A structure comprising a first material and a second material coupled to each other by means of a coupling agent

Abstract

The present invention relates to a structure comprising a first material, a second material and a coupling agent capable of coupling the first and the second material, the coupling agent comprising a moiety of formula (I) having a first nitrogen atom N' and a second nitrogen atom N"(formula (I)) with A comprising a chain of 2 to 4 carbon atoms, with said chain comprising a saturated linear chain or with at least 2 carbon atoms of said chain being part of a non-aromatic cyclic structure; with the first nitrogen N' being provided with a substituent L being capable of covalently binding with the first material, and with the moiety of formula (I) forming a covalent dynamic bond by means of the second nitrogen N" with the second material. The invention further relates to a method to provide such structure.

Description

A structure comprising a first material and a second material coupled to each other by means of a coupling agentField of the invention

[0001] The present invention relates to a structure comprising a first material and a second material with the first material coupled to the second material by a coupling agent comprising two amide functional groups connected to each other by a chain comprising 2 to 4 carbon atoms.

[0002] The invention further relates to a method to prepare such structure.Background art

[0003] Nowadays, composite materials comprising different materials, for example different polymer materials are abundantly used, for example in construction and automotive industry. Examples of such composite materials comprise multilayer materials as well as composite materials comprising fillers such as particles (nanoparticles) or fibres (nanofibres).

[0004] Structural adhesives are key to build lightweight composite materials. For most applications a strong bonding between the material is required.

[0005] However, the strong bond between the materials makes dismantling or recycling of the composite materials challenging. This is especially the case when thermosetting adhesives are applied, in which mouldable or lower viscosity reactive components are cross-linked, resulting in a rigid polymer network. The high viscosity or interaction imparted by the covalently cross-linked nature of structural adhesives causes problems with repositioning, repairing, and recycling of the assembled structure. As a result, there is a high need to design a programmable or responsive (de)bonding of multi-layered materials.

[0006] Heat triggerable reversible covalent bonds have been proposed to provide reliable changes in physical properties allowing removal of the adhesive. Examples of recent chemical platforms used for temperature-induced debonding include disulfide exchange, Diels-Alder chemistry, transesterification and boronic ester transesterification. Especially the well-reported furan- maleimide Diels-Alder system has attracted both academic and industrial attention with respect to its responsive properties. However, adoption of this system has been limited due to significant debonding even at temperatures below 100 °C and frequent complete liquification around 120 °C. Furthermore, the (re)generated furan and maleimide groups are not thermally robust and can undergo a variety of side reactions upon heating, including autopolymerisation.

[0007] Therefore, it is of great interest to investigate other chemical platforms that enable a more reliable and controlled debonding without the risk of unintended debonding.Summary of the invention

[0001] It is an object of the present invention to provide a structure comprising a first and a second material and a coupling agent capable of coupling the first and the second material thereby avoiding the problems of the prior art.

[0002] It is a further object of the present invention to provide a structure comprising a coupling agent that can be used within a wide temperature range, even at temperatures higher than 100 °C.

[0003] It is another object of the present invention to provide a structure comprising a first and a second material ensuring an adequate adhesion or interactivity between the first and the second material and allowing to reversibly control the adhesion or interactivity between the first and the second material.

[0004] It is a further object of the present invention to provide a structure comprising a first material and a second material having reduced stress at the interface of the first and the second material.

[0005] It is a further object of the present invention to provide a structure comprising a first and a second material whereby stress concentration is avoided at the interface of the first and the second material.

[0006] It is a further object of the present invention to provide a structure comprising multiple components that can be recycled easily.

[0007] It is a further object of the present invention to provide a structure that allows on-demand adhesive dismantling.

[0008] It is still a further object of the present invention to provide a method to provide a structure comprising a first material, a second material and a coupling agent capable of coupling (preferably releasably coupling) the first and the second material.

[0009] According to a first aspect of the present invention, a structure comprising a first material, a second material and a coupling agent capable of coupling, preferably releasably coupling, the first and the second material is provided. The coupling agent comprises a moiety of formula (I) having a first nitrogen atom N’ and a second nitrogen atom N”:with A comprising a chain of 2 to 4 carbon atoms, whereby the chain comprises a saturated linear chain or whereby at least 2 carbon atoms of the chain are part of a non-aromatic cyclic structure, preferably of a saturated or partially saturated cyclic structure; with the first nitrogen N’ being provided with a substituent L being capable of covalently binding with the first material, and with the moiety of formula (I) forming a covalent bond or being capable to form a covalent bond, in particular a covalent dynamic bond, by means of the second nitrogen N” with the second material.COUPLING AGENT

[0010] The structure according to the present invention comprises a first material and the second material, thereby defining an interface between the first and the second material. Preferably, the coupling agent is present at the interface between the first and the second material.

[0011] The coupling agent according to the present invention provides coupling (for example adhesion) between the first and the second material. An important advantage of the coupling agent according to the present invention compared to coupling agents known in the art is that the coupling is a releasable coupling. The debonding of the first and the second material can for example be controlled by applying heat.

[0012] The coupling agent according to the present invention has the further advantage to reduce the stress at the interface between the first and the second material.

[0013] For the purpose of the present invention the term ‘coupling agent’ refers to primers improving the adhesion between two materials as well as to compatibilizers improving the compatibility between two materials, for example between two polymer materials.A “primer” as described herein refers to a substance or composition applied to a surface of a first material before the application of a second material, for example an adhesive. Generally, primers are configured to enhance the adhesion between the first material (for example a substrate) and the second material (for example a polymer or an adhesive), ensuring an improved bond strength. Non-limiting examples of primers improving the interfacial properties such as the adhesion between two materials comprise for example primers improving the adhesion between two polymer layers, primers improving the interfacial properties such as the adhesion between a (metal) substrate and a polymer and primers improving the interfacial properties such as the adhesion between a filler (for example an inorganic filler) and a polymer.A “compatibilizer” as described herein refers to a substance or composition added to a formulation, a polymer, or a polymer blend. Generally, compatibilizers are configured to improve the miscibility and blending of at least a first and a second material, for example to improve the miscibility and blending of two or more polymers, preferably polymers of a different chemical composition. Nonlimiting examples of compatibilizers comprise agents promoting the interfacial adhesion between two polymers which are otherwise immiscible, for example nylon and polystyrene.

[0014] The substituent L is preferably selected from the group consisting of -SiXs groups, -PO3Y2 groups, alkene groups, alkyne groups, thiol groups, isocyanate groups, acrylate groups, acrylamide groups, catechol group and derivatives of a catechol group. Preferably, the moiety of formula (I) is covalently binding to the first material for example by means of a substituent X of a -SiXs group, a substituent Y of a -PO3Y2 group, by means of an alkene or alkyne, by means of a thiol group, an isocyanate, an acrylate, an acrylamide or by means of a catechol group or a derivative of a catechol group.

[0015] In case the substituent L comprises a -SiXs group, preferably at least one substituent X is selected from the group consisting of -OR1, -OC(=O)R1, whereby -R1is an alkyl, preferably aC1-C4 alkyl. In preferred embodiments each of the substituents X of a -SiXs group is selected from the group consisting of -OR1, -OC(=O)R1, whereby -R1is an alkyl, preferably a C1-C4 alkyl.

[0016] In case the substituent L comprises a -PO3Y2 group, preferably at least one substituent Y is selected from the group consisting of -H or -R2whereby -R2is an alkyl, preferably a C1-C4 alkyl. In preferred embodiments each of the substituents Y of a -PO3Y2 group is selected from the group consisting of -H or -R2whereby -R2is an alkyl, preferably a C1-C4 alkyl.

