WO2009127011A1

WO2009127011A1 - Modified condensation polymers

Info

Publication number: WO2009127011A1
Application number: PCT/AU2009/000479
Authority: WO
Inventors: Florian Hans Maximilian Graichen; Stella Kyi; Michael Shane O'shea; Gary Peeters
Original assignee: Commonwealth Scientific And Industrial Research Organisation; Grains Research And Development Corporation
Priority date: 2008-04-18
Filing date: 2009-04-17
Publication date: 2009-10-22

Abstract

The present invention relates to a method of preparing a polymer composition, the method comprising melt mixing an aliphatic condensation polymer with ricinoleic acid lactone.

Description

MODIFIED CONDENSATION POLYMERS

FIELD OF THE INVENTION

The present invention relates in general to condensation polymers. In particular, the invention relates to aliphatic condensation polymers having modified properties

BACKGROUND OF THE INVENTION

Condensation polymers such as polyesters and polyamides may be prepared with a diverse array of physical and chemical properties. For example, condensation polymers may vary widely in their stiffness, hardness, elasticity, tensile strength, density, and may or may not be susceptible to biodegradation.

Such diverse properties lend this class of polymer utility in many and varied applications including food packaging, building materials, medical implants, to name but a few.

As a subset of condensation polymers, aliphatic condensation polymers present their own unique physical and chemical properties. For example, aliphatic polyesters are known to exhibit good biodegradability. However, relative to their non-aliphatic counterparts and other commercial polymers (e.g. polyvinyl chloride and polypropylene), aliphatic condensation polymers can lack the physical and/or chemical properties required for use in certain applications. For example, despite exhibiting good biodegradability, polylactic acid has relatively poor flexibility and its use in film based applications (e.g. as a packaging material) is limited.

A number of techniques for improving the physical and/or chemical properties of aliphatic condensation polymers have been developed. For example, specialty monomers that can influence the physical and/or chemical properties of the polymer may be used in conjunction with the conventional monomers during the condensation polymerisation manufacturing process. However, deriving new and improved properties of condensation polymers in this way necessarily requires the use of rather specialised condensation polymerisation equipment.

An opportunity therefore remains to develop alternative methodology for preparing aliphatic condensation polymers with new and/or improved properties.

SUMMARY OF THE INVENTION

The present invention provides a method of preparing a polymer composition, the method comprising melt mixing an aliphatic condensation polymer with ricinoleic acid lactone.

By melt mixing the ricinoleic acid lactone with a preformed aliphatic condensation polymer, it has been found that the polymer backbone of the condensation polymer can be modified so as to incorporate ricinoleic acid residue. Furthermore, this process has been found to occur without significant loss of molecular weight of the condensation polymer, thereby minimising if not avoiding all together the need for any subsequent processing to build the molecular weight of the modified polymer.

The resulting modified condensation polymer includes as part its polymeric backbone ricinoleic acid residue. The presence of this residue as part of the polymer backbone is believed to impart new and/or improved properties to the modified condensation polymer.

Accordingly, the present invention further provides a method of modifying an aliphatic condensation polymer, the method comprising melt mixing the condensation polymer with ricinoleic acid lactone.

The methods of the invention can advantageously be performed using conventional melt mixing equipment known in the art. Generally, the methods will be performed by introducing the ricinoleic acid lactone and the condensation polymer individually or collectively into the appropriate melt mixing equipment. For example, the ricinoleic acid lactone might be introduced to condensation polymer already in a molten state, or a mixture of the ricinoleic acid lactone and the condensation polymer may be subjected to melt mixing.

The ricinoleic acid lactone might also be provided in the form of a composition such as a masterbatch or concentrate which is subsequently let down into an aliphatic condensation polymer to be modified. The composition will generally comprise the ricinoleic acid lactone and one or more polymers (commonly referred to as a carrier polymer(s)). The carrier polymer may be the same or different to the condensation polymer that is to be modified. In one embodiment, the carrier polymer(s) is an aliphatic condensation polymer. The composition may be a physical blend of the ricinoleic acid lactone and one or more carrier polymers, and/or may itself be prepared by melt mixing the ricinoleic acid lactone with one or more carrier polymers.

The present invention therefore also provides a composition for modifying an aliphatic condensation polymer, the composition comprising one or more carrier polymers and ricinoleic acid lactone and/or a product formed by melt mixing a composition comprising one or more carrier polymers and ricinoleic acid lactone.

hi one embodiment, the polymer composition comprises an aliphatic condensation polymer and ricinoleic acid lactone and/or a product formed by melt mixing a composition comprising an aliphatic condensation polymer and ricinoleic acid lactone.

Aliphatic condensation polymers modified in accordance with the invention have been found to exhibit new and/or improved properties such as improved flexibility relative to the condensation polymer prior to being modified.

Ricinoleic acid lactones used in accordance with the invention are prepared from ricinoleic acid, a renewable resource that can be derived from plants (e.g. Castor plant). - A -

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the expression "condensation polymer" is intended to mean a polymer that has been formed via a condensation or step-wise polymerisation reaction. Examples of condensation polymers include polyesters, polyamide and copolymers thereof. In a preferred embodiment of the invention, the condensation polymers used are polyesters, polyamides, and copolymers thereof.

Condensation polymers used in accordance with the invention are "aliphatic condensation polymers". By "aliphatic" condensation polymers is meant that the polymer backbone does not incorporate an aromatic moiety. Thus, polyethylene terephthalate (i.e. PET) is not an aliphatic polyester.

By the expression "polymer backbone" is meant the main structure of the polymer on to which substituents may be attached. The main structure of the polymer may be linear or branched.

The condensation polymers may also be acyclic (i.e. where the polymer backbone does not incorporate a cyclic moiety). Although the polymer backbone of the aliphatic condensation polymers will not incorporate an aromatic moiety (and possibly not a cyclic moiety), an aromatic or cyclic moiety may nonetheless be present in a position that is pendant from the polymer backbone. However, the aliphatic condensation polymers used in accordance with the invention will not generally comprise a pendant aromatic or cyclic moiety.

Aliphatic polyesters that may be used in the invention include homo- and copolymers of poly(hydroxyalkanoates) and homo- and copolymers of those aliphatic polyesters derived from the reaction product of one or more alkyldiols with one or more alkyldicarboxylic acids (or acyl derivatives). Miscible and immiscible blends of aliphatic polyesters may also be used. One class of aliphatic polyester includes poly(hydroxyalkanoates) derived by condensation or ring-opening polymerization of hydroxycarboxylic acids, or derivatives thereof. Suitable ρoly(hydroxyalkanoates) may be represented by the formula H(O — R^a — C(O) — )_nOH, where R^a is an alkylene moiety that may be linear or branched and n is a number from 1 to 20, preferably 1 to 12. R^a may further comprise one or more caternary (i.e. in chain) ether oxygen atoms. Generally the R^a group of the hydroxycarboxylic acids is such that the pendant hydroxyl group is a primary or secondary hydroxyl group.

Useful poly(hydroxyalkanoates) include, for example, homo- and copolymers of poly(3- hydroxybutyrate), poly(4-hydroxybutyrate), poly(3-hydroxyvalerate), poly(lactic acid) (also known as polylactide), poly(3-hydroxypropanoate), poly(4-hydropcntanoate), poly(3- hydroxypentanoate), poly(3-hydroxyhexanoate), poly(3-hydroxyheptanoate), poly(3- hydroxyoctanoate), polydioxanone, and polycaprolactone, polyglycolic acid (also known as polyglycolide). Copolymers of two or more of the above hydroxycarboxylic acids may also be used, for example, to provide for poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(lactate-co-3-hydroxypropanoate) and poly(glycolide-co-p-dioxanone). Blends of two or more of the poly(hydroxyalkanoates) may also be used.

A further class of aliphatic polyester includes those aliphatic polyesters derived from the reaction product of one or more alkyldiols with one or more alkyldicarboxylic acids (or acyl derivatives). Such polyesters may have the general formula (I):

(i)

where R and R° each independently represent an alkylene moiety that may be linear or branched having from 1 to 20, preferably 1 to 12 carbon atoms, and p is a number such that the ester is polymeric, and is preferably a number such that the molecular weight of the aliphatic polyester is 10,000 to 300,000, more preferably from about 30,000 to 200,000. Each m and n is independently 0 or 1. R and R^c may further comprise one or more caternary (i.e. in chain) ether oxygen atoms.

Examples of such aliphatic polyesters include those homo- and copolymers derived from (a) one or more of the following diacids (or derivative thereof): succinic acid, adipic acid, 1,12 dicarboxydodecane, fumaric acid, and maleic acid and (b) one of more of the following diols: ethylene glycol, polyethylene glycol, 1,2-propane diol, 1,3-propanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and polypropylene glycol, and (c) optionally a small amount, i.e. 0.5-7.0 mole % of a polyol with a functionality greater than two such as glycerol, or pentaerythritol.

