STAR POLYMERS HAVING A SILYL COUPLING

Abstract

The present invention relates to methods of forming star polymers having configurable architecture in which arms are synthesized by means of living anionic polymerization, with the arms being conjugated with a core, the core comprising m coupling groups, each coupling group having n methylene groups. The invention further relates to star polymers produced therefrom.

Claims

1. A process for producing star polymers comprising the steps of (a) providing a reaction mixture comprising one or more solvents, p mol of an initiator I.sup.(−)Z.sup.(+) and q mol of a monomer A or q mol of a monomer A and r mol of a monomer C where C≠A, wherein A and C are selected from the group consisting of dienes, 1,3-butadiene, isoprene, polar vinyl monomers, vinylpyridines, vinyl ketones, acrylates, methacrylates, acrylonitriles, styrene, ethylene oxide, propylene oxide and 1-ethoxyethylene glycidyl ether; (b) polymerizing A to afford I{poly(A)}.sup.(−)Z.sup.(+) or polymerizing A and C to afford I{poly(A-stat-C)}.sup.(−)Z.sup.(+) by living anionic polymerization; (c) optionally adding monomer B to the reaction mixture and living anionic polymerization of I{poly(A)}.sup.(−)Z.sup.(+) to afford I{poly(A)poly(B)}.sup.(−)Z.sup.(+), wherein B is selected from the group consisting of dienes, 1,3-butadiene, isoprene, polar vinyl monomers, vinylpyridines, vinyl ketones, acrylates, methacrylates, acrylonitrile, styrene, ethylene oxide, propylene oxide and 1-ethoxyethylene glycidyl ether and B≠A; (d) optionally adding monomer A to the reaction mixture and living anionic polymerization of I{poly(A)poly(B)}.sup.(−)Z.sup.(+) to afford I{poly(A)poly(B)poly(A)}.sup.(−)Z.sup.(+); (e) optionally performing the step sequence (c)-(d) a single or multiple times; (f) optionally performing step (c); (g) adding r mol of a core K to the reaction mixture and conjugating I{poly(A)}.sup.(−), I{poly(A-stat-C)}.sup.(−) or I{poly(A)-block-poly(B)}.sup.(−) with K to afford a star polymer [I{poly(A)}].sub.mK, [I{poly(A-stat-C)}].sub.mK or [I{poly(A)-block-poly(B)}].sub.mK; wherein the core K has the structure ##STR00009## where m=2-16 coupling groups each having n=2-20 methylene groups.

2. The process as claimed in claim 1, wherein R is a radical of an alkane, aromatic, tertiary amine, cyclic tertiary amine, polymer, polyether, polysiloxane, block copolymer or of silicon.

3. The process as claimed in claim 1, wherein R is a radical of a telechelic oligomer having two functional end groups (m=2).

4. The process as claimed in claim 1, wherein R in tetrahydrofuran has a pK.sub.a of 20 to 100.

5. The process as claimed in claim 1, wherein the reaction mixture contains one or more solvents selected from the group consisting of benzene, hexane, cyclohexane, toluene, tetrahydrofuran and dioxane.

6. A star polymer produced by the process as claimed in claim 1.

7. A star polymer of structure P ##STR00010## where m=2-16 arms each having n=2-20 methylene groups, wherein R is a radical of an alkane, aromatic, tertiary amine, cyclic tertiary amine, polymer, polyether, polysiloxane, block copolymer or of silicon (Si); and X has the structure I{poly(A)}-, I{poly(A-stat-C)}- where C≠A or I{poly(A)-block-poly(B)}- where B≠A and A, C, B are selected from the group consisting of dienes, 1,3-butadiene, isoprene, polar vinyl monomers, vinylpyridines, vinyl ketones, acrylates, methacrylates, acrylonitriles, styrene, ethylene oxide, propylene oxide and 1-ethoxyethylene glycidyl ether.

8. The star polymer as claimed in claim 7, wherein said star polymer has a polydispersity M.sub.w/M.sub.n≤2.

9. The star polymer as claimed in claim 7, wherein said star polymer has a molar mass M.sub.w where 2000 g.Math.mol.sup.−1≤M.sub.w≤200000 g.Math.mol.sup.−1.

10. The star polymer as claimed in claim 7, wherein A, C, B are selected from 1,3-butadiene, styrene or isoprene.

Description

[0156] FIG. 1 to 5 show GPC elugrams of arms synthesized by “living” anionic polymerization and star polymers produced therewith. Specifically:

[0157] FIG. 1 shows GPC elugrams of poly(styrene) arms and a four-armed star polymer produced therewith having a tetra[3-(dimethylchlorosilyl) propylsilane core;

[0158] FIG. 2 shows GPC elugrams of poly(isoprene-co-styrene) arms and a four-armed star polymer produced therewith having a tetra[3-(dimethylchlorosilyl)propyl]silane core;

[0159] FIG. 3 shows GPC elugrams of star polymers having four poly(isoprene-co-styrene) arms and a tetra[3-(dimethylchlorosilyl)propyl]silane core;

[0160] FIG. 4 shows GPC elugrams of poly(isoprene) arms and a three-armed star polymer produced therewith having a [(methylsilanetriyl)tris(propane-3,1-diyl)]tris(chlorodimethylsilane) core;

[0161] FIG. 5 shows GPC elugrams of poly(isoprene) arms and a two-armed star polymer produced therewith having a bis[3-(chlorodimethylsilyl)propyl]dimethylsilane core.