[0017] As specified above A comprises a chain of 2 to 4 carbon atoms. Such chain may comprise a saturated linear chain. Alternatively, at least 2 carbon atoms of such chain of 2 to 4 carbon atoms are part of a non-aromatic cyclic structure, preferably of a saturated or partially saturated cyclic structure. In preferred embodiments, 2 carbon atoms of A are part of a saturated hydrocarbon, for example of cyclopentane, cyclohexane or cycloheptane. In case the at least 2 carbon atoms are part of a partially saturated (and thus partially unsaturated) cyclic structure, the bonds between the at least 2 carbon atoms of A are preferably saturated.

[0018] At least one of the carbon atoms of A can be substituted. Preferred substituents comprise alkyls, for example methyl, ethyl, propyl or butyl. Preferably, the substituents of the carbon atoms of A do not comprise unsaturated carbon-carbon bonds.

[0019] It is clear that in case the at least 2 carbon atoms of A are part of cyclic structure, one or more other carbon atoms of such cyclic structure can be substituted.

[0020] The coupling agent according to the present invention is preferably obtainable by reaction of at least one compound B with at least one compound C. The at least one compound B comprises an imide or dicarboxamide, whereby the imide or dicarboxamide has 2 to 4 carbon atoms between the two carbonyl groups of the imide or dicarboxamide and whereby the imide or dicarboxamide are provided with the substituent L on the N atom of the imide or one or both N atoms of the dicarboxamide. Preferably, the at least one compound B comprises an imide, whereby the imide has 2 carbon atoms between the two carbonyl groups of the imide, and whereby the imide is provided with the substituent L on the N atom of the imide.The at least one compound C comprises at least one primary amine functional group.

[0021] Some preferred imides of compound B comprise N-substituted adipimide, N-substituted succinimide and N-substituted glutarimide. Other preferred N-substituted imides are given below:

[0022] A dicarboxamide refers to a compound having two carboxamide groups. Some preferred dicarboxamides of compound B comprise N-substituted adipamide, N-substituted succinamide and N-substituted glutaramide. Other preferred N-substituted dicarboxamides are given below:

[0023] Preferred substituents L comprise a -SiXs group, whereby at least one substituent X is selected from the group consisting of -OR1, -OC(=O)R1, whereby -R1is an alkyl, preferably a CI- 04 alkyl. Examples of such substituents comprise y-aminopropyltriethoxysilane, (aminoethylaminomethyl)phenyltrimetoxysilane, 3-Aminopropylmethyldiethoxysilanes and p- Aminophenyltrimethoxysilane. Some preferred substituted imides having a -SiXs group as substituent L are given below :

[0024] Other preferred substituents L comprise a -PO3Y2 group provided, with at least one at least one substituent Y selected from the group consisting of -H or -R2whereby -R2is an alkyl, preferably a C1-C4 alkyl. Examples of such substituents comprise alkyl phosphonates and phosphonic acids.Some preferred substituted imides having a -PO3Y2 group as substituent L are given below:

[0025] Other preferred substituents L comprise an alkene, an alkyne group, a thiol group, an isocyanate group, an acrylate group, a methacrylate group, an acrylamide group, methacrylamide group, a catechol group or a derivative of a catechol group. Some preferred substituted imides are given below:• Substituent L comprising an alkene or alkyne group;• Substituent L comprising an isocyanate:• Substituent L comprising an acrylate, methacrylate, acrylamide or methacrylamide group:• Substituent L comprising a catechol group or a derivative of a catechol group:

[0026] As mentioned above, the at least one compound C comprises at least one primary amine functional group. In particular embodiments the at least one compound C comprises a plurality of primary amine functional groups, for example 2, 3 or 4 primary amine functional groups.

[0027] In preferred embodiments the at least one compound C further comprises at least one group capable of polymerizing and / or copolymerizing to form the second material. In other preferred embodiments the at least one compound C further comprises at least one group capable to interact with a precursor to form the second material. In further embodiments the at least one compound C may further comprise at least one group capable of polymerizing and / or copolymerizing to form the second material and at least one compound C further comprises at least one group capable to interact with a precursor to form the second materialParticularly preferred examples of compound C comprise curing formulations containing primary amines such as epoxies, polyureas and nylon materials. Other preferred examples of compound C comprise a radical polymerizable group such as styrene, acrylates, methacrylates, acrylamides and methacrylamides.

[0028] Examples of suitable primary amines for curing formulations are given below

[0029] Other suitable amines comprise 4,7-dioxadecane-1 ,10-diamine, Diethylene Glycol Bis(3- aminopropyl) Ether, Jeffamine D230 and D400, Jeffamine XTJ-504 and XTJ-51 1 , pentaethylenehexamine (PEHA), hexamethylenediamine (HMDA), N-(2-aminoethyl)-1 ,3- propanediamine, N,N’-bis(3-aminopropyl)ethylenediamine and 3,9-bis (3-aminopropyl) 2,4,8,10- tetraoxaspiro (5,5)undecane.FIRST MATERIAL

[0030] The first material of the structure according to the present invention comprises for example a polymer material, a glass material, a silica or silica-based material, a carbon or carbon-based material, a metal or metal alloy, a ceramic material or a combination thereof.

[0031] Preferred polymer materials as first material comprise polyurethanes, polyacrylates, polypropylene, polyethylene, polystyrene, polyethylene oxide, polybutadiene, styrene-butadiene rubber, polyisoprene, polyethylene terephthalate, natural rubber, epoxidized natural rubber, polyvinyl alcohol, polydimethylsiloxane, polyamides and polyimides. Polymers can be oxidized through, for instance, plasma treatment prior to contacting compound B.

[0032] Preferred metal or metal alloys as first material comprise aluminium, titanium, copper, chromium, tin, zinc, iron, gold and alloys thereof.

[0033] In particular examples the first material comprises a substrate, for example a polymer substrate, a glass substrate, a silica or silica-based substrate, a carbon or carbon-based substrate, a metal or metal alloy substrate, a ceramic substrate or a combination thereof.Preferred polymer substrates comprise polyurethanes, polyacrylates, polypropylene, polyethylene, polystyrene, polyethylene oxide, polybutadiene, styrene-butadiene rubber, polyisoprene, polyethylene terephthalate, natural rubber, epoxidized natural rubber, polyvinyl alcohol, polydimethylsiloxane, polyamides and polyimides.Preferred metal or metal alloy substrates comprise aluminium, titanium, copper, chromium, tin, zinc, iron, gold and alloys thereof.

[0034] In case the first material comprises a substrate, any type of substrate can be considered. Preferred substrates comprise elongated substrates, either rigid or flexible substrates. The first material may for example comprise a sheet, a foil, a plate, a wire, a cable, a fibre, preferably long wires, long cables or long fibres or a combination thereof. Alternatively, the first material may comprise particulates, for example short wires, short cables or short fibres, or particles, for example powder particles, either having a spherical or irregular shape. It is clear that embodiments comprising different types of elongated substrates, different types of particulates or comprising combinations of elongated substrates and particulates can be considered as well.

[0035] For the purpose of the present invention, long wires, long cables or long fibres refer to wires, cables or fibres having an aspect ratio (defined as the ratio of the length of the fibre to the (equivalent) diameter of the wire, cable or fibre higher than 100, preferably higher than 200.For the purpose of the present invention, short wires, short cables or short fibres refer to wires, cables or fibres having an aspect ratio lower than 100, preferably between 20 and 100, or between 20 and 60. The equivalent diameter of a fibre is defined as (defined as the ratio of the length of the fibre to the (equivalent) diameter of the wire, cable or fibre higher than 100, preferably higher than 200.The term "equivalent diameter" refers to the diameter of an imaginary circle, which has the same surface as the surface of the wire, cable or fibre cut perpendicular to the major axis of the wire, cable or fibre.

