of a crosslinked polymer comprising a crosslinking moiety of formula III, •~««1and ■~««2will each represents a point of attachment to a repeating unit of formula I. In such instances, it will be understood that: (i) •~««1represents a point of attachment to the backbone oxygen atom in the repeating unit of formula I, and (ii) •>^2represents a point of attachment to the backbone X group in the repeating unit of formula I.

[0068] Crosslinking moieties of formula III may be formed by using a compound bearing 2 cyclic anhydride groups.

[0069] A variety of suitable L3groups exist. Particular, non-limiting examples include:

[0070] Crosslinked polymers of the first aspect may comprise a crosslinking moiety of formula IV:(IV)wherein1and ■n~u'2each represent a point of attachment to a polymeric chain comprising a repeating unit of formula I; andL4is a linking group.

[0071] In many instances of a crosslinked polymer comprising a crosslinking moiety of formula IV,1and2will each represents a point of attachment to a repeating unit of formula I. In such instances, it will be understood that: (i) represents a point of attachment to the backbone oxygen atom in the repeating unit of formula I, and (ii)2represents a point of attachment to the backbone X group in the repeating unit of formula I.

[0072] Crosslinking moieties of formula IV may be formed by using a compound bearing 2 epoxide groups. A variety of diepoxides are readily available, including:H:aQ CHSAlternatively, crosslinking moieties of formula IV may be formed by reaction of epoxides during or post-polymerisation. For example, epoxides suitable for undergoing post-polymerisation coupling reactions may be used, such as epoxides bearing complementary reactive groups (e.g., hydroxy and isocyanate; azido and alkynyl; thiol and alkenyl; etc.) and / or epoxides bearing photoreactive groups. It will therefore be understood that L4may take a variety of different forms.

[0073] Crosslinking moieties of formula IV may have a structure according to formula IVa:(IVa)whereinX, J and n have any of the definitions outlined hereinbefore in relation to formula I;1and •'w"2each represent a point of attachment to a polymeric chain comprising a repeating unit of formula I; andL4ais a linking group.

[0074] Crosslinking moieties of formula IV may therefore be formed by modification of some of the repeating units of formula I to allow coupling of their respective side chains.

[0075] In crosslinked polymers of the first aspect, the crosslinking moieties are present in small amounts relative to the amount of repeating unit of formula I. For example, crosslinked polymers of the first aspect may comprise 0.01 - 5 wt% of crosslinking moieties, suitably 0.01 - 3 wt%, and more suitably 0.01 - 1.5 wt%.

[0076] The polymer may have a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 - 500 kg mol-1, following the procedure described herein. Suitably, the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 -30 kg mol-1. More suitably, the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 -20 kg mol-1. Even more suitably, the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 1.5 - 15 kg mol-1. Yet more suitably, the polymer has a molecular weight (Mn) as determined by size exclusionchromatography of 1.5 - 12 kg mol-1. Most suitably, the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 1.5 - 10 kg mol-1.

[0077] The polymer may have a polydispersity index of <2.0 as determined by gel permeation chromatography following the procedure described herein. Suitably, the polymer has a polydispersity index of <1.8 as determined by gel permeation chromatography. More suitably, the polymer has a polydispersity index of <1.5 as determined by gel permeation chromatography. Even more suitably, the polymer has a polydispersity index of <1.3 as determined by gel permeation chromatography.

[0078] In some instances, the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 - 500 kg mol1and a polydispersity index of <2.0 as determined by gel permeation chromatography. Suitably, the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 - 20 kg mol1and / or a polydispersity index of <1.5 as determined by gel permeation chromatography. More suitably, the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 1.5 - 10 kg mol1and / or a polydispersity index of <1.3 as determined by gel permeation chromatography.

[0079] In certain instances, X is X1, J is O, n is a number 0-3, R1is H orY, and the polymer has a molecular weight (Mn) of 0.5 - 30 kg mol-1and a polydispersity index of <1.5. The structure of such polymers may be such that n is 0 and R1is H. The properties of such polymers may be such that the molecular weight (Mn) is 1.5 - 10 kg mol-1and the polydispersity index is <1.3.

[0080] In certain instances, X is X1, J is O, n is a number 1-3, R1is H orY, and the polymer has a molecular weight (Mn) of 0.5 - 15 kg mol-1and a polydispersity index of <1.5. The structure of such polymers may be such that n is 1 and R1is H. The properties of such polymers may be such that the molecular weight (Mn) is 1.5 - 12 kg mol-1and the polydispersity index is <1.3.

[0081] In certain instances, X isX1, J is O, n is a number 1-3, R1is H orY, and the polymer has a molecular weight (Mn) of 0.5 - 10 kg mol-1and a polydispersity index of <1.8 The structure of such polymers may be such that n is 3 and R1is H. The properties of such polymers may be such that the molecular weight (Mn) is 1.5 - 10 kg mol-1and the polydispersity index is <1.3.

[0082] In certain instances, X is X1, J is O, n is a number 0-3, R1is R2orY, and the polymer has a molecular weight (Mn) of 0.5 - 20 kg mol-1and a polydispersity index of <1.5. The structure of such polymers may be such that n is 0 and R1is R2, wherein R3is H. The properties of such polymers may be such that the molecular weight (Mn) is 1.5 - 15 kg mol-1(or 1.5 - 10 kg mol-1) and the polydispersity index is <1.3.

[0083] In certain instances, X is X2, J is O, n is a number 1-50, R1is H orY, and the polymer has a molecular weight (Mn) of 0.5 - 15 kg mol-1and a polydispersity index of <1.8. The structure ofsuch polymers may be such that n is 1-20 (e.g., 1-15) and R1is H, optionally wherein L1is: (i) a group L1a, in which two R4asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring, or (ii) a group L1b, in which V3and V5are C(R4a)pand V4is O. More particularly, L1may have a structure:and the properties of the polymer may be such that the molecular weight (Mn) is 1.5 - 10 kg mol-1and the polydispersity index is <1.6.

[0084] The polymer may have a structure according to formula II:B — [A]e(II)wherein:each A is a polymeric chain comprising a repeating unit of formula I;B is an end group to which each A is attached; ande is 1-6 (e.g., 1, 2, 3 or 4).

[0085] Each polymeric chain A suitably has a hydroxy-terminating polymeric backbone. Alternatively, each polymeric chain A suitably has a polymeric backbone terminating in COOH.

[0086] Polymers of the first aspect can be prepared by ring-opening copolymerisation of CO2(or a cyclic anhydride) with an epoxide in the presence of a chain transfer agent (CTA). The basic structure of a CTA will be familiar to those of ordinary skill in the art. Typically the CTA comprises at least one, but up to 6, OH and / or COOH groups that serve as sites for polymeric chain growth. Therefore, B may be a residue of a CTA.

[0087] CTAs bearing 3-6 OH and / or COOH groups may therefore be used to prepare starshaped polymers of the first aspect.

[0088] In some instances, B is an amine-containing group (e.g. a residue of an amine-containing CTA).

[0089] Where an OH-functionalised CTA has been used, each OH group becomes an ether moiety directly connecting the remainder of the CTA to a polymeric chain A. Therefore, the polymer may have a structure according to formula Ila:B'— fo— Al1 Je(IIa)wherein B’ is an end group to which each A is attached. It will be understood that the B’-O-moiety represents a deprotonated OH-functionalised CTA.

[0090] Where a COOH-functionalised CTA has been used, each COOH group becomes an ester moiety connecting the remainder of the CTA to a polymeric chain A via a linkage derived from the epoxide comonomer. Therefore, the polymer may have a structure according to formula lib:(IIb)Wherein J, n and R1are as defined for formula I; andB’ is an end group to which each A is attached. It will be understood that the B’-C(O)-O- moiety represents a deprotonated COOH-functionalised CTA.

[0091] A variety of CTAs may be used to prepare polymers of the first aspect. Particular, nonlimiting examples include:wherein xa is a number 1-100, xb is a number 1-100, xc is a number 1-4 and xd is a number 1- 20.

[0092] In the non-limiting examples of CTAs outlined above, it will be understood that OH and COOH moieties serve as sites for growth of polymeric chains A. Non-limiting examples of B and B’ will therefore be apparent from the foregoing discussion.

[0093] At least 25% of the repeating units within the polymer may have a structure according to formula I. Suitably, at least 50% of the repeating units within the polymer have a structure according to formula I. More suitably, at least 75% of the repeating units within the polymer have a structure according to formula I. Even more suitably, at least 85% of the repeating units within the polymer have a structure according to formula I. Yet even more suitably, at least 95% of the repeating units within the polymer have a structure according to formula I. In many instances, all repeating units within the polymer have a structure according to formula I. It will be understood that crosslinking moieties, as discussed hereinbefore, when present, are not to be interpreted as repeating units.

[0094] In another aspect, the invention provides precursors for polymers of the first aspect, said precursors also being polymeric. The precursors may be identical in structure to the polymers of the first aspect, except that terminal oxygen atoms in the side chain of the repeating unit are protected by a group that can be readily cleaved to yield the hydroxylated analogue. Therefore, the invention provides a polymer comprising a repeating unit of formula I, wherein X and n are as defined herein in relation to the first aspect, and R1is a protecting group or has a structure according to R2, in which each R3is a protecting group or the R3groups are linked to form a single protecting group.

[0095] A variety of protecting groups cleavable (e.g., hydrolysable) from the R1or R3positions to form hydroxy groups will be readily familiar to one of ordinary skill in the art. Purely for illustrative purposes, particular, non-limiting examples of R1and R2include:

[0096] Aside from the aforementioned differences at the R1and R2positions, the polymer precursors may have any of those structures outlined hereinbefore in relation to the first aspect. Similarly, the properties (e.g., molecular weight and / or polydispersity index) discussed hereinbefore in relation to the first aspect may also apply to the polymer precursors. In some instances, the second and third aspects of the invention may apply with equal weight to the polymer precursors.

[0097] In a second aspect, the invention provides a use of a polymer of the first aspect as a thickening agent, a binding agent, a stabilizing agent, a surfactant, a film-forming agent, a viscosity-modifying agent, an adhesion promoter or an encapsulation agent.

[0098] In a third aspect, the invention provides a liquid formulation comprising a polymer of the first aspect.

