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CATALYST FOR PROPYLENE POLYMERIZATION, CATALYST SYSTEM FOR PROPYLENE POLYMERIZATION, AND PREPARATION AND USE THEREOF

20230183394 · 2023-06-15

    Inventors

    Cpc classification

    International classification

    Abstract

    The present invention relates to a catalyst for propylene polymerization, a catalyst system for propylene polymerization and preparation and use thereof. The catalyst for propylene polymerization comprises: an activated magnesium halide, a titanium compound supported on the activated magnesium halide containing at least one Ti-halogen bond, and an internal electron donor compound selected from one or more of compounds having a structure of below Formula (1), wherein R.sub.1 and R.sub.6 are each independently selected from a C.sub.1-C.sub.12 straight or branched alkyl, a C.sub.3-C.sub.15 cycloalkyl or aryl, and R′ is H, a C.sub.1-C.sub.5 straight or branched alkyl, or phenyl; R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each independently selected from H, halogen, a C.sub.1-C.sub.12 straight or branched alkyl, a C.sub.3-C.sub.8 cycloalkyl, a C.sub.6-C.sub.15 aryl, or arylalkyl. The present invention can provide a catalyst showing high polymerization reaction activity and excellent stereospecificity, by applying a novel type of internal electron donor.

    ##STR00001##

    Claims

    1. A catalyst for propylene polymerization, comprising: an activated magnesium halide, a titanium compound supported on the activated magnesium halide, containing at least one Ti-halogen bond, and an internal electron donor compound; wherein the internal electron donor compound is one or more selected from the compounds having a structure of Formula (1): ##STR00036## wherein R.sub.1 and R.sub.6 are each independently selected from a C.sub.1-C.sub.12 straight or branched alkyl, a C.sub.3-C.sub.15 cycloalkyl, or an aryl, and R′ is H, a C.sub.1-C.sub.5 straight or branched alkyl, or phenyl; and R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each independently selected from H, halogen, a C.sub.1-C.sub.12 straight or branched alkyl, a C.sub.3-C.sub.8 cycloalkyl, a C.sub.6-C.sub.15 aryl, or an arylalkyl.

    2. The catalyst for propylene polymerization according to claim 1, wherein in Formula (1), R′ is methyl.

    3. The catalyst for propylene polymerization according to claim 2, wherein in Formula (1), R.sub.6 is selected from a C.sub.1-C.sub.12 straight or branched alkyl, or phenyl.

    4. The catalyst for propylene polymerization according to claim 3, wherein in Formula (1), R.sub.1 is selected from a C.sub.1-C.sub.12 straight or branched alkyl.

    5. The catalyst for propylene polymerization according to claim 4, wherein in Formula (1), R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are all H atoms.

    6. The catalyst for propylene polymerization according to claim 1, wherein the internal electron donor compound is any one or more selected from the following compounds: butyl 2-(N-methylbutylsulfonamido)benzoate; methyl 2-(N-methylphenylsulfonamido)benzoate; methyl 2-(N-methylbutylsulfonamido)benzoate; isopropyl 2-(N-methylphenylsulfonamido)benzoate; propyl 2-(N-methylbutylsulfonamido)benzoate; isobutyl 2-(N-methylethylsulfonamido)benzoate; methyl 2-(N-methylmethylsulfonamido)benzoate; neopentyl 2-(N-methylbutylsulfonamido)benzoate; cyclopentyl 2-(N-methylpropylsulfonamido)benzoate; cyclohexyl 2-(N-methylpropylsulfonamido)benzoate; methyl 2-(N-methylcyclopropylsulfonamido)benzoate; methyl 2-(N-methylcyclopentylsulfonamido)benzoate; methyl 2-(N-methylpentylsulfonamido)benzoate; isopropyl 2-(N-methylcyclohexylsulfonamido)benzoate; propyl 2-(N-methylheptylsulfonamido)benzoate; isobutyl 2-(N-methyl-p-tolylsulfonamido)benzoate; phenyl 2-(N-methylbutylsulfonamido)benzoate; isooctyl 2-(N-methylbutylsulfonamido)benzoate; p-tolyl 2-(N-methyl propyl sulfonamido)benzoate; ethyl 2-(N-methylethylsulfonamido)benzoate; ethyl 2-(N-methylpentylsulfonamido)benzoate; isobutyl 2-(N-methylphenylsulfonamido)benzoate; isobutyl 2-(N-methylbutylsulfonamido)benzoate; neopentyl 2-(N-methyl-p-tolylsulfonamido)benzoate; p-tolyl 2-(N-methylbutylsulfonamido)benzoate; isooctyl 2-(N-methylethylsulfonamido)benzoate; p-tolyl 2-(N-methylcyclohexylsulfonamido)benzoate; propyl 2-(N-methyl-β-naphthylsulfonamido)benzoate; methyl 2,3,4,5-tetramethyl-6-(N-methylsulfonamido)benzoate; methyl 4-bromo-6-(N-ethylsulfonamido)benzoate; methyl 3-isopropyl-6-(N-butylsulfonamido)benzoate; butyl 2-(N-butylsulfonamido)benzoate; methyl 2-(N-phenylsulfonamido)benzoate; methyl 2-(N-butylsulfonamido)benzoate; isopropyl 2-(N-phenylsulfonamido)benzoate; propyl 2-(N-butylsulfonamido)benzoate; and isobutyl 2-(N-ethylsulfonamido)benzoate.

