WO2018127379A1

WO2018127379A1 - Lactams from renewable resources and polyamides derived thereof

Info

Publication number: WO2018127379A1
Application number: PCT/EP2017/082909
Authority: WO
Inventors: Gururajan Padmanaban; Clément P. R. RAVET; Mangaleswaran SIVAPRAKASAM
Original assignee: Rhodia Operations
Priority date: 2017-01-09
Filing date: 2017-12-14
Publication date: 2018-07-12

Abstract

The present invention relates to alkylated lactams and their preparation method, notably from renewable resources. It also relates to the use thereof for producing polymers.

Description

LACTAMS FROM RENEWABLE RESOURCES AND POLYAMIDES

DERIVED THEREOF

This application claims priority to IN provisional application No. IN201721000934 filed on 09 Jan, 2017, the whole content of this application being incorporated herein by reference for all purposes.

BACKGROUND ART

Caprolactam is an important raw material for producing one form of polyamide, usually referred to as nylon-6. Caprolactam is ordinarily prepared from cyclohexanone-oxime by the Beckmann rearrangement. The process is effective and is used on an enormous commercial scale. However, the cost is quite high and so there remains a demand for a more economical process. More particularly, the desirability of manufacturing these important caprolactam materials, from renewable resources is increasing. One such renewable starting material is bio mass. It has been reported by Frost that biomass can be converted to a-amino-£-caprolactam by a combination of fermentation and chemical process (see U.S. Patent Publication NO. 2007/149777). This molecule has an extra amino group, in addition to the -NH- CO- group. However, all carbon atoms derived from biomass does not convert to monomers and polymers.

Thus it is an objective of the present invention by which renewable resources are used to obtain industrially useful lactam monomers and polymers, such as polyamides.

SUMMARY OF INVENTION

The present invention relates to alkylated lactams and their preparation method, notably from renewable resources. It also relates to the use thereof for producing polymers with all the carbon atoms derived from the renewable resource.

The present invention hereby provides novel lactam (L) monomers and polymers that may be prepared from cardanol, a renewable resource obtained from cashew nut shell liquid (CNSL). The present invention relates to a lactam (L) of formula (I) as follows:

wherein R represents C13-C24 aliphatic or oxyaliphatic moiety which is attached to any carbon atom of the ring except the carbonyl carbon atom and n is an integer of from 1 to 4.

The present invention also relates to a polymer comprising at least repeat units of formula (III) as follows:

wherein R represents C13-C24 aliphatic or oxyaliphatic moiety and n is an integer of from 1 to 4.The invention also concerns a process for producing a polymer comprising the ring-opening polymerisation of at least one lactam (L) as previously described with at least one catalyst and at least one initiator.

The invention also concerns an article or a part of an article comprising the polymer of the invention as well as a composition comprising at least a lactam (L) and a lactam (L') other than the lactam (L).

The present invention thus provides new lactams having an alkylated chain, their preparation with good yield. They may be prepared from cashew nut shell liquid, a non-edible by-product of the cashew nut industry, which means this compound is based on a renewable resource. These new lactams resulting from the Beckmann rearrangement have been used as monomer for the ring-opening polymerisation to produce polymers. The present invention thus provides polymers having specific properties such as internal plasticization, low water uptake, higher impact modulus and 100% bio- sourced. The presence of long alkyl chain lateral to the polymer chain would help impart a certain degree of disorder to the way the polymer chains pack in the solid state and help reduce the processing temperature.

The polymers of the present invention have decreased melting temperature and crystallization temperature. Incorporation of a C13-C24 alkyl or oxyalkyl chain, especially a n-pentadecyl chain, in the backbone of the polymer has influence on the thermic properties. Furthermore, long alkyl chain hinders the organization of the amide group, decreasing the crystallinity of the polymer. Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.

These and other features, aspects and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

DETAILED DESCRIPTION

Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively and any and all combinations of any or more of such steps or features.

Definitions

For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are collected here. These definitions should be read in the light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below.

The articles "a", "an" and "the" are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

The term "and/or" includes the meanings "and", "or" and also all the other possible combinations of the elements connected to this term.

The terms "comprise" and "comprising" are used in the inclusive, open sense, meaning that additional elements may be included. Throughout this specification, 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 element or step or group of element or steps but not the exclusion of any other element or step or group of element or steps.

The term "including" is used to mean "including but not limited to". "Including" and "including but not limited to" are used interchangeably.

The term "between" should be understood as being inclusive of the limits. The term "aliphatic" refers to nonaromatic hydrocarbon compounds or moieties in which the constituent carbon atoms can be straight-chain, branched chain, or cyclic, as in alicyclic compounds; saturated, as in the paraffins; or unsaturated, as in the olefins and alkynes.

As used herein, "alkyl" groups include saturated hydrocarbons having one or more carbon atoms, including straight-chain alkyl groups, such as methyl, ethyl, propyl, butyl etc, especially with C13-C24 carbon atoms; branched-chain alkyl groups, such as isopropyl, tert-butyl, sec-butyl, isobutyl etc, especially with C₁₃- C24 carbon atoms; cyclic alkyl groups (or "cycloalkyl" or "alicyclic" or "carbocyclic" groups), such as cyclopropyl, cyclopentyl, cyclohexyl etc, especially with C13-C24 carbon atoms. As used herein, "alkenyl" or "alkenyl group" refers to an aliphatic hydrocarbon radical which can be straight or branched, containing at least one carbon-carbon double bond. Examples of alkenyl groups include, but are not limited to, ethenyl, propenyl, n-butenyl, i-butenyl, 3-methylbut-2-enyl, n-pentenyl, heptenyl, octenyl, decenyl etc, especially with Ci₃-C₂4 carbon atoms.

The term "alkyne" refers to straight or branched chain hydrocarbon groups having at least one triple carbon to carbon bond, especially with Ci₃-C₂4 carbon atoms. The term "oxyaliphatic" refers to an aliphatic group interrupted by one or more ether linkage(s).

The term "aromatic diacid" is intended to denote a dicarboxylic acid, or a derivative thereof, comprising one or more than one aromatic group. Derivatives of said aromatic diacid are notably acid halogenides, especially chlorides, acid anhydrides, acid salts, acid amides and the like. The herein used expression "derivative thereof when used in combination with the expressions "acid", "diacid", "amine" or "diamies" is intended to denote whatever derivative thereof which is susceptible of reacting in poly condensation conditions to yield an amide bond.

The term "cycloaliphatic diamine" is intended to denote a compound comprising two amino moieties and at least one cycloaliphatic group or a derivative thereof. As used herein, the terminology "(C_n-C_m)" in reference to an organic group, wherein n and m are each integers, indicates that the group may contain from n carbon atoms to m carbon atoms per group.

Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a temperature range of about 120°C to about 150°C should be interpreted to include not only the explicitly recited limits of about 120°C to about 150°C, but also to include sub-ranges, such as 125°C to 145°C, 130°C to 150°C, and so forth, as well as individual amounts, including fractional amounts, within the specified ranges, such as 122.2°C, 140.6°C, and 141.3°C, for example. As used herein, the term "cyclic amide" denotes a cyclic molecule having at least one ring in its molecular structure containing at least one identifiable amide functional repeat unit. The amide functional unit is typically— NH— C(O)— but N-substitution is also possible, with, for example, a C_1-12 alkyl group. Figures

Figure 1 corresponds to DSC curves for 10% copolyamide 6 obtained in example 2. X-axis corresponds to temperature (°C). Y-axis corresponds to heat flow (W/g). Tc = 181.94°C. Tm=213.18°C.

Figure 2 corresponds to DSC curves for 20% copolyamide 6 obtained in example 2. X-axis corresponds to temperature (°C). Y-axis corresponds to heat flow (W/g). Tc = 177.12°C. Tm=212.82°C.

Figure 3 corresponds to DSC curves for 50%> copolyamide 6 obtained in example 2. X-axis corresponds to temperature (°C). Y-axis corresponds to heat flow (W/g). Tc = 126.09°C. Tm=177.94°C.

Lactam (L)

As discussed above, caprolactam is ordinarily prepared from cyclohexanone- oxime by the Beckmann rearrangement. The process is effective and is used on an enormous commercial scale. However, the cost is quite high and so there remains a demand for a more economical process. Thus, the present invention provides a process to produce alkylated lactams from renewable resources, especially from cashew nut shell liquid (CNSL), and further to produce polymers thereof. The present invention relates then to the lactam (L) of formula (I) as follows:

(I) wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety which is attached to any carbon atom of the ring except the carbonyl carbon atom and n is an integer of from 1 to 4, notably 1, 2, 3, or 4.

Preferably R is a C₁₃-C₁₇ aliphatic or oxyaliphatic moiety which is attached to any carbon atom of the ring except the carbonyl carbon atom. More preferably R is a Ci3, Ci4, Ci5, C₁₆, and/or C₁₇, preferably a C₁₅ aliphatic or oxyaliphatic moiety which is attached to any carbon atom of the ring except the carbonyl carbon atom. Preferably R is an aliphatic moiety in which the constituent carbon atoms can be straight-chain, branched chain, or cyclic chain. More preferably R is a straight- chain or branched-chain moiety. Most preferentially R is a straight-chain moiety.

The lactam (L) may also be represented by formula (la) as follows:

wherein, R is a C13-C24 aliphatic or oxyaliphatic moiety which is attached to any carbon atom of the ring except the carbonyl carbon atom.

The lactam (L) may also be represented by formula (lb) as follows:

O

C NH

R (lb)

The lactam (L) may also be represented by formula (Ic) as follows:

The lactam (L) may also be represented by formula (Id) as follows:

(Id) wherein, R is a C₁₃-C24 aliphatic or oxyaliphatic moiety which is attached to any carbon atom of the ring except the carbonyl carbon atom.

The lactam (L) may also be represented by the formula (Ie) as follows:

\ NH

C15H31 (Ie)

It is also perfectly possible to use a

The lactam (L) is preferably chosen in the group constituted by 3-n-(Ci₃-C₂4 alkyl)azepan-2-one, 4-n-(Ci₃-C₂4 alkyl)azepan-2-one, 5-n-(Ci₃-C₂4 alkyl)azepan- 2-one, 6-n-(Ci3-C₂4 alkyl)azepan-2-one and 7-n-(Ci3-C₂4 alkyl)azepan-2-one and mixtures thereof. More preferably the lactam (L) is a mixture of 4-n-(Ci₃-C₂4 alkyl)azepan-2-one and 6-n-(Ci₃-C₂4 alkyl)azepan-2-one.

The lactam (L) is preferably chosen in the group constituted by 3-n- pentadecylazepan-2-one, 4-n-pentadecylazepan-2-one, 5-n- pentadecylazepan-2- one, 6-n- pentadecylazepan-2-one and 7-n- pentadecylazepan-2-one and mixtures thereof. More preferably the lactam (L) is chosen from 4-n-pentadecylazepan-2- one, 6-n- pentadecylazepan-2-one or mixtures thereof. Still more preferably the lactam (L) is a mixture of 4-n-pentadecylazepan-2-one and 6-n- pentadecylazepan-2-one. Preparation of lactam

The present invention also relates to a process for the preparation of a comprising reacting at least:

- an oxime of formula (II) as follows:

wherein R represents C13-C24 aliphatic or oxyaliphatic moiety and n is an integer of from 1 to 4, and

- an acid. Preferably R is a C13-C17 aliphatic or oxyaliphatic moiety. More preferably R is a Ci3, CM, Ci5, Ci6, and/or C₁₇, preferably a C15 aliphatic or oxyaliphatic moiety. Preferably R is an aliphatic moiety in which the constituent carbon atoms can be straight-chain, branched chain, or cyclic chain. More preferably R is a straight- chain or branched-chain moiety. Most preferentially R is a straight-chain moiety.

The acid may be chosen in the group constituted by mineral acids, beckmann mixture, organic acids, solid acid catalyst, super acids and mixtures thereof.

The acid may be chosen in the group constituted by mineral acids, such as sulfuric acid or nitric acid; organic acids, such as acetic acid; Beckmann mixture, such as acetic acid, hydrogen chloride and acetic anhydride; super acids, such as trifluoroacetic acid or poly(tetrafluoroethylene-co-perfluoro-3,6-dioxa-4-methyl- 7-octensulfonic acid); solid acid catalysts such as poly(styrene-co-4- styrenesulfonic acid); poly (tetrafluoroethylene-co-perfluoro- (fluorosulfonylethoxy) vinyl ether) and mixtures thereof. Preferably, the acid is sulfuric acid.

Preferably the amount of acid is from 0.05 to 5 mole%, with respect to the oxime.

The preparation of lactam may take place at a temperature from 25°C to 150°C, preferably from 50°C to 100°C, more preferably from 70°C to 90°C notably at a temperature of 80°C.

Lactam (L) may be for instance prepared as follows

wherein R represents C13-C24 aliphatic or oxyaliphatic moiety and n is an integer of from 1 to 4, notably 1, 2, 3, or 4.

Lactam (L) may also be prepared as follows:

wherein R represents C13-C24 aliphatic or oxyaliphatic moiety.