[0099] The following numbered statements 1 to 90 are not claims, but instead describe some aspects and embodiments of the invention:1. A polymer comprising, consisting essentially of or consisting of a repeating unit of formula I:4xv / >4JoR1whereinX is:i) a group X1of structure:, orii) a group X2of structure:in which L1is a linker separating the two carbonyl groups by a distance of 3-4 bond lengths; n is a number 0 to 100;J is O, (2-22C)alkylene or CRaRb;Raand Rbare each independently H or (1 -10C)alkyl;R1is H, (1 -22C)alkyl, (2-22C)alkenyl, SO3’, SO3H, R2or Y;R2is a group:each R3is independently H or Y; andY is a group of structure:o o> AL 0Hin which L2is a linker separating the two carbonyl groups by a distance of 3-4 bond lengths.2. The polymer as defined in statement 1, wherein when n is 0, R1is not H.3. The polymer as defined in statement 1 or 2, wherein when X is a group X1, a carbonate linkage is formed between adjacent repeating units of formula I.4. The polymer as defined in statement 1, 2 or 3, wherein when X is a group X2, an ester linkage is formed between adjacent repeating units of formula I.5. The polymer as defined in any one of the preceding statements, wherein X is a group X1.6. The polymer as defined in any one of the preceding statements, wherein X is a group X2.7. The polymer as defined in any one of the preceding statements, wherein in L1, the 3-4 bond lengths is:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C, N and O, with the proviso that at least one (suitably at least two) of the three atoms is C.8. The polymer as defined in statement 7, wherein in L1, the 3-4 bond lengths is:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C and O, with the proviso that at least one (suitably at least two) of the three atoms is C.9. The polymer as defined in statement 7 or 8, wherein in L1, any of said C atoms participating in said 3-4 bond lengths is optionally substituted with one or two R4, and any of said N atoms participating in said 3-4 bond lengths is optionally substituted with one R5, wherein:(i) each R4is independently selected from (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R4x-R4y-R4z, and each R5is independently (1-22C)alkyl, wherein R4xis selected from absent, -S- and -(CH2)n-C(O)O-, R4yis -(CH2CH2O)i-and R4zis selected from H and (1-10C)alkyl, in which h is 0 or 1 and i is 1-100; and / or(ii) two R4substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.10. The polymer as defined in statement 9, wherein:(i) each R4is independently selected from (1 -15C)alkyl, (2-15C)alkenyl, (2-15C)alkynyl, (1-4C)alkylidene, halo and phenyl, and each R5is independently (1 -4C)alkyl; and / or(ii) two R4substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.11. The polymer as defined in statement 9, wherein:(i) each R4is independently selected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-4C)alkylidene, chloro, bromo and phenyl, and each R5is independently (1 -4C)alkyl; and / or (ii) two R4substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.12. The polymer as defined in statement 7 or 8, wherein L1has a structure L1aor L1b:l_1a |_1b= represents a single bond ora double bond;V1and V2are both C(R4a)m, in which m is 1 or 2;V3, V4and V5are each independently selected from C(R4a)p, in which p is 1 or 2, N(R5a)q, in which q is 0 or 1, and O, with the proviso that at least one (suitably at least two) of V3, V4and V5is C(R4a)p;each R4ais independently selected from hydrogen, (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R4x-R4y-R4zas defined hereinbefore, and each R5ais independently (1-22C)alkyl; and / ortwo R4asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.13. The polymer as defined in statement 12, wherein each R4ais independently selected from hydrogen, (1 -15C)alkyl, (2-15C)alkenyl, (2-15C)alkynyl, (1-4C)alkylidene, halo and phenyl, and each R5ais independently (1 -4C)alkyl; and / ortwo R4asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.14. The polymer as defined in statement 12, wherein each R4ais independently selected from hydrogen, (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-4C)alkylidene, chloro, bromo and phenyl, and each R5ais independently (1 -4C)alkyl; and / ortwo R4asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.15. The polymer as defined in any one of statements 9 to 14, wherein the 3-7 membered carbocyclic ring or 6-membered aromatic ring is optionally substituted with one or more R6, wherein each R6is independently selected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-10C)alkoxy, (1-4C)alkylidene, halo, amino, hydroxy, -B(OH)2and carboxy.16. The polymer as defined in statement 15, wherein the 3-7 membered carbocyclic ring or 6-membered aromatic ring is optionally substituted with one or more R6, wherein each R6is independently selected from (1 -4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl and chloro.17. The polymer as defined in any one of statement 1 to 7, wherein L1has a structure selected from:18. The polymer as defined in any one of the preceding statements, wherein in L2, the 3-4 bond lengths is:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C, N and O, with the proviso that at least one (suitably at least two) of the three atoms is C.19. The polymer as defined in statement 18, wherein in L2, the 3-4 bond lengths is:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C and O, with the proviso that at least one (suitably at least two) of the three atoms is C.20. The polymer as defined in statement 18 or 19, wherein in L2, any of said C atoms participating in said 3-4 bond lengths is optionally substituted with one or two R7, and any of said N atoms participating in said 3-4 bond lengths is optionally substituted with one R8, wherein:(i) each R7is independently selected from (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R7x-R7y-R7z, and each R8is independently (1-22C)alkyl, wherein R7xis selected from absent, -S- and -(CH2)j-C(O)O-, R7yis -(CH2CH2O)k-, and R7zis selected from H and (1-10C)alkyl, in which j is 0 or 1 and k is 1-100; and / or(ii) two R7substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.21. The polymer as defined in statement 20, wherein:(i) each R7is independently selected from (1 -15C)alkyl, (2-15C)alkenyl, (2-15C)alkynyl, (1-4C)alkylidene, halo and phenyl, and each R8is independently (1 -4C)alkyl; and / or(ii) two R7substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.22. The polymer as defined in statement 20, wherein:(i) each R7is independently selected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-4C)alkylidene, chloro, bromo and phenyl, and each R8is independently (1 -4C)alkyl; and / or (ii) two R7substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.23. The polymer as defined in statement 18 or 19, wherein L2has a structure L2aor L2b:_^.W1_W2|. -^-w3-w4-w5-^-|_2a |_2b= represents a single bond ora double bond;W1and W2are both C(R7a)x, in which x is 1 or 2;W3, W4and W5are each independently selected from C(R7a)y, in which y is 1 or 2, N(R8a)z, in which z is 0 or 1, and O, with the proviso that at least one (suitably at least two) of W3, W4and W5is C(R7a)y;each R7ais independently selected from hydrogen, (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R7x-R7y-R7zas defined hereinbefore, and each R8ais independently (1-22C)alkyl; and / ortwo R7asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.24. The polymer as defined in statement 23, wherein each R7ais independently selected from hydrogen, (1 -15C)alkyl, (2-15C)alkenyl, (2-15C)alkynyl, (1-4C)alkylidene, halo and phenyl, and each R8ais independently (1 -4C)alkyl; and / ortwo R7asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.25. The polymer as defined in statement 23, wherein each R7ais independently selected from hydrogen, (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-4C)alkylidene, chloro, bromo and phenyl, and each R8ais independently (1 -4C)alkyl; and / ortwo R7asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.26. The polymer as defined in any one of statements 20 to 25, wherein the 3-7 membered carbocyclic ring or 6-membered aromatic ring is optionally substituted with one or more R9, wherein each R9is independently selected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-10C)alkoxy, (1-4C)alkylidene, halo, amino, hydroxy, -B(OH)2and carboxy.27. The polymer as defined in statement 26, wherein the 3-7 membered carbocyclic ring or 6-membered aromatic ring is optionally substituted with one or more R9, wherein each R9is independently selected from (1 -4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl and chloro.28. The polymer as defined in any one of statement 1 to 18, wherein L2has a structure selected from:S-(CH2CH20)1-1OOHANC|29. The polymer as defined in any one of the preceding statements, wherein J is O.30. The polymer as defined in any one of the preceding statements, wherein R1is H or R2, and R3is H.31. The polymer as defined in any one of statements 1 to 29, wherein R1is R2or Y, and R3is Y.32. The polymer as defined in any one of statements 1 to 29, wherein R1is H, (1-22C)alkyl or (2-22C)alkenyl.33. The polymer as defined in any one of statements 1 to 29, wherein R1is R2or Y.34. The polymer as defined in any one of statements 1 to 29, wherein R1is H, (1-22C)alkyl, (2-22C)alkenyl or R2, and R3is H.35. The polymer as defined in any one of statements 1 to 29, wherein R1is H, (1-22C)alkyl, (2-22C)alkenyl or Y, and R3is H.36. The polymer as defined in any one of the preceding statements, wherein n is a number 0 to 80.37. The polymer as defined in any one of the preceding statements, wherein n is a number 0 to 50.38. The polymer as defined in any one of the preceding statements, wherein n is a number 0 to 20.39. The polymer as defined in any one of the preceding statements, wherein n is a number 0 to 4.40. The polymer as defined in any one of the preceding statements, wherein n is a number 0 to 3.41. The polymer as defined in any one of the preceding statements, wherein the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 - 500 kg mol-1.42. The polymer as defined in any one of the preceding statements, wherein the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 - 30 kg mol-1.43. The polymer as defined in any one of the preceding statements, wherein the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 - 20 kg mol-1.44. The polymer as defined in any one of the preceding statements, wherein the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5- 15 kg mol-1.45. The polymer as defined in any one of the preceding statements, wherein the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 1.5 - 12 kg mol-1.46. The polymer as defined in any one of the preceding statements, wherein the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 1.5 - 10 kg mol-1.47. The polymer as defined in any one of the preceding statements, wherein the polymer has a polydispersity index of <2.0 as determined by gel permeation chromatography.48. The polymer as defined in any one of the preceding statements, wherein the polymer has a polydispersity index of <1.8 as determined by gel permeation chromatography.49. The polymer as defined in any one of the preceding statements, wherein the polymer has a polydispersity index of <1.5 as determined by gel permeation chromatography.50. The polymer as defined in any one of the preceding statements, wherein the polymer has a polydispersity index of <1.3 as determined by gel permeation chromatography.51. The polymer as defined in any one of the preceding statement, wherein the polymer comprises only one repeating unit of formula I.52. The polymer as defined in any one of statements 1 to 50, wherein the polymer comprises 2 or more (e.g., 2 to 4) different repeating units of formula I.53. The polymer as defined in any one of statements 1 to 50, wherein the polymer comprises 2 or 3 different repeating units of formula I.54. The polymer as defined in any one of statements 1 to 51, wherein X is X1, J is O, n is 0 and R1is H, and wherein the polymer has a molecular weight (Mn) of 0.5 - 30 kg mol-1(e.g., 1.5 - 10 kg mol-1) and a polydispersity index of <1.5 (e.g., <1.3).55. The polymer as defined in any one of statements 1 to 51, wherein X is X1, J is O, n is 1 and R1is H, and wherein the polymer has a molecular weight (Mn) of 0.5 - 15 kg mol-1(e.g., 1.5 - 12 kg mol-1) and a polydispersity index of <1.5 (e.g., <1.3).56. The polymer as defined in any one of statements 1 to 51, wherein X is X1, J is O, n is 3 and R1is H, and wherein the polymer has a molecular weight (Mn) of 0.5 - 10 kg mol-1(e.g., 1.5 - 10 kg mol-1) and a polydispersity index of <1.8 (e.g., <1.3)57. The polymer as defined in any one of statements 1 to 51, wherein X is X1, J is O, n is 0, R1is R2and R3is H, and wherein the polymer has a molecular weight (Mn) of 0.5 - 20 kg mol-1(e.g., 1.5 - 15 kg mol-1) and a polydispersity index of <1.5 (e.g., <1.3).58. The polymer as defined in any one of statements 1 to 51, wherein X2, J is O, n is a number 1 -50, R1is H or Y, and the polymer has a molecular weight (Mn) of 0.5- 15 kg mol-1(e.g., 1.5 - 10 kg mol-1) and a polydispersity index of <1.8 (e.g., <1.6).59. The polymer as defined in statement 58, wherein n is a number 1-15, R1is H, and L1has a structure:60. The polymer as defined in any one of statements 1 to 53, wherein at least 25% of the repeating units within the polymer have a structure according to formula I.61. The polymer as defined in any one of statements 1 to 53, wherein at least 50% of the repeating units within the polymer have a structure according to formula I.62. The polymer as defined in any one of statements 1 to 53, wherein at least 75% of the repeating units within the polymer have a structure according to formula I.63. The polymer as defined in any one of statements 1 to 53, wherein at least 85% of the repeating units within the polymer have a structure according to formula I.64. The polymer as defined in any one of statements 1 to 53, wherein at least 95% of the repeating units within the polymer have a structure according to formula I.65. The polymer as defined in any one of statements 1 to 59, wherein all repeating units within the polymer have a structure according to formula I.66. The polymer as defined in any one of statements 1 to 53, wherein X is X1and the polymer comprises poly(carbonate) moieties and / or is a poly(carbonate).67. The polymer as defined in any one of statements 1 to 53, wherein X is X2and the polymer comprises poly(ester) moieties and / or is a poly(ester).68. The polymer as defined in any one of statements 1 to 53, wherein the polymer comprises a first repeating unit of formula I, in which X is X1, and a second repeating unit of formula I, in which X is X2, and the polymer comprises poly(carbonate-co-ester) moieties and / or is a poly(carbonate-co-ester).69. The polymer as defined in statement 68, wherein the polymer is a random copolymer, a block copolymer or an alternating copolymer.70. The polymer as defined in any preceding statement, wherein the polymer is linear.71. The polymer as defined in any preceding statement, wherein the polymer is crosslinked.72. The polymer as defined in statement 71, wherein the polymer comprises a crosslinking moiety of formula III:(HI)whereinJ, R1and n have any of the definitions outlined hereinbefore in relation to formula I;-«««1and2each represent a point of attachment to a polymeric chain comprising a repeating unit of formula I; andL3is a linker separating the two carbonyl groupsAC=O by a distance of 3-4 bond lengths and the two carbonyl groupsBC=O by a distance of 3-4 bond lengths.73. The polymer as defined in statement 72, wherein1and -«~«2each represents a point of attachment to a repeating unit of formula I.74. The polymer as defined in any one of statements 71 to 73, wherein the polymer comprises a crosslinking moiety of formula IV:(IV)wherein1and2each represent a point of attachment to a polymeric chain comprising a repeating unit of formula I; andL4is a linking group.75. The polymer as defined in statement 74, wherein1and2each represents a point of attachment to a repeating unit of formula I.76. The polymer as defined in statement 74 or 75, wherein the crosslinking moiety of formula IV has a structure according to formula IVa:(IVa)whereinX, J and n have any of the definitions outlined hereinbefore in relation to formula I;v»1and •«"«2each represent a point of attachment to a polymeric chain comprising a repeating unit of formula I; andL4ais a linking group.77. The polymer as defined in any one statements 71 to 76, wherein the polymer comprises 0.01 - 5 wt% of crosslinking moieties.78. The polymer as defined in any one statements 71 to 76, wherein the polymer comprises 0.01 - 3 wt% of crosslinking moieties.79. The polymer as defined in any one statements 71 to 76, wherein the polymer comprises 0.01 - 1.5 wt% of crosslinking moieties.80. The polymer as defined in any one of the preceding statements, wherein the polymer has a structure accordingly to formula II below:B — M1 Je(II)wherein:each A is a polymeric chain comprising a repeating unit of formula I;B is an end group to which each A is attached; ande is 1-6 (e.g., 1, 2, 3 or 4).81. The polymer as defined in statement 80, wherein each A has a hydroxy-terminating polymeric backbone.82. The polymer as defined in statement 80, wherein each A has a polymeric backbone terminating in COOH.83. A polymer comprising a repeating unit of formula I:whereinX is:i) a group X1of structure:, orii) a group X2of structure:in which L1is a linker separating the two carbonyl groups by a distance of 3-4 bond lengths; n is a number 0 to 100;J is O, (2-22C)alkylene or CRaRb;Raand Rbare each independently H or (1 -10C)alkyl;R1is PG or R2;R2is a group:each R3is PG, or both R3are linked to form PG;wherein PG is a protecting group that is removable to expose the oxygen atom(s) to which it is attached.84. The polymer as defined in statement 83, wherein except for the definition of R1, the polymer is as defined in any one of statements 1-61.85. The polymer as defined in statement 83 or 84, wherein PG is arylalkyl.86. The polymer as defined in statement 83 or 84, wherein PG is phenyl(1-3C)alkyl.87. The polymer as defined in statement 83 or 84, wherein R1is PG and PG is:or R1is R2, and both R3are linked to form PG, wherein PG is:88. A polymer as defined in any preceding statement, wherein the polymer has a structure, or repeating unit, as depicted in any of the accompanying figures or in any of the reaction schemes outlined in the Examples section.89. Use of a polymer as defined in any one of the preceding statements as a thickening agent, a binding agent, a stabilizing agent, a surfactant, a film-forming agent, a viscositymodifying agent, an adhesion promoter or an encapsulation agent.90. A liquid formulation comprising a polymer as defined in any one of the preceding statements.EXAMPLES