Such aliphatic polyesters may include polybutylenesuccinate homopolymer, polybutylene adipate homopolmer, polybutyleneadipate-succinate copolymer, polyethylenesuccinate- adipate copolymer, polyethylene adipate homopolymer.

Common commercially available aliphatic polyesters include polylactide, polyglycolide, polylactide-co-glycolide, poly(L-lactide-co-trimethylene carbonate), poly(dioxanone), poly(butylene succinate), and poly(butylene adipate).

Blends of two or more aliphatic polyesters may also be used in accordance with the invention.

Aliphatic polyamides that may be used in the invention include those characterised by the presence of recurring carbonamide groups that form part of the polymer backbone and which are separated from one another by at least two aliphatic carbon atoms. Suitable aliphatic polyamides therefore include those having recurring units represented by general formulae (II) or (III): O O I!

N Il R^d — C N R^e

H H (II)

(III)

or a combination thereof, in which R^d and R^e are the same or different and are each independently alkylene groups of at least two carbon atoms, for example alkylene having about two to about 20 carbon atoms, preferably alkylene having about two to about 12 carbon atoms.

Examples of such polyamides are those formed by the reaction of alkyldiamines and alkyldicarboxylic acids and include poly(tetramethylene adipamide) (nylon 4,6); poly(hexamethylene adipamide) (nylon 6,6); poly(hexamethylene azelamide) (nylon 6,9); poly(hexamethylene sebacamide) (nylon 6,10); poly(heptamethylene pimelamide) (nylon 7,7); poly(octamethylene suberamide) (nylon 8,8); poly(nonamethylene azelamide) (nylon 9,9); poly(decamethylene azelamide) (nylon 10,9); and the like.

Examples of polyamides are also those formed by polymerization of alkyl amino acids and derivatives thereof (e.g. lactams) and include poly(4-aminobutyric acid) (nylon 4); poly(6- aminohexanoic acid) (nylon 6); poly(7-amino-heptanoic acid) (nylon 7); poly(8- aminoocatanoic acid) (nylon 8); poly(9-aminononanoic acid) (nylon 9); poly(10- aminodecanoic acid) (nylon 10); poly(l l-aminoundecanoic acid) (nylon 11); poly(12- aminododecanoic acid) (nylon 12); and the like.

Blends of two or more aliphatic polyamides may also be used in accordance with the invention.

As used herein, the expression "ricinoleic acid lactone" is intended to mean a cyclic ester formed through the cyclic condensation of ricinoleic acid.

The most common form of ricinoleic acid is depicted by formula (IV):

The structure depicted by formula (IV) is a Cl 8 fatty acid with a cis-configured double bond in the 9^th position and a hydroxyl group in the 12^th position (i.e. cis-12- hydroxyoctadeca-9-enoic acid). Those skilled in the art will appreciate that ricinoleic acid has a number of isomeric structures. Lactones formed from all such structures may be used in accordance with the invention.

The most common source of ricinoleic acid is through the hydrolysis of castor oil.

Lactone structures of ricinoleic acid are known. When the ricinoleic acid is of a structure depicted by formula (IV), the lactone forms through the cyclic condensation of the carboxylic acid and C12 hydroxyl group.

Those skilled in the art will appreciate that ricinoleic acid may form a variety of lactone structures. For example, as shown below in Scheme 1, lactone structures of ricinoleic acid can include monolactone, dilactone, trilactone, tetralactone, pentalactone, and hexalactone structures.

Scheme 1: Examples of ricinoleic acid lactones that may be used in accordance with the invention.

There is no particular limitation regarding the ring size of the ricinoleic acid lactones that may be used in accordance with the invention.

The lactones used may also comprise a mixture of different ring sizes. For example, the ricinoleic acid lactone may comprise one or more mono-, di-, tri-, tetra-, penta-, and hexalactone structures.

Techniques for preparing ricinoleic acid lactones are known in the art. For example, they may be prepared as outlined in Biomacromolecules 2005, 6, 1679-1688. As used herein, the term "alkyl", used either alone or in compound words denotes straight chain, branched or cyclic alkyl, for example C_1-40 alkyl, or Ci_-20 or Ci_-I0. Examples of straight chain and branched alkyl include methyl, ethyl, π-propyl, isopropyl, n-butyl, sec- butyl, t-butyl, 7j-pentyl, 1,2-dimethylpropyl, 1,1-dimethyl-propyl, hexyl, 4-methylpentyl, 1- methylpentyl, 2-methylρentyl, 3-methylpentyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3- dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 1,2,2-trimethylproρyl, 1,1,2- trimethylpropyl, heptyl, 5-methylhexyl, 1-methylhexyl, 2,2-dimethylpentyl, 3,3- dimethylpentyl, 4,4-dimethylpentyl, 1,2-dimethylpentyl, 1,3-dimethylpentyl, 1,4- dimethyl-pentyl, 1,2,3-trimethylbutyl, 1,1,2-trimethylbutyl, 1,1,3-trimethylbutyl, octyl, 6- methylheptyl, 1-methylheptyl, 1,1,3,3-tetramethylbutyl, nonyl, 1-, 2-, 3-, 4-, 5-, 6- or 7- methyloctyl, 1-, 2-, 3-, 4- or 5-ethylheptyl, 1-, 2- or 3-propylhexyl, decyl, 1-, 2-, 3-, 4-, 5-, 6-, 7- and 8-methylnonyl, 1-, 2-, 3-, 4-, 5- or 6-ethyloctyl, 1-, 2-, 3- or 4-propylheptyl, undecyl, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-methyldecyl, 1-, 2-, 3-, A-, S-, 6- or 7-ethylnonyl, 1-, 2-, 3-, 4- or 5-propyloctyl, 1-, 2- or 3-butylheptyl, 1-pentylhexyl, dodecyl, 1-, 2-, 3-, A-, 5-, 6-, 7-, 8-, 9- or 10-methylraidecyl, 1-, 2-, 3-, A-, 5-, 6-, 7- or 8-ethyldecyl, 1-, 2-₅ 3-, A-, 5- or 6-propymonyl, 1-, 2-, 3- or 4-butyloctyl, 1-2-pentylheptyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonoadecyl, eicosyl and the like. Examples of cyclic alkyl include mono- or polycyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl and the like. Where an alkyl group is referred to generally as "propyl", butyl" etc, it will be understood that this can refer to any of straight, branched and cyclic isomers where appropriate. An alkyl group may be optionally substituted by one or more optional substituents as herein defined.

As used herein, term "alkenyl" denotes groups formed from straight chain, branched or cyclic hydrocarbon residues containing at least one carbon to carbon double bond including ethylenically mono-, di- or polyunsaturated alkyl or cycloalkyl groups as previously defined, for example C_2-40 alkenyl, or C_2-20 or C_2-io. Thus, alkenyl is intended to include propenyl, butylenyl, pentenyl, hexaenyl, heptaenyl, octaenyl, nonaenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nondecenyl, eicosenyl hydrocarbon groups with one or more carbon to carbon double bonds. Examples of alkenyl include vinyl, allyl, 1-methylvinyl, butenyl, iso-butenyl, 3-methyl-2-butenyl, 1-pentenyl, cyclopentenyl, 1-methyl- cyclopentenyl, 1-hexenyl, 3-hexenyl, cyclohexenyl, 1-heptenyl, 3-heptenyl, 1-octenyl, cyclooctenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1-decenyl, 3-decenyl, 1,3-butadienyl, 1,4- pentadienyl, 1,3-cyclopentadienyl, 1,3-hexadienyl, 1,4-hexadienyl, 1,3-cyclohexadienyl, 1,4-cyclohexadienyl, 1,3-cycloheptadienyl, 1,3,5-cycloheptatrienyl and 1,3,5,7- cyclooctatetraenyl. An alkenyl group may be optionally substituted by one or more optional substituents as herein defined.

As used herein the term "alkynyl" denotes groups formed from straight chain, branched or cyclic hydrocarbon residues containing at least one carbon-carbon triple bond including ethylenically mono-, di- or polyunsaturated alkyl or cycloalkyl groups as previously defined, for example, C_2-40 alkenyl, or C_2-20 or C_2-1O- Thus, alkynyl is intended to include propynyl, butylynyl, pentynyl, hexaynyl, heptaynyl, octaynyl, nonaynyl, decynyl, undecynyl, dodecynyl, tridecynyl, tetradecynyl, pentadecynyl, hexadecynyl, heptadecynyl, octadecynyl, nondecynyl, eicosynyl hydrocarbon groups with one or more carbon to carbon triple bonds. Examples of alkynyl include ethynyl, 1 -propynyl, 2-propynyl, and butynyl isomers, and pentynyl isomers. An alkynyl group may be optionally substituted by one or more optional substituents as herein defined.

