Block copolymer and method for preparing the same

Abstract

A block copolymer and a method for preparing the same are disclosed. The method comprises the following steps: (A) mixing a compound of formula (I), a catalyst of formula (II), and a first solvent to obtain a first mixture; (B) adding a first monomer into the first mixture for reaction to obtain a second mixture; and (C) adding a second monomer into the second mixture for reaction to obtain a third mixture; wherein the compound of formula (I) and the catalyst of formula (II) are as defined in the specification.

Claims

1. A method for preparing a block copolymer, comprising: (A) mixing a compound of formula (I), a catalyst of formula (II), and a first solvent to obtain a first mixture: ##STR00008## wherein A.sub.1 is a bond, O, or S; R.sub.1, R.sub.2, and R.sub.3 are each independently H, a C.sub.1-6 alkyl, —COOR.sub.4, or —CH.sub.2P(═O)R.sub.5R.sub.6; or R.sub.1 and R.sub.2 are bonded to each other to form a C.sub.4-8 cycloalkyl group or a C.sub.3-7 heterocycloalkyl group; or R.sub.2 and R.sub.3 are bonded to each other to form a C.sub.5-8 cycloalkyl group; and OTMS is OSiMe.sub.3; wherein R.sub.4, R.sub.5, and R.sub.6 are each independently a C.sub.1-6 alkyl, a C.sub.1-6 alkoxyl, -OTMS, or an amino group substituted by a C.sub.1-6 alkyl;
[M(O).sub.a].sup.m+X.sub.b.sup.n−  (II) wherein M(O).sub.a is VO, VO.sub.3, ZrO, HfO, WO.sub.2, MoO.sub.2, CrO.sub.2, or ReO.sub.3; X is Cl, Br, I, OAc, OC(O)Ar, OC(O)(CF.sub.2).sub.cCF.sub.3, OC(O)C.sub.12H.sub.25, OTf, OTs, SO.sub.4, SO.sub.3C.sub.12H.sub.25, acetylacetonate (acac), or a mixture thereof; b is an integer from 1 to 4; m is an integer from 2 to 4; n is an integer from 1 to 2; c is an integer from 1 to 6; Ar is a C.sub.6-20 aryl; Ac is C(O)CH.sub.3; Tf is trifluoromethylsulfonyl, and Ts is toluenesulfonyl; (B) adding a first monomer into the first mixture to obtain a second mixture; and (C) adding a second monomer into the second mixture to obtain a third mixture.

2. The method according to claim 1, further comprising a step of (D) adding the third mixture into a second solvent.

3. The method according to claim 2, wherein the second solvent is water, an alcohol, a C.sub.5-10 alkane, or a mixture thereof.

4. The method according to claim 1, wherein the first monomer and the second monomer are each independently an acrylate compound.

5. The method according to claim 1, wherein the first monomer and the second monomer are each independently a compound of formula (III) below: ##STR00009## wherein A.sub.2 is O or S; R.sub.7 is H, or a C.sub.1-6 alkyl; and R.sub.8 is a C.sub.1-12 alkyl, (CH.sub.2).sub.qN(R.sub.11).sub.2, CH.sub.2(CH.sub.2OCH.sub.2).sub.rCH.sub.2N(R.sub.12).sub.2, or CH.sub.2(CH.sub.2OCH.sub.2).sub.sCH.sub.2OR.sub.13; wherein R.sub.11, R.sub.12, and R.sub.13 are each independently a C.sub.1-6 alkyl; and q, r, and s are each independently an integer from 1 to 10.

6. The method according to claim 1, wherein the first monomer and the second monomer are each independently a compound of formula (IV) below: ##STR00010## wherein Y is O, NH, or S; R.sub.9 is H or a C.sub.1-6 alkyl; R.sub.10 is a C.sub.1-6 alkyl or a C.sub.6-20 aryl; and p is an integer from 1 to 12.

7. The method according to claim 1, further comprising adding a third monomer into the third mixture to obtain a fourth mixture after obtaining the third mixture in step (C).

8. The method according to claim 7, further comprising a step of (E) adding the fourth mixture into a second solvent.

9. The method according to claim 8, wherein the second solvent is water, an alcohol, a C.sub.5-10 alkane, or a mixture thereof.