[0100] One or more examples of the invention will now be described, for the purpose of illustration only, with reference to the accompanying figures:Fig. 1. Example crude1H-NMR (CDCI3) spectrum produced from reaction mixture of BGE and CO2used to calculate the conversion of BGE. Conversion of BGE (%) = P(BGE-a / f-CO2) integralgreen region) I (BGE integral-blue region)] = [([4.99-4.91 ppm) I ([3.14-3.09 ppm)]*100.Fig. 2. a)1H-NMR (CDCI3) spectrum of polymer P(BGE-alt-CO2). b) SEC elugrams (4 mg mL-1) (normalized Rl) of isolated P(BGE-alt-CO2) polycarbonates with different degrees of polymerization, c) MALDI-ToF spectrum of low molar mass P(BGE-alt-CO2) with DPN= 17. d) Plot of m / z vs DPN. Observed end group mass = 161.06 g mol-1, calculated end group mass = 161.25 g mol-1. Observed (average) distance between peaks = 208.06 g mol-1, theoretical Mn(repeat unit) = 208.21 g mol-1.Fig. 3.1H-NMR (CDCI3) spectrum of isolated P(BGE-a / f-CO2)s with different degree of polymerization.Fig. 4. MALDI-TOF spectra and SEC elugrams (4 mg mL-1) (THF vs polystyrene standards) of P(BGE-a / f-CO2) with different degree of polymerization.Fig. 5.31P-NMR (CDCI3) spectrum for end-group characterization of P(BGE-a / f-CO2).Fig. 6. Thermal stability of P(BEMO-alt-CO2)s obtained by (left) differential scanning calorimetry (obtained from the second heating scan) and by (right) thermogravimetric analysis (10 °C min-1). Fig. 7. Example crude1H-NMR (CDCI3) spectrum produced from reaction mixture of BEMO and CO2used to calculate the conversion of BEMO. Conversion of BEMO (%) = [(P(BEMO) integralgreen region) + cyclic carbonate (purple region) I (BEMO integral-blue region)] = [([5.10-5.00 ppm) + ([4.86-4.79 ppm) I ([3.24-3.17 ppm)]*100. Selectivity of P(BEMO-a / f-CO2)= P(BEMO-a / f-CO2) integral-green region) + cyclic carbonate (purple region)] = [([5.10-5.00 ppm) I ([4.86-4.79 PPm)].Fig. 8 a)1H-NMR (CDCI3) spectrum of polymer P(BEMO-a / f-CO2).b) SEC elugrams (4 mg mL-1) (normalized Rl) of isolated P(BEMO-a / f-CO2) polycarbonates with different degrees of polymerization, c) MALDI-ToF spectrum of low molar mass P(BEMO) with DPN= 13. d) Plot of m / z vs DPN. Observed end group mass = 161.04 g mol-1, calculated end group mass = 161.25 g mol-1. Observed (average) distance between peaks = 252.03 g mol-1, theoretical Mn(repeat unit) = 252.21 g mol-1.Fig. 9. Thermal stability of P(BEMO-alt-CO2)s obtained by (left) thermogravimetric analysis (10 °C min-1). and by (right) differential scanning calorimetry (obtained from the second heating scan). Fig. 10.1H-NMR (CDCI3) spectrum of P(IGG-a / f-CO2).Fig. 11. a)1H-NMR (CDCh) spectrum of polymer P(IGG-alt-CO2). b) SEC elugrams (4 mg mL-1) (normalized Rl) of isolated P(IGG-alt-CO2) polycarbonates with different degrees ofpolymerization, c) MALDI-ToF spectrum of low molar mass P(IGG-a / f-CO2) with DPN= 9. d) Plot of m / z vs DPN. Observed end group mass = 161.06 g mol-1, calculated end group mass = 161.25 g mol-1. Observed (average) distance between peaks = 234.14 g mol-1, theoretical Mn(repeat unit) = 232.23 g mol-1.Fig. 12.1H-NMR (CDCh) spectrum of isolated P(IGG-a / f-CO2)s with different degree of polymerization.Fig. 13. Thermal stability of P(IGG-alt-CO2)s obtained by (left) thermogravimetric analysis (10 °C min-1). and by (right) differential scanning calorimetry (obtained from the second heating scan). Fig. 14. a)1H-NMR (D2O) spectrum of poly((glyceryl glycerol) P(GG-alt-CO2). b) MALDI-ToF spectrum of low molar mass deprotected P(GG-alt-CO2) with DPN = 22. c) Plot of m / z vs DPN. Observed end group mass = 161.36 g mol-1, calculated end group mass = 161.25 g mol-1. Observed (average) distance between peaks = 191.98 g mol-1, theoretical Mn(repeat unit) = 192.06 g mol-1, d) SEC elugrams (1 mg mL-1) (normalized Rl) of isolated P(IGG-alt-CO2) (purple trace) and deprotected P(GG-alt-CO2) (blue trace), e) IR-ATR spectra of isolated P(IGG-a / f-CO2) (purple trace) and deprotected P(GG-alt-CO2) (blue trace).Fig. 15. SEC elugrams (4 mg mL-1) (normalized Rl) of isolated P(ME3MO-a / f-CO2) polycarbonates with different degrees of polymerization (top left). Thermal stability of P(ME3MO-a / f-CO2)s obtained by (top right) thermogravimetric analysis (10 °C min-1) and by (bottom) differential scanning calorimetry (obtained from the second heating scan).Fig. 16.1H-NMR (CDCI3) spectrum of isolated P(ME3MO-a / f-CO2) with different degree of polymerization.Fig. 17.1H-NMR (D2O) spectrum of isolated P(ME3MO-a / f-CO2) with different degree of polymerization.Fig. 18.1H-NMR (bottom) (CDCh) spectrum of P(BEMO-alt-CO2).1H-NMR (medium) (DMSO-d6) P(EMO-alt-CO2).1H-NMR (top) (DMF-d7) spectrum of P(EMO-alt-CO2)-SA.Fig. 19. SEC elugrams (4 mg mL-1) (normalized Rl) in THF of P(BEMO-alt-CO2) (left) and in DMF isolated P(EMO-alt-CO2) (right).Fig. 20.1H-NMR (bottom left) and13C-NMR (CDCh) (bottom right) and spectrum of ethoxyl vinyl glycidyl ether-alt-phthalic anhydride polyesterP(EVGE-alt-PA).1H-NMR (medium left) and13C-NMR (DMSO-de) (medium right) and spectrum of ethoxyl glycidyl ether-alt-phthalic anhydride P(EGE-alt-PA).1H-NMR (top left) and13C-NMR (DMF-d7) (top right) and spectrum of (succinic acid)ethoxyl glycidyl ether-alt-phthalic anhydride P(EGE-alt-PA)-SA.Fig. 21. SEC elugrams (4 mg mL-1) (normalized Rl) in THF of isolated ethoxyl vinyl glycidyl ether-alt-phthalic anhydride polyester P(EVGE-alt-PA) (left) and in DMF isolated ethoxyl glycidyl ether-alt-phthalic anhydride polyester P(EGE-alt-PA) (right).Fig. 22. Assigned H NMR spectrum (CDCI3, 500 MHz) of the purified polymer, poly(DGA-alt- ME3MO).Fig. 23. Assigned H NMR spectrum (CDCI3, 500 MHz) of the purified polymer, poly(DGA-alt- MGE-(PEG)5).Fig. 24. Assigned H NMR spectrum (CDCI3, 500 MHz) of the purified polymer, poly(DGA-alt- MGE-(PEG)I2).Fig. 25.1H NMR in CDCI3of MBA initiated P(GA-alt-IGG)10.Fig. 26.1H NMR in CDCh of MBA initiated P(GA-alt-IGG)2o.Fig. 27.1H NMR in CDCI3of MBA initiated P(GA-alt-IGG)40.Fig. 28.1H NMR in DMSO-d6 of P(GA-alt-DOL)io.Fig. 29.1H NMR in DMSO-d6 of P(GA-alt-DOL)20.Fig. 30.1H NMR in DMSO-d6 of P(GA-alt-DOL)40.Fig. 31.1H NMR in DMF-d7 of P(GA-alt-DOL-g-SA)20.Fig. 32.1H NMR in CDCI3of P(GA-alt-BGE)10.Fig. 33.1H NMR in DMF-d7 of P(GA-alt-MOL)10.Fig. 34.1H NMR in DMF-d7 of P(GA-alt-MOL-g-SA)10.1. Materials and methods

[0101] All manipulations involving air- and moisture-sensitive reagents were carried out either under an atmosphere of nitrogen gas using standard Schlenk techniques or under an atmosphere of nitrogen within an M. Braun glovebox MB-BL-01 maintained at <0.1 ppm of H2O and <0.1 ppm of O2. All solvents and chemicals were purchased from Sigma Aldrich, Acros Organics, Fluka or Fisher Scientific and used as received, unless otherwise state. Acetonitrile, pentane, tetrahydrofuran, toluene, and dimethylformamide were obtained from an SPS system, degassed by three freeze-pump-thaw cycles, further dried with 3 A molecular sieves, and stored under N2. Research-grade CO2(BOC, 99.99 %) was dried through a Drierlite column and two additional drying columns (Micro Torr, model number: MC1-804FV) in series before use.

[0102] Benzyl glycidyl ether (99%), tetrabutylammonium hydrogen sulfate (>99.0%), tetrabutylammonium bromide (>99.0%), DL-1,2-isopropylideneglycerol (98%), triethylene glycol monomethyl ether (>97.0%), sodium hydroxide (>98.0%), sodium hydride (90%) and (±) epichlorohydrin (>99.0%) were purchased from Sigma Aldrich. 2-(benzyloxy)ethanol (>98.0%) was purchased from TCI.

[0103] 4-Methylbenzyl alcohol (MBA, 98%, Sigma Aldrich) was recrystallised from petroleum ether and dried under vacuum and stored under nitrogen.

[0104] The catalyst [Co(lll) / K(l)] was synthesised from the dialdehyde pro-ligand (Enamime LTd.), ethylene diamine (Sigma-Aldrich, >99.0%), Co(OAc)2 (Sigma Aldrich, 99.99%), and KOAc (Sigma Aldrich, >99.0%) via a literature method7and was dried under vacuum during 2 days.

[0105] (DL-1,2-isopropylidene glyceryl)glycidyl ether (IGG) was synthesised via a literature method47and was purified by drying over CaH2, nBuLi and neat by fractional distillation, sequentially, and storage under N2atmosphere.

[0106] NMR spectroscopy. NMR data were acquired at 25 °C on a Bruker Avance III HD nanobay 400 MHz spectrometer (400.2 MHz1H, 100.613C, 162.031P), on a Bruker Avance III HD 500 MHz spectrometer (499.9 MHz1H, 125.7 MHz13C, and 202.4 MHz31P). Also a Bruker NEO 600, with broadband helium cryoprobe equipped with a 14.1T magnet (1H 600.4 MHz13C 151.0 MHz,31P 243.1 MHz).1H and13C{1H} spectra were referenced internally to solvent signals: chemical shifts are reported as parts per million relative to SiMe4. Deuterated solvents (Cambridge Isotope Laboratories Inc.) were used as received, except for application with moisture sensitive materials in which case they were dried over CaH2]vacuum distilled, and stored over molecular sieves prior to use.

[0107] Other spectroscopy. Fourier-Transform Infrared Spectroscopy (FT-IR) was measured on a Shimadzu IRSpirit.

[0108] Differential Scanning Calorimetry (DSC). Polymer samples were analysed on a DSC25 (TA Instruments), under a N2flow (50 mL min-1). Samples were heated (10 °C min-1) and equilibrated to 150 °C, to remove their thermal history, then cooled to -80 °C (10 °C min-1) before heating a second time to 150 °C, at a rate of 10 °C min-1. Glass transition temperatures (Tg) were determined from the midpoint of the transition in the second heating curve.

[0109] Thermal Gravimetric Analysis (TGA). Polymer samples were analysed on a TGA / DSC 1 (Mettler-Toledo Ltd), or a TGA5500 (TA Instruments). Polymer samples were heated from 30 to 700 °C at a rate of 10 °C min-1under N2flow (50 mL min-1).

[0110] MALDI-TOF Mass Spectrometry. MALDI-TOF analyses were carried out on a Bruker Autoflex Speed MALDI-TOF. Spectra were acquired in positive-reflectron mode. Spotting methodA, for polycarbonates: sample solutions of polymer (10 mg mL-1in THF), dithranol (10 mg mL-1in THF), and KTFA (10 mg mL-1in MeOH) were pre-mixed in 1:4:1 ratio and subsequently spotted onto a metal plate and allowed to fully evaporate before analysis. Spotting method B, for hydroxyl containing polycarbonates: sample solutions of polymer (10 mg mL-1in H2O), 2,5-Dihydroxybenzoic acid (10 mg mL-1in MeOH), and KTFA (10 mg mL-1in MeOH) were pre-mixed in 1:4:1:1 ratio and subsequently spotted onto a metal plate and allowed to fully evaporate before analysis.

[0111] Size Exclusion Chromatography (SEC). Polymer samples (2-10 mg) dissolved in HPLC grade THF (1.2 mL) were syringe filtered through 25 μm PTFE filters. Next, they were injected into Shimadzu LC-20AD SEC instrument, with two PSS SDV 5 pm linear M columns, heated to 30 °C. HPLC grade THF was used as the eluent, at a flow rate 1.0 mL min-1. Rl and UV detectors were calibrated using a series of narrow molecular weight polystyrene standards. Shimadzu SEC post run program was used to analyse the data.2. Synthesis of monomers2.1. Synthesis of 2-((2-(benzyloxy)ethoxy)methyl)oxirane (BEMO)NaH, THFfOi)16h, 25 °Cii) 4h, 85°C

[0112] NaH (3.0 g, 112.5 mmol) was suspended in anhydrous THF (100 mL). 2-(Benzyloxy)ethanol (15.1 g, 14.1 mL, 100 mmol) was added slowly and the solution was stirred at ambient temperature, for 2 h. Epichlorohydrin (37.9 g, 32 mL, 400 mmol) was added slowly, at 0 °C, and the solution was stirred at room temperature, for 16 h, followed by 4 h, at reflux. After the solution was cooled to room temperature, methanol was added to neutralize it. The reaction mixture was evaporated, then ethyl acetate (100 mL) was used to extract it. The organic phase was washed with NaHCO3solution (100 mL) and with brine (100 mL). Aqueous phases were extracted with ethyl acetate (100 mL) and the organic phases were combined and dried over Na2SO4. The reaction was evaporated to give a crude material, which was further purified by column chromatography (petroleum ether / ethyl acetate, 80:20) and distilled from CaH2by fractional distillation (104-106 °C, 2 x 10-1mbar). Yield = 85 %.