An alkenyl group may comprise a carbon to carbon triple bond and an alkynyl group may comprise a carbon to carbon double bond (i.e. so called ene-yne or yne-ene groups).

As used herein, the term "aryl" (or "carboaryl)" denotes any of single, polynuclear, conjugated and fused residues of aromatic hydrocarbon ring systems. Examples of aryl include phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, tetrahydronaphthyl, anthracenyl, dihydroanthracenyl, benzanthracenyl, dibenzanthracenyl, phenanthrenyl, fluorenyl, pyrenyl, idenyl, azulenyl, chrysenyl. Preferred aryl include phenyl and naphthyl. An aryl group may be optionally substituted by one or more optional substituents as herein defined. As used herein, the terms "alkylene", "alkenylene", and "arylene" are intended to denote the divalent forms of "alkyl", "alkenyl", and "aryl", respectively, as herein define.

In this specification "optionally substituted" is taken to mean that a group may or may not be substituted or fused (so as to form a condensed polycyclic group) with one, two, three or more of organic and inorganic groups (i.e. the optional substituent) including those selected from: alkyl, alkenyl, alkynyl, carbocyclyl, aryl, heterocyclyl, heteroaryl, acyl, aralkyl, alkaryl, alkheterocyclyl, alkheteroaryl, alkcarbocyclyl, halo, haloalkyl, haloalkenyl, haloalkynyl, haloaryl, halocarbocyclyl, haloheterocyclyl, haloheteroaryl, haloacyl, haloaryalkyl, hydroxy, hydroxyalkyl, hydroxyalkenyl, hydroxyalkynyl, hydroxycarbocyclyl, hydroxyaryl, hydroxyheterocyclyl, hydroxyheteroaryl, hydroxyacyl, hydroxyaralkyl, alkoxyalkyl, alkoxyalkenyl, alkoxyalkynyl, alkoxycarbocyclyl, alkoxyaryl, alkoxyheterocyclyl, alkoxyheteroaryl, alkoxyacyl, alkoxyaralkyl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, carbocyclyloxy, aralkyloxy, heteroaryloxy, heterocyclyloxy, acyloxy, haloalkoxy, haloalkenyloxy, haloalkynyloxy, haloaryloxy, halocarbocyclyloxy, halo aralkyloxy, haloheteroaryloxy, haloheterocyclyloxy, haloacyloxy, nitro, nitroalkyl, nitroalkenyl, nitroalkynyl, nitroaryl, nitroheterocyclyl, nitroheteroayl, nitrocarbocyclyl, nitroacyl, nitroaralkyl, amino (NH₂), alkylamino, dialkylamino, alkenylamino, alkynylamino, arylamino, diarylamino, aralkylamino, diaralkylamino, acylamino, diacylamino, heterocyclamino, heteroarylamino, carboxy, carboxyester, amido, alkylsulphonyloxy, arylsulphenyloxy, alkylsulphenyl, arylsulphenyl, thio, alkylthio, alkenylthio, alkynylthio, arylthio, aralkylthio, carbocyclylthio, heterocyclylthio, heteroarylthio, acylthio, sulfoxide, sulfonyl, sulfonamide, aminoalkyl, aminoalkenyl, aminoalkynyl, aminocarbocyclyl, aminoaryl, aminoheterocyclyl, aminoheteroaryl, aminoacyl, aminoaralkyl, thioalkyl, thioalkenyl, thioalkynyl, thiocarbocyclyl, thioaryl, thioheterocyclyl, thioheteroaryl, thioacyl, thioaralkyl, carboxyalkyl, carboxyalkenyl, carboxyalkynyl, carboxycarbocyclyl, carboxyaryl, carboxyheterocyclyl, carboxyheteroaryl, carboxyacyl, carboxyaralkyl, carboxyesteralkyl, carboxyesteralkenyl, carboxyesteralkynyl, carboxyestercarbocyclyl, carboxyesteraryl, carboxyesterheterocyclyl, carboxyesterheteroaryl, carboxyesteracyl, carboxyesteraralkyl, amidoalkyl, amidoalkenyl, amidoalkynyl, amidocarbocyclyl, amidoaryl, amidoheterocyclyl, amidoheteroaryl, amidoacyl, amidoaralkyl, formylalkyl, formylalkenyl, formylalkynyl, formylcarbocyclyl, formylaryl, formylheterocyclyl, formylheteroaryl, formylacyl, formylaralkyl, acylalkyl, acylalkenyl, acylalkynyl, acylcarbocyclyl, acylaryl, acylheterocyclyl, acylheteroaryl, acylacyl, acylaralkyl, sulfoxidealkyl, sulfoxidealkenyl, sulfoxidealkynyl, sulfoxidecarbocyclyl, sulfoxidearyl, sulfoxideheterocyclyl, sulfoxideheteroaryl, sulfoxideacyl, sulfoxidearalkyl, sulfonylalkyl, sulfonylalkenyl, sulfonylalkynyl, sulfonylcarbocyclyl, sulfonylaryl, sulfonylheterocyclyl, sulfonylheteroaryl, sulfonylacyl, sulfonylaralkyl, sulfonamidoalkyl, sulfonamidoalkenyl, sulfonamidoalkynyl, sulfonamidocarbocyclyl, sulfonamidoaryl, sulfonamidoheterocyclyl, sulfonamidoheteroaryl, sulfonamidoacyl, sulfonamidoaralkyl, nitroalkyl, nitroalkenyl, nitroalkynyl, nitrocarbocyclyl, nitroaryl, nitroheterocyclyl, nitroheteroaryl, nitroacyl, nitroaralkyl, cyano, sulfate and phosphate groups.

Preferred optional substituents include alkyl, (e.g. C_1-6 alkyl such as methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl), hydroxyalkyl (e.g. hydroxymethyl, hydroxyethyl, hydroxypropyl), alkoxyalkyl (e.g. methoxymethyl, methoxyethyl, methoxypropyl, ethoxymethyl, ethoxyethyl, ethoxypropyl etc) alkoxy (e.g. C_1-6 alkoxy such as methoxy, ethoxy, propoxy, butoxy, cyclopropoxy, cyclobutoxy), halo, trifluoromethyl, trichloromethyl, tribromomethyl, hydroxy, phenyl (which itself may be further substituted e.g., by C_1-6 alkyl, halo, hydroxy, hydroxyC_1-6 alkyl, C_1-6 alkoxy, haloC_1-6alkyl, cyano, nitro OC(O)C_1-6 alkyl, and amino), benzyl (wherein benzyl itself may be further substituted e.g., by C_1-6 alkyl, halo, hydroxy, hydroxyC_1-6alkyl, C_1-6 alkoxy, haloC_1-6 alkyl, cyano, nitro OC(O)C_1-6 alkyl, and amino), phenoxy (wherein phenyl itself may be further substituted e.g., by C_1-6 alkyl, halo, hydroxy, hydroxyC_1-6 alkyl, C_1-6 alkoxy, haloC_1-6 alkyl, cyano, nitro OC(O)C_1-6 alkyl, and amino), benzyloxy (wherein benzyl itself may be further substituted e.g., by C_1-6 alkyl, halo, hydroxy, hydroxyC_1-6 alkyl, C_1-6 alkoxy, haloC_1-6 alkyl, cyano, nitro OC(O)C_1-6 alkyl, and amino), amino, alkylaniino (e.g. C_1-6 alkyl, such as methylamino, ethylamino, propylamino etc), dialkylamino (e.g. C_1-6 alkyl, such as dimethylamino, diethylamino, dipropylamino), acylamino (e.g. NHC(O)CH₃), phenylamino (wherein phenyl itself may be further substituted e.g., by C_1-6 alkyl, halo, hydroxy hydroxyCi_-6 alkyl, C_1-6 alkoxy, haloC_1-6 alkyl, cyano, nitro OC(O)C_1-6 alkyl, and amino), nitro, formyl, -C(O)-alkyl (e.g. C_1-6 alkyl, such as acetyl), O-C(O)-alkyl (e.g. C_1- ₆alkyl, such as acetyloxy), benzoyl (wherein the phenyl group itself may be further substituted e.g., by C_1-6 alkyl, halo, hydroxy hydroxyC_1-6 alkyl, C_1-6 alkoxy, haloC_1-6 alkyl, cyano, nitro OC(O)C_1-6alkyl, and amino), replacement of CH₂ with C=O, CO₂H, C0₂alkyl (e.g. C_1-6 alkyl such as methyl ester, ethyl ester, propyl ester, butyl ester), CO₂phenyl (wherein phenyl itself may be further substituted e.g., by Ci_-6 alkyl, halo, hydroxy, hydroxyl Ci_-6 alkyl, C_1-6 alkoxy, halo Ci_-6 alkyl, cyano, nitro OC(O)Ci_-6 alkyl, and amino), CONH₂, CONHphenyl (wherein phenyl itself may be further substituted e.g., by d.₆ alkyl, halo, hydroxy, hydroxyl Ci_-6 alkyl, C_1-6 alkoxy, halo Ci_-6 alkyl, cyano, nitro OC(O)Ci_-6 alkyl, and amino), CONHbenzyl (wherein benzyl itself may be further substituted e.g., by Ci-₆ alkyl, halo, hydroxy hydroxyl Ci_-6 alkyl, C_1-6 alkoxy, halo C_1-6 alkyl, cyano, nitro OC(O)C_1-6 alkyl, and amino), CONHalkyl (e.g. C_1-6 alkyl such as methyl ester, ethyl ester, propyl ester, butyl amide) CONHdialkyl (e.g. C_1-6 alkyl) aminoalkyl (e.g., HN C_1-6 alkyl-, Ci_-6alkylHN-Ci_-6 alkyl- and (Ci_-6 alkyl)₂N-C_1-6 alkyl-), thioalkyl (e.g., HS C_1-6 alkyl-), carboxyalkyl (e.g., HO₂CC_1-6 alkyl-), carboxyesteralkyl (e.g., Ci_-6 alkylO₂CCi_-6 alkyl-), amidoalkyl (e.g., H₂N(O)CC_1-6 alkyl-, H(Ci_-6 alkyl)N(O)CC_1-6 alkyl-), formylalkyl (e.g., OHCCi -ealkyl-), acylalkyl (e.g., Ci_-6 alkyl(O)CC_1-6 alkyl-), nitroalkyl (e.g., O₂NCi_-6 alkyl-), sulfoxidealkyl (e.g., R(O)SCi_-5 alkyl, such as Ci_-6 alkyl(O)SCi_-6 alkyl-), sulfonylalkyl (e.g., R(O)₂SCi_-6 alkyl- such as Ci_-6 alkyl(O)₂SCi_-6 alkyl-), sulfonamidoalkyl (e.g., ₂HRN(0)SC_1- β alkyl, H(C_1-6 alkyl)N(O)SC_1-6 alkyl-).

