Functionalized Polymers

Abstract

The invention relates to a functionalized polymer to which at least one Diels-Alder adduct is covalently bonded, said Diels-Alder adduct containing a furan and a maleimide component and the furan or the maleimide component having a functional organyl group the molar mass of which is less than 800 g/mol.

Claims

1. A functionalized polymer which comprises at least one covalently bonded Diels-Alder adduct, the Diels-Alder adduct containing a furan component and a cyclic imide component, and the furan component or the cyclic imide component comprising a functional organyl radical whose molar mass is less than 800 g/mol, where the Diels-Alder adduct is bonded covalently via the furan component to the polymer, and the cyclic imide component comprises the functional organyl radical; or the Diels-Alder adduct is bonded covalently via the cyclic imide component to the polymer, and the furan component comprises the functional organyl radical.

2. The polymer as claimed in claim 1, wherein the functional organyl radical comprises an alkyl, a quaternary ammonium, a carboxylic acid or carboxylate, a sulfonamide, a hydroxyl or an amine group.

3. The polymer as claimed in claim 2, wherein the group is bonded directly or via a divalent linker unit to the imide nitrogen atom of the cyclic imide component or to a furan ring carbon atom of the furan component.

4. The polymer as claimed in claim 3, wherein the divalent linker unit has the following structure:
—(C.sub.1-10-alkylene).sub.a-(phenylene).sub.b-(C.sub.1-10-alkylene).sub.c- where a is 0 or 1, b is 0 or 1, c is 0 or 1, with the proviso that a+b+c≥1; and optionally the C.sub.1-10-alkylene group may be interrupted by one or more heteroatoms or at least one functional group.

5. The polymer as claimed in claim 1, wherein the functional organyl radical is one of the following radicals: an alkyl radical —C.sub.nH.sub.2n+1, where n=12-22, a radical of the following chemical formula:
—C.sub.nH.sub.2n—X where n=1-18, and X is a polar or ionic group; a radical of the following chemical formula:
—C.sub.nH.sub.2n—[N(C.sub.1-2-alkyl).sub.3].sup.+ where n is 1-9; a radical of the following chemical formula:
-(L).sub.m-SO.sub.2—NH—R where R is C.sub.1-4-alkyl, and L is a divalent linker unit.

6. The polymer as claimed in claim 1, wherein the cyclic imide component is a maleimide component or a citraconimide component.

7. The polymer as claimed in claim 1, wherein the Diels-Alder adduct is bonded in terminal position of the polymer and/or by side chains to the polymer or is incorporated via its furan component directly in the polymer chain.

8. The polymer as claimed in claim 1, wherein the polymer is polyacrylate, polymethacrylate, polyester, polyurethane, a polyurea, a polyamide, a polyesteramide or a polyether.

9. A process for preparing the functionalized polymer as claimed in claim 1, by (a1) preparing a furan-containing polymer, which comprises a covalently bonded furan compound, (a2) reacting the furan compound bonded covalently to the furan-containing polymer, in a Diels-Alder reaction, with a cyclic imide compound which contains a functional organyl radical having a molar mass of less than 800 g/mol or a precursor of this functional organyl radical.

10. The process as claimed in claim 9, wherein the furan-containing polymer is prepared in step (a1) by reacting a starting polymer which contains reactive groups with a furan compound; or the furan-containing polymer is obtained in step (a1) by a polymerization using a furan compound as monomer.

11. A process for preparing the functionalized polymer as claimed in claim 1, by (b1) preparing an imide-containing polymer which comprises a covalently bonded cyclic imide compound, (b2) reacting the cyclic imide compound bonded covalently to the imide-containing polymer, in a Diels-Alder reaction, with a furan compound which contains a functional organyl radical having a molar mass of less than 800 g/mol or a precursor of this functional organyl radical.

12. The process as claimed in claim 11, wherein the imide-containing polymer is prepared in step (b1) by reacting a starting polymer containing reactive groups with a cyclic imide compound.

