NL2009691C2

NL2009691C2 - Method for the manufacture of a polyamide-based and/or polyester-based polymer network.

Info

Publication number: NL2009691C2
Application number: NL2009691A
Authority: NL
Inventors: Erik Diederik Jurri N Visser; Martinus Adrianus Gertrudus Jansen
Original assignee: Hovis Internat B V
Priority date: 2012-10-24
Filing date: 2012-10-24
Publication date: 2014-04-29
Also published as: WO2014064137A1

Abstract

The present invention relates to a method for the manufacture of a polyamide-based and/or a polyester-based polymer network comprising: a) providing a polyunsaturated polyamide having at least two carbon-carbon double bonds alternating with at least two carbon-carbon single bonds, and/or a polyunsaturated polyester having at least two carbon-carbon double bonds alternating with at least two carbon-carbon single bonds, according to the formulae according to the present invention, wherein R', R1, R2, R are chosen from the group alkyls, cycloalkyls, alkenyls, cycloalkenyls and aryls, wherein R3 and R4 are chosen from the group H, and NH-(C=O)-(CH=CH-)nR*], wherein R* and is H or CH3, wherein n is 2 to 6 and x is 2 to 6 in formulae (I), and (III; and b) crosslinking the polyunsaturated polyamides and/or the polyunsaturated polyester according to the formulae according to the present invention, by free radical polymerization, thereby obtaining the polyester-based and/or polyamide-based polymer network.

Description

METHOD FOR THE MANUFACTURE OF A POLYAMIDE-BASED AND/OR POLYESTER-BASED POLYMER NETWORK

The present invention relates to a method for the 5 manufacture of a polyamide-based and/or a polyester-based polymer network. Further, the present invention relates to the polymers obtainable by the method and their use thereof.

Green engineering, in particular the manufacture of bio-10 based polymers and composites derived from plants or natural products is a rising industry. Green Engineering is the design, commercialization and use of processes and products that are feasible and economical while reducing pollution at the source and minimizing the risk to human health and the 15 environment. More particularly, green engineering focuses on bio-based material resources, availability, sustainability, bio-based polymer formation, extraction and refining technologies, and the need for integrated research in areas such as adhesives, resins, plastics, and composites derived 20 from plant oils, proteins, starches, and natural fibers in terms of structures, properties, manufacturing, and product performance .

Therefore, there is a continuous need to provide, at an industrial level, polymer networks derived from natural 25 sources, also designated as bio-based polymer networks.

Specifically, there is a need for providing stable polymer networks from natural sources in order to be used in industrial processes for the fabrication of adhesives, resins, plastics, and composites.

30

The goal of the present invention, amongst other goals, is to provide a polymer network fulfilling the requirements of green engineering, such as reducing the generation of 2 pollution at the source and minimizing the risk to human health and the environment, as well as providing a method that does not present the drawbacks of the prior art. More specifically, this goal is achieved by the method for the 5 manufacture of a (polyamide-based and/or a polyester-based) polymer network according to the present invention, comprising: a) providing a polyunsaturated polyamide having at least two carbon-carbon double bonds alternating with at least two 10 carbon-carbon single bonds according to formulae (I): f~ t « .., “ft; ,---¼. . ( ' \. : r* I; is r ^ '« A, da)

O

20 r I ψ \ R· v ''n

-E X

25 db) and/or a polyunsaturated polyamide having at least two carbon-carbon double bonds alternating with at least two carbon-carbon single bonds according to formula (II): 30

5 ... X

3 ” *·!·'_ F; R'

f\" H

10 ( Ha) and/or a polyunsaturated polyester having at least two carbon-carbon double bonds alternating with at least two 15 carbon-carbon single bonds according to formulae (III): 0 1! / \

R·, I

"k ,··' 1-. k.

Ό" ’p-"' I1 R* 2 0 \ /„ 11 L J x (Ilia) o

r / V

25 j / \ ,C , 1 "γ. "-· R O' ; R* ) \ / j ' n L J \ (mb) 30 wherein R', R1, R2, R are chosen from the group alkyls, cycloalkyls, alkenyls, cycloalkenyls and aryls, wherein R3 and R4 are chosen from the group -H, and -NH-(C=0)-(CH=CH-)nR*, 4 wherein R* and is H or CH3, wherein n>2 and wherein x in formulae (I), and (III) wherein x in formula (II) if at least one of R3 or R4 are 5 -NH-(C=0)-(CH=CH-)nR*, or wherein x >2 if both R3 and R4 are H; and b) crosslinking the polyunsaturated polyamide according to formula (I) and/or the polyunsaturated polyamide according to formula (II) and/or the polyunsaturated polyester 10 according to formula (III) by free radical polymerization, thereby obtaining the polyamide-based and/or polyester-based polymer network.

Accordingly, the polymer networks according to the present invention can be polyamide-based and/or polyester-based.

15

Formulae (I), (II) and (III) as recited above can also be respectively designated as (la) : R'-[NH-(C=0) - (CH=CH-)nR*]x; (lb) : R' - [ (0=C) -NH-CH2- (CH=CH-) nR* ] x; 20 (I la) : R3-R2-[N-(C=0) - (CH=CH-) n-R* ] X-R4-R4 (Ha) with R1 and R2 covalently bonded to the -N- of the amide between [ ] , and covalently bonded to R4 and R3 respectively. When any of the groups R3 and R4 are -NH- (C=0) - (CH=CH-) nR*, R2 and R1 are respectively covalently bonded to the -N of the amide; 25 (Ilia): R-[0-(0=C) - (CH=CH-)nR* ] x; (Illb) : R-[(0=0)-0- CH2-(CH=CH-)nR*]x.

Specifically, the method of the present invention allows preparing products in step a) which do not present any free 30 hydroxyl groups (-0H). The absence of hydroxyl groups in the present invention may reduce the viscosity of the obtained resins in step a), as well as increase the thermal stability of the products obtained. Further, the method according to 5 the present invention provide an increased freedom of choice of used starting materials and therefore, makes it easier to vary and/or modify the properties of the obtained polymer networks. Furthermore, the fully controlled 5 polymerization in step b) by free radical polymerization prevents drawbacks such as instability and/or polymerizations which are difficult to control because of the heat and/or air sensitivity. The polyamide-based polymer networks obtained by the present invention present an 10 increased thermal stability and strength.

In the context of the present invention, an amide can be a secondary or a tertiary amide. A secondary amide is a molecule of which the nitrogen atom of the function NH-(C=0) 15 is bonded to two carbon atoms. A tertiary amide is a molecule of which the nitrogen atom of the function NH-(C=0) is bonded to three carbon atoms.

In the context of the present invention, the moieties represented as CH2-(CH=CH-)n- and -(CH=CH)n- are aliphatic 20 (also designated as linear). These moieties can be substituted by any hydrocarbon substituent at any position of the chain. The substituent can be such as an alkyl, a cycloalkyl or an aryl or any organic group, such as a halogen, a thiol, a sulfide, a sulfone, a cyano, an ether, 25 or a nitro group. Said moieties provide the alternation of carbon-carbon double bonds with carbon-carbon single bonds. In the context of the present invention the polyunsaturated polyamides and polyesters comprise at least two carbon-carbon double bonds alternating with at least two carbon-30 carbon single bonds in the moiety between brackets [ ]. The expression "at least two (or more) carbon-carbon double bonds alternating with at least two (or more) carbon-carbon single bonds", is to be understood that at least two (or 6 more) carbon-carbon double bonds alternate with at least two (or more) carbon-carbon single bonds. This alternation can accordingly be represented as -C=C-C=C-C-. The alternation can also be at least two carbon-carbon double bonds 5 alternate with at least three carbon-carbon single bonds (-C-C=C-C=C-C-), or at least three carbon-carbon double bonds alternate with at least two carbon-carbon single bonds (-C=C-C=C-C=C-). The amount of carbon-carbon double bonds in said moiety can be at least two, at least three, at least 10 four, at least five, at least six. The amount of carbon- carbon single bonds in said moiety can be at least two, at least three, at least four, at least five, at least six. Any combination of alternation double/single bond as recited above is possible and advantageous in the present invention. 15 In the context of the present invention, the symbol R* represents a -H, or a methyl group (-CH3) .

In the context of the present invention, R3 and R4 are terminal groups, and can be chosen from the group H, and NH-(C=0)-(CH=CH-)nR* wherein R* is as defined above.