A specific lactam may be prepared as follows:

3-pentadecylcyclohexanone 4/ 6-n-pentadecylazepan-2-one

The present invention also relates to preparing the oxime of formula (II) from a renewable resource. The oxime may be prepared from cashew nut shell liquid (CNSL). Cashew nut shell liquid (CNSL) is an agricultural by-product abundantly available (4,450,000 tons worldwide) and non-competitive with food supply chain. Extracted from the shell of cashew nut produced by Anarcardium occidentale L., CNSL constitutes 18-27% of the total raw nut weight. Natural CNSL contains mainly anacardic acid which will be decarboxylated during the roasting process and technical grade CNSL contains mainly cardanol, cardol and 2-methylcardol.

Anacardic acid Cardanol Cardol 2-methyl

Cardol

All the carbon atoms in the oxime and subsequently in the capro lactam may be derived from the bio-based cardanol.

Production of polymer

The present invention also relates to the process for producing a polymer comprising the ring-opening polymerisation of at least one lactam (L) with at least one catalyst and at least one initiator, and optionally at least one monomer different from lactam (L).

The catalyst may be chosen in the group constituted by tin(octoate)2, tin isopropoxide, tin octanoate, tin chloride, tin oxide, zinc oxide and their binary catalysts; heterogenous catalysts such as montmorillanite catalyst, alkali metals, metal hydridres, metal amides and mixtures thereof. Preferably the catalyst is tin(octoate)2.

Preferably the amount of catalyst used is from 0.05wt% to 10wt%, more preferably from 0.05wt% to 5wt%, with respect to the weight of all the monomers used in the polymerization.

The initiator may be chosen in the group constituted by aliphatic amines comprising from Ci-Ci₆ atoms such as n-octyl amine, benzylamine, guanidine bases, PPG terminated amines (Jeffamine) and their mixtures thereof. Preferably the initiator is n-octyl amine.

Preferably the amount of initiator used is from 0.1 to 75wt%, more preferably from 0.5 to 10wt%, with respect to the weight of all the monomers used in the polymerization.

The polymers of the invention are generally prepared by a process comprising the ring opening polymerisation of the lactam (L). Examples of the ring opening polymerisation techniques include hydrolytic polymerisation (i.e., hydrolytic polycondensation polymerisation) and anionic ring-opening polymerisation. Hydrolytic polymerisation is most commonly used for the preparation of polyamides from lactams. Anionic ring opening polymerisation of a lactam to form a polyamide is particularly useful in the preparation of reaction injection molding (i.e., RIM) polyamides due to the short time required for the reaction, which makes it possible for the lactam to be polymerised in the mold.

Synthesis of the polymer may occur in solution in a solvent of the polyamide, preferably dimethylacetamide or l,3-dimethyl-2-imidazolidinone. The synthesis is advantageously carried out by a stage of dissolution in the solvent at a temperature from 50° C to 100° C, preferably from 20° C to 25° C followed by a stage of heating the solution comprising the monomer at a temperature ranging from 25° C to 250° C, preferably from 50° C to 200° C, and a stage of recovery of the polyamide formed by precipitation from a non-solvent such as toluene or xylene, or evaporation of the solvent.

It is also possible to produce the polymer in aqueous solution of the monomers. The polymer is obtained by heating, at high temperature and high pressure, an aqueous solution of the monomers or a liquid comprising the monomers, in order to evaporate the water and/or the liquid while preventing the formation of a solid phase.

The polymerisation medium can also comprise additives, such as antifoaming agents, chain limiters (ie. monofunctional molecules capable of reacting with the acid and/or amine functional groups), branching agents (i.e., molecules having at least three functional groups, capable of reacting with the amine and/or acid functional groups, chosen from carboxylic acid and amine groups), catalysts, stabilizers (such as UV, heat or light), mattifying agents (such as Ti0₂, and the like), lubricants or pigments.

The polymerisation reaction is generally carried out at a pressure of approximately 0.2-5 MPa, preferably 0.5-2.5 MPa, and at a temperature of approximately 100-330°C, preferably 180-300°C. The polymerisation is generally continued in the melt phase at atmospheric or reduced pressure so as to achieve the desired degree of progression.

The polymerisation product may be a molten polymer or prepolymer. At this stage, the reaction medium may comprise a vapour phase composed essentially of vapour of the elimination product, in particular water, which may have been formed and/or vaporized.

Molten polymer or prepolymer as formed above can be subjected to stages of separation of vapour phase and of finishing in order to achieve desired degree of polymerisation. The separation of the vapour phase can, for example, be carried out in a device of cyclone type for a continuous process. Such devices are known. The finishing, if any, may consists in maintaining the polymerisation product in the molten state, at a pressure in the region of atmospheric pressure or under reduced pressure, for a time sufficient to achieve the desired degree of progression. Such an operation is known to a person skilled in the art. The temperature of the finishing stage is advantageously greater than or equal to 180°C and in all cases greater than the solidification temperature of the polymer. The residence time in the finishing device is preferably greater than or equal to 5 minutes. The polymerisation product can be washed, in order to extract the oligomers and residual monomers, according to processes known for the washing of polyamide 6 (extraction in liquid phase into water or in gas phase).

The polymerisation product can also be subjected to a post-condensation stage in solid or liquid phase. This stage is known to a person skilled in the art and makes it possible to increase the degree of polymerisation to a desired value.

The polymer obtained by the process of the invention in molten form can thus be formed directly or can be extruded and granulated, for an optional post- condensation stage and/or for subsequent forming after melting.

Polymer

The polymer of the present invention may be a homopolymer or a copolymer. When a polymer is made by linking only one type of small molecule, or monomer, together, it is called a homopolymer. When two different types of monomers are joined in the same polymer chain, the polymer is called a copolymer. Copolymers may be for instance alternating copolymers, periodic copolymers, statistical copolymers or block copolymers. The polymer of the present invention may be then a polymer obtained by polymerization of at least one lactam (L) with at least one catalyst and at least one initiator, and optionally at least one monomer different from lactam (L). Said polymer may then comprise at least a repeat unit derived from at least one lactam (L) and optionally at least one repeat unit derived from a monomer different from lactam (L).

The polymer may notably be a polymer comprising at least the repeat units of formula (III) as follows:

wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety and n is an integer of from 1 to 4, notably 1, 2, 3 or 4. Preferably R is a C₁₃, C₁₄, C₁₅, C₁₆, and/or C₁₇, preferably a C₁₅ aliphatic or oxyaliphatic moiety. Preferably R is an aliphatic moiety in which the constituent carbon atoms can be straight-chain, branched chain, or cyclic chain. More preferably R is a straight-chain or branched-chain moiety. Most preferentially R is a straight-chain moiety.

Preferably the amount of repeat units of formula (III) is from 0.1 to 100wt%, more preferably from 10 to 90wt%, more specifically from 10 to 50wt%, with respect to the weight of all the monomers.

It may be for instance comprised from 1 to 100wt%, preferably from 10 to 100 wt%, more preferably from 20 to 100wt%, more specifically from 50 to 100wt%.