[0036] In other examples according to the present invention, the first material comprises a polymerized or copolymerised material, for example polyurethanes, polyacrylates, polypropylene, polyethylene, polystyrene, polyethylene oxide, polybutadiene, styrene-butadiene rubber, polyisoprene, polyethylene terephthalate, rubber, epoxidized rubber, polyvinyl alcohol, polydimethylsiloxane, polyamides and polyimides.SECOND MATERIAL

[0037] The second material preferably comprises a polymer material, and more preferably an epoxy-based or a nylon-based polymer. Preferred polymer materials comprise amine-cured epoxy resins, epoxidized natural rubber, amine-cured acrylate resins, nylon PA 6, nylon PA 6,6, PA 6T, Aramid, polyamide-imide, polypeptides, proteins, polyolefins, polyacrylates, polyacrylamides, polymethacrylates, polymethacrylamides.EXAMPLES OF STRUCTURES ACCORDING TO THE PRESENT INVENTION

[0038] A first group of structures according to the present invention comprises a first material, a second material and a primer as coupling agent. For the first group of structures the first material preferably comprises a polymer material, a glass material, a silica or silica-based material, a carbon or carbon-based material, a metal or metal alloy, a ceramic material or a combination thereof. Preferably, the first material comprises a polymer substrate, a glass substrate, a silica or silica- based substrate, a carbon or carbon-based substrate, a metal or metal alloy substrate, a ceramic substrate or a combination thereof. Preferred substrates comprise elongated substrates, either rigid or flexible substrates such as sheets, foils, plates, wires, cables, fibres, preferably long wires, long cables or long fibres or a combination thereof. Alternatively, the substrates comprise particulates, for example short wires, short cables or short fibres, or particles, for example powder particles, either having a spherical or irregular shape. It is clear that embodiments comprising different types of elongated substrates, different types of particulates or comprising combinations of elongated substrates and particulates can be considered as well.The second material comprises a polymer material, preferably an epoxy or epoxy-based material or a polyacrylate or polyacrylate-based material, for example an epoxy or epoxy- based adhesive or a polyacrylate or polyacrylate-based adhesive.

[0039] The structure according to the present invention may comprise at least one multilayer structure, comprising at least a layer of a first material, preferably comprising an elongated substrate, a layer of the second material, whereby the layer of the first material and the layer of the second material are coupled to each other by means of the coupling agent. Such structure may comprise one multilayer structure comprising a layer of a first material and a layer of a second material. Alternatively, such structure may comprise multiple multilayer structures, for example 2, 3, 4, 5, 10 or even more multilayer structures, with each multilayer structure comprising a layer of a first material, preferably comprising an elongated substrate, and a layer of a second material. It is clear that a multilayer structure may comprise one or more additional layers, for example one or more layers comprising the first material, one or more layers comprising the second material and / or one or more layers comprising a further material (other than the first material and the second material).

[0040] Examples of structures having a multilayer structure comprise multi-layered packaging structures. Multi-layered packaging structures comprise for example an adhesive resin such as amine-cured epoxy, polyacrylates or polyacrylamides between a thermoplastic resin layer such as polypropylene, polyethylene or polystyrene and a gas barrier layer comprising an inorganic or organic material. Examples of inorganic gas barriers comprise metal layers such as aluminium foils and aluminium deposition layers, and metal compound layers such as silicon oxide deposition layers, aluminium oxide deposition layers, and layers comprising siloxane, for polydimethylsiloxane. Examples of organic gas barrier comprise for example polyvinyl alcohol, polyamides and polyimides. Such multi-layered structures preferably comprise an adhesive layer between the thermoplastic resin layer and the gas barrier layer. In the particular example that the gas barrier layer comprises polyvinyl alcohol or polyamide (which are more hydrophilic compounds) and the thermoplastic layer comprises a polyolefin resin (which are more hydrophobic) an adhesion layer is required because of the poor adhesion between these two types of materials.

[0041] Other examples of structures having a multilayer structure comprise multi-layered structural backing material in walls, ceilings and floors. Such materials comprise an adhesive resin such as amine-cured epoxy, polyacrylates or polyacrylamides between a first material, for example a thermoplastic foam sheet made from homo or co-polymers of polyolefin or polybutadiene and a second material, for example a second adhesive resin such as polyvinyl alcohol or vinyl-acetate copolymers with an inorganic filler. Examples of the inorganic filler include calcium carbonate, calcium sulfate, aluminium oxide, magnesium oxide, calcium silicate, aluminium silicate, silicic anhydride, aluminium hydroxide, talc and clay.

[0042] In other embodiments, the structure according to the present invention comprises a composite material comprising a matrix material comprising the second material having particulates comprising the first material in the matrix material of the second material. The particulates of the first material are thereby coupled to the matrix material by means of the coupling agent.

[0043] Particulates comprise for example elongated particulates such as fibres, preferably short fibres. Alternatively or additionally, particulates comprise particles, for example powder particles. Such particles may comprise spherical particles or particles having an irregular shape. The particles preferably have an (equivalent) diameter ranging between, 1 and 100 pm, preferably 10 and 1000 nm, preferably between 10 and 100 nm.

[0044] Particulates such as fibres or particles comprise for example a polymer material, a glass material, a silica or silica-based material, a carbon or carbon-based material, aluminium oxide, magnesium oxide, calcium silicate, aluminium silicate, aluminium hydroxide, talc and clay.

[0045] Examples of structures comprising a composite material comprising a matrix material comprising particulates comprise fibre-reinforced composites. Particular examples comprise fibre- reinforced epoxy composites or fibre-reinforced acrylate-based composites.

[0046] Fibre-reinforced epoxy composite comprise for example a polymeric resin obtained by contacting a polyglycidyl derivative and a curing agent such as a polyamine mixture and comprising synthetic fibres, for example glass, carbon, Kevlar or Aramid fibres, embedded within the polymeric matrix. Due to their lightweight, good strength and good modulus, such composites are used for structural parts in various industries and also for sporting and leisure goods.

[0047] Fibre-reinforced acrylate-based composites comprise for example of a radically polymerizable resin such as an acrylate or a methacrylate and a multifunctional acrylate or methacrylate such as bisacrylates or bismethacrylates and synthetic fibres, for example glass, carbon, Kevlar or Aramid fibres, embedded within the polymeric matrix.

[0048] Other examples of structures comprising a composite material comprising a matrix material and particulates comprise a matrix material having nanoparticles embedded in the matrix material. Particular examples comprise epoxy nanocomposites comprising a polymeric resin obtained by contacting a polyglycidyl derivative and a curing agent such as a polyamine mixture and synthetic nanoparticles as silica, aluminium oxide and aluminium hydroxide within the polymeric matrix.

[0049] A second group of structures according to the present invention comprises a first material, a second material and a compatibilizer as coupling agent. Such structure comprise a blend of the first material and the second material, whereby the compatibility between the blend of the first material and the second material is improved by the coupling agent that substantially resides at the interface of the first material and the second material. The first material preferably comprises apolymer material, for example polystyrene, polyethylene, polypropylene, polybutadiene, polyisopropene, natural rubber or styrene-butadiene rubber and the second material comprises nylon PA6, nylon PA6,6, PA 6T, aramid or polymide-imide.

[0050] A particular preferred example of the second group of structures according to the present invention comprises a structure comprising a blend of a first material and a second material, with the first material being polystyrene and the second material being nylon.