20 In the context of the present invention, the symbols R, R', R1 and R2 represent part of the compound prepared in step a). In other words, R', R1 and R2, R are chosen from the group alkyls, cycloalkyls, alkenyls, cycloalkenyls and aryls. Advantageously, any of the groups R', R1 and R2, R may be 25 chosen from the group alkyls comprising at least six carbon atoms, cycloalkyls, alkenyls, cycloalkenyls and aryls. In the context of the present invention, the alkyls, cycloalkyls, alkenyls, cycloalkenyls and aryls can be substituted or not. They can be substituted by any organic 30 function such as ethers -0- (e.g. -0-alkyl, -Ο-alkenyl-, -0-cycloalkyl-, -O-cycloalkenyl, -O-cycloalkenyl, -O-aryl), or any hydrocarbon rests, such as any alkyl, any cycloalkyls, any alkenyls, any cycloalkenyls or any aryls.

7

Any of the groups R', R1 and R2, R accordingly can represent a linear alkyl, a cycloalkyl, or an aryl. Advantageously, the linear alkyl is a C1-C12 alkyl. More advantageously, any of the groups R', R1 and R2, R are chosen from the group 5 comprising methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, or any alkyl-substituted alkyl. Any of the groups R', R1 and R2, R may also be an alkyl comprising at least six carbon atoms, such 10 as in the range 6 to 12 carbon atoms, 7 to 12 carbon atoms, 8 to 12 carbon atoms. In the context of the present invention, any linear alkyls, or cycloalkyls, or aryl can be unsubstituted or substituted by an alkyl, an aryl, at least one functional group chosen from the group halogen (such as 15 F, Cl, Br, I), a thiol (-SH), sulfide (-S-), sulfone (- (0=S=0)-), cyano (-C=N), ether (-0-) and nitro (-N02) group. Advantageously, the cycloalkyl is chosen from the group cyclohexyl, cycloheptyl, cyclooctyl. Advantageously, the aryl is chosen from the group a phenyl, a benzyl, a naphtyl, 20 biphenyl.

Any of the groups R', R1 R2 and R can be alkyl comprising 1 to 20 carbon atoms, advantageously 1 to 12 carbon atoms, more advantageously 1 to 10 carbon atoms, most advantageously 1 to 6 carbon atoms or alternatively 6 to 12 25 carbon atoms, 6 to 10 carbon atoms.

Any of the groups R', R1 R2 and R can be an alkenyl, or a cycloalkenyl comprising one, two, three, four, five, or six carbon-carbon double bonds. These double bonds can alternate with carbon-carbon single bonds, or not. Any of the groups 30 R', R1 R2 and R may be an alkenyl, or a cycloalkenyl comprising at least two carbon-carbon double bonds, at least three carbon-carbon double bonds, at least four carbon-carbon double bonds. In the context of the present 8 invention, any linear alkenyls, or cycloalkenyls, can be unsubstituted or substituted by an alkyl, an aryl, at least one functional group chosen from the group halogen (such as F, Cl, Br, I), a thiol (-SH), a sulfide (-S-), a sulfone (-5 (0=S=0)-),a cyano (-C=N), a cyano (-C=N), an ether (-0-) and a nitro (-NO2) group. Advantageously, the cycloalkyl is chosen from the group cyclohexyl, cycloheptyl, cyclooctyl. Advantageously, the aryl is chosen from the group a phenyl, a benzyl, a naphtyl, biphenyl.

10 R', R1, R2 and R accordingly represent the groups as defined above which are substituted by x times the moieties in [ ] , such as -[NH-(C=0)-(CH=CH-)n-R* ] , or as represented in [] of any of the formulae (la), (lb), (Ila), (Ilia), (Illb).

In the present invention, x is at least equal to 2, 15 advantageously at least equal to 3.

R1 and R2 can be advantageously chosen from the group alkenyl, cycloalkenyl and aryl. If R1 can vary for each repeating moiety, i.e. with x being equal to or above 2, at least two R1 are present in the compound. These R1 can be 20 identical, or different.

In the context of the present invention, R’ is substituted by at least two moieties of - [NH- (0=C) -CH2 (CH=CH-) n-R* ] or -[(C=0)-NH-CH2(CH=CH-)n-R* ] . Accordingly, x is at least equal to 2, such as at least equal to 3, or at least equal to 4, 25 at least equal to 5, at least equal to 6. R' can advantageously be chosen from the group alkenyls, cycloalkenyls and aryls.

In the context of the present invention, any of the groups R', R1, R2 and R can be chosen from the groups comprising 30 alkenyls comprising 1 to 12 carbon atoms, such as 1 to 10 carbon atoms, 1 to 6 carbon atoms. In the context of the present invention, cycloalkenyls are cyclic alkenyls comprising at least one carbon-carbon double bonds, such as 9 1, 2, 3, 4 carbon-carbon double bonds (they may alternate with carbon-carbon single bonds, or not). In the context of the present invention, the aryls are aromatic rings comprising any number of carbon atoms, such as 6 to 12 5 carbon atoms. If any of R', R1, R2 and R are an aryl, x can be in the range 2 to 8.

Advantageously, R can be an alkyl comprising at least 6 carbon atoms (such as at least 7 carbon atoms, such as at least 8 carbon atoms, such as 10 carbon atoms), a 10 cycloalkyl, an alkenyl, or a cycloalkenyl, or an aryl. If R is an alkenyl or a cycloalkenyl, it may comprise one carbon-carbon double bond, or alternatively at least two double carbon-carbon bonds. Advantageously R can comprise at least two carbon-carbon double bonds alternating with at least two 15 carbon-carbon single bonds. R can be an aryl, such as a benzene ring (6 carbon atoms), or a naphthalene ring (10 carbon atoms). R is substituted by at least two moieties of -[0-(0=C)-CH2(CH=CH-)n-R*] , or -[(C=0)-0-CH2(CH=CH-) nR* ] . Accordingly, x is at least equal to 2, advantageously at 20 least equal to 3. If R is an aryl, x can be in the range 2 to 8 .

In the context of the present invention, when any of the groups R', R1, R2 and R are an alkenyl, or a cycloalkenyl, 25 they may include at least two carbon-carbon double bonds, advantageously they may, or not, include at least two carbon-carbon double bonds alternating with at least two carbon-carbon single bonds.

30 According to the present invention, n is ^2. Advantageously, n can be such as n^2, n^3, n>4, n^5, n>6.

In the context of the present invention, in any one of formulae (I), (II) and (III), n can be in the range 2 to 10.

10

This means that n can be in the range 2 to 10 in compounds according to formula (la), or to formula (lb), or to formula (Ila), or to formula (Ilia), or to formula (Illb). Advantageously, n can be in the range 2 to 6, more 5 advantageously 2 to 4. Further, n can also be in the range 4 to 10, such as 5 to 10, 6 to 10, 8 to 10.

Advantageously, n can be any value between 2 and 10, such as 2, 3, 4, 5, 6, 7, 8, 9, 10.

In the context of the present invention, the symbol 10 means "a value equal to, or above (superior to)".

According to the present invention, in any one of formulae (I), (II) and (III), x can be 2, 3, 4, 5, 6, 7, 8, 9, 10. In the context of the present invention, x can also be above or 15 equal to 3, above or equal to 4, above or equal to 5, above or equal to 6, above or equal to 8, above or equal to 10. Advantageously, x can be in the range, 2 to 10, more advantageously, 3 to 8. In the context of the present invention, x is ^2 in formulae (I), and (III) and x is ^1 in 20 formula (II) if at least one of R3 or R4 are -NH-(C=0)- (CH=CH-) nR*, or wherein x >2 if both R3 and R4 are H.

Within the present invention, it has been found that if x=l in formulae (I) and (III), the polymerization does not result in a polymer network such as described in the present 25 invention. Accordingly, if x=l, the polymerization does not lead to a polymer network, but to a different polymer structure, or to no polymer.

In formula (II), x can be 1, if at least one of R3 or R4 are a secondary amide -NH-(C=0)-(CH=CH-)nR* . In formula II, the 30 amount of amide units is as well at least two (one between [ ] and at least one as R3 or R4). Accordingly, the polymer network of the present invention is achieved with the properties mentioned herewith. If the amount of amide 11 moieties is not as defined in the context of the present invention, the crosslinking does not allow obtaining the polymer network according to the present invention.

In the context of the present invention, the moiety between 5 [ ] which is present at least two (x) times in the molecule, and the moiety comprising the carbon-carbon double bonds (moiety between ( ) which is present at least two times (n), are responsible for the cross-linking of the compounds obtained in step a), and therefore for the formation of the 10 polymer network according to the present invention.

Accordingly, if x=l and/or n=l, the compound formed in step a) does not result in a polymer network in step b) such as a polymer network according to the present invention, namely presenting an increased/improved thermal stability, and/or 15 an increased/improved strength, and/or an increased/improved viscosity.