It may be also for instance from 1 to 70wt%, preferably from 5 to 50wt%, more preferably from 5 to 30wt%, more specifically from 10 to 20wt%.

The amount of repeat units of formula (III) may be notably 0.1 , 1 , 5, 7, 10, 13, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100wt%, with respect to the weight of all the monomers, or any range comprised between these values.

The polymer may also comprise the repeat units of formula (Ilia), (Illb), (IIIc), (Did) and/or (Tile).

The polymer may notably be a polymer comprising at least the repeat units formula (Ilia) as follows:

(Ilia) wherein, R represents Ci₃-C₂₄ aliphatic or oxyaliphatic moiety.

The polymer may notably be polymer comprising at least the repeat units of formula (Illb) as follows:

(Illb) wherein, R represents Ci₃-C₂₄ aliphatic or oxyaliphatic moiety. The polymer may also be a polymer comprising at least the repeat units of formula (IIIc) as follows:

wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety.

The polymer may also be a polymer comprising at least the repeat units of formula (Hid) as follows:

wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety.

The polymer may also be a polymer comprising at least the repeat units of formula (Hie) as follows:

Preferably the amount of repeat units of formula (Ilia), (Illb), (IIIc), (Hid) or (Hie) is from 0.1 to 100wt%, more preferably from 10 to 90wt%, more specifically from 10 to 50wt%, with respect to the weight of all the monomers.

The polymer of the present invention may be then a homopolymer comprising the repeat units as previously mentioned, such as notably the repeat units of formula (III), (Ilia), (Illb), (IIIc), (Hid) or (Hie). The polymer of the present invention may be also a copolymer comprising the repeat units as previously mentioned, such as notably the repeat units of formula (III), (Ilia), (Illb), (IIIc), (Hid) and/or (Hie), optionally with at least one repeat unit derived from a monomer different from lactam (L). Preferably the polymer of the present invention is a copolymer comprising the repeat units as previously mentioned, such as notably the repeat units of formula (III), (Ilia), (Illb), (IIIc), (Hid) or (Ille), with at least one repeat unit derived from a monomer different from lactam (L).

The present invention also relates to a copolymer obtained by polymerisation of lactam (L) with lactam (L') other than the lactam (L).

The present invention also relates to a composition comprising at least a lactam (L) and at least one monomer different from lactam (L), notably a lactam (L'). The polymer comprising the repeat units of formula (Ilia), (Illb), (IIIc), (Hid) and/or (Ille) may further comprise repeat units derived from lactam (L').

Preferably the weight ratio of lactam (L) to lactam (L') is from 0.1 to 99.9%, more preferably from 2 to 98%, more specifically from 5 to 75%.

The lactam (L') may be chosen in the group constituted by capro lactam, 2- pyrrolidone, 2-piperidinone, 2-azetidinone and mixtures thereof. Preferably lactam (L') is caprolactam. The present invention also relates to a copolymer obtained by polymerization of lactam (L) with at least one diacid and at least one diamine.

Equimolar quantities of at least one diacid and one diamine may be chosen, such that the total number of moles of diacid and diamine functionalities remain the same. Total mole range of diacid and diamine is from 0.1 to 99.95% of the total number of moles of all the acid and amine functionalities in the reaction mass.

The diacid is preferably chosen in the group constituted by aliphatic diacids, aromatic diacids, acyclic aliphatic diacids and mixtures thereof. The aliphatic diacids may be chosen in the group constituted by oxalic acid (HOOC-COOH), malonic acid (HOOC-CH₂-COOH), succinic acid (HOOC-(CH₂)₂-COOH), glutaric acid (HOOC-(CH₂)₃-COOH), 2,2-dimethyl-glutaric acid [HOOC- C(CH₃)₂-(CH₂)₂-COOH], adipic acid [HOOC-(CH₂)₄-COOH], 2,4,4-trimethyl- adipic acid [HOOC-CH(CH₃)-CH₂-C(CH₃)₂-CH2-COOH], pimelic acid [HOOC- (CH₂)₅-COOH], suberic acid [HOOC-(CH₂)₆-COOH], azelaic acid [HOOC- (CH₂)₇-COOH], 1 ,4-norbornane dicarboxylic acid, 1,3-adamantane dicarboxylic acid, cis and/or trans cyclohexane-l,4-dicarboxylic acid and cis and/or trans cyclohexane-l,3-dicarboxylic acid and mixtures thereof. The aromatic diacids may be chosen in the group constituted by phthalic acids, including isophthalic acid (IA), 5-tert-butyl isophthalic acid, terephthalic acid (TA) and orthophthalic acid (OA), naphtalenedicarboxylic acids (including 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 1 ,4-naphthalene dicarboxylic acid, 2,3- naphthalene dicarboxylic acid, 1,8 -naphthalene dicarboxylic acid and 1,2- naphthalene dicarboxylic acid), 2,5-pyridinedicarboxylic acid, 2,4- pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, 2,2-bis(4- carboxyphenyl)propane, bis(4-carboxyphenyl)methane, 2,2-bis(4- carboxyphenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)ketone, 4,4'-bis(4- carboxyphenyl)sulfone, 2,2-bis(3-carboxyphenyl)propane, bis(3- carboxyphenyl)methane, 2,2-bis(3-carboxyphenyl)hexafluoropropane, 2,2-bis(3- carboxyphenyl)ketone, bis(3-carboxyphenoxy)benzene and mixtures thereof.

[0066] The acyclic aliphatic diacids may be chosen in the group constituted by sebacic acid [HOOC-(CH₂)₈-COOH], undecandioic acid [HOOC-(CH₂)₉- COOH], dodecandioic acid [HOOC-(CH₂)i₀-COOH], tridecandioic acid [HOOC-(CH₂)ii-COOH], tetradecandioic acid [HOOC-(CH₂)i₂-COOH], pentadecandioic acid [HOOC-(CH₂)i₃-COOH] and hexadecandioic acid [HOOC- (CH₂)i4-COOH] and mixtures thereof.