[0113] 1H NMR (CDCh, 25 °C, 600 MHz) 6 7.35-7.26 (m, Hh, Hi, Hj, 5H), 4.57 (s, Hg, 2H), 3.80 (dd, J = 11.6, 3.0 Hz, 1H, Hd), 3.75-3.62 (m, He, Hf, 4H), 3.45 (dd, J = 11.6, 5.9 Hz, 1 H, Hd), 3.17 (ddt, J = 5.8, 4.2, 2.9 Hz, 1 H, Hc), 2.80 (dd, J = 5.0, 4.1 Hz, 1 H, Ha), 2.62 (dd, J = 5.1, 2.7 Hz, 1 H, Hb).

[0114] 13C NMR (CDCh, 25 °C, 151 MHz) 6 138.2 (Hg), 128.4 (Hi), 127.8 (Hh), 127.6 (Hj), 73.3 (Hf), 72.0 (He), 70.8 (Hd), 69.4 (He), 50.8 (Hb), 44.3 (Ha).2.2. Synthesis of 2-[[2-[2-(Phenylmethoxy)ethoxy1ethoxy1methyl1oxiraneNaH, THFi)16h, 25 °Cii) 4h, 85°C

[0115] NaH (3.0 g, 112.5 mmol) was suspended in anhydrous THF (100 mL). Di(ethylene glycol) benzyl ether (19.6 g, 18 mL, 100 mmol) was added slowly and the solution was stirred at ambient temperature, for 2 h. Epichlorohydrin (37.9 g, 32mL, 400 mmol) was added slowly, at 0 °C, and the solution was stirred at room temperature, for 16 h, followed by 4 h, at reflux. After the solution was cooled to room temperature, methanol was added to neutralize it. The reaction mixture was evaporated, then ethyl acetate (100 mL) was used to extract it. The organic phase was washed with NaHCCh solution (100 mL) and with brine (100 mL). Aqueous phases were extracted with ethyl acetate (100 mL) and the organic phases were combined and dried over Na2SO4. The reaction was evaporated to give a crude material, which was further purified by column chromatography (petroleum ether / ethyl acetate, 80:20) and distilled from CaH2by fractional distillation (150-152 °C, 2 x 10-1mbar). Yield = 90 %.

[0116] 1H NMR (CDCh, 25 °C, 600 MHz) 6 7.35-7.26 (m, Hj, Hk, Hi, 5H), 4.56 (s, Hh, 2H), 3.81 (dd, J = 11.7, 3.0 Hz, Hc, 1 H), 3.75-3.66 (m, Hd, He, Hf, Hg, 4H), 3.46 (dd, J = 11.7, 5.8 Hz, Hc,1 H), 3.18 (ddt, J = 5.8, 4.2, 2.9 Hz, Hc, 1 H), 2.80 (dd, J = 5.0, 4.1 Hz, Ha, 1H), 2.62 (dd, J = 5.1, 2.7 Hz, Hb, 1 H).

[0117] 13C NMR (CDCh, 25 °C, 151 MHz) 6 138.3 (Hi), 128.4 (Hk), 127.7 (Hj), 127.6 (Hi), 73.3 (Hh), 72.0 (He), 70.8 (Hd), 70.7 (He), 70.7 (Hf), 69.5 (Hg), 50.8 (Hb), 44.3 (Ha).3. Synthesis of polymers3.1. Representative benzyl qlycidyl ether (BGE) / CO2ring-opening copolymerisationCat. [Co(lll) / K(l)]AcO = CH3(CO)O’

[0118] In a glovebox, a Schlenk was charged with [Co(l I l) / K(l)] catalyst (24.6 mg, 0.039 mmol), the required change transfer agent methyl benzyl alcohol (MBA) (192 mg, 1.57 mmol), and epoxide (6 mL, 6.44 g, 39.2 mmol) and stirred until the reaction mixture was homogeneous. Then, the reaction mixture was transferred into a 25 mL Parr reactor and removed from the glovebox. The reactor was pressurized to the desired CO2pressure and the temperature was set to 25 °C. The copolymerization was stirred at this temperature for the reaction duration, and quenched by addition of benzoic acid (10 equivalents vs catalyst). Crude samples were analysed by1H-NMR spectroscopy in CDCh to determine the reaction conversion and selectivity. The polymer was then precipitated three times into methanol or hexanes to remove any excess epoxide. Then, the resulting polymer was redissolved in CH2CI2and passed through a silica plug to remove the catalyst, to give the polymer as a colourless viscous solid.

[0119] 1H NMR (CDCh, 25 °C, 600 MHz): 6 7.36-7.22 (m, Hg, Hh, Hi, 5H); 7.15 (d, Ar- / 7 BMA end group); 5.10 (s, -CH2- BMA end group); 5.04 (bs, Hb, 1H); 4.57-4.47 (bs, Hd, 2H); 4.45-4.19 (bt, Ha, 2H); 3.63 (bs, Hc, 2H); 2.34 (s, -CW3BMA end group).

[0120] 13C NMR (CDCh, 25 °C, 151 MHz): 6 154.3-154.2 (Hi), 137.6 (He); 129.9 (Ar-H BMA end group); 128.5 (Hg), 127.8 (Hg); 127.7 (Hf); 74.4 (Hb); 72.0 (Hc); 73.4 (Hd); 69.9 (-CW2- BMA end group); 67.8 (Hc), 66.2 (Ha), 69.5 (Hg), 21.2 (-CW3BMA end group).

[0121] SEC: Mn= 3.0 kg mol1, 0 = 1.07

[0122] MALDI-ToF: Mn,ca / c(repeat unit) = 208.06 g mol-1, Mn, theoretical repeat unit) = 208.07 g mol’1; Mn,caic (end group) = 161.06 g mol-1, Mn, theoretical (end group) = 161.04 g mol-1.3.2. Representative BEMO / CO2ring-opening copolymerisationCat. [Co(lll) / K(l)]

[0123] In a glovebox, a Schlenk was charged with [Co(l I l) / K(l)] catalyst (19.3 mg, 0.031 mmol), the reguired change transfer agent methyl benzyl alcohol (MBA) (150.3 mg, 1.23 mmol), and epoxide (6 mL, 6.41 g, 30.8 mmol) and stirred until the reaction mixture was homogeneous. Then, the reaction mixture was transferred into a 25 mL Parr reactor and removed from the glovebox. The reactor was pressurized to the desired CO2pressure and the temperature was set to 25 °C. The copolymerization was stirred at this temperature for the reaction duration, and guenched by addition of benzoic acid (10 eguivalents vs catalyst). Crude samples were analysed by1H-NMR spectroscopy in CDCh to determine the reaction conversion and selectivity. The polymer (termed P(BEMO-a / f-CO2)) was then precipitated three times into methanol or hexanes to remove any excess epoxide. Then, the resulting polymer was redissolved in CH2CI2and passed through a silica plug to remove the catalyst, to give the polymer as a colourless viscous solid.

[0124] 1H NMR (CDCh, 25 °C, 600 MHz): 6 7.34-7.23 (m, Hh, Hi, Hj, 5H); 7.16 (d, Ar- / 7 BMA end group); 5.10 (s, -CH2- BMA end group); 5.02 (bs, Hb, 1H); 4.52 (bs, Hd, 2H); 4.46-4.16 (bt, Ha, 2H); 3.69-3.53 (bm, Hc, Hd, He, 6H); 2.33 (s, -CH3BMA end group).

[0125] 13C NMR (CDCh, 25 °C, 151 MHz): 6 154.3-154.2 (Hg), 138.2 (Hk); 129.3 and 128.6 (Ar-H BMA end group); 128.4 (Hi), 127.7 (Hb); 127.6 (Hj); 74.4 (Hb); 73.2 (Hf); 71.1 (Hc); 69.9 (-CH2- BMA end group); 69.3 (Hc), 68.9 (He), 21.2 (-CH3BMA end group).

[0126] SEC: Mn= 3.1 kg mol1, 0 = 1.07.

[0127] MALDI-ToF: Mn,ca / c(repeat unit) = 252.03 g mol-1, Mn, theoretical (repeat unit) = 252.10 g mol-1; Mn,caic (end group) = 161.04 g mol-1, Mn, theoretical (end group) = 161.04 g mol-1.3.3. Representative deprotection of P(BEMO-aff-CO2)20% Pd / C,40 bar H2,40 °C, 24h EtOAc / MeOH(7:3)

[0128] The polymer P(BEMO-a / f-CO2) was dissolved in a mixture of EtOAc: MeOH (7:3) and the solution was transferred into a high pressure reactor. Then, Pd / C (10 wt% respect to polymer) was impregnated with 50% water and added to the reactor. The autoclave was charged with H2to 40 bar and heated to 40 °C. After 24 h, the reactor was allowed to cool at room temperature. The pressure was released and the reaction mixture was filtered through a thin pad of celite. The solvent was removed under reduced pressure and the product was dried under vacuum to afford the polymer (P(EMO-a / f-CO2).oOH

[0129] 1H NMR (DMSO-d6, 25 °C, 500 MHz): 6 (ppm) 4.98 (bs, Hb, 1 H), 4.62 (bs, Hf, 1H), 4.37-4.22 (bm, Ha, 2H), 3.62-3.61 (bm, He, 2H), 3.49-3.43 (bm, Hd, He, 4H).

[0130] 13C NMR (DMSO-de, 25 °C, 500 MHz) 6 (ppm) 154.2 (Hg), 74.9 (IIb), 73.3 (Hd), 68.8 (He), 66.5 (IIa), 60.6 (He).3.4. Representative functionalization of P(EMO-a / f-CO2) by acylation reaction to form acidcontaining polycarbonate P(EMO-a / f-CO2)-SA0.05 eq DMAP, DMF, RT, 18h

[0131] The P(EMO-a / f-CO2), succinic anhydride (SA) and dimethylaminopyridine (DMAP) were dissolved in DMF to get a final concentration of 100 mg mL-1(respect to polymer). Then, the reaction mixture was stirred at ambient temperature for 24 h. The reaction mixture was purified by repetitive precipitation into diethyl ether to form succinic acid-functionalized P(EMO-a / f-CO2)-SA.O

[0132] 1H NMR (DMF-d7, 25 °C, 500 MHz): 6 (ppm) 5.10 (bs, Hb, 1H), 4.49-4.35 (bm, Ha, 2H), 4.23 (bs, He, 2H), 3.75-3.72 (bm, He, Hd, 4H), 2.61 (bs, Hf, Hh, 4H).

[0133] 13C NMR (DMF-d7, 25 °C, 500 MHz): 6 (ppm) 173.8-172.7 (Hg), 154.5 (Hf), 74.9 (IIb), 69.3 (Hd), 68.9 (He), 66.5 (IIa), 63.6 (He), 28.9 (Hh).3.5. Representative isopropylidene glyceryl qlycidyl ether (IGG) / CO2ring-opening copolymerisationCat [Co(lll) / K(l)lAcO = CH3(CO)O’

[0134] In a glovebox, a Schlenk was charged with [Co(l I l) / K(l)] catalyst (22.2 mg, 0.035 mmol), the reguired change transfer agent methyl benzyl alcohol (MBA) (171.5 mg, 2.83 mmol), and epoxide (6 mL, 6.61 g, 35.1 mmol) and stirred until the reaction mixture was homogeneous. Then, the reaction mixture was transferred into a 25 mL Parr reactor and removed from the glovebox. The reactor was pressurized to the desired CO2pressure and the temperature was set to 25 °C. The copolymerization was stirred at this temperature for the reaction duration, and guenched by addition of benzoic acid (10 eguivalents vs catalyst). Crude samples were analysed by1H-NMR spectroscopy in CDCh to determine the reaction conversion and selectivity. The polymer was then precipitated three times into methanol or hexanes to remove any excess epoxide. Then, the resulting polymer was redissolved in CH2CI2and passed through a silica plug to remove the catalyst, to give the polymer (termed P(IGG-a / f-CO2)) as a colourless viscous solid.

[0135] 1H NMR (CDCh, 25 °C, 600 MHz): 6 (ppm) 7.16 (d, Ar- / 7 BMA end group); 5.11 (s, -CH2- BMA end group); 5.02 (bs, Hb, 1 H); 4.46-4.25 (bm, Ha, 2H); 4.24-4.20 (bt, He, 1H); 4.05-3.99 (bm, Hf, 1 H); 3.74-3.65 (bm, Hc, Hf, 3H); 3.58-3.46 (bm, Hd, 2H); 2.34 (s, -CH3BMA end group), 1.39 (bs, Hg, 3H); 1.35 (bs, Hg, 3H)

[0136] 13C NMR (CDCh, 25 °C, 151 MHz): 6 (ppm) 154.3 (Hh), 129.4 and 128.7 (Ar-H BMA end group); 109.7 (Hi), 74.7 (He); 74.4 (Hb); 72.7 and 72.5 (Hd); 70.1 (-CH2- BMA end group); 69.3 (Hc), 66.7 (Hf), 66.1 (Ha), 26.9 and 25.5 (Hg), 21.4 (-CW3BMA end group)

[0137] SEC: Mn= 4.4 kg mol1, D = 1.10

[0138] MALDI-ToF (for 80 eguiv. of MBA): Mn,ca / c(repeat unit) = 232.14 g mol-1, Mn, theoretical (repeat unit) = 232.09 g mol-1; Mn,caic (end group) = 161.06 g mol-1, Mn, theoretical (end group) = 161.04 g mol-1.