According to an embodiment of the present invention, the polyunsaturated polyamides according to formulae (la), 20 and/or (Ila) are provided by the reaction of a polyamine with a compound chosen from the group a carboxylic acid, an ester, an acyl halide, an anhydride, wherein the carboxylic acid, the ester, the acyl halide, and the anhydride comprise at least two carbon-carbon double bonds alternating with at 25 least two carbon-carbon single bonds and wherein the amine groups of the polyamine are primary amines or secondary amines. A primary amine is a hydrocarbon comprising a NH2 group. A secondary amine is a hydrocarbon comprising a -NH-(two residues are substituting the -NH-). According to this 30 embodiment, the polymer network prepared by the method of the present invention is particularly suitable for adhesives, resins, plastics, and composites derived from plant oils, proteins, starches, and natural fibers in terms 12 of structures, properties, manufacturing, and present increased product performance, such as an increased stability.

In the context of the present invention, the polyamine is an 5 amine with more than two amine groups (i.e. primary amines -NH2; secondary amines -NH-), such as a diamine (two amine groups), a triamine (three amine groups), a tetraamine (four amine groups), pentaamine (five amine groups), hexaamine (six amine groups). In the context of the present invention, 10 a combination of primary and secondary amines is possible: for example molecules such as norspermidine (H2N(CH2)3NH(CH2)3NH2) , spermidine (H2N (CH2) 4NH (CH2) 3NH2) and spermine (H2N (CH2) 3NH (CH2) 4NH (CH2) 3NH2) .

According to the present invention, an embodiment for the 15 manufacture of the polyunsaturated polyamides is that the polyunsaturated polyamides as described in formula (la) are provided by the reaction of a conjugated base of an amide which can react with a compound bearing a leaving group, such as a triflate, a sulfonate, a sulfate, an alkyl 20 dihalide XR'X (by nucleophilic substitution). Additionally the conjugated base of the amide also comprises at least two carbon-carbon double bonds alternating with at least two carbon-carbon single bonds.

According to an embodiment of the present invention, the 25 polyunsaturated polyester according to formula (III) is provided by the reaction of a polyol with a compound chosen from the group an carboxylic acid, an ester, an acyl halide, an anhydride, wherein the carboxylic acid, the ester, the acyl halide, and the anhydride comprise at least two carbon-30 carbon double bonds alternating with at least two carbon-carbon single bonds wherein the polyol comprises at least one carbon-carbon double bonds, advantageously, at least two carbon-carbon double bonds, more advantageously, at least 13 three carbon-carbon double bonds. The polyol can as well comprise only carbon-carbon single bonds. According to this embodiment, the polymer network prepared by the method of the present invention is particularly suitable for 5 adhesives, resins, coatings, plastics, and composites derived from plant oils, proteins, starches, and natural fibers in terms of structures, properties, manufacturing, and present increased product performance, such as an increased stability.

10 In the context of the present invention, the polyol is an alcohol with at least two alcohol groups (-OH), such as a diol, a triol (three alcohol groups), or a tetraol (four alcohol groups), a pentaol (five alcohol groups), an hexaol (six alcohol groups). The alcohol can be primary, secondary 15 or tertiary alcohols. Advantageously, in the context of the present invention, the polyols are primary alcohols.

Examples of polyols can be ethylene glycol, glycerol, pentaerythritol. The polyols can also include an ether function (-0-), or be substituted by an alkyl, a cycloalkyl, 20 an alkenyl, a cylcoalkenyl, or an aryl.

According to the present invention, an embodiment for the manufacture of the polyunsaturated polyesters is that the polyunsaturated polyesters as described by formula (Ilia) are provided by the reaction of a conjugated base of a 25 carboxylic acid which can react with an alkyl dihalide (XRX). A conjugated base of a (primary) carboxylic acid which can be an alkali metal carboxylate (such as Na+, K+) which reacts with an alkyl halide (or alkyl with other good leaving group via a nucleophilic substitution reaction.

30 Accordingly, the polyunsaturated polyester according to formula (Ilia) can also be provided by the reaction of a conjugated base of an amide which can react with a leaving group, such as a triflate, a sulfonate, a sulfate, an alkyl 14 dihalide XR'X (by nucleophilic substitution). Additionally the conjugated base of the amide also comprises at least two carbon-carbon double bonds alternating with at least two carbon-carbon single bonds. An example is the reaction of a 5 alkyl dihalide with a alkali metal carboxylate, such as sodium or potassium sorbate.

In the context of the present invention, any of the compounds used in a particular embodiment of the present invention and chosen from the group an carboxylic acid, an 10 alkali metal carboxylate, an ester, an acyl halide, an anhydride, wherein the carboxylic acid, the conjugated base of an amide(for amide preparation), the alkali metal carboxylate (for ester preparation), the ester, the acyl halide, and the anhydride comprise at least two carbon-15 carbon double bonds alternating with at least two carbon-carbon single bonds can advantageously be derivatives of sorbic acid. The sorbic acid derivative, more specifically the conjugated double bond in the 2,4-hexadiene moiety of the sorbic acid, is responsible for the cross-linking of the 20 compounds obtained in step a), and therefore to the formation of the polymer network according to the present invention.

Sorbic acid (trans, trans-2,4-hexadienoic acid) is naturally derived from the berries of the rowan tree (Sorbus aucuparia 25 Linne). Sorbic acid (SA) and its mineral salts: sodium sorbate (NaSA)(E201), potassium sorbate (KSA) (E202) and calcium sorbate (CaSA) (E203) are commercially produced in varying chemical pathways to produce a white crystalline powder that is used as a preservative to inhibit the growth 30 of moulds, yeasts and fungi. It is not effective against bacteria. Its optimal pH values are below 6.5. The main differences between the salts are their varying solubility in water and they are preferred over sorbic acid itself.

15

Sodium sorbate is used in the same range of products as sorbic acid, including wine, dairy products (cheese, buttermilk, fermented milk, yoghurt, margarine and blends), fruit juice, fruit nectar, jams, confectionary, soft drinks, 5 rye bread, beverage whiteners etc.

A group of compounds that are closely related to SA are alkyl sorbates such as methyl sorbate and ethyl sorbate. Another group of compounds based on SA are alkali sorbates such as sodium sorbate and potassium sorbate. A building 10 block that can be synthesized from SA is sorboyl chloride.

The alkali salt of SA can be prepared (in-situ) using alkali (hydrogen) carbonates (NaHC03, KHC03, Na2C03, K2C03)

The compound that reacts with the alkali sorbate salt consists of an alkyl or activated aryl and should have at 15 least two leaving groups. The reaction can be done in protic solvents (for SnI reactions) or aprotic solvents (for Sn2 reactions). Primary alkylhalides (with 2 or more halogens) and secondary alkylhalides (with 2 or more halogens) are preferably used in SN2 reactions. Examples of good leaving 20 groups in SN2 reactions are Br- and I- ions, alkanesulfonate ions, alkyl sulfate ions, triflate ions. Tertiary alkylhalides (with 2 or more halogens) are preferably used in SnI reactions.

25 Aryl groups in the moiety R', R1, R2 and R should have strong electron withdrawing groups (nitrogroups (N02) , nitriles (CN)) at the ortho/para position with respect to the leaving group) that activates the ring towards nucleophilic substitution .

30 According to the present invention, the above-mentioned sorbic acid derivatives are reacted with a compound chosen from the group a diol (such as any hydroxyphenol, benzene dimethanol, or any aliphatic diol), a triol, a tetraol, a 16 pentaol, an hexaol, a diamine, a triamine, and a tetraamine during step a), after which the reaction product is polymerized into a polymer network by free-radical polymerization during step b). Advantageously, the reaction 5 products after step a) and the polymer network do not contain unreacted groups.

According to one aspect of the present invention, polymer networks with similar properties than the polymer network obtained after steps a) and b) according to the present 10 method can also be obtained with polyunsaturated polyethers. The formation of said polyether-based polymer networks can occur via the reaction of a polyunsaturated alcohol comprising at least two carbon-carbon double bonds alternating with at least two carbon-carbon single bonds 15 with an alkali hydride (NaH, KH) to obtain an alkoxide (or alcoholate). An example of said polyunsaturated alcohol can be sorbic alcohol (CH3 (CH=CH) 2CH2OH) . Then, the obtained alkoxide (for example the reaction of sodium hexa-2,4-dien-1-olate (or sorbolate)) can react with a molecule bearing at 20 least two leaving groups (such as alkyl dihalides, alkyl disulfonates, cycloalkyl dihalides, cycloalkyl disulfonates, activated aryl dihalides, activated aryl disulfonates or any compounds known in the art comprising a leaving group) and therefore form a polyether compound. The polyether compound 25 obtained can than be cured such as defined in step b) of the present method and therefore form a polyether-based polymer network. The advantages, preferences and definitions for the method according to the present invention are also applicable for the method for manufacturing a polyether-30 based polymer network.