The diamine may be chosen in the group constituted by aliphatic diamines, aromatic diamines, cycloaliphatic diamines, acyclic aliphatic diamines and mixtures thereof. The aliphatic diamines may be chosen in the group constituted by 1 ,2-diaminoethane, 1,2-diaminopropane, propylene- 1,3-diamine, 1,3- diamino butane, 1 ,4-diamino butane, 1,5-diaminopentane, 1 ,4-diamino- 1,1- dimethylbutane, 1 ,4-diamino- 1 -ethylbutane, 1 ,4-diamino- 1 ,2-dimethylbutane,

1.4- diamino- 1 ,3-dimethylbutane, 1 ,4-diamino- 1 ,4-dimethylbutane, 1 ,4-diamino- 2,3-dimethylbutane, 1,2-diamino-l-butylethane, 1,6-diaminohexane, 1,7- diamino heptane, 1,8-diamino-octane, l,6-diamino-2,5-dimethylhexane, 1,6- diamino-2,4-dimethylhexane, l,6-diamino-3,3-dimethylhexane, l,6-diamino-2,2- dimethylhexane, 1,9-diaminononane, 2-methylpentamethylenediamine, 1,6- diamino-2,2,4-trimethylhexane, 1 ,6-diamino-2,4,4-trimethylhexane, 1 ,7- diamino-2,3-dimethylheptane, 1 ,7-diamino-2,4-dimethylheptane, 1 ,7-diamino-

2.5- dimethylheptane, l,7-diamino-2,2-dimethylheptane and bis(3-methyl- 4aminocyclohexyl)-methane and mixtures thereof. The aromatic diamines may be chosen in the group constituted by meta-phenylene diamine, p-phenylene diamine (PPD), 3,4'-diaminodiphenyl ether (3,4'-ODA), 4,4'-diaminodiphenyl ether (4,4'-ODA), meta-xylylene diamine and para-xylylene diamine and mixtures thereof. The cycloaliphatic diamines may be chosen in the group constituted by 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,3- bis(aminomethyl)cyclohexane (BAC), l,4-bis(aminomethyl)cyclohexane, and isophorononediamine (IPDA) and mixtures thereof. The acyclic aliphatic diamines may be chosen in the group constituted by 1,10-diaminodecane, 1,8- diamino- 1 ,3-dimethyloctane, 1 ,8-diamino- 1 ,4-dimethyloctane, 1 ,8-diamino-2,4- dimethyloctane, l,8-diamino-3,4-dimethyloctane, l,8-diamino-4,5- dimethyloctane, 1 ,8-diamino-2,2-dimethyloctane, 1 ,8-diamino-3,3- dimethyloctane, 1 ,8-diamino-4,4-dimethyloctane, 1 ,6-diamino-2,4- diethylhexane, l,9-diamino-5-methylnonane, 1,11-diaminoundecane, 1,12- diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15- diaminopentadecane and 1,16-diaminohexadecane and mixtures thereof.

The polymer comprising the repeat units of formula (III) may also further comprise repeat units derived from lactam (L'). The copolymer of the invention may also comprise one or several other types of monomers such as for instance a compound comprising at least 3 acid functions or a compound comprising at least 3 amine functions. Polymer of the invention may further comprise repeat units of polyamide 6, polyamide 7, polyamide 6.6, polyamide 10, polyamide 11, polyamide 12, polyamide 6.9, polyamide 5.10, polyamide 6.10, polyamide 6.12, polyamide 6.14, polyamide 10.10, polyamide 10.12, polyamide 10.14, polyamide 10.18, polyamide 12.12, polyamide 4.6, polyamide 6.18, polyamide 6.36, polyamide 9.T, polyamide MXD6, polyamide 6.6/6.T, polyamide 6.6/MPMD.T, polyamide 66.61, polyamide PXD6, polyamide (CHM6), polyamide (CHM9), polyamide (CHM10), polyamide (CHM18), polyamide (MXD,T), polyamide (MXD,I), polyamide (MPMD,I), polyamide (6,T), polyamide (6,1), polyamide (6, CHD), polyamide (10.CHD), polyamide (MXD,CHD), polyamide (CHM, CHD), polyamide (MPMD,CHD), polyamide (CHM,T), polyamide (CHM,I) and polyamide (CHM, 4) and copolymers based on these (co)polyamides. Polymer of the invention may preferably comprise repeat units of polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 66.6 and copolymers based on these (co)polyamides.

Polymer comprising the repeat units of formula (III), (Ilia), (Illb), (IIIc), (Hid) and/or (Hie) may further comprise repeat units of polyamide 6, polyamide 7, polyamide 6.6, polyamide 10, polyamide 11, polyamide 12, polyamide 6.9, polyamide 5.10, polyamide 6.10, polyamide 6.12, polyamide 6.14, polyamide 10.10, polyamide 10.12, polyamide 10.14, polyamide 10.18, polyamide 12.12, polyamide 4.6, polyamide 6.18, polyamide 6.36, polyamide 9.T, polyamide MXD6, polyamide 6.6/6.T, polyamide 6.6/MPMD.T, polyamide 66.61, polyamide PXD6, polyamide (CHM6), polyamide (CHM9), polyamide (CHM 10), polyamide (CHM 18), polyamide (MXD,T), polyamide (MXD,I), polyamide (MPMD,I), polyamide (6,T), polyamide (6,1), polyamide (6, CHD), polyamide (10,CHD), polyamide (MXD,CHD), polyamide (CHM, CHD), polyamide (MPMD,CHD), polyamide (CHM,T), polyamide (CHM,I) and polyamide (CHM, 4) and copolymers based on these (co)polyamides. Polymer comprising the repeat units of formula (III), (Ilia), (Illb), (IIIc), (Hid) and/or (Hie) may preferably comprise repeat units of polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 66.6 and copolymers based on these (co)polyamides.

Examples of polymers

The polymer of the invention can, for example, be:

- PA (I)/6 which is synthesized from capro lactam and from the monomer of formula (I), with R = C13-C24 aliphatic or oxyaliphatic moiety, notably with n=l or 2 or 3 or 4. Preferably the amount of monomer of formula (I) is from 0.1 wt% to 90wt%, more preferably from 10wt% to 50wt%, with respect to the weight of all the monomers.

- PA (Ia)/6 which is synthesized from capro lactam and from the monomer of formula (la), with R = C13-C24 aliphatic or oxyaliphatic moiety. Preferably the amount of monomer of formula (la) is from 0.1 wt% to 90wt%, more preferably from 10wt% to 50wt%, with respect to the weight of all the monomers. - PA (Ie)/6 which is synthesized from capro lactam and from the monomer of formula (Ie). Preferably the amount of monomer of formula (Ie) is from 0.1 wt% to 90wt%, more preferably from 10wt% to 50wt%, with respect to the weight of all the monomers.

- PA (I)/l l (synthesized from 11-aminoundecanoic acid and from the monomer of formula (I), with R = C13-C24 aliphatic or oxyaliphatic moiety, notably with n=l or 2 or 3 or 4).

- PA (I)/ 12 (synthesized from dodecano lactam and from the monomer of formula (I), with R = C13-C24 aliphatic or oxyaliphatic moiety, notably with n=l or 2 or 3 or 4).

- PA (I)/66 (synthesized from the monomer of formula (I), with R = C13-C24 aliphatic or oxyaliphatic moiety, notably with n=l or 2 or 3 or 4 and from Nylon salt, notably composed of a stoichiometric amount of adipic acid and of hexamethy lenediamine) .