[0139] A literature procedure for hydroxyl end group analysis using31P1H NMR spectroscopy was followed.8A mixture of a stock solution (40 pL), excess 2-chloro-4,4,5,5-tetramethyl dioxaphospholane (40 pL) and the polymer sample (20 mg) was added to an NMR tube and shaken. The mixture was allowed to react for 6 h before spectra were measured. The stock solution consists of bisphenol A (400 mg) and of [Cr(acac)3] (5.5 mg), in pyridine (10 mL)3.6. Representative deprotection of P(IGG-aff-CO2)MeOH / THF (1:1) - ► Dowex® 50WX8 10 % w / wH2O (10 % v / v) 50 °C, 24 h

[0140] The acetal protecting groups of P(IGG-a / f-CO2) were removed by addition of 10 w / w% acidic ion exchange resin (Dowex® 50WX8) (100 mg) (with respect to polymer (1 g) and dissolved in a solvent MeOH / THF (1:1) mixture (8 mL), and final addition of H2O (ca. 10 v / %) (1 mL) to get a final concentration of 100 mg mL-1. Then, the reaction mixture was heated to 50 °C without stirring. The ion exchange resin was removed by centrifugation and the solution was concentrated in vacuum and then dried in vacuum overnight. Yields: 90%-100%.

[0141] 1H NMR (CDCh, 25 °C, 600 MHz): 6 (ppm) 7.24 (dd, J = 48.3, 7.8 Hz, Ar- / 7 BMA end group, 1 H); 5.11 (s, -CH2- BMA end group); 4.97 (bs, Hb, 1 H); 4.39-4.23 (bt, Ha, 2H); 3.65-3.54 (bm, Hc, He, 3H); 3.48-3.41 (bm, Hd, 1H); 3.38-3.27 (bm, Hd, Hf, 3H); 2.31 (s, -CW3BMA end group).

[0142] 13C NMR (CDCh, 25 °C, 600 MHz): 6 (ppm) 154.5-154.2 (Hh), 138.3, 132.8, 129.5 and 128.9 (Ar- / - / BMA end group); 74.9-74.8 (Hb); 73.4 (Hd); 70.9 (He); 69.6 (-CH2- BMA end group); 69.0 (Hc), 66.6-66.5 (Ha), 63.3 (Hf), 21.2 (-CW3BMA end group).

[0143] SEC (DMF): Mn= 8.2 kg mol1, D = 1.06

[0144] MALDI-ToF: Mn,ca / c(repeat unit) = 191.98 g mol-1, Mn, theoretical (repeat unit) = 192.06 g mol-1; Mn,caic (end group) = 161.36 g mol-1, Mn, theoretical (end group) = 161.04 g mol-1.3.7. Representative ethoxyl vinyl qlycidyl ether (EVGE) / phthalic anhydride (PA) ring-opening copolymerisationCat. fBu-P-,:NMe2Me2N. | NMe2P IIN

[0145] Inside a nitrogen filled glovebox, the catalyst Pi-f-Bu, the chain transfer agent phthalic acid, phthalic anhydride (PA) and ethoxyl vinyl glycidyl ether (EVGE) ([Pi-f-Bu Cat]:[PA]:[Epoxide] [CTA] = 1:400:3000:20, 100 °C.) were mixed in a dried vial eguipped with a magnetic stirrer bar. The vial was sealed and heated to 100 °C in an oil bath for the time stated. Aliguots of the reaction mixture were taken inside the glovebox, and1H-NMR spectra of the crudes were measured in CDCI3. The polymerizations were guenched by exposing the reaction mixture to air and cooling it down to ambient temperature. The reaction mixture was purified by repetitive precipitation into diethyl ether. SEC samples were prepared by dissolving the purified product (termed P(EVGE-aZf-PA)) in HPLC grade THF (4 mg mL-1) and filtered before use.

[0146] 1H NMR (CDCI3, 25 °C, 500 MHz): 6 (ppm) 67.75-7.65 (bd, Hg, 2H), 7.50 (bs, Hf, 2H), 6.42 (bm, Hh, 1H), 5.51 (bs, Hb, 1H), 4.63- 4.60 (bd, Ha, 2H), 4.18-4.12 (bd, Hi, 2H), 4.03-3.97 (bd, Hi, 1H), 3.78-3.69 (bm, He, Hd, He, 6H).

[0147] 13C NMR (CDCI3, 25 °C, 151 MHz): 6 (ppm) 6166.6 (Hj), 151.7 (Hh), 131.2 (Hf), 129.08 (Hg), 86.82 (Hi), 71.44 (IIb), 69.95 (Hd), 69.25 (He), 67.27 (He), 63.83 (IIa).3.8. Representative deprotection of P(EVGE-aff-PA)

[0148] P(EVGE-aZf-PA) was reacted with 10 w / w % acidic ion exchange resin (Dowex® 50WX8) (with respect to polymer) with both being suspended in a solvent MeOH / THF (1:1) mixture, and by addition of H2O (10 v / v%) to get a final concentration of 100 mg mL-1. Then, the reaction mixture was heated to 50 °C without stirring. The ion exchange resin was removed by centrifugation and the solution was concentrated in vacuum and then dried in vacuum overnight to yield P(EGE-aff-PA). Yields: 90%-100%.

[0149] 1H NMR (DMSO-d6, 25 °C, 500 MHz): 6 (ppm) 6 7.72-7.61 (bm, Hf, Hg, 4H), 5.40 (bs, Hb, 1H), 4.63 (bs, Hh, 1H), 4.53-4.46 (bm, Ha, 2H), 3.68 (bs, He, 2H), 3.49-3.45 (bm, Hd, He, 4H).

[0150] 13C NMR (DMSO-de, 25 °C, 500 MHz): 6 (ppm) 166.2 (Hi), 131.8-130.9 (Hf), 128.8 (Hg), 72.8 (Hd), 71.5 (IIb), 68.4 (He), 63.7 (IIa), 60.1 (He).3.9. Representative functionalization of P(EGE-aff-PA) by acylation reaction to form acidcontaining polyester P(EGE-a / f-PA)-SA005 eq DMAP, DMF, RT, 18h

[0151] The P(EGE-aZf-PA), succinic anhydride (SA) and dimethylaminopyridine (DMAP) were dissolved in DMF to get a final concentration of 100 mg mL-1(respect to polymer). Then, the reaction mixture was stirred at ambient temperature for 24 h. The reaction mixture was purified by repetitive precipitation into diethyl ether to form succinic acid-functionalized P(EGE-aff-PA)-SA.

[0152] 1H NMR (DMF-d7, 25 °C, 500 MHz): 6 (ppm) 7.85-7.81 (bd, Hg, 2H), 7.70 (bs, Hf, 2H), 5.58 (bs, Hb, 1H), 4.70-4.61 (bm, Ha, 2H), 4.23 (bs, He, 2H), 3.89-3.76 (bm, He, Hd, 4H), 2.58 (bs, Hh, 4H).

[0153] 13C NMR (DMF-d7, 25 °C, 500 MHz): 6 (ppm) 174.5-173.5 (Hj), 167.7 (Hi), 133.1-132.5 (Hf), 130.2- 130.1 (Hg), 72.8 (IIb), 70.3 (Hd), 70.0 (He), 64.9 (IIa), 64.5 (H3), 29.87-26.91 (Hh).3.10. Ring-opening copolymerisation of diglvcolic anhydride (PGA) and ME3MO to form PCDGA-a / f-ME3MO)

[0154] To a 4 mL reaction vessel in a glovebox (N2 atmosphere), DGA (140 mg, 1.21 mmol) was added to diglycolic acid (5.4 mg, 0.04 mmol), followed by dry degassed toluene (2 mL), The ME3MO epoxide (275 mg, 1.25 mmol) and P2-f-Bu (2.0 M THF solution, 2.5 pL, 0.005 mmol). The reaction vessel was heated to 100 °C, with rapid stirring. After 16 h the reaction vessel was exposed to air, the catalysis was quenched (acetic acid) and the polymer solution was concentrated. The monomer conversions were determined by1H NMR spectroscopic analysis of the crude reaction mixture (100 % for both monomers). The reaction mixture was precipitated three times from hexane (3 x 50 mL) and dried in vacuo to isolate the viscous polymer (310 mg, 75% yield).

[0155] 1H NMR (CDCI3, 400 MHz, 298 K): 6 (ppm) = 5.28 (s, 1xH, e), 4.46 (m, 1xH, f), 4.24 (b m, 5xH, f+g), 4.00 (s, 1H, e (end group)), 3.64 (b m, 14xH, b+c+d), 3.38 (s, 3xH, a). SEC (THF, PS calib.): Mn= 3.0 kg mol1, D = 1.42.3.11. Ring-opening copolymerisation of diglvcolic anhydride (DGA) and MGE-(PEG)s to form P(DGA-a / f-MGE-(PEG)5)

[0156] To a 4 mL reaction vessel in a glovebox (N2atmosphere), DGA (140 mg, 1.21 mmol) was added to diglycolic acid (5.4 mg, 0.04 mmol), followed by dry degassed toluene (2 mL), The MGE-(PEG)5(1.25 mmol) and P2-f-Bu (2.0 M THF solution, 2.5 pL, 0.005 mmol). The reactionvessel was heated to 100 °C, with rapid stirring. After 16 h the reaction vessel was exposed to air, the catalysis was quenched (acetic acid) and the polymer solution was concentrated. The monomer conversions were determined by1H NMR spectroscopic analysis of the crude reaction mixture (100 % for DGA). The reaction mixture was precipitated three times from hexane (3 x 50 mL) and dried in vacuo to isolate the viscous polymer (310 mg, 75% yield) (Figure 6.4). The polymer was characterised by NMR spectroscopy and by SEC. It showed an M^NMR) of 10.8 kg / mol determined by integration of the polymer end-group resonance at 3.98 ppm against the polyester signals from 5.28-4.24 ppm. It also showed Mn(SEc, THF) of 1.5 kg / mol with a dispersity of 1.25. It showed a glass transition temperature of -43 °C.3.12. Ring-opening copolymerisation of diqlycolic anhydride (DGA) and MGE-(PEG)I2to form P(DGA-aff-MGE-(PEG)i2)

[0157] To a 4 mL reaction vessel in a glovebox (N2atmosphere), DGA (140 mg, 1.21 mmol) was added to diglycolic acid (5.4 mg, 0.04 mmol), followed by dry degassed toluene (2 mL), the MGE-(PEG)I2(1.25 mmol) and P2-f-Bu (2.0 M THF solution, 2.5 pL, 0.005 mmol). The reaction vessel was heated to 100 °C, with rapid stirring. After 16 h the reaction vessel was exposed to air, the catalysis was quenched (acetic acid) and the polymer solution was concentrated. The monomer conversions were determined by1H NMR spectroscopic analysis of the crude reaction mixture (100 % for DGA). The reaction mixture was precipitated three times from hexane (3 x 50 mL) and dried in vacuo to isolate the viscous polymer (310 mg, 75% yield). The polymer was characterised by NMR spectroscopy and by SEC. It showed an MA(NMR) of 18.6 kg / mol determined by integration of the polymer end-group resonance at 3.98 ppm against the polyester signals from 5.28-4.24 ppm. It also showed Mn(SEc, THF) of 2.5 kg / mol with a dispersity of 1.34. It showed a glass transition temperature of -53 °C and a crystallization temperature of -13 °C.3.13. General procedure for the synthesis of P(GA-a / MGG)w

[0158] Caesium(l)pivalate (CsOPiv, 0.135 g, 0.577 mmol, 1 eq.), methyl benzyl alcohol (MBA, 0.353 g, 2.89 mmol, 5 eq.), glycolic anhydride (GA, 3.29 g, 28.8 mmol, 50 eq.), IGG (27.14 g, 144.2 mmol, 250 eq.) and magnetic stirrer bar were added to a 40 mL glass vial under inert atmosphere (nitrogen filled glovebox, <0.5 ppm O2, <0.5 ppm H2O). Reaction was stirred at 100 °C for 8.8 hours. Reaction was run to ~95% GA conversion, monitored by1H NMR. Reaction was quenched by exposing contents to air. Reaction contents were dissolved in dichloromethane and precipitated in hexane to remove excess monomers, the extent of removal was monitored by1H NMR. Catalyst residue was removed by flushing polymer through silica plug using dichloromethane as an eluent. Polymer was dried under vacuum for 3 days. Fig. 25 provides the1H NMR of p(GA-a / f-IGG)io3.14. General procedure for the synthesis of P(GA-a / f-IGG)20

[0159] CsOPiv (0.135 g, 0.577 mmol, 1 eq.), MBA (0.176 g, 1.44 mmol, 2.5 eq.), GA (3.290 g, 28.8 mmol, 50 eq.), IGG (27.140 g, 144.2 mmol, 250 eq.) and magnetic stirrer bar were added to a 40 mL glass vial under inert atmosphere (nitrogen filled glovebox, <0.5 ppm O2, <0.5 ppm H2O). Reaction was stirred at 100 °C for 16.5 hours. Reaction was run to ~95% GA conversion, monitored by1H NMR. Reaction was quenched by exposing contents to air. Reaction contents were dissolved in dichloromethane and precipitated in hexane to remove excess monomers, the extent of removal was monitored by1H NMR. Catalyst residue was removed by flushing polymer through silica plug using dichloromethane as an eluent. Polymer was dried under vacuum for 3 days. Fig. 26 provides the1H NMR spectrum of p(GA-alt-IGG)20.3.15. General procedure for the synthesis of P(GA-a / f-IGG)4o.