According to an embodiment of the present invention, the polyunsaturated polyamides according to formulae (lb) are 17 provided by the reaction of a compound comprising at least two organic groups chosen from the group carboxylic acid, ester, acyl halide, anhydride with 2,4-hexadien 1-amine (CH3-CH2=CH-CH=CH-CH2NH2) . According to this embodiment, the 5 polymer network prepared by the method of the present invention is particularly suitable for adhesives, resins, coatings, plastics, and composites derived from plant oils, proteins, starches, and natural fibers in terms of structures, properties, manufacturing, and present increased 10 product performance, such as an increased stability.

According to an embodiment of the present invention, the polyunsaturated polyester according to formula (Illb) is provided by the reaction of a compound comprising at least 15 two organic groups chosen from the group carboxylic acid, ester, acyl halide, anhydride with 2,4-hexadien l-ol (CH3-CH2=CH-CH=CH-CH20H). According to this embodiment, the polymer network prepared by the method of the present invention is particularly suitable for adhesives, resins, 20 coatings, plastics, and composites derived from plant oils, proteins, starches, and natural fibers in terms of structures, properties, manufacturing, and present increased product performance, such as an increased stability.

25 According to an embodiment of the present invention, the carboxylic acid, the alkali metal carboxylate, the ester, the acyl halide, and the anhydride can be derivatives of sorbic acid and represented according to the formula (IV): (IV) 18 wherein Z is chosen from the group -OH, 0”M+, O-alkyl (such as methyl or ethyl), halide, 0-(C=0)-alkyl (such as methyl, ethyl, propyl, butyl, pentyl, hexyl), 0-(C=0)-alkenyl (such as propenyl, butenyl, pentenyl, hexenyl, hexadienyl), 5 wherein M is any alkali metal, such as lithium (Li), sodium (Na), potassium (K), cesium (Cs) , francium (Fr) . Preferred are Na and K. Compound (IV) can also be substituted by an alkyl, or an aryl, or an -O-alkyl, or an -0-aryl.

10 According to the present invention, step b) can be carried out at a temperature above the melting temperature range of the polyester and/or polyamide obtained in step a). In the context of the present invention, the melting temperature range can be one temperature or an interval of temperatures 15 at which the melting (transformation from solid to liquid state) is occurring.

A reactive diluent (or a reactive solvent) can also be added before or during step b) of the present method. Reactive diluents are monomers with low viscosity which have at least 20 one reactive vinyl group and form homogeneous mixtures with the previously described resins obtained after steps a). Examples of reactive diluents are methyl methacrylate, styrene, methyl acrylate. The reactive diluents are advantageously bio-based. Examples of bio-based reactive 25 diluents are myrcene, limonene, pinene (alpha, beta). Other additives can also be used, such as chain transfer agents, dyes, fillers, flame retarding compounds, nucleating agents and inhibitors (such as hydroquinone). Other (partly) biobased materials containing reactive vinyl groups can be 30 added as well. An example is commercially available acrylated soybean oil.

19

Advantageously, in of the method according to the present invention, the polymerization is step b), that is a free radical polymerization (i.e. curing) can be done thermally (addition of thermally decomposable initiators) or by UV-5 irradiation (addition of photoinitiators).

In the context of the present invention, step b) is carried out at the melting temperature interval (or melting point) of the product obtained in step a) . In step b) , the cross-linking is carried out in a way that any decomposition of 10 the compound to be cross-linked, is prevented. For example, step b) can be carried out at a temperature of at most 150°C, preferably at most at 140°C. Advantageously, the temperature is in the range 10 to 150°C, 10 to 140°C, 10 to 100°C, more advantageously in the range 10 to 90°C. Preferably, the 15 polymerization is carried out at a temperature of at least 10°C, more advantageously at least 20°C. The polymerization can be preferably carried out at room temperature, i.e. at atmospheric pressure at temperatures in the range in the range 20 to 150°C or in the range 20 to 140°C. Step b) can 20 also be carried out at higher temperatures, provided no degradation of the products occurs.

Accordingly, step b) is a curing step. In the curing step, free radicals are obtained in order to carry out the polymerization, via thermal or UV initiation using suitable 25 peroxides. Advantageously, the curing temperature can be, in certain cases, room temperature. Advantageously, the curing can be carried out at a first temperature during a predetermined period of time and the temperature is then increased (post-curing). Advantageously, the polymerization 30 in step b) is carried out in the presence of an initiator. The polymerization initiator can be selected from the conventional initiators for free-radical polymerization.

They include in particular organic peroxy compounds, such as 20 peroxides, peroxycarbonates and peresters. Combinations of peroxy compounds can also be used. Typical examples of the suitable peroxy initiators are C6-C20 acyl peroxides such as decanoyl peroxide, benzoyl peroxide, octanoyl peroxide, 5 stearyl peroxide, 3,5,5-trimethyl hexanoyl peroxide, peresters of C2-Ci8 acids and C1-C5 alkyl groups, such as t-butylperbenzoate, t-butylperacetate, t-butyl-perpivalate, t-butylperisobutyrate and t-butyl-peroxylaurate, and hydroperoxides and dihydrocarbyl (C3-C10) peroxides, such as 10 diisopropylbenzene hydroperoxide, di-t-butyl peroxide, cumyl hydroperoxide, dicumyl peroxide or combinations thereof. Radical initiators different from peroxy compounds are not excluded. A suitable example of such a compound is α,α'-azobisisobutyronitrile. The amount of radical initiator is 15 suitably from 0.01 to 3% wt, based on the weight of the product obtained after step a). Typical examples of suitable photoinitiators are alpha hydroxyketones such as 1-hydroxy-cyclohexyl -phenyl -ketone, 2-Hydroxy-2-methyl-l-phenyl-propan-l-one. Another group is the bis-acyl phosphine oxides 20 (bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide) . Typically 1-4 wt% of photoinitiator is used. Further, an accelerator may be added. Examples are cobalt naphthenate, cobalt octoate, cobalt acetate, cobalt neodecanoate, cobalt(II) 2-ethylhexanoate. Typical 25 concentrations are 5-100 ppm (0.0005-0.01 wt% based on the weight of resin), although higher Co-concentrations are not excluded.

Another aspect of the present invention relates to the 30 polymer network comprising a free radical polymerization crosslinked compound as defined in the formulae (I) to (III) according to the present invention. The polymer network are accordingly polyamide-based and/or the polyester-based 21 polymer network obtainable by the method according to the present invention.

All the definitions, advantages and preferences described above for the method according to the present invention are 5 applicable to all the aspects of the present invention.

Yet another aspect of the present invention relates to a composite polymer material comprising the polyamide-based and/or the polyester-based according to the present 10 invention. Specifically, said polymer network manufactured according to the method of the present invention can be part of a coating composition and/or composite polymer material such as glass fiber, wood flour, cork, stone, sand, basalt, flax and jute, quartz. Further, said polymer network can be 15 used for its binding properties, alone or in a composition such as in glues, e.g. for glues between metals, glass, wood based materials or plastics.

Accordingly, another aspect of the present invention relates 20 to the polyamide-based and/or the polyester-based polymer network material is used in adhesives or in coating materials. Adhesives are materials that fix items together. Adhesives cure (harden) by either evaporating a solvent or by chemical reactions that occur between two or more 25 constituents. Adhesives are advantageous for joining thin or dissimilar materials, as well as in applications where a vibration-damping joint is needed. Coating materials are covering materials that are applied to the surface of an object, usually referred to as the substrate. In many cases 30 coatings are applied to improve surface properties of the substrate, such as appearance, adhesion, wettability, corrosion resistance, wear resistance, and scratch resistance. In other cases, in particular in printing 22 processes and semiconductor device fabrication (where the substrate is a wafer), the coating forms an essential part of the finished product.

5 The present invention is further described, without being limited to, by the figures and examples hereafter.

23

Figures

Figure 1. Chemical structure of PrDSAl_2 diester

Figure 2. 1H-NMR spectrum of BDSA1_2 diester in 5 CDC13.