[0051] According to a second aspect of the present invention a method to provide a structure comprising a first material, a second material and a coupling agent capable of coupling (preferably releasably coupling) the first and the second material is provided. The method preferably comprises the steps of a) providing a first material comprising a polymer material, a glass material, a silica or silica- based material, a carbon or carbon-based material, a metal or metal alloy, a ceramic material or a combination thereof; b) contacting the first material with a mixture comprising at least one compound B, at least one compound C and optionally a precursor to form the second material and / or a further material capable to polymerize or copolymerize to form the second material; the at least one compound B comprises an imide or dicarboxamide having 2 to 4 carbon atoms between the two carbonyl groups of the imide or dicarboxamide and being provided with the substituent L on the N atom of the imide or dicarboxamide or on at least one N atom of the dicarboxamide, the substituent L being capable of covalently binding to the first material, the at least one compound C comprising at least one primary amine functional group and optionally comprising at least one group capable of polymerizing and / or copolymerizing to form the second material and / or at least one group capable to interact with a precursor to form the second material; c) optionally contacting the material obtained in step b) with an additional precursor capable to form the second material and / or with an additional further material capable to polymerize and / or copolymerize to form the second material, the second material comprising a polymer material.

[0052] In accordance with the method according to an aspect of the invention described herein above, the coupling agent functions as a primer. In this case, the coupling agent is applied to the surface of the first material before the second material is applied. The first material preferably comprises a polymer material, a glass material, a silica or silica-based material, a carbon or carbonbased material, a metal or metal alloy, a ceramic material or a combination thereof. Preferably, the first material comprises a polymer substrate, a glass substrate, a silica or silica-based substrate, a carbon or carbon-based substrate, a metal or metal alloy substrate, a ceramic substrate or acombination thereof. Preferred substrates comprise elongated substrates, either rigid or flexible substrates such as sheets, foils, plates, wires, cables, fibres, preferably long wires, long cables or long fibres or a combination thereof. Alternatively, the substrates comprise particulates, for example short wires, short cables or short fibres, or particles, for example powder particles, either having a spherical or irregular shape. It is clear that embodiments comprising different types of elongated substrates, different types of particulates or comprising combinations of elongated substrates and particulates can be considered as well.The second material comprises a polymer material, preferably an epoxy or epoxy-based material or a polyacrylate or polyacrylate-based material, for example an epoxy or epoxy- based adhesive or a polyacrylate or polyacrylate-based adhesive.

[0053] In case compound C comprises a dicarboximide, either one N atom or two N atoms can be provided with a substituent L.

[0054] The substituent L comprises preferably a -SiXs group, a -PO3Y2 group, an alkene or alkyne group, a thiol group, an isocyanate group, an acrylate group, an acrylamide group, a catechol group or derivative of a catechol group.

[0055] In case the substituent L comprises a -SiXs group, at least one substituent X is selected from the group consisting of -OR1, -OC(=O)R1, whereby -R1is an alkyl, preferably a C1-C4 alkyl.

[0056] In case the substituent L comprises a -PO3Y2 group, at least one substituent Y is selected from the group consisting of -H or -R2whereby -R2is an alkyl, preferably a C1-C4 alkyl.

[0057] In preferred embodiments, the at least one compound C further comprises at least one group capable of polymerizing and / or copolymerizing to form the second material and / or at least one group capable to interact with a precursor to form the second material.

[0058] In other embodiments, the at least one compound C comprises a precursor for forming the second material or a compound capable of reacting with a precursor for forming the second material.

[0059] Some preferred methods to provide a structure comprising a first material, a second material and a coupling agent capable of coupling (preferably releasably coupling) the first and the second material are given below. For each of these methods compound B and compound C may comprise any compound as specified above. For each of these methods the first material and the second material may comprise any material as specified above. In particular, the first material may comprise a substrate. Preferred substrates comprise elongated substrate, for example sheets, foils, plates, wires, cables or fibres, preferably long wires, long cables or long fibres or combinationsthereof or particulates, for example short wires, short cables or short fibres or particles, for example powder particles or combinations thereof.

[0060] A first example comprises a method comprising the steps of a) providing a first material, for example a substrate; b) contacting the first material with a mixture comprising at least one compound B and at least one compound C; c) contacting the material obtained in step b) with an additional precursor capable to form the second material.

[0061] A second example comprises a method comprising the steps; a) providing a first material, for example a substrate; b) contacting the first material with a mixture comprising at least one compound B and at least one compound C; c) contacting the material obtained in step b) with an additional further material capable to polymerize and / or copolymerize to form the second material.

[0062] A third example comprises a method comprising the steps; a) providing a first material, for example a substrate; b) contacting the first material with a mixture comprising at least one compound B and at least one compound C; c) contacting the material obtained in step b) with an additional precursor capable to form the second material and with an additional further material capable to polymerize and / or copolymerize to form the second material.

[0063] A fourth example comprises a method comprising the steps; a) providing a first material, for example a substrate; b) contacting the first material with a mixture comprising at least one compound B, at least one compound C and at least one precursor to form the second material.

[0064] A fifth example comprises a method comprising the steps; a) providing a first material, for example a substrate; b) contacting the first material with a mixture comprising at least one compound B, at least one compound C and a precursor to form the second material c) contacting the material obtained in step b) with an additional precursor capable to form the second material.

[0065] A sixth example comprises a method comprising the steps; a) providing a first material, for example a substrate;b) contacting the first material with a mixture comprising at least one compound B, at least one compound C and a further material capable to polymerize or copolymerize to form the second material.

[0066] A seventh example comprises a method comprising the steps; a) providing a first material, for example a substrate; b) contacting the first material with a mixture comprising at least one compound B, at least one compound C and a further material capable to polymerize or copolymerize to form the second material c) contacting the material obtained in step b) with an additional further material capable to polymerize and / or copolymerize to form the second material.

[0067] According to a further aspect of the present invention, a further method to provide a structure comprising a first material, a second material and a coupling agent capable of coupling (preferably releasably coupling) the first and the second material may comprise the steps of a) providing a first mixture comprising at least one compound B and in addition a precursor to form the first material and / or a further material capable to polymerize or copolymerize to form the first material, with the at least one compound B comprising an imide or dicarboxamide having 2 to 4 carbon atoms between the two carbonyl groups of the imide or dicarboxamide and being provided with the substituent L on the N atom of the imide or on at least one N atom of the dicarboxamide, the substituent L being capable of covalently binding to form he first material; the first material comprising a polymer material. b) providing a second mixture comprising at least one compound C and optionally a precursor to form the second material and / or a further material capable to polymerize or copolymerize to form the second material, with the at least one compound C comprising at least one primary amine functional group and optionally comprising at least one group capable of polymerizing and / or copolymerizing to form the second material and / or at least one group capable to interact with a precursor to form the second material, the second material comprising a polymer material; c) mixing the first mixture and the second mixture thereby forming the coupling agent at the interface of the first and the second material.

[0068] In accordance with the method according to an aspect of the invention described herein above, the coupling agent functions as a compatibilizer. In this case, the coupling agent improves the compatibility between the first and the second material. The first material comprises preferably a first thermoplastic polymer, such as polystyrene, polyethylene, polypropylene or copolymers thereof. The second material comprise preferably a second thermoplastic polymer, for example nylon PA 6, nylon PA 6,6, PA 6T, Aramid, polyamide-imide or copolymers thereof.

[0069] In an exemplary embodiment, the method may comprise the steps of; a) providing a first mixture comprising at least one compound B, styrene, and optionally an initiator capable to polymerize or copolymerize to form a first material comprising a modified polystyrene material; i) providing a second mixture comprising at least one compound C, adipic acid, and hexamethylene diamine capable to polymerize or copolymerize to form a second material comprising a modified nylon 6,6 material; ii) mixing the first mixture and the second mixture thereby forming a coupling agent at the interface of the first and second material.