    7. The catalyst for propylene polymerization according to claim 1, wherein the precursor of the activated magnesium halide is a magnesium halide alcoholate having a general formula of Mg(OR.sup.1).sub.2-mX.sub.m.Math.n(R.sup.2OH), wherein R.sup.1 is selected from a C.sub.1-C.sub.20 alkyl, X is halogen, m is 1 or 2, n is a fractional or integer number satisfying 0<n<5, and R.sup.2 is selected from a C.sub.1-C.sub.20 alkyl.

    8. The catalyst for propylene polymerization according to claim 7, wherein the magnesium halide in the magnesium halide alcoholate comprises one or more of magnesium chloride, magnesium bromide, magnesium chloride methoxide, and magnesium chloride ethoxide; and the alcohol in the magnesium halide alcoholate comprises one or more of methanol, ethanol, propanol, isopropanol, butanol and isobutanol.

    9. The catalyst for propylene polymerization according to claim 8, wherein, in the magnesium halide alcoholate, the magnesium halide is magnesium chloride and the alcohol is ethanol.

    10. The catalyst for propylene polymerization according to claim 1, wherein the titanium compound comprises one or more of titanium chloride trialkoxide, titanium dichloride dialkoxide, titanium trichloride alkoxide, titanium tetrachloride and titanium tetrabromide.

    11. The catalyst for propylene polymerization according to claim 10, wherein the titanium compound is titanium tetrachloride.

    12. The catalyst for propylene polymerization according to claim 1, wherein based on 100% of the total mass of the catalyst for propylene polymerization, the content of the magnesium element is 10% to 25% by mass, the content of the titanium element is 1% to 15% by mass, the total content of halogen in the magnesium halide and the titanium compound is 40% to 60% by mass, and the content of the internal electron donor is 1% to 10% by mass.

    13. A method for preparing the catalyst for propylene polymerization according to claim 1, comprising the steps of: (S1) adding the precursor of the activated magnesium halide to a portion of the titanium compound liquid, and cooling them to a first predetermined temperature to allow a reaction to proceed; (S2) increasing gradually the temperature to a second predetermined temperature, adding the internal electron donor compound, and allowing the reaction to continue; (S3) adding the remainder of the titanium compound at a third predetermined temperature, allowing the reaction to continue, and filtering the reaction system after the reaction is completed, to obtain a solid residue; and (S4) washing and drying the solid residue to obtain the catalyst for propylene polymerization.

    14. The method according to claim 13, wherein in step (S2) the molar ratio of the magnesium element to the internal electron donor compound is 1:1 to 20:1.

    15. The method according to claim 13, wherein in step (S1), the first predetermined temperature is −40° C. to 0° C., and the reaction proceeds fora period of 0.1 h to 3 h; in step (S2), the second predetermined temperature is 40° C. to 100° C., and the reaction proceeds for a period of 0.5 h to 3 h; in step (S3), the third predetermined temperature is 80° C. to 140° C., and the reaction proceeds for a period of 0.5 h to 3 h.

    16. A catalyst system for propylene polymerization, comprising the catalyst for propylene polymerization according to claim 1, a co-catalyst, and an external electron donor.

    17. The catalyst system for propylene polymerization according to claim 16, wherein the co-catalyst is an alkyl aluminum compound having a general formula of AlR.sup.3.sub.pX.sub.3-p, wherein R.sup.3 is a C.sub.1-C.sub.20 alkyl group; X is halogen; and p is an integer satisfying 1≤p≤3; and the external electron donor is a siloxane compound having a general formula of R.sup.4.sub.qSi(OR.sup.5).sub.4-q, wherein R.sup.4 is a C.sub.1-C.sub.10 alkyl, cycloalkyl or aryl group; R.sup.5 is an alkyl having 1 to 4 carbon atoms; and q is an integer satisfying 0≤n≤3.

    18. The catalyst system for propylene polymerization according to claim 16, wherein the co-catalyst comprises one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum monohydride, diisobutylaluminum monohydride, diethylaluminum monochloride, diisobutylaluminum monochloride, and ethylaluminum dichloride.