The term "halogen" ("halo") denotes fluorine, chlorine, bromine or iodine (fluoro, chloro, bromo or iodo). Preferred halogens are chlorine, bromine or iodine.

The term "carbocyclyl" includes any of non-aromatic monocyclic, polycyclic, fused or conjugated hydrocarbon residues, preferably C_3-20 (e-g. C_3-I0 or C_3-8). The rings may be saturated, e.g. cycloalkyl, or may possess one or more double bonds (cycloalkenyl) and/or one or more triple bonds (cycloalkynyl). Particularly preferred carbocyclyl moieties are 5-6-membered or 9-10 membered ring systems. Suitable examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cyclopentenyl, cyclohexenyl, cyclooctenyl, cyclopentadienyl, cyclohexadienyl, cyclooctatetraenyl, indanyl, decalinyl and indenyl.

The term "heterocyclyl" when used alone or in compound words includes any of monocyclic, polycyclic, fused or conjugated hydrocarbon residues, preferably C_3-20 (e.g. C_3-10 or C₃.₈) wherein one or more carbon atoms are replaced by a heteroatom so as to provide a non-aromatic residue. Suitable heteroatoms include O, N, S, P and Se, particularly O, N and S. Where two or more carbon atoms are replaced, this may be by two or more of the same heteroatom or by different heteroatoms. The heterocyclyl group may be saturated or partially unsaturated, i.e. possess one or more double bonds. Particularly preferred heterocyclyl are 5-6 and 9-10 membered heterocyclyl. Suitable examples of heterocyclyl groups may include azridinyl, oxiranyl, thiiranyl, azetidinyl, oxetanyl, thietanyl, 2H-pyrrolyl, pyrrolidinyl, pyrrolinyl, piperidyl, piperazinyl, morpholinyl, indolinyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, thiomorpholinyl, dioxanyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydropyrrolyl, tetrahydrothiophenyl, pyrazolinyl, dioxalanyl, thiazolidinyl, isoxazolidinyl, dihydropyranyl, oxazinyl, thiazinyl, thiomorpholinyl, oxathianyl, dithianyl, trioxanyl, thiadiazinyl, dithiazinyl, trithianyl, azepinyl, oxepinyl, thiepinyl, indenyl, indanyl, 3H-indolyl, isoindolinyl, 4H-quinolazinyl, chromenyl, chromanyl, isochromanyl, pyranyl and dihydropyranyl.

The term "heteroaryl" includes any of monocyclic, polycyclic, fused or conjugated hydrocarbon residues, wherein one or more carbon atoms are replaced by a heteroatom so as to provide an aromatic residue. Preferred heteroaryl have 3-20 ring atoms, e.g. 3-10. Particularly preferred heteroaryl are 5-6 and 9-10 membered bicyclic ring systems. Suitable heteroatoms include, O, N, S, P and Se, particularly O, N and S. Where two or more carbon atoms are replaced, this may be by two or more of the same heteroatom or by different heteroatoms. Suitable examples of heteroaryl groups may include pyridyl, pyrrolyl, thienyl, imidazolyl, furanyl, benzothienyl, isobenzothienyl, benzofuranyl, isobenzofuranyl, indolyl, isoindolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolizinyl, quinolyl, isoquinolyl, phthalazinyl, 1,5-naphthyridinyl, quinozalinyl, quinazolinyl, quinolinyl, oxazolyl, thiazolyl, isothiazolyl, isoxazolyl, triazolyl, oxadialzolyl, oxatriazolyl, triazinyl, and furazanyl.

The term "acyl" either alone or in compound words denotes a group containing the moiety C=O (and not being a carboxylic acid, ester or amide) Preferred acyl includes C(O)-R^X, wherein R^x is hydrogen or an alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl residue. Examples of acyl include formyl, straight chain or branched alkanoyl (e.g. C_1-2o) such as, acetyl, propanoyl, butanoyl, 2-methylpropanoyl, pentanoyl, 2,2- dimethylpropanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, undecanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, pentadecanoyl, hexadecanoyl, heptadecanoyl, octadecanoyl, nonadecanoyl and icosanoyl; cycloalkylcarbonyl such as cyclopropylcarbonyl cyclobutylcarbonyl, cyclopentylcarbonyl and cyclohexylcarbonyl; aroyl such as benzoyl, toluoyl and naphthoyl; aralkanoyl such as phenylalkanoyl (e.g. phenylacetyl, phenylpropanoyl, phenylbutanoyl, phenylisobutylyl, phenylpentanoyl and phenylhexanoyl) and naphthylalkanoyl (e.g. naphthylacetyl, naphthylpropanoyl and naphthylbutanoyl]; aralkenoyl such as phenylalkenoyl (e.g. phenylpropenoyl, phenylbutenoyl, phenylmethacryloyl, phenylpentenoyl and phenylhexenoyl and naphthylalkenoyl (e.g. naphthylpropenoyl, naphthylbutenoyl and naphthylpentenoyl); aryloxyalkanoyl such as phenoxyacetyl and phenoxypropionyl; arylthiocarbamoyl such as phenylthiocarbamoyl; arylglyoxyloyl such as phenylglyoxyloyl and naphthylglyoxyloyl; arylsulfonyl such as phenylsulfonyl and napthylsulfonyl; heterocycliccarbonyl; heterocyclicalkanoyl such as thienylacetyl, thienylpropanoyl, thienylbutanoyl, thienylpentanoyl, thienylhexanoyl, thiazolylacetyl, thiadiazolylacetyl and tetrazolylacetyl; heterocyclicalkenoyl such as heterocyclicpropenoyl, heterocyclicbutenoyl, heterocyclicpentenoyl and heterocyclichexenoyl; and heterocyclicglyoxyloyl such as thiazolyglyoxyloyl and thienylglyoxyloyl. The R^x residue may be optionally substituted as described herein.

The term "sulfoxide", either alone or in a compound word, refers to a group -S(O)R^y wherein R^y is selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, carbocyclyl, and aralkyl. Examples of preferred R^y include C_1-20alkyl, phenyl and benzyl.

The term "sulfonyl", either alone or in a compound word, refers to a group S(O)₂-R^y, wherein R^y is selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, carbocyclyl and aralkyl. Examples of preferred R^y include C_1-20alkyl, phenyl and benzyl.