[0070] Another aspect of the invention relates to a structure obtained or obtainable by means of any one of the methods as disclosed herein. It should be clear that (preferred) embodiments of the first aspect of the invention are also (preferred) embodiments of the structure obtained or obtainable by means of any one of the methods as disclosed herein.

[0071] Another aspect of the invention relates to the use of a structure as disclosed herein for generating heat-debondable adhesives. In particular, heat-treatment of an adhesive comprising the structure as disclosed herein may provide loss of the adhesive properties of said adhesive. Preferably, loss of adhesion is achieved without damaging material(s) adhered by the adhesive.

[0072] Another aspect of the invention relates to the use of a structure as disclosed herein for the manufacturing of multilayer structures comprising at least a layer of a first material and a layer of a second material, whereby the layer of the first material and the layer of the second material are coupled to each other by means of a coupling agent and wherein the layer of the first material and the layer of the second material are configured for thermoreversible detachment. In particular, heattreatment of the multilayer structure may provide loss off the adhesive properties between the first and the second material.

[0073] Another aspect of the invention relates to the use of a structure as disclosed herein for the manufacturing of composite structures comprising a matrix material as second material and particulates as first material. In particular the invention relates reinforced composites, for example fibre-reinforce composites wherein the one or more fibers of the composite are configured for thermoreversible detachment from the composite matrix. In particular, heat-treatment of the composite matrix comprising the fibers may provide loss of the adhesive properties between the composite matrix and the fibers.

[0074] Another aspect of the invention relates to the use of a structure as disclosed herein for generating compatibilized polymer blends.Brief description of the drawings

[0075] The present invention will be discussed in more detail below, with reference to the attached drawings, in which:Figures 1 a)-g) schematically illustrate the covalently binding of different types of substituents L of a moiety of formula (I) to the first material.Figures 2a)-d) are schematic illustrations of the synthesis of an epoxy network using a reference formulation (ER) as curing agent (Figure 2a) )and using three formulations (PGA- 1 , PGA-2 and PGA-3) being the reaction product of at least one imide and at least one primary amine (Figure 2b), Figure 2c) and Figure 2d) ).Figure 3 shows the stress-strain curves of the dynamic polyamide epoxy materials (PGA- 1 , PGA-2 and PGA-3) and of the epoxy reference (ER).Figure 4 shows the stress-relaxation data of PGA-2, highlighting the impact of bond dissociation on rheology.Figure 5a), Figure 5b) and Figure 5c) respectively show the corresponding relaxation data (Arrhenius curve), the dissociation (Van ‘t Hoff plot) and the apparent viscosity in function of temperature of PGA-2 after evaluation of stress-relaxation.Figure 6a) shows the creep data of PGA-2 by applying a shear stress of 2000 Pa for 5000s from 60 to 120 °C. Figure 6b) shows the corresponding zero-shear viscosity in function of temperature, highlighting the high creep resistance or controllable debonding, for PGA-2.Figure 7 is a schematic illustration of the synthesis of a succinimide-based and glutarimide- based silane primer (ER-S and ER-G). The silane primers were used to provide the coupling between the first material and the second material according to the present invention. Moreover, a commercially available epoxy-based silane primer (ER-E) is also included as a reference.Figure 8 shows the X-ray photoelectron spectroscopy data of the modified metal surfaces after application of the silanes given in Figure 7 and after curing the adhesive formulation, indicating the presence of nitrogen atoms at the surface. This analysis confirmed the successful coupling of the imide-containing silane primers to a first material according to the present invention.Figure 9 shows the bond strength of the epoxy reference resin (ER) compared to adding 2 wt% of a silane primer (ER-S, ER-G and ER-E).Figure 10 shows the attenuated total reflection infrared spectrum after the lap-shear experiment using imide-containing silane primers (ER-S and ER-G). Investigation of the residual material displayed amide signals, indicative of successful coupling of the imide- containing silane primers (ER-S and ER-G) to a second material according to the present invention.Figure 11 shows the bond strength after re-using bonded aluminium plates that contain an imide-silane promoter.Figure 12 shows the bond strength of the dynamic epoxy resins (PGA-1 , PGA-2 and PGA- 3) and of the epoxy reference (ER).Figure 13 shows the bond strength before and after re-using bonded aluminium plates of PGA-1 , PGA-2 and PGA-3.Figure 14 shows the bond strength of PGA-2 doped with an epoxide-silane (PGA-2-E) and glutarimide-silane (PGA-2-G) primer.Figure 15 shows the compatibilising of polystyrene with polyamide according to the present invention, with Figure 15a) showing the synthesis of styrene-succinimide (StSu), Figure 15 b) showing the copolymerising of styrene with styrene-succinimide to form PScoPSSu, and Figure 15c) showing the synthesis of polyamide.Figure 16 shows the Fourier Transform InfraRed measurements of the compatibilized mixture (top), polyamide (middle) and PScoPSSu (bottom).Description of embodiments

[0076] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings are only schematic and are non-limiting. The size of some of the elements in the drawing may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

[0077] When referring to the endpoints of a range, the endpoints values of the range are included.

[0078] When describing the invention, the terms used are construed in accordance with the following definitions, unless indicated otherwise.

[0079] The term ‘and / or’ when listing two or more items, means that any one of the listed items can by employed by itself or that any combination of two or more of the listed items can be employed.

[0080] Figures 1 a)-1g) schematically illustrate the covalently binding of different types of substituents L of a moiety of formula (I) with the first material.In particular, figure 1 a)-1g) respectively show the covalently binding of a -SiXs substituent, a -PO3Y2, an alkene group, a thiol group, an isocyanate group, an acrylate group and a catechol group as substituent L of the moiety of formula (I).

[0081] In the subsequent sections structures according to the present invention comprising a primer as coupling agent as well as comprising a compatibilizer as coupling agent are described.STRUCTURE COMPRISING A FIRST MATERIAL, A SECOND MATERIAL AND A PRIMER AS COUPLING AGENT

[0082] To evaluate the potential (de)bonding and reuse of a structure according to the present invention using a primer as coupling agent, a number of comparative examples and examples according to the present invention are investigated.

[0083] For the comparative examples bulk materials comprising an epoxy network are synthesised. A reference formulation (ER) and three formulations (PGA-1 , PGA-2 and PGA-3) each comprising a mixture of an imide or dicarboxamide (compound B) and a compound comprising at least one primary amine functional group (compound C) are considered. The interaction of the mixtures with a second material (epoxy) is investigated. Therefore the reference formulation and the three formulations PGA-1 , PGA-2 and PGA-3 are cured using an epoxy hardener. Thermal and mechanical properties of the different formulations are evaluated. Furthermore, rheology experiments of the obtained epoxy materials are performed to determine the dynamic material properties.

[0084] For the examples according to the present invention, structures comprising a first material, a second material and a coupling agent are provided. The (de)bonding and reuse of the adhesives is evaluated through lap-shear experiments.

[0085] A first series of examples comprises metal substrates (first material) provided with a coupling agent (primer) applied to the metal substrates whereby the coupling agent is obtained by adding a silane primer to the above mentioned reference formulation ER, thereby introducing dynamic units at the surface of the metal substrate.A second series of examples comprises structures comprising a metal substrate (first material) provided with a coupling agent (primer) applied to a metal substrates whereby the coupling agent is obtained by adding a silane primer to the above mentioned formulations PGA-1 , PGA-2 and PGA- 3 formulations, thereby introducing dynamic units at the surface of the metal substrate and having dynamic units in the epoxy material. Two imide-silane primers, a succinimide-based silane primer (ER-S) and a glutarimide-based silane primer capable to interact with a precursor to form the second material are considered. Their performance is compared to a commercial epoxide-silane primer (ER-E).In further experiments other structures comprising LDPE (low density polyethylene) and polycarbonate substrates were evaluated.Synthesis of the formulations

[0086] The synthesis procedures of the comparative bulk examples are illustrated in Figures 2a)- d). 3 different polyamide curing agents were prepared (PGA-1 , PGA-2 and PGA-3) by polycondensation of the corresponding ester(s). The results are compared to a reference material (ER).