- PA (I)/66/6 (synthesized from caprolactam, Nylon salt, notably composed of a stoichiometric amount of adipic acid and of hexamethy lenediamine and from the monomer of formula (I), with R = C13-C24 aliphatic or oxyaliphatic moiety, notably with n=l or 2 or 3 or 4).

- PA (Ia)/11 (synthesized from 11-aminoundecanoic acid and from the monomer of formula (la), with R = C13-C24 aliphatic or oxyaliphatic moiety).

- PA (la)/ 12 (synthesized from dodecano lactam and from the monomer of formula (la), with R = C13-C24 aliphatic or oxyaliphatic moiety).

- PA (Ia)/66 (synthesized from the monomer of formula (la), with R = C13-C24 aliphatic or oxyaliphatic moiety and from Nylon salt, notably composed of a stoichiometric amount of adipic acid and of hexamethy lenediamine).

- PA (Ia)/66/6 (synthesized from caprolactam, Nylon salt, notably composed of a stoichiometric amount of adipic acid and of hexamethylenediamine and from the monomer of formula (la), with R = C13-C24 aliphatic or oxyaliphatic moiety).

- PA (Ie)/11 (synthesized from 11-aminoundecanoic acid and from the monomer of formula (Ie)).

- PA (Ie)/12 (synthesized from dodecano lactam and from the monomer of formula (Ie).

- PA (Ie)/66 (synthesized from the monomer of formula (Ie) and from Nylon salt, notably composed of a stoichiometric amount of adipic acid and of hexamethylenediamine).

- PA (Ie)/66/6 (synthesized from caprolactam, Nylon salt, notably composed of a stoichiometric amount of adipic acid and of hexamethylenediamine and from the monomer of formula (Ie)). The polymer of the invention may have number-average molar mass M_n of from 2000 to 2000000 g/mol, preferably from 3000 to 200000 g/mol and more preferentially still from 4000 to 100000 g/mol. The number-average molar masses are determined by various known methods, such as gel permeation chromatography. Composition

The present invention also concerns a composition comprising at least a polymer as previously described, and optionally fillers and/or additives.

Preferably the amount of polymer as previously described in the composition is from 0.5 to 95wt% in the composition, more preferably from 0.5 to 50wt%, with respect to the total weight of the composition. The present invention also concerns a composition comprising at least a polymer comprising the repeat units of formula (III), and optionally fillers and/or additives. The present invention notably concerns a composition comprising at least a polymer comprising the repeat units of formula (Ilia), (Illb) (IIIc) (Hid) and/or (Hie), and optionally fillers and/or additives.

The composition of the invention may also comprise an other polymer, preferably a thermoplastic polymer such as for instance a thermoplastic polymer chosen in the group constituted by: acrylic, acrylonitrile butadiene styrenea (ABS), polyamides, polylactic acids, polycarbonates, polyether sulfones, polyetherether ketones, polyetherimides, polyethylene, polypropylenes, polyphenylene oxides, polyphenylene sulphide, polypropylenes, polystyrene and polyvinyl chloride, or mixture thereof.

The additives may be chosen in the group constituted by halogen-containing flame retardant agents, halogen-free flame retardant agents, stabilizers, antioxidants, light protection agents, UV stabilizers, UV absorbers, UV blockers, inorganic heat stabilizers, organic heat stabilizers, conductivity additives, optical brighteners, processing aids, nucleation agents, crystallization accelerators, crystallization inhibitors, flow aids, lubricants, mold-release agents, softeners and mixtures thereof.

The fillers may be chosen in the group constituted by mineral fillers such as talc, mica, kaolin, calcium carbonate, calcium silicate, magnesium carbonate; glass fibers, carbon fibers, synthetic polymeric fiber, aramid fiber, aluminium fiber, titanium fiber, magnesium fiber, boron carbide fibers, rock wool fiber, steel fiber, wollastonite and mixtures thereof. Preferably the amount of fillers in the composition is from 1 to 60wt% in the composition, more preferably from 5 to 40wt%, with respect to the total weight of the composition. Application

The present invention also relates to an article or a part of an article comprising the composition as previously described or the polymer as previously described. The article or the part of article may consist of the composition of the invention. The present invention also relates to an article or a part of an article comprising the polymer comprising the repeat units of formula (III). The invention also relates to an article or a part of an article comprising the polymer comprising the repeat units of formula (Ilia), (Illb) (IIIc) (Hid) and/or (Hie).

Articles may be for instance fitting parts, snap fit parts, mutually moveable parts, functional elements, operating elements, tracking elements, adjustment elements, carrier elements, frame elements, switches, connectors and housings, which can be notably produced by injection molding, extrusion or other shaping technologies. The disclosure will now be illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Other examples are also possible which are within the scope of the present disclosure. EXPERIMENTAL PART

Materials:

3-pentadecylcyclohexanone oxime is obtained by reported procedure of National Chemical Laboratory (NCL), Pune INDIA

( http ://ncl.csircentral.net/821 / 1 /th 1692.pdf)

Example 1: Synthesis of pentadecylazepan-2-one (pentadecylcaprolactam)

3-pentadecyclohexanone oxime was dissolved in minimum amount of concentrated sulfuric acid and stirred for 30 minutes. This mixture was added dropwise to a small amount of concentrated acid using addition funnel in a two- neck round bottom flash headed with condenser. The reaction was performed at 80°C for 45 min. After cooling at 25°C, the flask was put on an ice bath. The sulfuric acid was carefully quenched by diluted ammonia solution until the pH turned alkaline. The crude product was extracted with dichloromethane and washed with water and brine. The organic layer was dried over anhydrous sodium sulfate, filtered and dichloromethane was removed using a rotary evaporator. The powder obtained was purified by column using an ethyl acetate: petroleum ether system as eluent with a gradually increase of ethyl acetate part. Total yield: 80% M.P: 82°C. After synthesis of the pentadecylcaprolactam (mixture of isomers), the latter was purified by column chromatography using an eluent system composed of petroleum ether-ethyl acetate, with gradual increase of the ethyl acetate part. White solid obtained was dried and kept under argon atmosphere. Commercial caprolactam was first added to toluene in round bottom flask and placed on a rotavap until toluene was completely evaporated. After drying on high vacuum pump, the caprolactam was recrystallized in a 7: 1 hexane: dichloromethane system. The crystals were dried for 2 hours under high vacuum and kept under argon atmosphere. Pentadecylcaprolactam (mixture of isomers) obtained was characterized by 1H- NMR and ¹³C-NMR. NMR spectra were recorded on a Bruker 200 or 400 MHz spectrometer. 1H NMR (DMSO, 500 MHz) spectra of pentadecylcaprolactam (mixture of regioisomers):

δ: 7.91-7.85 (m, 1H), 5.33-5.31 (m, 2H), 4.52-4.51 (m, 1H), 3.74-3.70 (m, 1H), 3.50-3.35 (m, 5H), 3.13-3.06 (m, 8H), 2.07-2.03 (m, 2H), 2.00-1.95 (m, 4H), 1.83-1.80 (m, 2H), 1.49-1.45 (m, 2H), 1.24-1.28 (m, 20H), 0.85 (t, 3H)

¹³C NMR (400 MHz, TFA-d, + DMSO-d6, mixture of regioisomers):

19.8, 21.8, 24.5, 25.9, 28.7-29.0 (merged peaks), 31.3, 32.0, 32.4, 33.1, 35.1,

35.2, 35.5, 36.1, 37.6, 44.1, 48.5, 182.9, 183.8 Example 2: Polymerisation of 10% wt pentadecylcaprolactam/caprolactam

In an oven dried Schlenk tube containing magnetic needle, pentadecylcaprolactam was weighed (409.2 mg). Then caprolactam was added as fast as possible (3.34g). The Schlenk was closed with glass stopper and put under high vacuum for a minimum time of 10 hours.