The term "sulfonamide", either alone or in a compound word, refers to a group S(O)NR^yR^y wherein each R^y is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, carbocyclyl, and aralkyl. Examples of preferred R^y include C_1- ₂₀alkyl, phenyl and benzyl. In a preferred embodiment at least one R^y is hydrogen. In another form, both R^y are hydrogen.

The term, "amino" is used here in its broadest sense as understood in the art and includes groups of the formula NR^AR^B wherein R^A and R^B may be any independently selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, carbocyclyl, heteroaryl, heterocyclyl, aralkyl, and acyl. R^A and R^B, together with the nitrogen to which they are attached, may also form a monocyclic, or polycyclic ring system e.g. a 3-10 membered ring, particularly, 5-6 and 9- 10 membered systems. Examples of "amino" include NH₂, NHalkyl (e.g. C_1-2oalkyl), NHaryl (e.g. NHphenyl), NHaralkyl (e.g. NHbenzyl), NHacyl (e.g. NHC(O)C_1-20alkyl, NHC(O)ρhenyl), Nalkylalkyl (wherein each alkyl, for example C_1-20, may be the same or different) and 5 or 6 membered rings, optionally containing one or more same or different heteroatoms (e.g. O, N and S).

The term "amido" is used here in its broadest sense as understood in the art and includes groups having the formula C(O)NR^AR^B, wherein R^A and R^B are as defined as above. Examples of amido include C(O)NH₂, C(O)NHalkyl (e.g. C_1-20alkyl), C(O)NHaryl (e.g. C(O)NHphenyl), C(O)NHaralkyl (e.g. C(O)NHbenzyl), C(O)NHacyl (e.g. C(O)NHC(O)Ci_-20alkyl, C(O)NHC(O)phenyl), C(O)Nalkylalkyl (wherein each alkyl, for example C_1-20, may be the same or different) and 5 or 6 membered rings, optionally containing one or more same or different heteroatoms (e.g. O, N and S).

The term "carboxy ester" is used here in its broadest sense as understood in the art and includes groups having the formula CO₂R², wherein R^z may be selected from groups including alkyl, alkenyl, alkynyl, aryl, carbocyclyl, heteroaryl, heterocyclyl, aralkyl, and acyl. Examples of carboxy ester include CO₂C_1-20alkyl, CC^aryl (e.g.. CO₂phenyl), CO₂aralkyl (e.g. CO₂ benzyl).

The term "heteroatom" or "hetero" as used herein in its broadest sense refers to any atom other than a carbon atom which may be a member of a cyclic organic group. Particular examples of heteroatoms include nitrogen, oxygen, sulfur, phosphorous, boron, silicon, selenium and tellurium, more particularly nitrogen, oxygen and sulfur.

In accordance with the invention, there is provided a method of preparing a polymer composition, the method comprising melt mixing an aliphatic condensation polymer with ricinoleic acid lactone. Melt mixing can be performed using methods well known in the art. For example, melt mixing may be achieved using continuous extrusion equipment such as twin screw extruders, single screw extruders, other multiple screw extruders and Farell mixers. Semi-continuous or batch processing equipment may also be used to achieve melt mixing. Examples of such equipment include injection moulders, Banbury mixers and batch mixers. Static melt mixing equipment may also be used.

By melt mixing the aliphatic condensation polymer and the ricinoleic acid lactone, it has been found that the ricinoleic acid lactone can undergo reaction with the condensation polymer so as to incorporate the ring opened form of the lactone as part of the condensation polymer backbone. The polymer composition resulting from the melt mixing process will therefore comprise modified aliphatic condensation polymer having ricinoleic acid incorporated as part of its polymer backbone. The polymer composition may also comprise a proportion of ricinoleic acid lactone that has not undergone reaction with the aliphatic condensation polymer and/or polymer that has formed through ring opening polymerisation of the ricinoleic acid lactone.

Those skilled in the art will appreciate that by ricinoleic acid being "incorporated" as part of the polymer backbone of the aliphatic condensation polymer is meant that the ricinoleic acid lactone ring opens and becomes covalently bound to the polymer backbone. Without wishing to be limited by theory, it is believed that this process at least involves the ring opened lactone being covalently bound to a terminal end of the polymer backbone, possibly followed by inter and/or intra polymer chain rearrangement of the ring opened lactone such that it becomes located at a non-terminal position within the polymer backbone (e.g. through a transesterification process).

For example, an aliphatic condensation polymer modified with ricinoleic acid dilactone in accordance with the invention may comprise within its polymer backbone the ring opened residue of the lactone as illustrated below in Scheme 2. The modified polymer will of course generally comprise within its polymer backbone a number of such ring opened residues.

Scheme 2: An illustration of an aliphatic condensation polymer modified using ricinoleic acid dilactone in accordance with the invention, where A and B represent the remainder of the condensation polymer.

With reference to Scheme 2, the aliphatic condensation polymer can be seen to comprise the ring opened residue of the ricinoleic acid dilactone as part of its polymer backbone. The ring opened residue of the ricinoleic acid dilactone itself can be seen to be formed from the condensed residues of two units of ricinoleic acid. Accordingly, the modified condensation polymer may be described as comprising ricinoleic acid residue within its polymer backbone.

The ricinoleic acid residue(s) that forms part of the polymer backbone of the modified condensation polymer is believed to modify the properties of the polymer. In particular, each ricinoleic acid residue in effect extends the chain length of the polymer backbone by

12 carbon atoms and also introduces a pendant C6 hydrocarbon chain to the backbone.

Without wishing to be limited by theory, it is believed that this "in-chain" extension of, and the pendant chain addition to, the polymer backbone gives rise to the modified properties of the condensation polymer.

For example, aliphatic polyesters ( e.g. polylactic acid and polybutylene succinate adipate) and aliphatic polyamides ( e.g. nylon 11) modified in accordance with the invention have been shown to exhibit improved flexibility and are also expected to exhibit higher hydrophobicity as well as altered biodegradability.

Thus, the invention further provides a method of modifying an aliphatic condensation polymer, the method comprising melt mixing the condensation polymer and ricinoleic acid lactone.

By a ricinoleic acid residue being incorporated as part of the polymer backbone of the aliphatic condensation polymer, it will be appreciated that the polymer backbone will consequently comprise a double bond presented by the ricinoleic acid residue. The modified condensation polymer in accordance with the invention can therefore be advantageously undergo reaction through this double bond. For example, the double bond may take part in crosslinking reactions (i.e. oxidative crosslinking similar to that which occurs in alkyd paints or free radical mediated reactions), and free radical mediated grafting reactions.

The presence of a ricinoleic acid residue double bond within the polymer backbone of the modified aliphatic condensation polymers may also be used as a reactive site to tether organic or inorganic moieties to the polymer backbone. The organic or inorganic moieties may be conveniently tethered to the ricinoleic acid lactone prior to it being melt mixed with the aliphatic condensation polymer, or tethered to the ricinoleic acid lactone residue after the cyclic ester has been melt mixed with the aliphatic condensation polymer.

A condensation catalyst may also be employed in order to enhance the melt phase reaction between the aliphatic condensation polymer and the ricinoleic acid lactone. Typical condensation catalysts include Lewis acids such as antimony trioxide, titanium oxide and dibutyl tindilaurate.

Melt mixing of the aliphatic condensation polymer and the ricinoleic acid lactone may also be conducted in the presence of one or more additives such as fillers, pigments, stabilisers, blowing agents, nucleating agents, and chain coupling and/or branching agents.

Chain coupling and/or branching agents may be used in accordance with the invention to promote an increase in the molecular weight of and/or chain branching in the aliphatic condensation polymer. Such agents include polyfunctional acid anhydrides, epoxy compounds, oxazoline derivatives, oxazolinone derivatives, lactams and related species.

Preferred chain coupling and/or branching agents include one or more of the following:

Polyepoxides such as bis(3,4-epoxycyclohexylmethyl) adipate; N,N-diglycidyl benzamide (and related diepoxies); N,N-diglycidyl aniline and derivatives; N,N-diglycidylhydantoin, uracil, barbituric acid or isocyanuric acid derivatives; N,N-diglycidyl diimides; N₅N- diglycidyl imidazolones; epoxy novolaks; phenyl glycidyl ether; diethyleneglycol diglycidyl ether; Epikote 815 (diglycidyl ether of bisphenol A-epichlorohydrin oligomer).