[0087] As reference an amine mixture was chosen by combining Priamine 1074 (1), 2, 2, 4(2, 4,4)- trimethyl-1 ,6-hexanediamine (2), triethylenetetramine (3) and 1 ,3-cyclohexanebis(methylamine) (4) in a ratio of 3:3:1 :3 (Figure 2a)-d) noted as amine mixture). First, bisphenol A diglycidyl ether (8) was contacted with this amine mixture in an epoxy-to-amine ratio (E / NH) of 1 .0 (Figure 2a) ).

[0088] The aforementioned amine mixture was condensed with dimethyl glutarate (5) at 80 °C for 16 hours, yielding a first curing agent (PGA-1 , Figure 2b) ). Since it was desirable to obtain a polyamide with two amine end groups, a stoichiometric excess of NH groups of 1.04 eq. was theoretically calculated, which was incapable of further chain-growth when all the dimethyl ester monomer was consumed. As a result, roughly 65 mol% of the available NH groups was reacted to a dynamic amide bond, to endow sufficient reversible behaviour. Further increasing the excess of NH functionalities can lead to a relatively larger amount of static or permanent bonds, hampering material flow.

[0089] In a further example a portion (0.06 eq.) of amine compound (2) in the aforementioned amine mixture was replaced with 2-(1-piperazinyl)ethylamine (6), yielding a second curing agent (PGA-2, Figure 2c) ). In this way, the degree of polymerisation is reduced, without the need to reduce the amount of dynamic amide bonds. The secondary amine (6) was expected to be more sterically hindered to react with dimethyl glutarate than the more accessible primary amines and could thus act as a chain stopper, increasing the relative amount of secondary amine chain-ends while decreasing the total amount of excess "NH" groups to 0.98 eq. and keeping ~67 mol% dynamic amide bonds.

[0090] In a further example a portion of dimethyl glutarate is replaced with the more reactive succinate ester (7) to obtain mixture PGA-3 (Figure 2 d) ).

[0091] After using each prior mentioned mixture (RE; PGA1-3) to cure the above mentioned epoxy compound at 120 °C for 5 hours under vacuum, ATR-FTIR (Attenuated Total Reflectance - Fourier Transform Infrared) analysis and Soxhlet extraction with THF (tetra hydrofuran) were used to verify network formation (see Table 1).Thermal and mechanical properties

[0092] To evaluate the thermal properties of the comparative bulk examples, DSC (differential scanning calorimetry) and TGA (Thermogravimetric analysis) were performed.

[0093] Promising results could be obtained with glass transition temperature (Tg) values in the range of 43 to 62 °C and Td5% values situated around 355 °C (Table 1). Moreover, the isothermal mass loss was determined to be less than 1.5 % weight loss after 2 hours at 250 °C, which was indicative for a high thermal stability.

[0094] This means that processing and application of the epoxy materials is possible within a wide temperature range. Reprocessing was done via compression moulding at 250 °C for 5 min with an applied pressure of 4 tons.Table 1 . Overview of thermomechanical properties and relaxation data of (modified) epoxy networksaDetermined from the second heating in DSC analysis (10 °C. min1).bTGA onset temperatures after 5% weight loss (Tds%).cSwelling ratio obtained from a four-sample measurement in THF at rt for 24 h.dSoluble fraction was obtained from Soxhlet extraction in THF for 24 h.eObtained by fitting to a stretched single exponential decay.fApparent Young’s modulus (E’) and toughness (W) determined from tensile testing (preload 0.05 N and 10 mm / min). These values are relative and for comparison purposes only.

[0095] As a good balance between toughness and mechanical strength of the cross-linked epoxy materials is important, the tensile properties of the dynamic epoxy materials and of the epoxy reference material are compared with their apparent Young’s modulus (E’) and toughness. From the stress-strain curves depicted in Figure 3, a clear shift from brittle to more ductile behaviour could be observed when using the dynamic polyamide curing agents. More specifically, an increase in toughness of up to a factor ~10 only came at a cost of a decrease of 10% in E’ with apparent values ranging from 0.3 to 0.8 GPa. These results highlight the improved mechanical properties when introducing dynamic polyamide bonds, and in particular PGAs, into epoxy resins.Viscoelastic behaviour of dynamic polyamide-epoxy networks

[0096] Rheology measurements of the obtained epoxy materials were used to determine dynamic material properties. The amount of reversible polyamide bonds was theoretically calculated to be 65-67 mol% compared to the “static” epoxy bonds (vide supra). As depicted in Figure 4 for PGA-2, both a decrease in initial relaxation modulus (Go) due to decross-linking and an increase in relaxation due to bond exchange could be observed at elevated temperatures. Moreover, relaxation followed a clear deviation from canonical single Maxwell behaviour as a result of the large structural variety of the polyamide curing agent. Therefore, relaxation times (T*KWW) could be obtained by a least squares fitting to a Kohlrausch-Williams-Watts (KWW) stretched exponential decay function (equation 1), which takes into account differences in relaxation of the composing network segments. Average stretching factors (p) between 0.2 and 0.5 were obtained, which correspond quite well to values obtained for the relaxation of segmental dynamics. When comparing the relaxation data, no large variation could be observed when changing the amine or ester monomer mixture, highlighting the fact that chain diffusion has a large impact on the rate of network rearrangement. This can be explained by the fact that while the rate determining step for dynamic behaviour is bond dissociation, association with another dissociated intermediate is required for bond exchange. In other words, when diffusion is more demanding or needs to occur over largervolumes, stress-relaxation can be slower compared to a freely moving system.G(t) = Goe ( —TKW — —W I'3equation 1)

[0097] According to the Maxwell relation (?? [T]both the modulus (G) related to crosslinking density and relaxation (T) give rise to a viscosity decrease. As a result, it is worthwhile to investigate both parameters as a function of temperature (Figure 5). While the rate determining step for bond exchange is the dissociation of a dicarboxamide unit (Figure 5a) ), sufficient decross-linking above 230 °C resulted in an increased relaxation rate due to the generation of free chain-ends and decrease in elasticity (Figure 5b) ). An apparent temperature dependence of material flow could then be calculated from the Maxwell relation (Figure 5c) ).

[0098] By taking both relaxation and dissociation into account, an almost 3-fold increase in the slope of the viscosity curve could be determined at elevated temperatures (drop from ~1010to 106Pa.s). These results highlighted the potential of this system to show maximal viscosity during use ( / .e. thermoset behaviour), while reaching low viscosities within the temperature range of typical nylon processing ( / .e. 230 °C to 280 °C). Importantly, the main difference between the reported system and nylon is that a viscoelastic ‘melt’ state is achieved through covalent decross-linking rather than breaking inter-chain hydrogen bonds.