At the end of 10 hours, vacuum was replaced by argon in order to process to the weighing of initiator and catalyst compound. Tin(octoate)2 (195.5mg, 1% mol) was first introduced by the side arm of the Schlenk tube using a glass syringe and steel needle dried in oven. Then octylamine (49.8mg, l%mol) was introduced by the same process. High vacuum was applied for only 10 minutes and the Schlenk tube was closed under vacuum. This tube was then dipped in an already hot oil bath at 220-230°C. After lOh, increase of viscosity, light coloration and condensation/sublimation drops on top were observed. After 24h, the viscosity increased, making the needle almost unefficient. After 48h, a solid mass was obtained. Except some loss on the top of the Schlenk tube, the weigh was approximately the same of the feed (3.5g instead of 3.7g).

Purification of polymer obtained

510mg of polymer was dissolved in 7.5ml of hot acetic acid (clear solution obtained around 60-80°C). After cooling down, a paste/gel like solution was obtained. At 25°C, 4 ml of acetic acid was added and the gel was dispersed by agitation until obtaining a free flowing solution. This solution was poured on a Whatman filter paper. Some of the acetic acid was removed by filtration. 10 ml more of acetic acid was added and kept for filtration. The yellow pale solid on the paper was washed with acetone (3x25ml) in order to replace acetic acid by a lower ebullition solvent. After no more drops of acetone coming from the filter, the solid mass was put on a petri dish and kept in an oven at 60°C overnight.

Since both monomers were soluble in acetic acid and acetone as well as the catalyst and initiator, this process should be an efficient way of purification. Moreover, low molecular weight polyamide would normally be dissolved in acetic acid at room temperature. The compositions of copolymerisation tried are summarized in the following Table 1 : Table 1: Experimental parameters of copolymerisation experiments

Example 3: Solubility test

Solubility test had been conducted on 10%, 20% and 50% copolymer (50mg in lmL of solvent). Results are shown in the following Table 2:

-: insoluble; +-: soluble at 80°C, precipitate at 25°C; +: soluble at 25°C

It appears then that the copolymer (10%wt and 20%wt) of the invention is partially soluble in acetic acid and precipitates at 25°C. This solvent has a good solvation for monomers/ catalysts and initiator and thus qualifies as an efficient way of purification of polymers.

Example 4: Characterization of copolymers

Theoretical degree of polymerization (DP_nitheo) of copolymers had been calculated using the ratio of mole of monomers weighed on mole of initiator, as described in the following formula :

n(caprolactam) + n pentadecylcaprolactani) Theoretical molecular weight (M_nitheo) was calculated from DP_nitheo as follows:

,theo = DP_n ,theo x M_w(mix)

M_w(mix) being the molecular weight representative of the proportion of capro lactam (CPL) and 4/6-pentadecylazepan-2-one (PDA-2-one).

(M_w(mix)=%mol(CPL)M_w(CPL)+%mol(PDA-2-one)M_w(PDA-2-one))

Thermogravimetric analysis (TGA) had been conducted on TA instrument Q500. Gel permeation chromatography was performed on Waters pump-515 using refractive index (RI) detector Shodex 101 through PLgel Minmax B columns and analysed with Clarity GPC software. PMMA standards were used for comparison. All data brought by gel permeation chromatography, differential scanning calorimetry and thermogravimetric analysis are gathered in the following Table 3:

Differential Scanning Calorimetry (DSC) had been conducted on TA instrument Q2000. The curves are given in Figure 1, 2 and 3 for 10%>, 20%> and 50%> copolyamide 6 respectively. From the above results, it appears that the incorporation of a C13-C24 alkyl or oxyalkyl chain, especially a n-pentadecyl chain, in the backbone of the copolymer have effect on the thermic properties. Long alkyl chain hinders the organization of the amide group, decreasing the crystallinity of the copolymer. Also there is a decrease in the melting temperature and crystallization temperature.

It appears that the copolymers of the invention are high molecular weight polymers with M_n higher than 10,000 g/mol. Crystallinity of the copolymer was calculated using the ratio between the enthalpy of fusion of each copolymer (given by DSC analysis by calculation of the area of the endothermic peak) on the enthalpy of fusion of a 100% crystalline polyamide 6 reported by James Mark in the Polymer Data Handbook {MARK, J. E., Polymer Data Handbook, Oxford Uni.; 1999) with the following formula:

AH_f

Crystallinity (%) = ¹ x 100%

H_fref = 188 J/g

When percent of incorporation of the substituted caprolactam increases, T_m, T_c, thermal stability and crystallinity decreases due to the chain alignment as shown in below Table 4:

T Temperature at which there is a loss of 5% wt of copolymer Tio_%: Temperature at which there is a loss of 10% wt of copolymer

Td_eg: Temperature at which maximum decomposition of copolymer occurs

It appears from Table 4 that while increasing the mole percentage of incorporation of a n-pentadecyl chain directly attached to the backbone of a polyamide 6, the temperature of melting, temperature of crystallization and the crystallinity decrease. At equivalent mechanical properties, a decrease of the melting temperature will allow a lower processing temperature and then this will reduce the need of energy to process this copolymer, that is to say an economic and sustainability benefic impact. Moreover, this low melting temperature may give the ability to copolyamide 6 to be processed in a 3D printer.

Claims

C L A I M S

1. A lactam (L) of formula (I) as follows:

(I) wherein R represents C13-C24 aliphatic or oxyaliphatic moiety which is attached to any carbon atom of the ring except the carbonyl carbon atom and n is an integer of from 1 to 4.

2. The lactam (L) of claim 1, wherein R is a C13-C17 aliphatic or oxyaliphatic moiety.

3. The lactam (L) according to claim 1 or 2, wherein R is a C13, C₁₄, C₁₅, Ci6, and/or C₁₇, aliphatic or oxyaliphatic moiety.