Polyoxazolines/Polyoxazolones such as 2,2-bis(2-oxazoline); 1,3-phenylene bis(2- oxazoline-2), l,2-bis(2-oxazolinyl-2)ethane; 2-phenyl-l,3-oxazoline; 2,2'-bis(5,6-dihydro- 4H-l,3-oxazoline); N,N'-hexamethylenebis (carbamoyl-2-oxazoline; bis[5(4H)- oxazolone); bis(4H-3,lbenzoxazin-4-one); 2,2'-bis(H-3,l-benzozin-4-one). Poryfunctional acid anhydrides such as pyromellitic dianhydride, benzophenonetetracarboxylic acid dianhydride, cyclopentanetetracarboxylic dianhydride, diphenyl sulphone tetracarboxylic dianhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3- methyl-3-cyclohexene-l,2-dicarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)thioether dianhydride, bisphenol-A bisether dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 2,3,6,7- naphthalenetetracarboxylic acid dianhydride, bis(3,4-dicarboxyphenyl)sulphone dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 2,2',3,3 - biphenyltetracarboxylic acid, hydroquinone bisether dianhydride, 3,4,9, 10-perylene tetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 3,4- dicarboxy-l,2,3,4-tetrahydro-lnaphthalene-succinic acid dianhydride, bicyclo(2,2)oct-7- ene-2,3,5,6-tetracarboxylic acid dianhydride, tetrahydrofuran-2,3,4,5-tetracarboxylic acid dianhydride, 2,2-bis(3,4dicarboxyphenyl)propane dianhydride, 3,3',4,4'- biphenyltetracarboxylic acid dianhydride, 4,4'-oxydiphthalic dianhydride (ODPA), and ethylenediamine tetraacetic acid dianhydride (EDTAh).

It is also possible to use acid anhydride containing polymers or copolymers as the acid anhydride component.

Suitable polyfunctional acid anhydrides include pyromellitic dianhydride, 1,2,3,4- cyclopentanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and tetrahydrofuran-2,3,4,5-tetracarboxylic acid dianhydride. Most preferably the polyfunctional acid anhydride is pyromellitic dianhydride.

Polyacyllactams such as N,N'-terephthaloylbis(caprolactarn) and N₅N¹- terephthaloylbis(laurolactam) may also be employed.

The polymer composition resulting from the methods of the invention may also be subjected to a subsequent solid state condensation polymerisation process. This further processing step can assist with building the molecular weight of the modified aliphatic condensation polymer and can advantageously be conducted using conventional solid state condensation polymerisation techniques and equipment.

When performing the methods of the invention, it may be convenient to provide the ricinoleic acid lactone, optionally together with any other additives that are to be used, in the form of a composition that can be used for producing the modified aliphatic condensation polymer. This composition may be provided in the form of a physical blend of the respective components and/or in the form a melt mixed product.

The invention therefore also provides a composition for modifying an aliphatic condensation polymer, the composition comprising one or more carrier polymers and ricinoleic acid lactone, and/or a product formed by melt mixing a composition comprising one or more carrier polymers and ricinoleic acid lactone.

The carrier polymer may in fact be the aliphatic condensation polymer that is to be modified in accordance with the invention. In that case the composition may siniplistically be a physical blend of the ricinoleic acid lactone and the polymer, and the method of the invention is preformed by melt mixing that composition.

It may also be desirable to provide at least the ricinoleic acid lactone in the form of a masterbatch or concentrate which can be subsequently melt mixed with an aliphatic condensation polymer that is to be modified in accordance with the invention.

As used herein, the term "masterbatch" or "concentrate" (to be used synonymously herein) has the common meaning as would be understood by one skilled in the art. With particular reference to the present invention, these terms are therefore intended to mean a composition comprising the ricinoleic acid lactone and one or more carrier polymers, which composition is to be subsequently let down in an aliphatic condensation polymer in order to perform the methods of the invention.

The masterbatch may be formed by melt mixing the ricinoleic acid lactone with a carrier polymer that is considered appropriate under the circumstance to be melt mixed with the aliphatic condensation polymer that is to be modified. The carrier polymer may be an aliphatic condensation polymer, for example an aliphatic condensation polymer of the same type as the one that is to be modified.

Where the carrier polymer is an aliphatic condensation polymer, it will be appreciated that the process of making the masterbatch in effect employs the method of the invention. However, by qualifying the product a "masterbatch", it will also be appreciated that the intention is for the masterbatch to be employed in performing the methods of the invention. In other words, it is the intention that the masterbatch will comprise unreacted ricinoleic acid lactone that can be subsequently melt mixed with an aliphatic condensation polymer so as to perform the methods of the invention.

A masterbatch formed by melt mixing the ricinoleic acid lactone with an aliphatic condensation polymer may itself comprise aliphatic condensation polymer that has been modified in accordance with the invention. Melt mixing this modified aliphatic condensation polymer per se with further aliphatic condensation polymer (as will be the case when the masterbatch is melt mixed with an aliphatic condensation polymer) can itself result in the further aliphatic condensation polymer being modified as described herein (e.g. in the case of polyesters, through transesterification reactions).

Aliphatic condensation polymers that may be used as a carrier polymer in the compositions of the invention include those described herein.

Preparing a masterbatch by melt mixing the ricinoleic acid lactone with an aliphatic condensation polymer and then subsequently melt mixing the masterbatch with an aliphatic condensation polymer is believed to provide a more efficient and effective means of incorporating ricinoleic acid residue as part of the polymer backbone of the aliphatic condensation polymer.

Those skilled in the art will appreciate that the appropriate temperature at which a given polymer is to be melt mixed with the cyclic ester will vary depending on the type of polymer being employed. Generally, melt mixing of the cyclic ester and the aliphatic condensation polymers will be conducted at a temperature ranging from about 12O⁰C to about 240°C.

Provided that the properties of the aliphatic condensation polymer is modified in at least some way, there is no particular limitation on the amount of ricinoleic acid lactone that can be melt mixed with the aliphatic condensation polymer. However, the ricinoleic acid lactone will generally be used in an amount ranging from about 5 wt.% to about 35 wt.%, preferably 5 wt.% to about 20 wt.%, relative to the total mass of the ricinoleic acid lactone and the aliphatic condensation polymer.

Where the ricinoleic acid lactone is melt mixed with an aliphatic condensation polymer to prepare a masterbatch, the ricinoleic acid lactone will generally be used in an amount ranging from about 30 wt.% to about 80 wt.%, relative to total mass of the ricinoleic acid lactone and the one or more carrier polymers.

The ricinoleic acid lactones used in accordance with the methods of the invention can impart to the resulting modified aliphatic condensation polymers properties such as improved flexibility, an alteration in its hardness (either decreased through the presence of the "in-chain" and pendant chain features of the ricinoleic acid residue, or increased through crosslinking induced from reaction of the double bond presented by the ricinoleic acid residue), an alteration of its surface properties (e.g. due to the hydrophobicity provided by the ricinoleic acid residue), altered degradation rates (either decreased through the hydrophobic character provided by the ricinoleic acid residue, or increased through introduction via the double bond presented by the ricinoleic acid residue of hydroliticly liable groups to a relatively stable base condensation polymer), an alteration in its stiffness (either decreased through the presence of the ricinoleic acid residue, or increased through crosslinking induced from reaction of the double bond presented by the ricinoleic acid residue), and improved melt viscosity or melt strength resulting directly from the presence of the ricinoleic acid residue, or through long chain branching induced from reaction of the double bond presented by the ricinoleic acid residue and the base condensation polymer.

Using the methods of the invention, an aliphatic condensation polymer may be converted into a thermoset polymer via reaction of double bonds presented by the ricinoleic acid residue (e.g. oxidative crosslinking of a coating product produced from the modified polymer, or crosslinking reactions where the modified condensation polymer is included in the formulation of a thermoset resin such as an unsaturated polyester, vinyl ester resin, epoxy resin etc).

The stability (e.g. UV) or colourfastness of a modified aliphatic condensation polymer prepared in accordance with the invention may be improved by using the double bonds presented by the ricinoleic acid residues to tethering an appropriate moiety (e.g. a moiety such as stabilisers (hindered phenols and hindered amine like stabilisers), alkoxy amines, dyes, and bioactive materials).

The modified condensation polymers of the invention can be utilised in applications ranging from: films for packaging applications, injection moulded articles, blow moulded containers, sheet products, thermoformed items, coatings, adhesives, fibres, scaffolds for medical applications including tissue repair and drug delivery.

The present invention will hereinafter be further described with reference to the following non-limiting examples.