[0160] CsOPiv (0.135 g, 0.577 mmol, 1 eq.), MBA (88 mg, 0.72 mmol, 1.25 eq.), GA (3.290 g, 28.8 mmol, 50 eq.), IGG (27.140 g, 144.2 mmol, 250 eq.) and magnetic stirrer bar were added to a 40 mL glass vial under inert atmosphere (nitrogen filled glovebox, <0.5 ppm O2, <0.5 ppm H2O). Reaction was stirred at 100 °C for 20.0 hours. Reaction was run to ~95% GA conversion, monitored by1H NMR. Reaction was quenched by exposing contents to air. Reaction contents were dissolved in dichloromethane and precipitated in hexane to remove excess monomers, the extent of removal was monitored by1H NMR. Catalyst residue was removed by flushing polymerthrough silica plug using dichloromethane as an eluent. Polymer was dried under vacuum for 3 days. Fig. 27 provides the1H NMR spectrum of p(GA-alt-IGG)4o.3.16. General procedure for the synthesis of P(GA-a / f-DOL)i0.

[0161] P(GA-alt-IGG)w (8.7 g) was dissolved in acetic acid (33.1 mL), dichloromethane (16.6 mL) and water (8.3 mL). Reaction solution and magnetic stirrer bar were combined in 100 mL round bottom flask. Reaction was stirred at room temperature for 72 hours. Solvents were removed under vacuum at room temperature. Residue was mixed with acetone and precipitated in diethyl ether to removed residual acetic acid. Polymer was dried under vacuum for 7 days at room temperature. Fig. 28 provides the1H NMR spectrum of P(GA-alt-DOL)w.3.17. General procedure for the synthesis of P(GA-a / f-DOL)20.

[0162] P(GA-alt-IGG)2o (7.6 g) was dissolved in acetic acid (28.6 mL), dichloromethane (14.3 mL) and water (7.1 mL). Reaction solution and magnetic stirrer bar were combined in 100 mL round bottom flask. Reaction was stirred at room temperature for 72 hours. Solvents were removed under vacuum at room temperature. Residue was mixed with acetone and precipitated in diethyl ether to removed residual acetic acid. Polymer was dried under vacuum for 7 days at room temperature. Fig. 29 provides the1H NMR spectrum of P(GA-alt-DOL)2o.3.18. General procedure for the synthesis of PfGA-a / f-DOL

[0163] P(GA-alt-IGG)4o (6.7 g) was dissolved in acetic acid (25.4 mL), dichloromethane (12.7 mL) and water (6.3 mL). Reaction solution and magnetic stirrer bar were combined in 100 mL round bottom flask. Reaction was stirred at room temperature for 72 hours. Solvents were removed under vacuum at room temperature. Residue was mixed with acetone and precipitated in diethyl ether to removed residual acetic acid. Polymer was dried under vacuum for 7 days at room temperature. Fig. 30 provides the1H NMR spectrum of P(GA-alt-DOL)4o.3.19. General procedure for the synthesis of P(GA-a / f-DOL-q-SA)i0.

[0164] P(GA-alt-DOL)w (109.8 mg, 0.419 mmol, 20 eq.) was dissolved in DMF (1.1 mL) and combined with 4-dimethylaminopyridine (2.5 mg, 0.02 mmol, 1 eq.), succinic anhydride (SA, 85.9 mg, 0.858 mmol, 42 eq.) and magnetic stirrer bar in 4 mL vial under inert atmosphere (nitrogen filled glovebox, <0.5 ppm O2, <0.5 ppm H2O). Reaction was stirred at room temperature for 4 days. Reaction was run to ~95% alcohol group functionalisation, monitored by31P NMR (method reported by A. Spyros et al8. Reactions contents were dissolved in methanol and precipitated indiethyl ether to remove solvent and excess succinic anhydride. Fig. 31 provides the1H NMR spectrum of P(GA-alt-DOL-g-SA)2o.3.20. General procedure for the synthesis of P(GA-a / f-BGE)i0.

[0165] CsOPiv (10.3 mg, 0.044 mmol, 1 eq.), MBA (107.5 mg, 0.880 mmol, 20 eq.), GA (1.0 g, 8.76 mmol, 200 eq.), BGE (7.2 g, 43.8 mmol, 1000 eq.) and magnetic stirrer bar were added to a 40 mL glass vial under inert atmosphere (nitrogen filled glovebox, <0.5 ppm O2, <0.5 ppm H2O). Reaction was stirred at 100 °C for 12.5 hours. Reaction was run to ~95% GA conversion, monitored by1H NMR. Reaction was quenched by exposing contents to air. Reaction contents were dissolved in dichloromethane and precipitated in hexane to remove excess monomers, the extent of removal was monitored by1H NMR. Catalyst residue was removed by flushing polymer through silica plug using dichloromethane as an eluent. Polymer was dried under vacuum for 3 days. Fig. 32 provides the1H NMR spectrum of P(GA-alt-BGE)w.3.21. General procedure for the synthesis of P(GA-a / f-MOL)io.

[0166] P(GA-alt-BGE)w (2.0 g) was dissolved in tetrahydrofuran (13.3 mL) and combined with Pd on C (10 % wt. Pd, 400 mg). Reaction contents were transferred to a high-pressure reactor, filled with hydrogen (40 bar), and left to stir for 48 hours at 40 °C. Solid catalyst was removed by filtration. Solvent was removed under vacuum at room temperature. Fig. 33 provides the1H NMR spectrum of P(GA-alt-MOL)w.3.22. General procedure for the synthesis of P(GA-a / f-MOL-q-SA)i0.

[0167] P(GA-alt-MOL)w (0.35 g, 1.86 mmol, 20 eq.) was dissolved in DMF (3.5 mL) and combined with 4-dimethylaminopyridine (11.2 mg, 0.092 mmol, 1 eq.), succinic anhydride (SA, 204.8 mg, 2.05 mmol, 22 eq.) and magnetic stirrer bar in 4 mL vial under inert atmosphere (nitrogen filled glovebox, <0.5 ppm O2, <0.5 ppm H2O). Reaction was stirred at room temperature for 12 hours. Reaction was run to ~95% alcohol group functionalisation, monitored by31P NMR (method reported by A. Spyros et al8. Reactions contents were dissolved in methanol and precipitated in diethyl ether to remove solvent and excess succinic anhydride. Fig. 34 provides the1H NMR spectrum of P(GA-alt-MOL-g-SA)w.4. Results and discussion4.1. P(BGE-alt-CO2')

[0168] Poly((benzyl glycidyl ether) carbonate)s P(BGE-a / f-CO2) were synthesised via the copolymerization of benzyl glycidyl ether (BGE), with CO2, using methyl benzyl alcohol (MBA) as the chain transfer agent (CTA) and [Co(l I l) / K(l)] as the catalyst. Polymerizations were conducted with different equivalents of MBA, all reaction were conducted in neat epoxide at 25 °C over 24h, and were quenched by addition of benzoic acid (Table 1).

[0169] When the polymerization was conducted with 40 equiv of MBA with respect to catalyst (1 equiv), the resulting P(BGE-a / f-CO2) showed a monomodal molar mass distribution (Mn= 3.0 kg mol-1, £> = 1.07) by size exclusion chromatography (in THF vs polystyrene standards).1H-NMR spectroscopy of the crude polymer showed, 99% carbonate linkages, with no evidence of any polyether bonds formed (Figure 1). After precipitation from MeOH and silica-plug filtration from CH2CI2solution, the polymer resulted in a colourless highly viscous liquid. By1H-NMR spectroscopy, the polymer showed the expected spectrum for P(BGE-a / f-CO2) copolymer in CDCh. The resonances at <5 = 4.95 ppm and <5 = 4.45-1.19 ppm, correspond to the polycarbonatebackbone and at 6 = 7.36-7.22 ppm and <5 = 4.57-4.57 ppm to the benzylic group in the side chain (Figure 2a).Table 1. Ring-opening copolymerization of benzyl glycidyl ether (BGE) with CO2 using methyl benzyl alcohol (MBA) as a chain transfer agent (CTA) in with the [Co(III) / K(I)] as the catalyst?Cat. [Co(lll) / K(l)]AcO = CH3(CO)O’ Entry [CTA] Time Coin.* PC select. DPNCMniNMRdM„, SEC‘ DeTs%f Tgs(eq') (h) (%) (%) (kg mol-1) (kg mol-1) (°C) (°C) 1 I 21 62 --99 — — 28.2 1.15 231 12 2 10 23 69 >99 70 14.7 9.9 1.07 213 84 40 22 68 >99 17 3.7 3.0 1.07 189 1 Reaction conditions: |Co(lll) / K(l)| catalyst (0.1 mol %), BGE = (6 mL neat, 6.6 M, 39.4 mmol), CTA= methyl benzyl alcohol; 20 bar COz; 25 °C.bBGE conversion determined from the relative integrals in the II NMR spectrum of the reaction mixture of P(BGE-a / t-CC>2) (8 = 4.95 ppm) and BGE (8 = 3.11 ppm).cDPN determined from the relative integrals in the II NMR sped nun of the purified polymer of P(BGE-a / t-CC>2) (8 = 4.95 ppm) and the MBA (CTA) (8 = 2.34 ppm).dM„, NMR = [(DPN * MW BGE + CO2 (208.2 g mol ') + MW CTA (122.2 g mol ')].eDetermined by size exclusion chromatography (SEC) in THF against polystyrene standards.^ Obtained from the second heating scan by differential scanning calorimetry (10 °C min ').sObtained bythermogravimetric analysis (10 °C min ')•

[0170] When the polymerization was conducted with 1 equiv of MBA with respect to catalyst (1 equiv), the resulting P(BGE-a / f-CO2) showed a bimodal molar mass distribution (Mn= 28.2 kg mol-1, £> = 1.15) by size exclusion chromatography (in THF vs polystyrene standards). This is attributed to chains which are catalyst initiated and chain initiated from MBA. The quantity of catalyst initiated polymer chain decreases with polymerizations conducted with increased number of equivalents of CTA, resulting in the desired monomodal SEC traces when >10 equiv of MBA are used. The molar mass of the resulting polymers are progressively reduced as the quantity of CTA increases, allowing access to P(BGE) with controllable Mnvalues (9.9-3.0 Kg mol-1) and low molar mass distributions (£> < 1.07) (Figure 2b). By1H-NMR spectroscopy, the signals at <5 = 2.34, 5.10 and 7.15 ppm, correspond to the MBA initiator are evident when >10equiv are used, and the determination of the polymer composition can be perform by1H-NMR end group analysis (Figure 3).

[0171] MALDI-ToF data show one major distribution for polymer with Mn10 kg mol-1, corresponding to P(BGE-a / f-CO2) polyols (Figure 4). In the specific case for the polymer with (Mn= 3.0 kg mol-1, £> < 1.07), end group characterization by MALDI-ToF was used to resolve the homopolymer end group, which confirms the presence of MBA as the CTA used for the polyol formation (Figure 2c, d). Additionally, by31P{1H}-NMR spectroscopy end group analysis, the signal at <5 = 146.2 ppm also confirms the presence of hydroxyl terminated polymers (Figure 5).

[0172] The thermal stability of the P(BGE-a / f-CO2)s was investigated by thermogravimetric analysis (TGA), under a N2atmosphere (heating rate 10 °C min-1gradient to 700 °C). The polymers showed decreasing T5% (temperature that represents 5% loss of the original mass of the polymer) with decreasing Mn(7s% ranging from 231 to 189 °C), as expected. The polymer degradation for all samples occurred in a single-step process. Differential scanning calorimetry (DSC) showed no evidence for melt transitions, which is consistent with amorphous polymers. The glass transition temperature (Tg) in this series increases with increasing Mn(Tg ranging from 1-12 °C) (Figure 6).4.2. P(BEMO-a / f-CO2)

[0173] The monomer 2-(2-(benzyloxy)ethoxy)methyl oxirane (BEMO) was synthesised from the corresponding 2-(benzyloxy)ethanol and epichlorohydrin using NaH in THF at 25 °C. The synthesis product was isolate in ca. 85%, after column chromatography and distillation from CaH2.