Figure 3. Chemical structure of cis-trans CHDMSA1_2 diester 10 Figure 4. 1H-NMR spectrum of cis-trans CHDMSA1_2 in CDCI3

Figure 5. IR spectrum of BDSA1_2 ester resin (before curing) 15

Figure 6. IR spectrum of BDSA1_2 thermoset (after curing)

Figure 7. IR spectrum of cis-trans CHDMSA1_2 20 ester monomer (before curing)

Figure 8. IR spectrum of cis-trans CHDMSA1_2 thermoset (after curing) 25 Figure 9. TGA curves of BDSA1_2 via SN2 before and after curing by free radical polymerization .

Figure 10. TGA curves of cis-trans CHDMSA1_2 via 30 SN2 before and after curing by free radical polymerization.

24

Examples

The chemical structures of SA and useful derivates for synthesis of polyesters or polyamides can be found in table 1.

5

Table 1: Sorbic acid and derivates with a 2,4-hexadiene moiety .

o 10 !1 ,R a) Sorbin:· An:·id ,,/ SX ,/ /¾¾ Z' ’’V.

··' // A,.· Oh b t AlkAli s<>rbAt.n? 0 j suc h as s<xliim / '^ΐν../'" /^/ Xso A- s or bate and 15 : pn. t AS S ium S<M"b A té 0 a) Sorbate esters I such as methyl /Ao. /--, ; / // // 'ORI sorbate and ethyl sorbat e

20 O

1 d)· i>n;>rb:>yl chlccride ο O e) Sorbic li ......

11 : /. λ J. anhydride1 //./ 1Ό . . // : 2 5 ^ // 'oh f) sorbic alcohol .../ /-,.,./ /// NH_, g) Sorbic amine 30

Sorbic anhydride should be able to result in a thermoset by free radical polymerization. However, the anhydride 25 ((C=0)-O-(0=C)) linkages will react with water to result in carboxylic acid end groups.

5 For the preparation of compounds consisting of 2 or more 2,4-hexadien moieties, the choice of starting materials depends on the route for synthesis that will be followed.

The prepared model compounds are schematically depicted in table 2a and 2b. Some model compounds were prepared in 10 duplex using different methods. The recipes for synthesis as well as analysis of these model compounds will be discussed.

Table 2a: Chemical structures of synthesized model compounds 15 ö 5 (¾) (Φ JJ (0 CD II (Φ (b)

Ca) (c) (e) ° (g) ° (e) (c) (a)

PrDSAl_2 diester based on 1,3-propanediol and sorbate moieties 2 0 5 (a) (a) (c) (e) ° (e) ¢0 (Φ (b) o BDSA12: diester based on 1,4-butanediol and sorbate moiet ies 25 “ (in(I) 77 77 “ ° ,-1 (e) (c) (a) (b) (Φ II W / \_ \ / (ί) (Φ © (a) (0 « ^ CHDMSA1 2: diester based on 1,4-cyclohexanedimethanol 30 (cis/trans mixture) and sorbate moieties 26

Table 2b: Chemical structures of synthesized model compounds Ö Ö ^ g THMPrSAl 3: triester based on 1,1,1- tris(hydroxymethyl)propane and sorbate moieties 5 o BDMSAl_2: diester based on 1,4-benzenedimethanol and sorbate moieties Ö 20 BSAl_2: monoester based on 1-butanol and sorbate moiety A) Esters with 2 or more 2,4-hexadienoate moieties 25 1) Method: Acid catalyzed direct esterification (DE): an alcohol with sorbic acid (SA). Catalyst: p-toluene sulfonic acid (PTSA).

30 Prepared are: a) PrDSAl_2 (DE) b) BDSA1_2 (DE) c) CHDMSA1_2 (DE) 27 d) THMPrSA1_3 (DE) e) BDMSA1_2 (DE) 2) Method: Esterification via intermediate: sorboyl chloride 5 (SAC1) al) Preparation of SAC1 from SA with thionyl chloride a2) Esterification of SAC1 with an alcohol 3) Method: SN2 reaction: an alkylbromide with potassium 10 sorbate (KSA) in an aprotic solvent 1,3-Dimethyl-3,4,5, 6- tetrahydro-2 (Iff) -pyrimidinone (DMPU) .

a) PrDSAl_2 (SN2) b) BDSA1_2 (SN2) c) BSA1_1 (SN2) 15

Method 1) Direct esterification reactions

General remark: For model compounds la-le which are prepared via method 1 (direct esterification), 0.04-0.05 wt% hydroquinone was added to the reaction mixture to prevent 20 premature polymerization during synthesis.

la) Propanediol (PrD) + Sorbic Acid (SA): PrDSAl_2 A three-necked flask, containing 10.7 g (0.14 moles) PrD, 47.1 g SA (0.42 moles, 3.0 mole equivalents based on PrD), 25 3.87 g PTSA (0.020 moles, 0.14 mole equivalents based on BD), 23 mg hydroquinone (0.04 wt% based on the weighed amount of BD + SA) and 180 ml toluene was placed in an oil bath. The reaction mixture was heated to 125 °C while applying a continuous stirring rate of 300 rpm and a 30 nitrogen flow of 0.5 L/min. The reaction was stopped after 8 hours. The mixture was allowed to cool to room temperature which resulted in crystallization of the excess of SA.

28

Purification

Dissolution tests showed that pure SA does not dissolve in toluene .

The reaction mixture was diluted with toluene and stirred at 5 room temperature. The unreacted SA was removed from the reaction mixture by filtration. The filtrate was collected in a large beaker to which an aqueous sodium bicarbonate solution was added under rapid stirring. Stirring was continued for 30 min to allow residual PTSA to react with 10 the sodium bicarbonate (CO2 development). The mixture was subsequently poured into a separation funnel and allowed to phase separate.

The aqueous layer was removed and the toluene layer containing the reaction product was dried over magnesium 15 sulfate. The magnesium sulfate was filtered off and the clear slightly yellowish solution was concentrated using a rotary evaporator. An off-white product was obtained. The last traces of toluene were removed by placing the solid material in a vacuum oven at 30 °C overnight. 1H-NMR 20 spectroscopy of the final PrDSAl_2 product did not show any traces of PTSA. The yield of the obtained product was: 38.6 g (yield is: 72%) .

lb) Butanediol (BD) + Sorbic Acid (SA): BDSA1_2 25 The same setup with Dean Stark trap was used for the synthesis of BDSA1_2. A three-necked flask, containing 11.7 g (0.13 moles) BD, 35.9 g SA (0.32 moles, 2.5 mole equivalents based on BD), 3.62 g PTSA (0.019 moles, 0.14 mole equivalents based on BD), 29 mg hydroquinone (0.06 wt% 30 based on the weighed amount of BD + SA) and 160 ml toluene was placed in an oil bath. The reaction mixture was heated to 125 °C while applying a continuous stirring rate of 300 rpm and a nitrogen flow of 0.5 L/min. The reaction was 29 stopped after 6.5 hours. The mixture was allowed to cool to room temperature which resulted in crystallization of the excess of SA.

5 Purification

The reaction mixture was purified by extraction with a NaHCCh solution in a similar way as described for the synthesis of PrDSAl_2. The obtained off-white solid product was examined with 1H-NMR spectroscopy. The final BDSA1_2 product did not 10 show any traces of PTSA. The yield of the obtained BDSA1_2 product was 17.35 g (48 %).

lc) Cyclohexanedimethanol (CHDM) + Sorbic Acid (SA): CHDMSA1_2 15

The same setup with Dean Stark trap was used for the synthesis of CHDMSA1_2. A three-necked flask, containing 18.8 g (0.13 moles) CHDM, 43.8 g SA (0.39 moles, 3.0 mol equivalents based on CHDM), 4.07 g PTSA (0.021 moles, 0.16 20 mol equivalents based on CHDM), 28 mg hydroquinone (0.045 wt% based on the weighed amount of CHDM + SA) and 185 ml toluene was placed in an oil bath. The flask was equipped with a nitrogen inlet and a Dean Stark trap to collect water that was formed during the reaction as condensation product 25 from the esterification reaction; the toluene, with lower density than water, will flow back into the three-necked flask. A condenser was placed on top of the Dean Stark trap. The reaction mixture was heated to 125 °C while a continuous stirring rate of 300 rpm was applied. The flask was 30 continuously purged with a nitrogen flow of 0.5 L/min. After 3.5 hours, the water level inside the Dean Stark trap did not further increase. The reaction was stopped after 7.5 30 hours. The mixture was allowed to cool to room temperature which resulted in crystallization of the excess of SA.

Purification 5 The reaction mixture was purified by extraction with a NaHCCh solution in a similar way as described for the synthesis of PrDSAl_2. The obtained off-white solid product was examined with 1H-NMR spectroscopy. The final BDSA1_2 product did not show any traces of PTSA. The weight of the obtained 10 CHDMSA1_2 product was 34.7 g (yield: 80 %).