EXAMPLES

General

Proton NMR spectra were obtained on Bruker A V400 and Bruker A V200 spectrometer, operating at 400 MHz and 200 MHz. AU spectra were obtained at 23°C unless specified. Chemical shifts are reported in parts per million (ppm) on the δ scale and relative to the chloroform peak at 7.26 ppm (¹H) or the TMS peak at 0.00 ppm (¹H). Oven dried glassware was used in all reactions carried out under an inert atmosphere (either dry nitrogen or argon). All starting materials and reagents were obtained commercially unless otherwise stated. Removal of solvents "under reduced pressure" refers to the process of bulk solvent removal by rotary evaporation (low vacuum pump) followed by application of high vacuum pump (oil pump) for a minimum of 30 min. Analytical thin layer chromatography (TLC) was performed on plastic-backed Merck Kieselgel KGoOF₂₅₄ silica plates and visualised using short wave ultraviolet light, potassium permanganate or phosphomolybdate dip. Flash chromatography was performed using 230-400 mesh Merck Silica Gel 60 following established guidelines under positive pressure. Tetrahydrofuran and dichloromethane were obtained from a solvent dispensing system under an inert atmosphere. All other reagents and solvents were used as purchased.

Monomer Synthesis and Characterisation

Synthesis of macrolactones from ricinoleic acid (^"RALI

A dry 2000 ml three-neck, round bottom flask, equipped with a magnetic stirrer, condenser and dropping funnel with a nitrogen inlet (through a serum cap) was charged with 900 ml of ethanol free dry chloroform, 13.7 g of DCC, 12.2 g of DMAP, and 10.5 g of DMAP x HCl. The resulting solution was brought to reflux and a solution of 10 g of ricinoleic acid in 100 ml of ethanol- free dry chloroform was added dropwise for 5 h. After the addition was completed, the dropping funnel was removed, the reaction mixture was cooled to room temperature, and stirring was continued for an additional 1O h under nitrogen. Methanol (40 ml) and acetic acid (7.5 ml, 4.0 equiv.) were added to the reaction flask and stirring was continued for 30 min, at which time no DCC was detected by TLC analysis (10% EtOAc-hexane on silica gel plates). Further TLC analysis of the mixture of CH₂Cl₂-hexane (50:50), v/v) revealed the formation of the desired lactone. The reaction mixture was concentrated to 200 ml, diluted with 800 ml of diethyl ether, filtered and the solvent evaporated to dryness. The residue was dissolved in a minimal amount of hexane and applied to a 30 x 550 mm chromatography column (150 g) (1:15 lactone - silica) a silica gel (230 - 400 mesh) slurry packed in hexane. Elution was started with hexane, then dichloromethane was gradually added and final elution was performed with a mixture of CH₂Cl₂-hexane (50:50), v/v). 3.8 1 of eluent was collected and evaporated to dryness under reduced pressure giving the ricinoleic acid lactone mixture (7.5 g).

¹H-NMR (CDCl₃, 400 MHz): δ[ppm] = 0.88 (tr, 3H, J = 7.3 Hz), 1.09 - 1.42 (m, 16H), 1.47 - 1.68 (m, 4H), 1,92 - 2.11 (m, 2H), 2.19 - 2.36 (m, 4H)₃ 4.88 (quint, IH, J = 6.2 Hz), 5.28 - 5.38 (m, IH), 5.41 - 5.51 (m, IH)

Polymers Used for Melt Mixing

The following polymers were used to produce the examples for melt mixing with the lactones:

PLA = Polylactic acid - Natureworks 305 ID, supplied by Cargill, USA Nylon 11 = Rilsan BESNO TL (Check?), supplied by Arkema, France

PBAS =Polybutylene co adipic / succinic acid - Bionolle, supplied by Showa Denko Japan.

Catalyst

Tin (II) 2 Ethyl Hexanoate, supplied by Sigma Aldrich Dibutyl tin di-laurate (DBTDL), supplied by Sigma Aldrich

Methods for Melt Mixing

(A) Twin Screw Extruder - Liquid injection of Lactone. [EL]

Melt mixing reactions were carried out in a Thermo Prism 16mm twin screw extruder fitted with segmented screws and individually heated barrel segments (see Scheme 3) Prism 16mm

Co -Rotating Screw

Vent Vent Vent Vent Port Liquid p, Port Port Port (Sealed) Fθθds H (Sealed) (Sealed) (Sealed)

C2 C3 C4 C 5 CB C7 C3 C9 C 1 Q Melt 15 ⁰C 15 °c 14O⁰C 19O⁰C 190 ⁰C 185⁰C 185⁰C 180⁰C 18O⁰C PlIlIlI)

S M\ \l\ ^ \l\ \l\ \l\ \l\ \l\ \N \l\ \l\ \K \K M-TUUWl/K \l\ M\ \l\ \l\ \l\ MKM \l\ \K \l\ M\ \l HHJlll\ \l\ \l\ \l\ \l\ \l\ \l\ \I\\W

Scheme 3: Schematic setup of the Prism twin screw extruder use to melt modify the polymers with the lactone.

The lactone monomer was dried under vacuum at 80C with stirring. The lactone was mixed with 0.1 wt% of the liquid catalyst and then charged into the 25mL SGE syringe which was fitted to a Harvard Syringe pump, operated at room temperature. The syringe pump was connected to the extruder via a polyolefm transfer line to dispense the lactone into the barrel of the twin screw extruder.

The gravimetric output of the Harvard syringe pump was calibrated at a number of relevant volumetric throughput rates prior to connecting to the extruder.

The polymer was dried in a small scale hopper drier using dry air at temperatures according to the manufacturer's recommendations. All samples were dried to < lOOppm water, as measured using an Arizona Instruments moisture analyser.

The dried polymer was fed to the extruder via a Barrell single screw volumetric feeder. The feeder and extruder hopper were flushed with dry air to prevent moisture ingress. The gravimetric output of the feeder and extruder were monitored by collecting samples before and after collecting samples.

The extruder was fitted with a lmm rod die and operated at a throughput of rate of approximately 25g/hour. The exact throughput rate was determined for each sample. The extruded samples which were subsequently melt pressed were collected in sample jars purged with dry nitrogen. Melt pressing was carried in an IHMS melt press ( 250 by 250mm plattern) fitted with brass plates through water could be passed to cool the sample after pressing. Samples were pressed between Teflon sheets. A 150 by 150 by 0.150 mm shim plate was used for the melt pressing.

Extruded strand samples were also collected for each composition.

(B) Melt mixing in round bottom flasks [RBF]

Polymers were dried using the same methodology as was used for the extrusion samples. The lactone samples were vacuum dried prior to use.

The 25ml round bottom flasks used for the experiments were cleaned, fitted with large magnetic spinbars and dried in an oven set at 80C. Upon removal from the oven the flasks were stoppered and allowed to cool. Upon opening the flasks to add the reagents, the flasks were flushed with dry nitrogen.

Approximately 5g of the selected polymer was added to each flask, the required amount of lactone and 3 drops of Tin (II) 2 Ethyl Hexanoate catalyst.

The flasks were then placed in a silicone oil bath on top of a magnetic stirrer hotplate. The oil temperature was controlled to the desired temperature ( 210C for PLA, 240C for Nylon 11) and monitored via a calibrated thermometer.

Samples were allowed to heat and stir for 20min. At the 5min, 10 and 15min points the tops were removed and the samples were stirred more vigorously with spatula while being gently flushed with dry nitrogen.

At the completion of the reaction the samples were stoppered and allowed to cool. For melt pressing samples were reheated in a vacuum oven, sub-samples were removed from the flasks and were melt pressed using the same procedure as was used for the extrusion samples.

(C) Melt mixing in round bottom flasks - method with overhead stirring [RBF-2]

The 100ml round bottom flasks used for the experiments were cleaned and dried in an oven set at 80C. Upon removal from the oven the flasks were stoppered and allowed to cool. Upon opening the flasks to add the reagents, the flasks were flushed with dry nitrogen. The flasks were then fitted with metal stirrers having two blades. The stirrers were connected to overhead drive motors. The stirrers were held in place by a glass adapter fitted with a Teflon bearing fitted with a rubber seal. The glass adaptor was also fitted with a water cooled Leibig condenser and a separate nitrogen inlet to prevent moisture ingress.

Approximately 2Og of the selected polymer was added to each flask, the required amount of lactone and 20 drops of DBTDL catalyst.

The flasks fitted with the adaptors, condensers and stirrers were then placed in a silicone oil bath on top of a magnetic stirrer hotplate. The oil temperature was controlled to the desired temperature ( 200C for PLA, 250C for Nylon 11) and monitored via a calibrated thermometer.

Samples were allowed to heat and stir for times up to 240min. The rate of stirring was set between 100 to 200 rpm. The exact rate adjusted to give good mixing to best provide the incorporation of the lactone modifier.