[0174] Poly(2-(2-(benzyloxy)ethoxy)methyl carbonate)s P(BEMO-a / f-CO2) were synthesised via the copolymerization of BEMO with CO2, using methyl benzyl alcohol (MBA) with [Co(l I l) / K(l)] as the catalyst (Table 2).Table 2. Ring-opening copolymerization of 2-(2-(benzyloxy)ethoxy)methyl oxirane (BEMO) with CO2 using methyl benzyl alcohol (MBA) as a chain transfer agent (CT A) in with the [Co(III) / K(I)] as the catalyst?Cat. [Co(lll) / K(l)]Entry CTA Time Cony / PC select. DPNCMniNMRdM„, SEC‘ DeTs%f Tgs(equiv) (h) (%) (%) (kg mol-1) (kg mol-1) (°C) (°C) llillllliilllliillli 2 20 72 81 97 40 10.2 6.3 1.05 234 -354 80 72 93 96 13 3.4 2.5 1.08 214 -34 “Reaction conditions: [Co(III) / BC(I)] catalyst (0.1 mol %), BEMO = (6 mL neat, 5.1 M, 39.4 mmol), CTA= methyl benzyl alcohol; 30 bar CO2; 25 °C. " BEMO conversion determined from the relative integrals in the II NMR sped rum of the reaction mixture of P(BEMO-a / t-CO2) (8 = 5.04 ppm), cyclic carbonate (8 = 4.83 ppm) and BEMO (8 = 3.20 ppm). “ Polymer selectivity determined by the relative integrals in the 1H-NMR spectra of P(BEMO-a / / -CO2) (5.04 ppm, 1H) against cyclic carbonate (8 = 4.83 ppm, 1H). “ DPN determined from the relative integrals in the II NMR sped rum of the purified polymer of P(BEMO-a / t-CC>2) (8 = 4.95 ppm) and the MBA (CTA) (8 = 2.34 ppm).dM„, NMR = [(DPN * MW BEMO + CO2 (252.21 g mol1) + MW CTA (122.2 g mol-1)].eDetermined by size exclusion chromatography (SEC) in THF against polystyrene standards. Obtained from the secondheating scan by differential scanning calorimetry (10 °C min s Obtained by thermogravimetric analysis (10 °C min

[0175] When the polymerization was performed with 40 equiv of MBA (as the CTA), with respect to catalyst (1 equiv) at 30 bar CO2at 25 °C, after 24 h, only ca. 40% epoxide conversion (with 93% selectivity to polymer) was observed by1H-NMR spectroscopy (Figure 7). The polymerization reaction was repeated under the same reaction conditions for a longer period in order to improve conversion. After 72 h, the epoxide conversion increased to ca. 96% (with 98% polycarbonate selectivity formation) and there was no evidence of any ether linkage formation. The polymer was purified by precipitation from hexanes and silica-plug filtration from CH2CI2 solution; the polymer was a colourless viscous liquid. The resulting P(BEMO-a / f-CO2) showed a monomodal molar mass distribution (Mn= 4.4 kg mol-1, £> = 1.06) by size exclusion chromatography (in THF vs polystyrene standards).

[0176] Polymer characterization by1H-NMR spectroscopy (in CDCh), showed resonances at <5 = 5.02 ppm and <5 = 4.46-4.16 ppm, which correspond to the polycarbonate backbone; at <5 = 7.34-7.23 ppm and <5 = 4.52 ppm which are assigned to the benzylic side chain group, and theresonances at 6 = 3.69-3.53 ppm are assigned to the methylene protons corresponding to the ethylene glycol unit (Figure 8a).

[0177] Subsequent polymerizations were performed with different of equivalents of MBA (equiv = 10, 20 and 80) with respect to catalyst (1 equiv), and the molar mass of the resulting polymers were progressively reduced with increasing MBA. The materials presented monomodal SEC traces from > 20 equiv of MBA, allowing access to P(BEMO-a / f-CO2) with controllable Mnvalues (11.8-2.5 Kg mol-1) and low molar mass distributions (£> < 1.07) (Figure 8b). By1H-NMR spectroscopy, the signals at <5 = 7.16, 5.10 and 2.33 ppm, were assigned to the MBA initiator and they are evident when >10 equiv were used, and the corresponding polymer composition was determined by1H-NMR end group analysis. In the specific case forthe polymer with Mn= 3.0 kg mol-1(£> < 1.07), end group characterization by MALDI-ToF was used to resolve the end group, which also confirms the presence of MBA as initiator and polyol formation (Figure 8c, d).

[0178] The thermal stability of the P(BEMO-a / f-CO2)s was investigated by thermogravimetric analysis (TGA) under a N2atmosphere (heating rate 10 °C min-1gradient to 700 °C). In general, the polymers showed decreasing T5% with decreasing Mn(T5% ranging from 234 to 214°C) with a single step process degradation. Differential scanning calorimetry (DSC) showed no evidence for melt transitions, which is consistent with amorphous polymers. The glass transition temperature (Tg) of the resulting polymers ranged from -30 to -35 °C (Figure 9).4.3. P(IGG-aff-CO2)

[0179] The monomer (DL-1,2-isopropylidene glyceryl) glycidyl ether (IGG) was synthesised from DL-1,2-isopropylideneglycol and epichlorohydrin, in a mixture of H2G / Toluene (1:1) using NaOH and [NBu4]Br as the base and phase-transfer agent, respectively, at 25 °C during 48h. The product was further purified by column separation and successively distillations (from CaH2, n-BuLi and neat) and was isolated in ca. 40% yield.

[0180] The first attempt to prepare poly((isopropylidene glyceryl glycidyl ether) carbonate)s (P(IGG-a / f-CO2)) was via the copolymerization of IGG with 20 bar CO2, using methyl benzyl alcohol (MBA) as the chain transfer agent (CTA) and the [Co(l I l) / K(l)] catalyst. The polymerization was run in neat epoxide, at 25 °C for ca.74-81 h, and the reaction was quenched with benzoic acid (Table 3).Table 3. Ring-opening copolymerization of (DL-l,2-isopropylidene glyceryl) glycidyl ether (IGG) with CO2 using methyl benzyl alcohol (MBA) as a chain transfer agent (CT A) in with the [Co(III) / K(I)] as the catalyst?Cat. [Co(lll) / K(l)]AcO = CH3(CO)O- Entry CTA Time Com.* PC select.b(equiv) (h) (%) (%) (kg mol-1) (kg mol-1) (°C) (°C) 1 IO 81 81 96 91 21.3 14.9 1.12 199 4 2 20 79 79 94 41 9.6 8.3 1.10 231 -154 80 74 74 82 9 2.2 2.0 1.11 180 -37 “ Reaction conditions: [ Co( 111 ) / K( I ) ] catalyst (0.1 mol %), IGG = (6 mL neat, 5.6 M, 39.4 mmol), CTA= methyl benzyl alcohol; 20 bar COi; 25 °C. " IGG conversion determined from the relative integrals in the I l-N MR spectrum of the reaction mixture of P(IGG-« / / -CO>) (8 = 5.02 ppm), cyclic carbonate (8 = 4.81 ppm) and IGG (8 = 3.15 ppm).cPolymer selectivity determined by the relative integrals in the 1H-NMR spectra of P(IGG-« / / -CO>) (5.02 ppm, 1H) against cyclic carbonate (8 = 4.81 ppm, 1H).ddetermined from the relative integrals in the II NMR spectrum of the purified polymer of P( IGG-o / z-COj) (8 = 4.95 ppm) and the MBA (CTA) (8 = 2.34 ppm).!* MW IGG + CO2 (232.23 g mob1) + MW CTA (122.2 g mol1)], Determined by size exclusion chromatography (SEC) in THF against polystyrene standards. ' Obtained from the second heatingscan by differential scanning calorimetry (10 °C min-1).sObtained by thermogravimetric analysis (10 °C min-1).

[0181] When the polymerization was conducted with 10 equiv of MBA (as CTA) with respect to catalyst (1 eq), the crude reaction, showed ca. 34% conversion to polymer after 24h, with 99% polycarbonate selectivity and no evidence of ether linkage formation. In order to increase the conversion, the polymerization was performed under the same conditions for 72h, the crude reaction showed 78% conversion to polymer with 97% polycarbonate selectivity product.

[0182] When the polymerization was performed with 40 equiv of MBA (as the CTA), with respect to catalyst (1 equiv) at 20 bar CO2at 25 °C, after 74 h, 74% epoxide conversion (with 81% selectivity to polymer) was observed by1H-NMR spectroscopy (Figure 10). The polymer was purified by precipitation from cold ethanol (- 30 °C) and silica-plug filtration from CH2CI2 solution; the polymer was a colourless viscous liquid. The resulting P(IGG-a / f-CO2) showed a monomodal molar mass distribution (Mn= 4.4 kg mol-1, £> = 1.10) by size exclusion chromatography (in THF vs polystyrene standards). Characterization by1H-NMR spectroscopy, the signals at 6 = 5.02 ppm and at 6 = 4.46-4.25 ppm assigned to the diagnostic methine-carbonate (-OC(O)O-C / 7(R)-CH2) and methylene-carbonate (-OC(O)O-CH(R)-C / 72) of the polymer backbone, respectively. The signals in the region between 6 = 3.74 ppm and 6 = 3.46 ppm are assigned to the polymer side-chain and the diagnostic methyl groups (-C / 3) to the signal at 6 = 1.39 and 1.35 ppm (Figure 11a).

[0183] The quantity of catalyst initiated polymer chain decreases with polymerizations conducted with increased number of equivalents of CTA, resulting in the desired monomodal SEC traces when > 20 equiv of MBA are used. The molar mass of the resulting polymers are progressively reduced as the quantity of CTA increases, allowing access to P(IGG-a / f-CO2) with controllable Mnvalues (14.9-2.0 kg mol-1) and low molar mass distributions (£> < 1.12) (Figure 11b).

[0184] By1H-NMR spectroscopy, the signals at 2.34, 5.11 and 7.16 ppm, which correspond to the MBA initiator are evident when >10 equiv are used, and1H-NMR end group analysis can be used to determine the corresponding polymer composition (Figure 12). In the specific case for the polymer (Mn= 2.0 kg mol-1, £> < 1.11), end group characterization by MALDI-ToF was used to resolve the homopolymer end group, which confirms the presence of MBA as initiator and polyol formation (Figure 11c,c).

[0185] The thermal stability of the P(IGG-a / f-CO2)s was investigated by thermogravimetric analysis (TGA) under a N2atmosphere (heating rate 10 °C min-1gradient to 700 °C). The polymers showed decreasing T5% (temperature that represents 5% loss of the original mass of the polymer) with decreasing Mn(7s% ranging from 231 to 189 °C). All the polymers degraded in a single step process. Differential scanning calorimetry (DSC) showed no evidence for melt transitions, which is consistent with amorphous polymers. The glass transition temperature (Tg) in this series increases with increasing Mn(Tgranging from -37 - 12 °C) (Figure 13).

[0186] Next, the P(IGG) was treated under acidic conditions in order to remove the protecting acetal group to form the corresponding dihydroxyl-functionalized polycarbonate.

[0187] Initial studies focused on the deprotection of P(IGG-a / f-CO2) (Mn= 8.3 kg mol-1, £> = 1.10) using an acidic ion exchange resin in a THF / MeOH / H2O (1:1:0.5 v / v) mixture at 40 °C (10 % w / w with respect to polymer) with final polymer concentration of 100 mg mL-1. From the supernatant, aliquots for1H-NMR spectroscopy after 4 h and 20 h were taken, and surprisingly, the same deprotection conversion was observed in both cases. After 24 h, as solids precipitated from solution which were isolated along with the supernatant solution. This attempted deprotection showed that some material is soluble in DMSO-de by1H-NMR spectroscopy, which showed absence of both the methyl signals from the acetal group (1.39 and 1.35 ppm).

[0188] In order to obtain a fully soluble hydroxyl-functionalized polycarbonate, the deprotection of a lower molar mass P(IGG-a / f-CO2) (Mn= 4.4 kg mol-1, £> = 1.10) was attempted. Using thesame previous reaction conditions but increasing the temperature to at 50 °C, the polymer deprotection can be followed by1H -NMR spectroscopy, and after 24 h, full deprotection was achieved, as confirmed by1H NMR spectroscopy in DMSO-d6. After removal of the solvents, the1H NMR spectrum (in DMSO-d6) showed broad signals, in the aliphatic region, consistent with the formation of a hydroxyl-functionalized polycarbonate.

[0189] The structural characterization of the resulting poly((glyceryl glycerol) P(GG-a / f-CO2) was undertaken by NMR spectroscopy. The1H NMR spectrum (in DMSO-de) showed broad signals in the aliphatic and also in the aromatic region, and the integration was consistent for the proposed repeat unit. First, the signals at 6 = 1.39 ppm and 6 = 1.35 ppm are not observed, which correspond to the loss of the acetal protecting group. The signals at 6 = 4.97 ppm and 6 = 4.31 ppm are assigned to the methine-carbonate (-OC(O)O-C / 7(R)-CH2) and methylenecarbonate (-OC(O)O-CH(R)-C / 72) linkages of the polymer backbone, respectively. The signals in the region between 6 = 3.65 ppm and 6 = 3.17 ppm are assigned to the polymer sidechain. Notably, both in the1H- and13C-NMR spectra, all the signals from the CTA corresponding to methyl benzyl alcohol are resolved. The13C-NMR spectrum shows a main broad carbonyl peak centered at 6 = 154.2 ppm.

[0190] The polymer was soluble in D2O (Figure 14a), and in DMSO-de. Additionally, end group characterization by MALDI-ToF confirmed both the deprotection reaction and the presence of MBA as initiator and polyol formation (Figure 14b,c). The resulting dihydroxyl-substituted polycarbonate was characterized by size exclusion chromatography (in DMF vs polystyrene standards) showing a narrow molar mass distribution (Mn= 8.2 kg mol-1, £> = 1.06) similar to the P(IGG-a / f-CO2) precursor (Mn= 5.7 kg mol-1, £> = 1.08) (Figure 14d). The polycarbonate backbone is stable under the acidic hydrolysis conditions as confirmed by SEC.