[0099] The temperature-dependent evolution of the shear storage modulus (G') confirmed the loss of cross-linking density upon heating and recovery upon cooling. Moreover, to verify the dimensional stability or retained cohesion during use, creep experiments were conducted from 60 °C to 120 °C by applying a constant shear stress (cr) of 2 kPa over the course of 5000 s (Figure 6a) ). The resulting strain (s) was monitored as a function of time and an apparent creep rate (E) was obtained from the steady-state time regime. Subsequently, zero shear viscosity (? / 0) values could be determined from the Kelvin-Voigt definition (? / 0= cr / s, Figure 6b )). With q0between 1013and 1014Pa.s and only a small decrease as a function of temperature, a high resistance to creep deformation could be concluded within the investigated temperature range.Adhesion properties of dynamic polyamide-epoxy networks using aluminium substrates

[0100] To determine the potential (de)bonding and reuse of the (modified) epoxy adhesives, lap shear tests were performed using aluminium plates and using standard dimensions according to ASTM 1002D. Two imide-silane primers, a succinimide-based and a glutarimide-based silane primer (9 (ER-S) and 10 (ER-G) in Figure 7) capable to interact with a precursor to form the second material are prepared and their performance is compared to a commercial epoxide-silane primer (11 (ER-E) in Figure 7)). The synthesis of the succinimide-based and the glutarimide-based silane primer is illustrated in Figure 7). Simply applying the silane primers (compound 9 and 10) to the metal surface of the aluminium substrates and curing the adhesive formulation results in the formation of dynamic amide bonds at the surface. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were performed on a modified metal surface and confirmed thatsuch adhesion promoters indeed migrate to the surface and effectively bond to form a primer layer (Figure 8).

[0101] First, the impact of reversible adhesion was tested on the ER formulation described above, while comparing the effect of the addition of 2 wt% of silane compound 9, 10 and 11 . Silane-modified surfaces are obtained by dipping the aluminium plates in a 4:1 ethanol:water mixture comprising a specific percentage of silane primer, resulting in a thin coating of 10-100 nm. As shown in Figure 9, all silane-modified surfaces showed an almost 2-fold increase in interfacial bond strength from 4 MPa to 7 MPa. Moreover, ATR-FTIR analysis of the ruptured adhesives containing imide-silane primers revealed the presence of carbonyl stretches corresponding to an amide bond (Figure 10). When trying to reassemble the same substrates and adhesives by heating at 250 °C for 2 minutes and gradually cooling down, the imide-based primers showed full recovery of adhesion strength (Figure 11). Although applicant does not want to be bound by any theory, it is hypothesized that the small dynamic silane layer allowed rewetting of the metal surface as a result of chain relaxation in the rubber state, topological defects at the surface, and stress-relaxation when shifting the amideimide equilibrium. In contrast, when the adhesive joints were heated and cooled down rapidly, quenching of the dynamic chemistry resulted in complete debonding.

[0102] The same (de)bonding experiments were repeated for the dynamic polyamide-epoxy formulations PGA-1 , PGA-2 and PGA-3 and compared to the reference sample ER (Figure 12)). With a clear ~2-fold increase in bond strength for all modified epoxy samples, one can conclude that adhesion increases upon addition of dynamic amide bonds. Interestingly, PGA-1 and PGA-2 allowed to recover adhesive properties when re-using the aluminium plates (250 °C for 2 minutes), while PGA-3 only showed partial recovery (Figure 13).

[0103] The differential behaviour of PGA and PGA-PSA was in line with previous observations regarding the lower thermal onset of dissociation of succinamide groups compared to glutaramide ones. Nonetheless, all samples could be debonded efficiently.

[0104] When combining the formulation corresponding to PGA-2 with the glutarimide-silane primer 10 (PGA-2-G) and epoxide-silane primer 11 (PGA-2-E), drastically different bonding behaviour could be observed (Figure 14)). While only showing a mild increase in bond strength, using PGA- 2-G resulted in a lower error in (re)bonding since both covalent adhesion and cohesion could be simultaneously restored. PGA-2-E displayed the highest bond strength, which was attributed to the difference in reactivity between an epoxide and imide functional group. However, adhesion properties could not be recovered as a result of covalent bonding to the metal surface. The difference in bond strength recovery between PGA-2-G and PGA-2-E, also had an effect on their debonding capacity. More specifically, PGA-2-G allowed efficient debonding after heating at 250 °C for 2 minutes and rapid cooling, while PGA-2-E was still partially bound.Adhesion properties of dynamic polyamide-epoxy networks using aluminium substrates

[0105] To determine the potential (de)bonding and reuse of the (modified) epoxy adhesives, lap shear tests were performed using LDPE (low density polyethylene) and polycarbonate plates. The succinimide-based silane primer (ER-S) described above was applied on the plates. Plates provided with the ER-S primer were glued together using the ER formulation described above.The ER-S primer did not adhere to the LDPE plates but did adhere well to the polycarbonate plates. The ER formulation ensures that the polycarbonate plates stick well together.

[0106] In a further experiment a commercially available cyanoacrylate adhesive (Best-CA221) was used instead of the ER formulation. It was possible to glue plates provided with the ER-S using this commercially available cyanoacrylate adhesive. Furthermore, the plates could be pulled apart by means of a tensile test ASTM D1002).To proof the reuse, the plates were heated (to a temperature of 200 °C) and the time was measured till debonding of the plates was observed. Debonding occurred after less than 1 minute.Then, the plates were glued again by pushing them firmly against each other. Tensile tests were also performed with these plates. The tensile strength is about 4 times lower than the initial strength.STRUCTURE COMPRISING A FIRST MATERIAL, A SECOND MATERIAL AND A COMPATIBILIZER AS COUPLING AGENT

[0107] The example below illustrates the compatibilizing of polystyrene with polyamides using a coupling agent according to the present invention. First a styrene-cyclic imide monomer (styrenesuccinimide (StSu)) is synthesized and subsequently, copolymerized with styrene to form PScoPSSu. Then polyamide is synthesized and compatibilized with the PScoPSSu.Synthesis of a Styrene-Succinimide (StSu) monomer

[0108] Styrene-succinimide monomer was synthesized as shown in Figure 15 a). In a 1 L round bottom flask equipped with a stirring bar succinimide (14.28 g, 144.15 mmol, 1 .1 eq) and potassium carbonate (21.73 g, 157.25 mmol, 1.2 eq) were suspended in acetonitrile (450 mL). The mixture was stirred for 5 to 10 minutes after which vinyl benzylchloride and a spatula tip of sodium iodide was added. The reaction mixture was heated to 60 °C and stirred continuously for 2 days. The solvent was removed in vacuo and the crude was redissolved in chloroform (300 mL). This solution was washed with water (2x 200 mL) and brine (2 x 200 mL). The organic phase was dried over magnesium sulfate, filtered and concentrated. The resulting product was dried overnight in a vacuum oven at 40°C, yielding 25.824 g (91 %) of pale yellow viscous oil. (1H NMR (400 MHz, DMSO) 5 7.48 - 7.35 (m, 2H), 121 - 7.18 (m, 2H), 6.70 (dd, J = 17.6, 10.9 Hz, 1 H), 5.80 (dd, J = 17.7, 1.0 Hz, 1 H), 5.24 (dd, J = 10.9, 1.0 Hz, 1 H), 4.52 (s, 2H), 2.68 (s, 4H))Copolymerisation of styrene with StSu

[0109] Styrene was copolymerized with StSu as shown in Figure 15b). Styrene (10 g, 96.01 mmol, 95 eq), StSu (1.09 g, 5.05 mmol, 5 eq) and AIBN (24.89 mg, 0.151 mmol, 0.15 eq) were dissolved in dimethylacetamide (50 mL) in a 100 mL round bottom flask equipped with a stirring bar. The flask was closed with a rubber septum and purged with argon for 30 minutes. Then the flask was brought in a preheated oil bath (at 80°C) and the polymerisation mixtures was stirred at this temperature. After 1 day, the reaction mixture was precipitated in a tenfold excess of methanol (500 mL) that was cooled in liquid nitrogen. After filtration, the copolymer was dried in vacuo at 40°C. (Mn= 20 kDa, D = 4.4). From NMR integrations a succinimide content of 5.5 % could be calculated.Polyamide synthesis

[0110] An example of a monofunctional polyamide was obtained by reacting an excess of bisamine (here 1 .3 equivalents of 2,2,4-trimethylhexane-1 ,6-diamine) with a bisester (here 1 eq dimethyl suberate). After reaction at 100°C in vacuum overnight, a monofunctional ester (here 0.15 equivalents methyl hexanoate) was added to endcap half of the amino groups and obtain a monoamine. The synthesis of the polyamide is illustrated in Figure 15 c).Compatibilising the PScoPSSu with the polyamide

[0111] In a next step, compatibilising a polystyrene phase with a polyamide phase was exemplified by combining the above synthesised polystyrene-co-styrenesuccinimide with the monofunctional polyamide, so that the succinimide:NH2 ratio equals 1 . After heating to 140°C for 1 hour and slowly cooling to room temperature, the material was carefully removed from the vial and samples were submitted for DSC analysis and Fourier Transform InfraRed (FTIR) measurements. The FTIR measurements confirmed that the succinimide groups are disappeared.