4. The lactam (L) according to anyone of claims 1 to 3, wherein R is an aliphatic moiety in which the constituent carbon atoms can be straight-chain, branched-chain, or cyclic chain.

5. The lactam (L) according to anyone of claims 1 to 4, wherein it corresponds to formula (la) as follows:

6. The lactam (L) according to anyone of claims 1 to 4, wherein it corresponds to formula (lb) as follows:

7. The lactam (L) according to anyone of claims 1 to 4, wherein it corresponds to formula (Ic) as follows:

8. The lactam (L) according to anyone of claims 1 to 4, wherein it corresponds to formula (Ic) as follows:

9. The lactam (L) according to anyone of claims 1 to 4, wherein it corresponds to formula (Ie) as follows:

10. The lactam (L) according to anyone of claims 1 to 4, wherein it corresponds to a mixture as follows:

11. The lactam (L) according to anyone of claims 1 to 4, wherein lactam (L) is chosen in the group constituted by 3-n-(Ci₃-C₂4 alkyl)azepan-2-one, 4-n- (Ci3-C₂4 alkyl)azepan-2-one, 5-n-(Ci3-C₂4 alkyl)azepan-2-one, 6-n-(Ci3-C₂4 alkyl)azepan-2-one and 7-n-(Ci₃-C₂4 alkyl)azepan-2-one and mixtures thereof.

12. A process for the preparation of a lactam comprising reacting: - at least an oxime of formula (II) as follows:

wherein R represents Ci₃-C₂4 aliphatic or oxyaliphatic moiety and n is an integer of from 1 to 4, and - an acid.

13. The process according to claim 12, wherein the acid is chosen in the group constituted by mineral acids, beckmann mixture, organic acids, solid acid catalyst, super acids and mixtures thereof.

14. The process according to claim 12 or 13, wherein the amount of acid is from 0.05 to 5 mole%, with respect to the oxime.

15. The process according to anyone of claims 12 to 14, wherein the oxime of formula (II) has been prepared from cashew nut shell liquid.

16. A process for producing a polymer comprising the ring-opening polymerisation of at least one lactam (L) with at least one catalyst and at least one initiator, and optionally at least one monomer different from lactam (L).

17. The process according to claim 16, wherein the catalyst is chosen in the group constituted by tin(octoate)2, tin isopropoxide, tin octanoate, tin chloride, tin oxide, zinc oxide and their binary catalysts; heterogenous catalysts such as montmorillanite catalyst, alkali metals, metal hydridres, metal amides and mixtures thereof.

18. The process according to claim 16 or 17, wherein the polymer is obtained by polymerisation of at least one lactam (L) with at least one monomer different from lactam (L).

19. A polymer obtained by polymerization of at least one lactam (L) with at least one catalyst and at least one initiator, and optionally at least one monomer different from lactam (L).

20. A polymer comprising at least the repeat units of formula (III) as follows:

wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety and n is an integer of from 1 to 4, notably 1, 2, 3 or 4.

21. The polymer of claim 19 or 20, wherein R is a C13-C17 aliphatic or oxyaliphatic moiety.

22. The polymer according to anyone of claims 19 to 21, wherein R is a Ci3, C_M, Ci5, Ci6, and/or C₁₇, aliphatic or oxyaliphatic moiety.

23. The polymer according to anyone of claims 19 to 22, wherein R is an aliphatic moiety in which the constituent carbon atoms can be straight-chain, branched-chain, or cyclic chain.

24. The polymer according to anyone of claims 19 to 23, wherein said polymer comprises from 0.1 to 100wt% of repeat units of formula (III), with respect to the weight of all monomers.

25. The polymer according to anyone of claims 19 to 24, wherein it comprises at least the repeat units of formula (Ilia) as follows:

(Ilia) wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety.

26. The polymer according to anyone of claims 19 to 24, wherein it comprises at least the repeat units of formula (Illb) as follows:

(nib) wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety.

27. The polymer according to anyone of claims 19 to 24, wherein it comprises at least the repeat units of formula (IIIc) as follows:

wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety.

28. The polymer according to anyone of claims 19 to 24, wherein it comprises at least the repeat units of formula (Hid) as follows:

wherein, R represents C13-C24 aliphatic or oxyaliphatic moiety.

29. The polymer according to anyone of claims 19 to 24, wherein it comprises at least the repeat units of formula (Hie) as follows:

30. The polymer according to anyone of claims 19 to 29, wherein it is a homopolymer.

31. The polymer according to anyone of claims 19 to 29, wherein it is a copolymer comprising the repeat units of formula (III) with at least one repeat unit derived from a monomer different from lactam (L).

32. The polymer according to anyone of claims 19 to 29 and 31, wherein it is a copolymer obtained by polymerisation of lactam (L) with lactam (L') other than the lactam (L).

33. The polymer according to claim 32, wherein the weight ratio of lactam (L) to lactam (L') is from 1 to 99%.

34. The polymer according to claim 32 or 33, wherein the lactam (L') is chosen in the group constituted by caprolactam, 2-pyrrolidone, 2-piperidinone, 2-azetidinone and mixtures thereof.

35. The polymer according to anyone of claims 19 to 29 and 31 to 33, wherein it is a copolymer obtained by polymerization of lactam (L) with at least one diacid and at least one diamine.

36. The polymer according to anyone of claims 19 to 29 and 31 to 35, wherein it further comprise repeat units of polyamide 6, polyamide 7, polyamide 6.6, polyamide 10, polyamide 11 , polyamide 12, polyamide 6.9, polyamide 5.10, polyamide 6.10, polyamide 6.12, polyamide 6.14, polyamide 10.10, polyamide 10.12, polyamide 10.14, polyamide 10.18, polyamide 12.12, polyamide 4.6, polyamide 6.18, polyamide 6.36, polyamide 9.T, polyamide MXD6, polyamide 6.6/6.T, polyamide 6.6/MPMD.T, polyamide 66.61, polyamide PXD6, polyamide (CHM6), polyamide (CHM9), polyamide (CHM10), polyamide (CHM18), polyamide (MXD,T), polyamide (MXD,I), polyamide (MPMD,I), polyamide (6,T), polyamide (6,1), polyamide (6, CHD), polyamide (10,CHD), polyamide (MXD,CHD), polyamide (CHM, CHD), polyamide (MPMD,CHD), polyamide (CHM,T), polyamide (CHM,I) and polyamide (CHM, 4) and copolymers based on these (co)polyamides.

37. A composition comprising at least a polymer according to anyone of claims 19 to 36, and optionally fillers and/or additives.

38. An article or a part of an article comprising the composition according to claim 37.

39. A composition comprising: - at least one lactam (L) according to anyone of claims 1 to 11 preparable by the process according to anyone of claims 12 to 15, and - at least one monomer different from lactam (L).