Alternative purification:

After completion of the esterification reaction, the obtained reaction mixture was filtrated. Toluene was removed 15 using a rotary evaporator. The obtained solid CHDMSA1_2 was dissolved in minimal amount of dichloromethane and subjected to column chromatography using basic A1203 (Brockmann I) as column packing and pure dichloromethane as eluens. The final CHDMSA1_2 product was obtained as a white solid. 1H-NMR 20 spectroscopy of the CHDMSA1_2 did not show any traces of PTSA.

Id) 1,1,1-tris(hydroxymethane)propan (THMPr) + Sorbic Acid (SA): THMPrSA1_3 25 The same setup with Dean Stark trap was used for the synthesis of THMPrSAl_3. A three-necked flask, containing 12.8 g (0.095 moles) THMPr, 48.0 g SA (0.43 moles, 4.5 mol equivalents based on THMPr), 3.0 g PTSA (0.016 moles, 0.165 mol equivalents based on THMPr), 26 mg hydroquinone (0.04 30 wt% based on the weighed amount of THMPr + SA) and 180 ml toluene was placed in an oil bath. The flask was equipped with a nitrogen inlet and a Dean Stark trap to collect water that was formed during the reaction as condensation product 31 from the esterification reaction; the toluene, with lower density than water, will flow back into the three-necked flask. A condenser was placed on top of the Dean Stark trap. The reaction mixture was heated to 125 °C while a continuous 5 stirring rate of 300 rpm was applied. The flask was continuously purged with a nitrogen flow of 0.5 L/min. After 3.5 hours, the water level inside the Dean Stark trap did not further increase. The reaction was stopped after 8 hours. The mixture was allowed to cool to room temperature 10 which resulted in crystallization of the excess of SA.

Purification

The reaction mixture was purified by extraction with a NaHC03 solution in a similar way as described for the synthesis of 15 PrDSAl_2. The obtained off-white solid product was examined with 1H-NMR spectroscopy. The final THMPrSAl_3 product did not show any traces of PTSA.

Ie) 1,4-benzenedimethanol (BDM)+ Sorbic acid (SA): BDMSA1_2 20

The same setup with Dean Stark trap was used for the synthesis of BDMSA1_2. A three-necked flask, containing 13.9 g (0.10 moles) BDM, 50.8 g SA (0.45 moles, 4.5 mol equivalents based on BDM), 3.1 g PTSA (0.017 moles, 0.165 25 mol equivalents based on BDM), 26 mg hydroquinone (0.04 wt% based on the weighed amount of BDM + SA) and 180 ml toluene was placed in an oil bath. The flask was equipped with a nitrogen inlet and a Dean Stark trap to collect water that was formed during the reaction as condensation product from 30 the esterification reaction; the toluene, with lower density than water, will flow back into the three-necked flask. A condenser was placed on top of the Dean Stark trap. The reaction mixture was heated to 125 °C while a continuous 32 stirring rate of 300 rpm was applied. The flask was continuously purged with a nitrogen flow of 0.5 L/min. After 3.5 hours, the water level inside the Dean Stark trap did not further increase. The reaction was stopped after 8 5 hours. The mixture was allowed to cool to room temperature which resulted in crystallization of the excess of SA.

Purification

The reaction mixture was purified by extraction with a NaHCCb 10 solution in a similar way as described for the synthesis of PrDSAl_2. The obtained off-white solid product was examined with 1H-NMR spectroscopy. The final BDMSA1_2 product did not show any traces of PTSA. The weight of the obtained BDMSA1_2 product was 26.3 g (yield: 80 %).

15

Method 2) Esterification via sorboyl chloride (SAC1) 2al) Sorbic Acid (SA) + thionyl chloride (S0C12): SAC1 20 A three necked flask, equipped with a nitrogen inlet and reflux cooler was placed 7.86 g SA (0.070 moles) and 65 ml CHCI3. A droplet funnel, containing 11.1 g SOCI2 (0.093 moles) was connected to the three necked flask. A gas washing bottle, containing 1 N NaOH solution, was attached 25 to the reflux cooler to neutralize and dissolve the HCI/SO2 vapor that was developed during the reaction. The S0C12 was dropwise added during a period of 1 h under continuous stirring at room temperature. After all S0C12 was added, the reaction was heated to 65 °C and kept at this temperature 30 for 5 h. The reaction was then allowed to cool down and the mixture was continued to stir at room temperature overnight. The reaction mixture was subsequently heated again to 80 °C and the CHCI3 was removed by distillation. The reaction 33 mixture was then cooled to 0 °c using an ice bath. The excess thionyl chloride was removed under high vacuum. The obtained low viscous colorless liquid product (SAC1) was directly used for the reaction with BD.

5 2a2) Butanediol (BD) + Sorboyl chloride (SAC1): BDSA1_2 A three necked flask, containing approximately 7.8 g SAC1 (0.06 moles, assuming 85 % conversion) was cooled down to 0 °C using an ice bath. Subsequently, 25 ml dry 10 dichloromethane was added to the SAC1. A solution, containing 2.6 g BD (0.029 moles) and 5.1 g dry pyridine (0.064 moles) in 25 ml dry dichloromethane, was added dropwise to the SAC1 solution via a droplet funnel. During the addition of the BD/pyridine solution, the reaction 15 mixture turned yellow. After lh, the addition was completed and the reaction was allowed to come to room temperature.

The stirring of the reaction mixture was continued overnight. The yellow color of the reaction mixture became more intense.

20

Purification

The reaction mixture was washed 2 times with 100 ml 0.5 N HC1 solution. After phase separation, the dichloromethane layer was removed and washed with NaHC03. The 25 dichloromethane layer was subsequently removed, dried over magnesium sulfate and then concentrated using a rotary evaporator. The solid material was subsequently purified by column chromatography using basic aluminum oxide and mixture of 60:40 %(v/v) chloroform: heptaneas eluens. The fractions 30 with no impurities were added together and the eluens was removed by rotary evaporation.

34

Method 3) Nucleophilic substitution reactions (SN2) 3a) 1,3-dibromopropane + potassium sorbate (KSA): PrSAl_2 58.24 g KSA (0.39 moles) was added to a 300 ml double wall 5 reactor, equipped with motorized stirrer and nitrogen inlet. Subsequently, 120 ml DMPU was added. The solution was stirred at 300 rpm whereas a nitrogen flow of 0.5 L/min was applied. 13.14 g 1,3-dibromopropane (0.065 moles) was added via a funnel to the reactor. Subsequently, approximately 60 10 ml DMPU was used to rinse the funnel to make sure that no residual 1,3-dibromopropane was left behind in the funnel. The temperature of the oil bath was set at 32 °C (approximately 30 °C inside the reactor). The reaction was continued for 3 days.

15

Purification

The reaction mixture was poured into a beaker containing 800 ml water which resulted in formation of a white precipitate. The suspension was stirred at room temperature for 20 approximately 20 min. The suspension was then filtrated and washed with 500 ml demiwater. The white powder was dried overnight in a vacuum oven at 35 °C. The total yield was: 14.7 g (86 %) .

25 3b) 1,4-dibromobutane + Potassium sorbate (KSA): BDSA1_2 42.1 g KSA (0.28 moles) was added to a 300 ml double wall reactor, equipped with motorized stirrer and nitrogen inlet. Subsequently, 100 ml DMPU was added. The solution was 30 stirred at 300 rpm whereas a nitrogen flow of 0.5 L/min was applied. 10.1 g 1,4-dibromobutane (0.047 moles) was added via a funnel to the reactor. Subsequently, approximately 30 ml DMPU was used to rinse the funnel to make sure that no 35 residual 1,4-dibromobutane was left behind in the funnel.

The temperature of the oil bath was set at 32 °C (approximately 30 °C inside the reactor). The reaction was continued for 3 days.

5

Purification

The reaction mixture was poured into a beaker containing 800 ml water which resulted in formation of a white precipitate. The suspension was stirred at room temperature for 10 approximately 20 min. The suspension was then filtrated and washed with 250 ml demiwater. The white powder was dried overnight in a vacuum oven at 35 °C. The total yield was: 11.7 g (90 %) .

15 3c) 1-bromobutane + potassium sorbate (KSA): BSA1_1 49.6 g KSA (0.33 moles) and 100 ml DMPU were added to a 300 ml double wall reactor, equipped with motorized stirrer and nitrogen inlet. The reaction mixture was stirred at 250 rpm 20 whereas a nitrogen flow of 0.5 L/min was applied.