[0191] ATR FT-IR also confirmed the acetal deprotection of P(IGG-a / f-CO2) by the loss of C-H stretching and bending vibrations (2987 and 1371 cm-1) of the isopropylidene group and the appearance of a broad O-H stretching vibration (3373 cm-1) (Figure 14e).4.4. P(ME3MO-a / f-CO2)

[0192] The synthesis of the monomer 2-((2-(2-(2-methoxyethoxy) ethoxy)ethoxy)methyl)oxirane (ME3MO) was synthesised from the corresponding triethylene glycol monomethyl ether and epichlorohydrin using NaOH and [NBu4]HSO4as the base and phase-transfer agent, respectively, at 0 °C. The synthesis yields the product ca. 27% and the purified by sequential distillation (from CaH2, nBuLi and neat).Table 4. Ring-opening copolymerization of 2-((2-(2-(2-methoxyethoxy)ethoxy)ethoxy)methyl) oxirane (ME3MO) with CO2 using methyl benzyl alcohol (MBA) as a chain trasfer agent (CT A) in with the [Co(III) / K(I)] as the catalystCat. [Co(lll) / K(l)]AcO = CH3(CO)O’ Entry CTA Time Coin / PC select.6MniNMRdTs%f Tgs(equiv) (h) (%) (%) (kgtnol-1) (kg mol’1) (°C) (°C)2 20 24 42 98 23 6.2 4.0 1.62 229 -51 ^iiiiiiiiiiiiiiisil 4 80 23 38 86 6 1.7 0.7 1.15 196 -55 Reaction conditions: [Co(III) / K(I)] catalyst (0.1 mol %), ME3MO = (6 mL neat, 4.8 M, 39.4 mmol), CTA= methyl benzyl alcohol; 30 bar CO2; 25 °C.bME3MO conversion determined from the relative integrals in the I l-NMR spectrum of the reaction mixture of PtMEsMO-a / t-COi) (8 = 4.95 ppm), cyclic carbonate (8 = 4.75 ppm) and ME3MO (8 = 3.09 ppm).cPolymer selectivity determined by the relative integrals in the I l-NMR spectra of P(ME3MO-a / t-CC>2) (4.95 ppm, 1H) against cyclic carbonate (8 = 4.75 ppm, 1H).ddetermined from the relative integrals in the II NMR spectrum of the purified polymer of P(MEiMO-o / / - CO2) (8 = 4.95 ppm) and the MBA (CTA) (8 = 2.34 ppm).!M„, * MW ME3MO + CO2 (264.28 g mob1) + MW CTA (122.2 g mol-1)]. Determined by size exclusion chromatography (SEC) in THF against polystyrene standards. ’’ Obtained from the second heating scan by differential scanning calorimetry (10 °C mingObtained by thermogravimetric analysis (10 °Cmin ').

[0193] The first attempt to prepare the polycarbonate was via the copolymerization of ME3MO with CO2 using methyl benzyl alcohol (MBA) as a chain transfer agent (CTA) with [Co(ll l) / K(l)] as the catalyst. The first polymerization reaction was attempted with 1 eq of CTA in neat epoxide at 20 bar of CO2, stirred at 25 °C. After 23 h, the resulting reaction mixture was a gel which was insoluble in CH2CI2, CHCI3, THF, DMSO, and DMF. Upon vacuum treatment, the gummy solid became a liquid, in which an aliquot was taken, and by1H-NMR spectroscopy (in MeOD) the soluble portion of the crude reaction showed ca. 42% conversion to polymer with 32% polycarbonate selectivity (Table 4).

[0194] In orderto prevent the formation ofthis insoluble material, performing the polymerization under the same reaction conditions using 10 eq of MBA as CTA but increased CO2pressure to 30 bar, by1H-NMR spectroscopy of the crude reaction (in CDCI3), it was observed increased conversion to polymer (ca. 57%) with 99% polycarbonate selectivity. The resulting P(MEsMO-alt-CC>2), after precipitation from hexanes and silica-plug filtration from CH2CI2 solution, showed a multimodal molar mass distribution (Mn= 18.9 kg mol-1, £> = 2.31) by size exclusion chromatography (in THF vs polystyrene standards) which is attributed in some part to chains which are catalyst initiated, chain initiates from MBA and / or unknown monomer impurities. The quantity of catalyst initiated polymer chain decreases with polymerizations conducted with increased number of equivalents of CTA, resulting in the bimodal SEC traces when > 20 equiv of MBA are used. The molar mass of the resulting polymers are progressively reduced as the quantity of CTA increases, allowing access to P(ME3MO-a / f-CO2) with Mnvalues (4.0-0.7 Kg mol-1) and narrow molar mass distributions (£> ranging from 1.15 to 1.62) (Figure 15).

[0195] By1H-NMR spectroscopy, the signals at 2.25 and 7.07 ppm, are assigned to the MBA initiator and are evident when >20 equiv are used, and1H-NMR end group analysis was used to determine the corresponding polymer composition (Figure 16). All the polymers are water soluble, and1H-NMR spectroscopy characterization in D2O was achieved at 40 mg mL-1concentration (Figure 17).

[0196] The thermal stability of the P(ME3MO-a / f-CO2)s was investigated by thermogravimetric analysis (TGA) under a N2atmosphere (heating rate 10 °C min-1gradient to 700 °C). The polymers showed Ts% ranging from 196 to 238 °C. All the polymers degraded in a single step process. Differential scanning calorimetry (DSC) showed no evidence for melt transitions, which is consistent with amorphous polymers. The glass transition temperature (Tg) in this series increases with increasing Mn (Tgranging from -55 — 47 °C) (Figure 15).

[0197] While specific embodiments of the invention have been described herein forthe purpose of reference and illustration, various modifications will be apparent to a person skilled in the art without departing from the scope of the invention as defined by the appended claims.BIBLIOGRAPHY(1) Erothu, H.; Kumar, A. C. Hydrophilic Polymers. In Biomedical Applications of Polymeric Materials and Composites, 2016; pp 163-185.(2) Kelly, C. L. Addressing the sustainability challenges for polymers in liquid formulations. Chem. Sci. 2023, 14 (25), 6820-6825, 10.1039 / D3SC90086J. DOI: 10.1039 / D3SC90086J.(3) Backer, S. A.; Leal, L. Biodegradability as an Off-Ramp for the Circular Economy: Investigations into Biodegradable Polymers for Home and Personal Care. Acc. Chem. Res. 2022, 55 (15), 2011-2018. DOI: 10.1021 / acs.accounts.2c00336.(4) Polymers in Liquid Formulations. Technical report: A landscape view of the global PLFs market, Royal Society of Chemistry, 2021. https: / / www.rsc.org / globalassets / 22-new-perspectives / sustainability / liquid-polymers / rsc-po lymer-liquid-formulations-technical-report.pdf. (Accessed 12 / 10 / 2023)(5) Wang, C.; Wang, Z.; Zhang, X. Amphiphilic Building Blocks for Self-Assembly: From Amphiphiles to Supra-amphiphiles. Acc. Chem. Res. 2012, 45 (4), 608-618. DOI: 10.1021 / ar200226d.(6) Haque, F. M.; Ishibashi, J. S. A.; Lidston, C. A. L.; Shao, H.; Bates, F. S.; Chang, A. B.; Coates, G. W.; Cramer, C. J.; Dauenhauer, P. J.; Dichtel, W. R.; et al. Defining the Macromolecules of Tomorrow through Synergistic Sustainable Polymer Research. Chemical Reviews 2022, 122 (6), 6322-6373. DOI: 10.1021 / acs.chemrev.1c00173.(7) Deacy, A. C.; Moreby, E.; Phanopoulos, A.; Williams, C. K. Co(III) / Alkali-Metal(I) Heterodinuclear Catalysts for the Ring-Opening Copolymerization of CO2 and Propylene Oxide. J. Am. Chem. Soc. 2020, 142 (45), 19150-19160. DOI: 10.1021 / jacs.0c07980.(8) Spyros, A.; Argyropoulos, D. S.; Marchessault, R. H. A Study of Poly(hydroxyalkanoate)s by Quantitative ³¹P NMR Spectroscopy: Molecular Weight and Chain Cleavage. Macromolecules 1997, 30(2), 327-329. DOI: 10.1021 / ma9601979.

Claims

1. CLAIMS1. A polymer comprising a repeating unit of formula I:R1whereinX is:i) a group X1of structure:> A0 orii) a group X2of structure:0 Oin which L1is a linker separating the two carbonyl groups by a distance of 3-4 bond lengths; n is a number 0 to 100;J is O, (2-22C)alkylene or CRaRb;Raand Rbare each independently H or (1 -10C)alkyl;R1is H, (1 -22C)alkyl, (2-22C)alkenyl, SO3’, SO3H, R2or Y;R2is a group:Y^0R3(DR3each R3is independently H or Y; andY is a group of structure:O O> AL 0Hin which L2is a linker separating the two carbonyl groups by a distance of 3-4 bond lengths.

2. The polymer as claimed in claim 1, wherein J is O.

3. The polymer as claimed in claim 1 or 2, wherein X is X1and the polymer comprises poly(carbonate) moieties and / or is a poly(carbonate).

4. The polymer as claimed in claim 1 or 2, wherein X is X2and the polymer comprises poly(ester) moieties and / or is a poly(ester).

5. The polymer as claimed in any one of the preceding claims, wherein in L1, the 3-4 bond lengths is:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C, N and O, with the proviso that at least one (suitably at least two) of the three atoms is C.

6. The polymer as claimed in claim 5, wherein in L1, any of said C atoms participating in said 3-4 bond lengths is optionally substituted with one or two R4, and any of said N atoms participating in said 3-4 bond lengths is optionally substituted with one R5, wherein:(i) each R4is independently selected from (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R4x-R4y-R4z, and each R5is independently (1-22C)alkyl, wherein R4xis selected from absent, -S- and -(CH2)h-C(O)O-, R4yis -(CH2CH2O)i-, and R4zis selected from H and (1-10C)alkyl, in which h is 0 or 1 and i is 1-100; and / or(ii) two R4substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

7. The polymer as claimed in claim 5, wherein L1has a structure L1aor L1b:l_1a |_1b= represents a single bond ora double bond;V1and V2are both C(R4a)m, in which m is 1 or 2;V3, V4and V5are each independently selected from C(R4a)p, in which p is 1 or 2, N(R5a)q, in which q is 0 or 1, and O, with the proviso that at least one (suitably at least two) of V3, V4and V5is C(R4a)P;each R4ais independently selected from hydrogen, (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R4x-R4y-R4zas defined hereinbefore, and each R5ais independently (1-22C)alkyl; and / ortwo R4asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

8. The polymer as claimed in claim 7, wherein each R4ais independently selected from hydrogen, (1 -15C)alkyl, (2-15C)alkenyl, (2-15C)alkynyl, (1-4C)alkylidene, halo and phenyl, and each R5ais independently (1 -4C)alkyl; and / ortwo R4asubstituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

9. The polymer as claimed in any one of claims 6-8, wherein the 3-7 membered carbocyclic ring or 6-membered aromatic ring is optionally substituted with one or more R6, wherein each R6is independently selected from (1 -10C)alkyl, (2-10C)alkenyl, (2-10C)alkynyl, (1-10C)alkoxy, (1-4C)alkylidene, halo, amino, hydroxy, -B(OH)2 and carboxy.

10. The polymer as claimed in claim 9, wherein the 3-7 membered carbocyclic ring or 6-membered aromatic ring is optionally substituted with one or more R6, wherein each R6is independently selected from (1 -4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl and chloro.

11. The polymer as claimed in any one of claim 1, 2 or 4, wherein L1has a structure selected from:S-(CH2CH20)1-10oHan(j12. The polymer as claimed in any one of the preceding claims, wherein in L2, the 3-4 bond lengths is:(i) 3 bond lengths, formed by two atoms separating the two carbonyl groups, said two atoms being C; or(ii) 4 bond lengths, formed by three atoms separating the two carbonyl groups, said three atoms being independently selected from C, N and O, with the proviso that at least one (suitably at least two) of the three atoms is C.

13. The polymer as claimed in claim 12, wherein in L2, any of said C atoms participating in said 3-4 bond lengths is optionally substituted with one or two R7, and any of said N atoms participating in said 3-4 bond lengths is optionally substituted with one R8, wherein:(i) each R7is independently selected from (1-22C)alkyl, (2-22C)alkenyl, (2-22C)alkynyl, (1-4C)alkylidene, halo, phenyl, and a group R7x-R7y-R7z, and each R8is independently (1-22C)alkyl, wherein R7xis selected from absent, -S- and -(CH2)j-C(O)O-, R7yis -(CH2CH2O)k-, and R7zis selected from H and (1-10C)alkyl, in which j is 0 or 1 and k is 1-100; and / or(ii) two R7substituents are linked such that when taken together with the atom(s) to which they are attached, they form a 3-7 membered carbocyclic ring or a 6-membered aromatic ring.

14. The polymer as claimed in any one of claim 1 to 12, wherein L2has a structure selected from:(CH2)13CH3. CI4H27 ■S-(CH2CH2O)1.100Hanc|15. The polymer as claimed in any one of the preceding claims, wherein R1is H, (1-22C)alkyl, (2-22C)alkenyl or R2, and R3is H.

16. The polymer as claimed in any one of claims 1 to 14, wherein R1is R2or Y, and R3is Y.17 The polymer as claimed in any one of the preceding claims, wherein the polymer comprises 2 or more (e.g., 2 to 4) different repeating units of formula I.

18. The polymer as claimed in any one of the preceding claims, wherein the polymer is linear.

19. The polymer as claimed in any one of claims 1 to 17, wherein the polymer is crosslinked.

20. The polymer as claimed in any one of the preceding claims, wherein the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 - 500 kg mol1and the polymer has a polydispersity index of <1.5 as determined by gel permeation chromatography.

21. The polymer as claimed in any one of the preceding claims, wherein the polymer has a molecular weight (Mn) as determined by size exclusion chromatography of 0.5 - 20 kg mol1and the polymer has a polydispersity index of <1.3 as determined by gel permeation chromatography.

22. The polymer as claimed in any one of the preceding claims, wherein the polymer has a structure accordingly to formula II below:B — kLlJe(II)wherein:each A is a polymeric chain comprising a repeating unit of formula I;B is an end group to which each A is attached; ande is 1-6 (e.g., 1, 2, 3 or 4).

23. The polymer as claimed in claim 22, wherein each A has a hydroxy-terminating polymeric backbone.

24. Use of a polymer as claimed in any one of the preceding claims as a thickening agent, a binding agent, a stabilizing agent, a surfactant, a film-forming agent, a viscosity-modifying agent, an adhesion promoter or an encapsulation agent.

25. A liquid formulation comprising a polymer as claimed in any one claims 1 to 23.

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