[0162] FIG. 6 to 18 show NMR spectra of cores/coupling reagents and their precursors and of star polymers. Specifically:

[0163] FIG. 6 shows a .sup.1H-NMR spectrum of a tetraallylsilane precursor (400 MHz, CDCl.sub.3);

[0164] FIG. 7 shows a .sup.1H-NMR spectrum of a triallyl(methyl)silane precursor (400 MHz, CDCl.sub.3);

[0165] FIG. 8 shows a .sup.1H-NMR spectrum of a tetra[3-(dimethylchlorosilyl)propyl]silane core (400 MHz, CDCl.sub.3);

[0166] FIG. 9 shows a .sup.1H-NMR spectrum of a [(methylsilanetriyl)tris(propane-3,1-diyl)]tris(chlorodimethylsilane) core (400 MHz, CDCl.sub.3);

[0167] FIG. 10 shows a .sup.13C-NMR spectrum of a [(methylsilanetriyl)tris(propane-3,1-diyl)]tris(chlorodimethylsilane) core (400 MHz, CDCl.sub.3);

[0168] FIG. 11 shows a .sup.1H-NMR spectrum of a bis[3-(chlorodimethylsilyl)propyl]dimethylsilane core (400 MHz, C.sub.6D.sub.6);

[0169] FIG. 12 shows a .sup.13C-NMR spectrum of a bis[3-(chlorodimethylsilyl)propyl]dimethylsilane core (400 MHz, C.sub.6D.sub.6);

[0170] FIG. 13 shows a .sup.1H-NMR spectrum of a polystyrene arm (400 MHz, CDCl.sub.3);

[0171] FIG. 14 shows a .sup.1H-NMR spectrum of a star polymer having four polystyrene arms, a core derived from tetra[3-(dimethylchlorosilyl)propyl]silane and a nominal molar weight of 12 kg.Math.mol.sup.−1 (400 MHz, CDCl.sub.3);

[0172] FIG. 15 shows a .sup.1H-NMR spectrum of a poly(isoprene-co-styrene) arm having a nominal molar weight of 10 kg.Math.mol.sup.−1 (400 MHz, CDCl.sub.3);

[0173] FIG. 16 shows a .sup.1H-NMR spectrum of a star polymer having four poly(isoprene-co-styrene) arms, a core derived from tetra[3-(dimethylchlorosilyl)propyl]silane and a nominal molar weight of 40 kg.Math.mol.sup.−1 (400 MHz, CDCl.sub.3);

[0174] FIG. 17 shows a .sup.1H-NMR spectrum of a star polymer having three poly(isoprene) arms, a core derived from [(methylsilanetriyl)tris(propane-3,1-diyl)]tris(chlorodimethylsilane) and a nominal molar weight of 27 kg.Math.mol.sup.−1 (400 MHz, CDCl.sub.3);

[0175] FIG. 18 shows a .sup.1H-NMR spectrum of a star polymer having two poly(isoprene) arms, a core derived from bis[3-(chlorodimethylsilyl)propyl]dimethylsilane and a nominal molar weight of 18 kg.Math.mol.sup.−1 (400 MHz, CDCl.sub.3).

METHODS OF MEASUREMENT

[0176] In the context of the present invention the weights and weight distributions of the arm and star polymers produced were determined by gel permeation chromatography (GPC/SEC) in tetrahydrofuran (THF) at a temperature in the range from 25° C. to 30° C., standard pressure (985-1010 hPa) and typical atmospheric humidity (40-100% rH) (source: Measuring station of the Institute for Atmospheric Physics, Johannes Gutenberg University Mainz).

[0177] Unless otherwise stated all chemicals and solvents were obtained from commercial suppliers (Acros, Sigma-Aldrich, Fisher Scientific, Fluka, Riedel-de-Haën, Roth) and—except for drying of the solvents and monomers—used without further purification. Deuterated solvents were obtained from Deutero GmbH (Kastellaun, Germany).

[0178] Gel Permeation Chromatoraphy (GPC/SEC)

[0179] GPC/SEC measurements were carried out according to DIN 55672-3 2016-01 at a temperature of 25° C. to 30° C. on an Agilent 1100 HPLC system with a refractive index detector (RI detector Agilent 2160 Infinity), UV detector (275 nm), online viscometer and an SDV column set (SDV 103, SDV 105, SDV 106) from Polymer Standard Service GmbH (referred to hereinbelow as PSS). Tetrahydrofuran (THF) was used as the solvent for the polymers to be analyzed and as an eluent with a volume flow of 1 ml min.sup.−1. The THF-dissolved polymers for analysis were injected into the GPC column using a Waters 717 plus autosampler. Calibration was carried out using polystyrene standards from PSS. Elugrams were evaluate using the software PSS WinGPC Unity from PSS.

[0180] NMR Spectroscopy

[0181] .sup.1H- and .sup.13C-NMR spectra were recorded on an Avance 11 400 instrument (400 MHz, 5 mm BBFO head with z-gradient and ATM) from Bruker at a frequency of 400 MHz (.sup.1H) or 101 MHz (.sup.13C). Kinetic in situ .sup.1H-NMR measurements were carried out using a Bruker Avance III HD 400 spectrometer equipped with a 5 mm BBFO-SmartProbe sensor (Z-gradient sensor), ATM and SampleXPress 60 autosampler. Chemical shifts are reported in ppm and relate to the proton signal of the deuterated solvent.