Subsequently, 15.2 g 1-bromobutane (0.11 moles) was added via a funnel to the reactor. Approximately 60 ml DMPU was used to rinse the funnel to make sure that no residual 1-bromobutane was left behind. The temperature of the oil bath 25 was set at 32 °C (approximately 30 °C inside the reactor). The reaction was continued for 3 days.

Purification

The reaction mixture was slowly poured into a beaker 30 containing approximately 250 ml water of approximately 5 °C which resulted in formation of a white emulsion. The aqueous layer was subsequently extracted with n-heptane in a separation funnel and allowed to phase separate. After 36 extraction, the aqueous layer was transparent. The n-heptane layer was concentrated using a rotary evaporator. The yield of the colorless low viscous ester was: 10.2 g (54.4%).

5 Curing procedure A silicon mold was preheated in a vacuum oven at either 90 °C or 120 °C (only for CHDMSA1_2 monomer). Samples of unsaturated ester monomer were heated above their melting 10 temperature (typically 20 °C above Tm) until completely molten. The samples were stirred with a magnetic stirrer and the initiator (3 wt% MEKP or 3 wt% TBPB) was added. Almost directly after that, the samples were poured into the silicon mold. The curing was performed under nitrogen 15 atmosphere. After 5 h, the temperature was increased from 90 °C to 100 °C. The nitrogen flow was subsequently replaced with vacuum and the samples were left in the oven for additional curing overnight.

20 The CHDMSA1_2 samples were kept under nitrogen atmosphere at 120 °C for 5-5.5 h. After this period, the samples were removed from the oven and allowed to cool down to room temperature.

25 Curing results

The results of the curing experiment are shown in table 3.

It was observed from this table that the curing reaction of all diesters resulted in hard materials. However, the 30 monoesters remained liquid which implies that no significant curing occurred.

37

Table 3: Curing results of several synthesized model compounds

Sample name : Type of Curing prograni1 Curing result at reaction1 room tenperature

PrDSAl 2 1 90 °C, 1¾: 5 hrs glassy material ; 100 'C, vacuum: overnight BDSAl 2 1 90 "C, 1½: 5 hrs glassy material 100 "C, vacuum: overnight CHDMSAl_2i 1 120 "C, H2: 5 hrs glassy material THMPSAl 3i Ï 90 “C, H2: 5 hrs glassy material 10 — 100 °C, vacuum: overnight

PrDSAl 2 3 90 °C, 1½: 5 hrs glassy material 100 °C, vacuum: overnight BDSAl 2 3 90 °C, H2: 5 hrs glassy material 100 °C, vacuum: overnight

Butyl 3 90 “C 5 hrs Remained liquid 15 sorbate J( curing program stopped alter 5 h) a Type of reaction: number 1 refers to direct esterification between an alcohol and sorbic acid; number 3 refers to Sn2 20 reaction using potassium sorbate and an alkylbromide.

b Samples were cured using 3 wt% 2-butanone peroxide in 32 wt% phthalate free plasticizer mixture. For CHDMSA1_2, 3 wt% tert-butyl peroxybenzoate was used.

25 Characterization of synthesized model compounds

Chemical structure analysis: 1H-NMR spectroscopy BDDSA1_2 ester monomer 30

The chemical structure of BDDSA1_2 is schematically shown in figure 1. The corresponding 1H-NMR spectrum is show in figure 2 (1H-NMR spectrum of BDDSA1_2 diester in CDCI3) . Peak (f) at 38 4.15 ppm corresponds to the two protons which are attached to the same C atom as the ester group.

5 Cis-trans CHDMSA1_2 ester monomer

The chemical structure of cis-trans CHDMSA1_2 ester is shown in figure 3. The corresponding 1H-NMR spectrum is shown in figure 4 (1H-NMR spectrum of cis-trans 1,2-CHDMSAl_2. CDCI3) . 10 The 1H-NMR spectrum of the starting material cyclohexanedimethanol (not shown here) shows 2 peaks (due to cis/trans) at approximately 3.5 ppm. These peaks originate from the two protons which are attached to the same C atom as the hydroxyl group (-CH2-OH).

15 Due to the esterification, these peaks have shifted from 3.5 to approximately 4 ppm (peaks denoted with f*) as can be observed from the 1H-NMR spectrum of CHDMSA1_2 ester. Consequently, a mixture of cis and trans esters has been formed. The absence of peaks at 3.5 ppm shows that no 20 hydroxyl groups are present anymore.

In the figure 3, the chemical structure of cis,trans CHDMSA1_2 ester is represented. The protons denoted with (f*) and (g*) give multiple peaks due to cis-trans isomerism 25

Chemical structure analysis: IR spectroscopy BDSA1_2 ester monomer and BDSA1_2 thermoset 30 The IR spectrum of BDSA1_2 ester before and after curing (i.e. thermoset) is shown in figures 5 and 6, respectively. Table 4 shows the most important IR absorption bands for the BDSA1_2 ester monomer and thermoset.

39

The IR spectrum of BDSA1_2 monomer does not show any OH stretching bands and hydrogen bonded OH stretching bands. In addition, a strong C=0 stretching band is observed at 1700 5 cm'1 together with a C-0 stretching band at 1243 cm'1.

Consequently, the BDSA1_2 monomer consists of an ester as was also verified by 1H-NMR spectroscopy (1H-NMR spectrum of BDSA1_2 is shown in figure 2). The vinyl groups of the 2,4-hexadiene moiety have absorption bands at 1643 and 1617 cm-1.

10

The IR spectrum of the cured BDSA1_2 material (see figure 6) shows that the absorption bands corresponding to the vinyl groups are significantly smaller compared with the same absorption bands of the BDSA1_2 monomer (or ester resin 15 before curing) (see figure 5).

Hence, polymerization has occurred during the curing reaction. In addition, there are still some vinyl groups present. The absorption band at 969 cm'1 most likely is the result from trans CH=CH groups in branched 3-hexenoate (CH3-20 CHR-CH=CH-CHR-COO-) moieties which may be formed during curing.

25 40

Table 4. Assigned IR absorption bands from BDSA1_2 ester monomer and BDSA1_2 thermoset IR absorption bands BDSAl 2 ester monomer Wavenumber, cm'1 -= ;---—-—-· · ' 1-; — ;-^-1

OH stretching and hydrogen bonded OH jHo significant J

5 stretching j band(s) j

Methyl and methylene C-H stretching: j 2850-3050 j 0=0 stretchiester 1700 C=C stretching, symmetric stretching - 1643 j

C=0 stretching,: .-antisymmetric stretching j - 1617 J

C-0 stretching from ester 1243, possibly 1186

Conjugated CH=CH-CH=CH trans-trans-trans i and./ or 1138 wag from £, 4“hexadiene moiety : 1001 _ IR absorption bands BDSAl 2 themoset Wavenumber, cm'1 OH stretching and hydrogen bonded OH : Hc significant . stretching. band (s)

Methyl and methylene C-H stretching : £85:0:-:3050 C=0 stretching from ester : 172:6 C=C stretching, symmetric stretching - 1645 decreased C=C stretching, antisymmetric, stretching j - 1618 decreased 15 C-O stretching from ester: 1£40, possibly 1153 j CH=CH trans wag (possibly from branched 969 (most likely) hexenoate moieti e s) _ 20 Cis-trans CHDMSA1_2 ester monomer and cis-trans CHDMSA1_2 thermoset

The FTIR spectrum of CHDMSA1_2 ester before and after curing are shown in figures 7 and 8, respectively. Table 5 shows 25 the most important IR absorption bands for the CHDMSA1_2 ester monomer and thermoset.

Similar to the BDSA1_2 system, the C=C stretching bands of CHDMSA1_2 decrease in height after curing which confirms 30 that free radical polymerization occurred. Also here a strong absorption band at approximately 970 cm'1 is present which may be attributed to trans CH=CH groups from 3-hexenoate moieties.

41

Table 5. Assigned IR absorption bands from BDSA1_2 ester monomer and BDSA1_2 thermoset i IE. absorption bands cis-trans CHDMSAl_2 Wavenumber, cm-1 _ s ester monomer 3 — - · - - — ’ —— — — 1 j ............................ —|....................

•OH stretching and hydrogen bonded OH No significant- I stretching band(s) iMethyl and methylene C-H stretching 2850-3050 jC=0 stretching from ester 1699 I C=C stretching, symmetric stretching - 1643 I C=C stretching, antisymmetric stretching - 1611 J C-O stretching from ester 1243, possibly 1198 ]_q Conjugated CH=CH-CK=CH trans-trans-trans and/or 1136¾ wag from 2,4-hexadienoic moiety_ 1001 _ IR absorption bands cis-trans CHDMSA1 2 Wavenumber, cm"1 thermoset OH stretching and hydrogen; bonded OH No significant stretching band (s)

Methyl and methylene C-H stretching 2850-3050 0=Ό stretching from ester 1727 15 C=C stretching, symmetric stretching - 1645 decreased C=C stretching, antisymmetric stretching - 1618 decreased C-O stretching from ester;: 1237, possibly 1142 CI^CH trans wag (possibly from branched 970 (most likely) 3-hexenoate moieties).