10. The method according to claim 7, wherein the first monomer, the second monomer, and the third monomer are each independently an acrylate compound.

11. The method according to claim 1, wherein the first solvent is an ether solvent.

12. The method according to claim 1, wherein the catalyst is present in an amount of 0.1 wt % to 20 wt %, based on a total weight of the first mixture.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(1) The detailed description of the present disclosure is described below by way of specific embodiments, and those skilled in the art can readily appreciate the other advantages and efficacies of the present disclosure from the specification. The present disclosure may also be implemented or applied by other different embodiments. The details of the specification may also be applied to various aspects and applications, and various modifications and variations may be made without departing from the spirit of the present invention.

(2) Synthesis of the Catalyst

(3) In the present embodiment, the catalyst can be synthesized according to the following reaction formulae.
V(O)SO.sub.4(aq)+BaX.sub.2(aq).fwdarw.V(O)X.sub.2(aq)+BaSO.sub.4(s)
V(O)SO.sub.4(aq)+Ba(OC(O)R).sub.2(aq).fwdarw.V(O)(OC(O)R).sub.2(aq)+BaSO.sub.4(s)
V(O)SO.sub.4(aq)+Ba(OTf).sub.2(aq).fwdarw.V(O)(OTf).sub.2(aq)+BaSO.sub.4(s)
V(O)SO.sub.4(aq)+Ba(OTs).sub.2(aq).fwdarw.V(O)(OTs).sub.2(aq)+BaSO.sub.4(s)
V(O)SO.sub.4(aq)+Ba[(O.sub.3SC.sub.6H.sub.4CHCH.sub.2).sub.11].sub.2(aq).fwdarw.V(O)[(O.sub.3SC.sub.6H.sub.4CHCH.sub.2).sub.n].sub.2(aq)+BaSO.sub.4(s)

(4) Vanadium sulphate (VOSO.sub.4-5H.sub.2O, 2.5 mmol) was placed in a dry double-necked round bottom flask (50 mL), followed by anhydrous methanol (2.5 mL). To the resulting solution, a solution of BaX.sub.2 (1 equivalent, 2.5 mmol) (for example, Ba(OAc).sub.2, BaOTs.sub.2, BaOTf.sub.2, or Ba[(O.sub.3SC.sub.6H.sub.4CHCH.sub.2).sub.n].sub.2) in methanol (2.5 mL) was slowly added at room temperature. After stirring for 30 minutes, the reaction mixture is cloudy and is accompanied by a large amount of barium sulfate precipitation. The mixture was filtered through a plug of celite, and the obtained filtrate was evaporated to give a dark blue solid. The resulting solid was dried under vacuum at 120° C. for 4 hours. The product obtained can be stored in a dry box for several weeks and can be used directly.

Synthesis of Block Copolymer

Example 1

(5) To a round bottom flask (100 mL) containing the benzoic acid oxovanadium catalyst (2.5 mg), 1-methoxy-2-methyl-1-(trimethylsilyloxy)propene (MTS, 0.20 mL, 0.99 mmol) dissolved in tetrahydrofuran (20 mL) was added. The round bottom flask was previously sealed with a membrane and purged with argon gas. Then, butyl methacrylate (BuMA, 2.2 mL, 11.2 mmol) was injected, and the temperature was raised from 20° C. to 33° C. After 30 minutes, the exothermic reaction was weak, and two 0.1 mL aliquots of the reaction solution were extracted and analyzed by GPC and .sup.1H NMR, respectively. Afterwards, 2-(dimethylamino)ethyl methacrylate (DMAEMA, 2.65 mL, 15.7 mmol) was added and the temperature was observed to rise from 22° C. to 34° C. The crude product was poured into hexane to induce precipitation, and the purified copolymer was filtered to remove small molecule impurities, obtaining a final product.

(6) .sup.1H NMR (400 MHz, CDCl.sub.3) δ 0.88 (br, 55H), 0.94 (br, 56H), 1.04 (br, 39H), 1.40 (br, 40H), 1.61 (br, 35H), 1.81-1.90 (br, 82H), 2.28 (br, 107H), 2.56 (br, 36H), 3.94 (br, 33H), 4.06 (br, 35H).

(7) Mn=4104 (THF); Mw=4785; PDI=1.17.