13. The process as claimed in claim 9, wherein the cyclic imide compound is a compound of the following formula (II): ##STR00007## where R.sup.6 and R.sup.7, independently of one another, are hydrogen or C.sub.1-4-alkyl; the functional organyl radical R.sup.5 comprises an alkyl group, a quaternary ammonium group, a carboxylic acid or carboxylate group, a sulfonamide group, an amine group, a hydroxyl group, or a combination of at least two of these groups.

14. The process as claimed in claim 9, wherein the furan compound has the following formula (I): ##STR00008## where the radicals R.sup.1, R.sup.2, R.sup.3 and R.sup.4, independently of one another, are hydrogen, an alkyl, amide, carbonyl, carboxyl, hydroxymethyl, thiomethyl, aldehyde, ester, aminoethyl, vinyl, vinyl ether, allyl, allyl ether, thiomethyl, acrylic acid or C.sub.1-4-alkyl acrylate, methacrylic acid or C.sub.1-4-alkyl methacrylate or isocyanatomethyl group, with the proviso that at least one of the radicals R.sup.1-R.sup.4 is neither hydrogen nor alkyl.

Description

EXAMPLES

Example 1: Preparation of the Functionalized Polyurethane

[0123] The following OH-functional compounds were reacted with the following diisocyanate under the below-specified conditions to form an NCO-terminated polyurethane.

[0124] 61.78 g of polypropylene glycol 1000, 2.12 g of trimethylolpropane and 36.14 g of methylendiphenyl isocyanate (MDI) were reacted at 95° C. for 2 h to give an NCO-terminated polyurethane. Catalyst: 0.06 m % Borchikar® 0244.

[0125] This initial polymer having terminal NCO groups was reacted with furfuryl alcohol under the following conditions:

[0126] 100 g of the NCO-terminated starting polymer were admixed with 11.80 g of furfuryl alcohol and the mixture was stirred at 95° C. for a further 2 h.

[0127] A furan-containing polymer was obtained, which had the covalently bonded furan compound at the end.

[0128] The furan-containing polymer was reacted with the following cyclic imide compound under the conditions stated below:

[0129] The furan-containing polymer was reacted at 100° C. in the melt with N-octadecyl maleimide (i.e., a cyclic imide comprising —C.sub.18H.sub.37 as functional organyl radical). The furan:maleimide ratio was 1:0.8.

[0130] This gave a functionalized polyurethane which in terminal position had the Diels-Alder adducts.

Example 2: Preparation of the Functionalized Polymethacrylate

[0131] Furfuryl methacrylate was polymerized together with the following (meth)acrylates under the conditions described below to give a polymethacrylate:

[0132] Methyl methacrylate and furfuryl methacrylate were dissolved in a molar ratio of 70:30 in toluene. 0.1 m % AlBN was added as initiator, and the mixture was stirred at 90° C. for 4 h.

[0133] The furan-containing polymethacrylate was reacted with the following cyclic imide compound under the conditions stated below:

[0134] The furan-containing polymer was dissolved in toluene and reacted with N-octadecyl maleimide (i.e., a cyclic imide which comprises —C.sub.18H.sub.37 as functional organyl radical) at 90° C. The furan:maleimide ratio was 1:0.9.

[0135] This gave the functionalized polymethacrylate, with the Diels-Alder adducts being bonded with the polymer chain via side chains.

[0136] Through the functional organyl radical in the cyclic imide components of the Diels-Alder adduct, the polymer was able to be provided in a targeted way with a hydrophobic effect. If, for example, a biocidal or hydrophilic organyl radical is used instead of the hydrophobic organyl radical, it is possible to obtain a functionalized polymer having biocidal or hydrophilic properties.

[0137] Because the Diels-Alder adduct containing the functional organyl radical is bonded covalently to the polymer, any uncontrolled release of additives is prevented. Moreover, the Diels-Alder adduct may be cleaved thermally as and when required, such as during recycling of the polymer, for example. As a result of this controlled cleaving of the Diels-Alder adduct, it is possible to detach the component carrying the functional organyl radical (the furan component or the cyclic imide component) from the polymer. The polymer backbone is retained and continues to comprise a covalently bonded furan or cyclic imide component. Through a Diels-Alder reaction of this remaining component (e.g., the furan component) with the suitable reaction partner (e.g., a maleimide compound with functional organyl radical), it is possible for further functionalization to be carried out.