Claims

Claims1. A structure comprising a first material, a second material and a coupling agent capable of coupling the first and the second material, the first material comprising a polymer material, a glass material, a silica or silica-based material, a carbon or carbon-based material, a metal or metal alloy, a ceramic material or a combination thereof, the second material comprising a polymer material, the coupling agent comprising a moiety of formula (I) having a first nitrogen atom N’ and a second nitrogen atom N”with A comprising a chain of 2 to 4 carbon atoms, with said chain comprising a saturated linear chain or with at least 2 carbon atoms of said chain being part of a non-aromatic cyclic structure; with the first nitrogen N’ being provided with a substituent L being capable of covalently binding with the first material, and with the moiety of formula (I) forming a covalent dynamic bond by means of the second nitrogen N” with the second material.

2. The structure according to claim 1 , wherein the coupling agent is present at the interface between the first and the second material.

3. The structure according to claim 1 or claim 2, wherein the substituent L is selected from the group consisting of -SiXs groups, -PO3Y2 groups, alkene groups, alkyne groups, thiol groups, isocyanate groups, acrylate groups, acrylamide groups, catechol group and derivatives of a catechol group; with the -SiXs group comprising at least one X being selected from the group consisting of - OR1, -OC(=O)R1, whereby -R1is an alkyl; with the -PO3Y2 group comprising at least one Y being selected from the group consisting of -H or -R2, whereby -R2is an alkyl.

4. The structure according to claim 3, wherein the substituent L comprises a -SiXs group with each X of the -SiXs group being selected from the group consisting of -R1, -OR1, -OC(=O)R1, whereby -R1is an alkyl group or wherein the substituent L comprises a -PO3Y2 group with each Y of the -PO3Y2 group being selected from the group consisting of -H or -R2whereby - R2is an alkyl.

5. The structure according to any one of the preceding claims, wherein the non-aromatic cyclic structure comprises a saturated cyclic structure or a partially saturated cyclic structure whereby the at least 2 carbon atoms of A comprise saturated bonds.

6. The structure according to any one of the preceding claims, wherein at least one of the at least 2 carbon atoms of the chain A is substituted.

7. The structure according to any one of the preceding claims, wherein the moiety of formula (I) is obtainable by reaction of at least one compound B with at least one compound C, with the at least one compound B comprising an imide or dicarboxamide, with the imide or dicarboxamide having 2 to 4 carbon atoms between the two carbonyl groups of the imide or dicarboxamide and being provided with the substituent L on the N atom of the imide or on at least one N atom of the dicarboxamide and with the at least one compound C comprising at least one primary amine functional group.

8. The structure according to claim 7, wherein the at least one compound C further comprises at least one group capable of polymerizing and / or copolymerizing to form the second material and / or at least one group capable to interact with a precursor to form the second material.

9. The structure according to claim 7 or claim 8, wherein the at least one compound C comprises a compound selected from the group consisting of epoxies, polyureas, nylon, styrene, acrylates, methacrylates, acrylamides and methacrylamides.

10. The structure according to any one of the preceding claims, wherein the first material comprises a polymer material selected from the group consisting of polyurethanes, polyacrylates, polypropylene, polyethylene, polystyrene, polyethylene oxide, polybutadiene, styrene-butadiene rubber, polyisoprene, polyethylene terephthalate, natural rubber, epoxidized natural rubber, polyvinyl alcohol, polydimethylsiloxane, polyamides and polyimides or wherein the first material comprises a metal or metal alloy selected from the group of aluminium, titanium, copper, chromium, tin, zinc, iron, gold and alloys thereof and / or wherein the second material comprises an epoxy-based polymer or a nylon-based polymer.11 . The structure according to any one of the preceding claims, wherein the structure comprises at least one multilayer structure comprising a layer of the first material and a layer of the second material, whereby the layer of the first material and the layer of the second material are coupled to each other by means of the coupling agent.

12. The structure according to any one of claims 1 to 10, wherein the structure comprises a composite structure comprising a matrix material comprising the second material andparticulates comprising the first material embedded in the matrix material, whereby the particulates and the matrix material are coupled to each other by means of the coupling agent.

13. A method to provide a structure comprising a first material, a second material and a coupling agent capable of coupling the first and the second material, the method comprising the steps of a) providing a first material, comprising a polymer material, a glass material, a silica or silica-based material, a carbon or carbon-based material, a metal or metal alloy, a ceramic material or a combination thereof; b) contacting the first material with a mixture comprising at least one compound B, at least one compound C and optionally a precursor to form the second material and / or a further material capable to polymerize or copolymerize to form the second material; the at least one compound B comprises an imide or dicarboxamide having 2 to 4 carbon atoms between the two carbonyl groups of the imide or dicarboxamide and being provided with the substituent L on the N atom of the imide or on at least one N atom of the dicarboxamide, the substituent L being capable of covalently binding to the first material, the at least one compound C comprising at least one primary amine functional group and optionally comprising at least one group capable of polymerizing and / or copolymerizing to form the second material and / or at least one group capable to interact with a precursor to form the second material; c) optionally contacting the material obtained in step b) with an additional precursor capable to form the second material and / or with an additional further material capable to polymerize and / or copolymerize to form the second material, the second material comprising a polymer material.

14. The method according to claim 13, wherein the substituent L a -SiXs group, a -PO3Y2 group, an alkene or alkyne group, a thiol group, an isocyanate group, an acrylate group, an acrylamide group, a catechol group or derivative of a catechol group; with the -SiXs group comprising at least one X being selected from the group consisting of - OR1, -OC(=O)R1, whereby -R1is an alkyl; with the -PO3Y2 group comprising at least one Y being selected from the group consisting of -H or -R2whereby -R2is an alkyl.

15. A method to provide a structure comprising a first material, a second material and a coupling agent capable of coupling the first and the second material, the method comprising the steps ofa) providing a first mixture comprising at least one compound B and in addition a precursor to form the first material and / or a further material capable to polymerize or copolymerize to form the first material, with the at least one compound B comprising an imide or dicarboxamide having 2 to 4 carbon atoms between the two carbonyl groups of the imide or dicarboxamide and being provided with the substituent L on the N atom of the imide or on at least one N atom of the dicarboxamide, the substituent L being capable of covalently binding to form the first material; the first material comprising a polymer material; b) providing a second mixture comprising at least one compound C and optionally a precursor to form the second material and / or a further material capable to polymerize or copolymerize to form the second material, with the at least one compound C comprising at least one primary amine functional group and optionally comprising at least one group capable of polymerizing and / or copolymerizing to form the second material and / or at least one group capable to interact with a precursor to form the second material, the second material comprising a polymer material; c) mixing the first mixture and the second mixture thereby forming the coupling agent at the interface of the first and the second material.

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