20 Thermal properties analysis

Thermogravimetric analysis (TGA) TGA measurements of the synthesized unsaturated SA esters 25 and he corresponding thermosets obtained after curing were measured by TGA. The TGA curves of BDSA1_2 (SN2) monomer and corresponding thermoset are shown in figure 9. The cured BDSA1_2 material has an increased heat resistance compared with the original monomer. This is a clear indication that 30 free radical polymerization reactions have occurred during the curing process. A similar TGA result is obtained for the CHDMSA1_2 (DE) monomer as can be observed from the corresponding TGA curve as is shown in figure 10. It can be seen that the thermal stability of the cured CHDMSA1_2 42 material is even higher compared with the cured BDSA1_2 sample .

In Figure 9, the TGA curves of BDSA1_2 via SN2 before curing are represented (—) and after curing by free radical 5 polymerization, they are represented (—) .

In Figure 10, the TGA curves of CHDMSA1_2 before curing are represented (—) and after curing by free radical polymerization, they are represented (—) .

10

Differential Scanning Calorimetry (DSC)

The melting temperatures of the synthesized unsaturated SA esters were determined by DSC measurements. The results are 15 summarized in Table 6.

43

Table 6: Thermal properties of synthesized unsaturated SA ester monomers.

: Sample name Type of Curing program? Curing result at 5 i reaction1 room tenperature ; PrDSAl 2 1 9° °c r ' 5 hrs glassy material

100 ?C, vacuum: overnight I

BDSAl 2 1 90 “C, H2: 5 hrs glassy material 100 ’C, vacuum: overnight CHDMS Al 2 j 1 120 ‘C, H;: 5 hrs glassy material ^ TUMPSAl 3 1 90 °C, ΪΓ : 5 hrs glassy material 100 ‘C j vacuum: overnight

PrDSAl 2 3 90 °C, H;: 5 hrs glassy material 100 ‘C, vacuum: overnight BDSAl 2 3 90 'C, 11: 5 hrs glassy material 100rtf vacuum: overnight

]_ 5 Butyl 3 90 “c 5 hi's j Remained liguid I

sorbate louring program stopped after 5 h) a Tm was taken from the second heating run. Heating and cooling rates of 10 °C/min were used.

20 b Cold crystallization and recrystallization occurred upon heating. Determination of Tm, onset and AHfus was not possible. c CHDMSA1_2 is a mixture of cis and trans. Therefore, two melting peaks were observed.

d Type of reaction: number 1 refers to direct esterification 25 between an alcohol and sorbic acid; number 3 refers to SN2 reaction using potassium sorbate and an alkylbromide.

Dynamic Mechanical Thermal Analysis (DMTA) 30

The glass transition temperatures of the obtained thermosets were determined with DMTA. The results are shown in table 7.

44

Table 7: DMTA measurements of thermosets from synthesized model compounds

Sample name jfegpe o£ Tga [°C] E' E''

reaction [GPa] at 25 [MPa] at 25 °C

___°C

PrDSAl_2 IS 88 1.9 77 BDSA12 1 77 1.4 54 CHDMSA12 1 72b 1.4 39 16 3b 10 THMPSA13 1 * * *

XylSAl_2 1 * * *

PrDSAl_2 3 f * * BDSA12 3 74 1.4 74

Ethyl CoiiÉiercial h0 DMTA measurement possible , sample sorbate ; Butyl 3: Ho DMTA measurement possible sorbate a The Tg was determined by taking the onset of the storage 20 modulus curvature.

b CHDMSA1_2 monomer is a mixture of cis and trans. As a result, the cured CHDMSA1_2 resin two Tg values were obtained.

*not measured 25

Viscosity measurements

Viscosity measurements of the polymer network obtained by the method of the present invention have a suitable viscosity for further treatment or handling.

30

Claims

A method for preparing a polymer network comprising: a) providing a polyunsaturated polyamide which has at least two carbon-carbon double bonds that alternate with at least two carbon-carbon single bonds according to formulas (I): T; Ö! "V ·. h1 H X 'II * - J x i-. - Jx (Ia) (Ib) and / or a polyunsaturated polyamide which has at least two carbon-carbon double bonds that alternate with at least two carbon-carbon single bonds according to formula (II): r R * 2 0 R: b Ji X '—η1 "' - - * X (Ha) 25 and / or a polyunsaturated polyester which has at least two carbon-carbon double bonds that alternate with at least two carbon-carbon single bonds according to formulas (III): 30. o R ·. / '· Ƒ' "L" e. \ ^ Pr * r ίΞΡ '\ 4 v ,. 4 I-X (Ilia) (11 Ib) wherein R 1, R 1, R 2, R are selected from the group alkyl, cycloalkyl, alkenyl, cycloalkenyl and aryl, wherein R 1 and R 2 are selected from the group H and NH- (C = 0) - (CH = CH-) n R *], where R * is H or CH3, where n ^ 2 and where x ^ 2 in formulas (I) and (III) where x ^ 1 in formula (II ) if at least one of R1 or R2 is -NH- (C = O) - (CH = CH-) n R *, or wherein x 10 ^ 2 if both R1 and R2 are H; and b) crosslinking the polyunsaturated polyamide of the formula (I) and / or the polyunsaturated polyamide of the formula (II) and / or the polyunsaturated polyester of the formula (III) by free radical polymerization, to thereby obtain the polymer network.

2. Method according to claim 1, wherein n is in the range of 2 to 10 in at least one of the formulas (I), (II) and (III). The method of claim 1, wherein x is 3, 4, 5 or 6 in at least one of the formulas (I), (II) and (III). 2. Process according to any one of claims 1 to 3, wherein the polyunsaturated polyamides according to the formulas (Ia) and / or (Ha) are obtained by the reaction of one polyamine with a compound selected from the group consisting of a carboxylic acid, an ester, an acyl halide and an anhydride, wherein the carboxylic acid, the ester, the acyl halide, and the anhydride comprise at least two carbon-carbon double bonds that alternate with at least two carbon-carbon single bonds, wherein the amine groups of the polyamine are primary or secondary amines.

The process according to any of claims 1 to 3, wherein the polyunsaturated polyester of the formula (IIIa) is obtained by the reaction of a polyol with a compound selected from the group consisting of a carboxylic acid, an ester, a acyl halide and an anhydride wherein the carboxylic acid, ester, acyl halide and anhydride comprises at least two carbon-carbon double bonds that alternate with at least two carbon-carbon single bonds, the polyol having at least one carbon-carbon single bond includes.

The process according to any of claims 1 to 3, wherein the polyunsaturated polyester of the formula (IIIa) is provided by the reaction of an alkyl dihalide with an alkali metal carboxylate, wherein the alkali metal carboxylate has at least two carbon-carbon double bonds which alternate with at least two carbon-carbon single bonds wherein the polyol comprises at least one carbon-carbon double bond. 25

7. A method according to claim 1 or 2, wherein the polyunsaturated polyamide of the formula (Ib) is provided by the reaction of a compound comprising at least two organic groups selected from the group consisting of a carboxylic acid, an ester, an acyl halide and an anhydride with a 2,4-hexadiene-1-amine.

8. A method according to claim 1 or 2, wherein the polyunsaturated polyester of the formula (Illb) is provided by the reaction of a compound comprising at least two organic groups selected from the group consisting of a carboxylic acid, an ester, an acyl halide , and an anhydride with a 2,4-hexadiene 1-ol.

9. Process according to any of claims 4 to 6, wherein the carboxylic acid, the alkali metal carboxylate, the ester, the acyl halide and the anhydride are represented according to the formula (IV): Z is selected from the group consisting of -OH, 0ΊΜ +, 0-alkyl, halide, 0- (C = 0) -alkyl, 0- (0 = 0) - alkenyl, where M + is an alkali metal.

10. A method according to any one of claims 1 to 9, wherein step b) is added at a temperature above the melting temperature range of the polyamide and / or the polyester obtained in step a).

11. Polymer network comprising at least one compound cross-linked with formulas (I) to (III) by a free-radical polymerization as defined in the method according to one of claims 1 to 10.

A composite polymeric material comprising the polymer network of claim 11.

An adhesive comprising the polymer network according to claim 11.

A coating material comprising the polymer network according to claim 11.