Example 2

(8) To a round bottom flask (100 mL) containing the benzoic acid oxovanadium catalyst (2.5 mg), 1-methoxy-2-methyl-1-(trimethylsilyloxy)propene (MTS, 0.20 mL, 0.99 mmol) dissolved in tetrahydrofuran (20 mL) was added. The round bottom flask was previously sealed with a membrane and purged with argon gas. Then, hexyl methacrylate (HexMA, 2.2 mL, 11.2 mmol) was injected, and the temperature was raised from 20° C. to 33° C. After 30 minutes, the exothermic reaction was weak, and two 0.1 mL aliquots of the reaction solution were extracted and analyzed by GPC and .sup.1H NMR, respectively. Afterwards, PEGMA (0.095 mL (a 50 vol % solution), 2.1 mmol, MW=500) dissolved in tetrahydrofuran was added and the temperature was raised from 25° C. to 27° C. Next, two 0.1 mL aliquots were extracted and analyzed by GPC and .sup.1H NMR, respectively. Afterwards, 2-(dimethylamino)ethyl methacrylate (DMAEMA, 2.65 mL, 15.7 mmol) was added and the temperature was observed to rise from 22° C. to 34° C. The crude product was poured into hexane to induce precipitation, and the purified copolymer was filtered to remove small molecule impurities, obtaining a final product.

(9) .sup.1H NMR (400 MHz, CDCl.sub.3) δ 0.90 (br, 50H), 1.00 (br, 21H), 1.32 (br, 46H), 1.61-1.68 (br, 23H), 1.81-1.98 (br, 31H), 2.28 (br, 58H), 2.56 (br, 19H), 3.38 (br, 3H), 3.55 (br, 3H), 3.64 (br, 18H), 3.92 (br, 14H), 4.06 (br, 21H).

(10) Mn=6249 (THF); Mw=7811; PDI=1.25.

Example 3

(11) To a round bottom flask (100 mL) containing the benzoic acid oxovanadium catalyst (2.5 mg), 1-methoxy-2-methyl-1-(trimethylsilyloxy)propene (MT S, 0.20 mL, 0.99 mmol) dissolved in tetrahydrofuran (20 mL) was added. The round bottom flask was previously sealed with a membrane and purged with argon gas. Then, a diacrylate compound (6.0 mL (a 33.3 vol % solution), 2.9 mmol) dissolved in tetrahydrofuran was added and the temperature was raised from 25° C. to 27° C. Next, two 0.1 mL aliquots were extracted and analyzed by GPC and .sup.1H NMR, respectively. Afterwards, hexyl methacrylate (HexMA, 1.0 mL, 5.9 mmol) was injected, and the temperature was raised from 20° C. to 33° C. After 30 minutes, the exothermic reaction was weak, and two 0.1 mL aliquots of the reaction solution were extracted and analyzed by GPC and .sup.1H NMR, respectively. The crude product was poured into hexane to induce precipitation, and the purified copolymer was filtered to remove small molecule impurities, obtaining a final product.

(12) .sup.1H NMR (400 MHz, CDCl.sub.3) δ 0.99-1.18 (br, 10H), 1.32-1.35 (br, 7H), 1.62 (s, 8H), 1.95 (br, 3H), 3.64-3.71 (br, 17H), 3.83 (s, 2H), 3.95 (s, 2H), 6.79 (br, 2H), 7.11 (br, 2H).

(13) Mn=6249 (THF); Mw=7811; PDI=1.25.

(14) Dispersion Effect Test

(15) The copolymer of Example 3 (1 g) and the commercially available dispersant (1 g) were dissolved in 1 mL of tetrahydrofuran, into which 135 uL of yellow pigment (from a solution of 500 mg yellow pigment in 3 mL of tetrahydrofuran) was added, followed by grinding and stirring for 30 seconds. The dispersion of the yellow pigment was observed and shown in Table 1.

(16) TABLE-US-00001 TABLE 1 Dispersion effect Particle suspension Copolymer of Excellent No particle suspension or uneven Example 2 dispersion Copolymer of Excellent No particle suspension or uneven Example 3 dispersion Commercially Good Significant particle suspension available dispersant

(17) The above specific embodiments are to be construed as illustrative only and do not limit the remainder of this disclosure in any way.

(18) Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.