At the completion of the reaction the stirrers and condensers were removed and samples were poured from the flasks under a blanket of dry nitrogen. The samples were then allowed to cool. For melt pressing samples were reheated in a vacuum oven, sub-samples were removed for analysis from the flasks and were melt pressed using the same procedure as was used for the extrusion samples.

Characterisation of Polymers

Polymer samples were characterised by a number of techniques as described below.

NMR- Nuclear Magnetic Resonance

Proton NMR spectra were obtained on Bruker AV400 and Bruker AV200 spectrometer, operating at 400 MHz and 200 MHz. All spectra were obtained at 23⁰C unless specified. Chemical shifts are reported in parts per million (ppm) on the δ scale and relative to the chloroform peak at 7.26 ppm (¹H) or the TMS peak at 0.00 ppm (¹H).

Tensile Testing

Tensile testing was carried out using an mstron 5500R machine. Melt pressed film samples were cut into tensile bars ( Length = 31.5mm, Width= 4.2mm, Gauge length= 15mm) using a compression cutter. Samples were conditioned in a controlled temperature and humidity room for 48 hours prior to testing. Samples were tested according to ASTM 882 at a crosshead speed of 7.5mm/min.

Differential Scanning Calorimetry

The thermal behaviour of the samples was determined by differential scanning calorimetry ( DSC) using a Mettler Toloedo DSC 85 Ie DSC system. Samples were weighed into 40ul pans and lids were crimped onto the pans. A hole was then made in the lids with a 20 gauge needle to prevent pressurisation. All scans were carried out at a scanning rate of 10 degrees Celsius (C) per minute. Scan were typically as follows; (i) heating from 20 to either 180C ( polyesters) or 220C ( polyamides); (ii) then the pans were held at the elevated temperature for 3 minutes;(iii) then cooled at 10 C/min. to -20 C; (iv) samples were held at the sub-ambient temperature for 3 minutes and (v) then the samples were heated to the elevated temperature ( 180 or 220C) at a rate of 10 C/min. The transition temperatures, and enthalpies for crystallisation and melting were determined for each samples. The DSC was calibrated using an Indium standard.

Gel Permeation Chromatography

Molecular weights of polymers were characterized by gel permeation chromatography (GPC) performed in tetrahydrofuran (THF) 1.0 niL/min, 25°C using a Waters GPC instrument, with a Waters 2414 Refractive Index Detector, a series of four Polymer

Laboratories PLGeI columns (3 x5 μm Mixed-C and 1x3 μm Mixed-E), and Empower Pro

Software. The GPC was calibrated with narrow polydispersity polystyrene standards

(Polymer Laboratories EasiCal, MW from 264 to 256000), and molecular weights are reported as polystyrene equivalents.

Examples Prepared:

fastcat was used as catalyst # RA = mole% expressed as % ricinoleic acid compared to moles of monomer in the polymer being modified. ANALYSIS

NMR

MoI % of ricinoleic acid in sample = [1/3 integral ricinoleic CH₃]/[l/3 integral ricinoleic CH₃ + integral PLA-H]

Minimal mol % of ricinoleic acid incorporated into the polymer

= [integral PLA-ricinoleic acid H]/[integral PLA-ricinoleic acid H + integral PLA-H]

integration over H from PLA

TENSILE

DSC

# DSC data taken from first heat cycle of sample a - PLA and Nylon 11 controls are for samples which have been melt mixed under the same conditions. Times represent melt mixing times, b - Major peak in bold

GPC

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims

1. A method of preparing a polymer composition, the method comprising melt mixing an aliphatic condensation polymer with ricinoleic acid lactone.

2. The method according to claim 1, wherein the aliphatic condensation polymer is selected from polyesters, polyamides, copolymers thereof, and blends thereof.

3. The method according to claim 2, wherein the polyesters are poly(hydroxyalkanoates).

4. The method according to claim 3, wherein the poly(hydroxyalkanoates) are selected from homo- and copolymers of poly(3-hydroxybutyrate), poly(4- hydroxybutyrate), poly(3-hydroxyvalerate), poly(lactic acid), poly(3-hydroxypropanoate), poly(4-hydropcntanoate), poly(3-hydroxypentanoate), poly(3-hydroxyhexanoate), poly(3- hydroxyheptanoate), poly(3-hydroxyoctanoate), polydioxanone, polycaprolactone, polyglycolic acid, and blends thereof.

5. The method according to claim 2, wherein the polyesters are a reaction product of one or more alkyldiols with one or more alkyldicarboxylic acids or their acyl derivatives.

6. The method according to claim 5, wherein the polyesters are a reaction product of (a) one or more alkyldicarboxylic acids selected from succinic acid, adipic acid, 1,12 dicarboxydodecane, fumaric acid, and maleic acid, and (b) one of more alkyldiols selected from ethylene glycol, polyethylene glycol, 1,2-propane diol, 1,3-propanediol, 1,2- propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and polypropylene glycol.

7. The method according to claim 6, wherein the polyesters are selected from polybutylenesuccinate homopolymer, polybutylene adipate homopolmer, polybutyleneadipate-succinate copolymer, polyethylenesuccinate-adipate copolymer, polyethylene adipate homopolymer, and blends thereof.

8. The method according to claim 2, wherein the polyamides are a reaction product of one or more alkyldiamines with one or more alkyldicarboxylic acids.

9. The method according to claim 8, wherein the polyamides are selected from poly(tetramethylene adipamide) (nylon 4,6), poly(hexamethylene adipamide) (nylon 6,6), poly(hexamethylene azelamide) (nylon 6,9), poly(hexamethylene sebacamide) (nylon 6,10), poly(heptamethylene pimelamide) (nylon 7,7), poly(octamethylene suberamide) (nylon 8,8), poly(nonamethylene azelamide) (nylon 9,9), and poly(decamethylene azelamide) (nylon 10,9).

10. The method according to claim 2, wherein the polyamides are a polymerised product of one or more alkylamino acids and/or lactam derivative thereof.

11. The method according to claim 10, wherein the polyamides are selected from poly(4-aminobutyric acid) (nylon 4), poly(6-aminohexanoic acid) (nylon 6), poly(7-amino- heptanoic acid) (nylon 7), poly(8-aminoocatanoic acid) (nylon 8), poly(9-aminononanoic acid) (nylon 9), poly(10-aminodecanoic acid) (nylon 10), poly(l l-aminoundecanoic acid) (nylon 11), poly(12-aminododecanoic acid) (nylon 12), and blends thereof.

12. The method according to any one of claims 1 to 11, wherein the ricinoleic acid lactone comprises one or more of monolactone, dilactone, trilactone, tetralactone, pentalactone, or hexalactone of ricinoleic acid.

13. The method according to any one of claims 1 to 12, wherein about 5.wt% to about 35 wt. % of the ricinoleic acid lactone is melt mixed with the aliphatic condensation polymer, relative to the total mass of the ricinoleic acid lactone and the aliphatic condensation polymer.

14. The method according to any one of claims 1 to 12, wherein the ricinoleic acid lactone is provided in the form of a composition comprising one or more carrier polymers and the ricinoleic acid lactone and/or a product formed by melt mixing a composition comprising one or more carrier polymers and the ricinoleic acid lactone.

15. The method according to claim 14, wherein the ricinoleic acid lactone composition is prepared by melt mixing a composition comprising the ricinoleic acid lactone and the one or more carrier polymers.

16. The method according to claim 14 or 15, wherein the one or more carrier polymers is an aliphatic condensation polymer of the same type as the aliphatic condensation polymer used in claim 1.

17. The method according to claim 16, wherein about 3O.wt% to about 80 wt. % of the ricinoleic acid lactone is melt mixed with the aliphatic condensation polymer, relative to the total mass of the ricinoleic acid lactone and the aliphatic condensation polymer in the ricinoleic acid lactone composition.

18. A polymer composition prepared by a method according to any one of claims 1 to 17.

19. A polymer composition for modifying an aliphatic condensation polymer, the composition comprising one or more carrier polymers and ricinoleic acid lactone, and/or a product formed by melt mixing a composition comprising one or more carrier polymers and ricinoleic acid lactone.

20. The polymer composition according to claim 19, wherein the one or more carrier polymers is an aliphatic condensation polymer.

21. The polymer composition according to claim 19 or 20, wherein the aliphatic condensation polymer is selected from polyesters, polyamides, copolymers thereof, and blends thereof.

22. The polymer composition according to any one of claims 19 to 21, wherein the ricinoleic acid lactone comprises one or more of monolactone, dilactone, trilactone, tetralactone, pentalactone, or hexalactone of ricinoleic acid.

23. A polymer composition comprising an aliphatic condensation polymer and ricinoleic acid lactone, and/or a product formed by melt mixing a composition comprising an aliphatic condensation polymer and ricinoleic acid lactone.