    19. The catalyst system for propylene polymerization according to claim 16, wherein the external electron donor comprises one or more of methylcyclohexyldimethoxysilane phenyltrimethoxysilane, phenyltriethoxysilane, and diphenyldimethoxysilane.

    20. The catalyst system for propylene polymerization according to claim 16, wherein the molar ratio of titanium in the catalyst for propylene polymerization to aluminum in the co-catalyst is 1:1 to 1:2,000; and the molar ratio Si/Ti of Si in the external electron donor to Ti in the catalyst for propylene polymerization is 1:1 to 1:100.

    21. (canceled)

    Description

    BRIEF DESCRIPTION OF DRAWINGS

    [0104] FIG. 1 shows the .sup.1H spectrum of butyl 2-(N-methylbutylsulfonamido)benzoate obtained in Example 1;

    [0105] FIG. 2 shows the .sup.13C spectrum of butyl 2-(N-methylbutylsulfonamido)benzoate obtained in Example 1;

    [0106] FIG. 3 shows the .sup.1H spectrum of methyl 2-(N-methylphenylsulfonamido)benzoate obtained in Example 2;

    [0107] FIG. 4 shows the .sup.13C spectrum of methyl 2-(N-methylphenylsulfonamido)benzoate obtained in Example 2;

    [0108] FIG. 5 shows the .sup.1H spectrum of methyl 2-(N-methylbutylsulfonamido)benzoate obtained in Example 3;

    [0109] FIG. 6 shows the .sup.13C spectrum of methyl 2-(N-methylbutylsulfonamido)benzoate obtained in Example 3;

    [0110] FIG. 7 shows the .sup.1H spectrum of isopropyl 2-(N-methylphenylsulfonamido)benzoate obtained in Example 4;

    [0111] FIG. 8 shows the .sup.13C spectrum of isopropyl 2-(N-methylphenylsulfonamido)benzoate obtained in Example 4;

    [0112] FIG. 9 shows the .sup.1H spectrum of propyl 2-(N-methylbutylsulfonamido)benzoate obtained in Example 5;

    [0113] FIG. 10 shows the .sup.13C spectrum of propyl 2-(N-methylbutylsulfonamido)benzoate obtained in Example 5;

    [0114] FIG. 11 shows the .sup.1H spectrum of isobutyl 2-(N-methylethylsulfamoyl)benzoate obtained in Example 6;

    [0115] FIG. 12 shows the .sup.13C spectrum of isobutyl 2-(N-methylethylsulfonamido)benzoate obtained in Example 6.

    DETAILED DESCRIPTION OF THE INVENTION

    [0116] The present invention is further described below in connection with preferred embodiments to illustrate the present invention more clearly. It should be understood by those skilled in the art that the specific contents described below are illustrative and not limiting, and should not be construed to limit the scope of protection of the present invention.

    Test Procedures

    [0117] (1) The structures of the synthesized electron donor compounds were determined by NMR.
    (2) The isotacticity of the polymer products was determined by the boiling n-heptane extraction method according to National Standard GB/T 2412-2008.
    (3) The catalyst activity was calculated based on the mass ratio of the polymer produced by the reaction to the input catalyst.

    Part I. Synthesis of Compounds

    Example 1

    [0118] This Example provides butyl 2-(N-methylbutylsulfonamido)benzoate having a structure of:

    ##STR00030##

    which is prepared by the following method:

    [0119] Step (1): To a 1000 mL flask, 30.0 g 2-aminobenzoic acid, 800 mL n-butanol, and 50 mL concentrated H.sub.2SO.sub.4 (98.3% by mass) were added, and allowed to react continuously for about 36 h under heating in an oil bath at 100° C. and under stirring. Then the reaction solution was transferred to a 2000 mL flask, the n-butanol and water were removed, and the orange-yellow residue liquid was dissolved in 600 mL water and transferred to a 2000 mL beaker, to which an appropriate amount of NaHCO.sub.3 was added to neutralize excess H.sub.2SO.sub.4 until no bubbles were generated (pH≤7). Then about 300 mL dichloromethane was added thereto for extraction, the organic phase was separated, and the solvent was removed to obtain a crude product.

    [0120] The resultant is purified by column chromatography to obtain 16.62 g oily butyl 2-aminobenzoate, in a yield of 39%.

    [0121] Step (2): To a 250 mL flask, 12.00 g butyl 2-aminobenzoate, 50 mL tetrahydrofuran and 11 mL triethylamine were added; and then 12 g butyl sulfonyl chloride dissolved in 70 mL ethyl acetate was added dropwise to the flask, followed by stirring for about 42 h. Afterwards, the reaction solution was transferred to a 1000 mL separatory funnel, and about 300 mL water was added thereto. The resultant was extracted with ethyl acetate, and the solvent was removed to obtain a crude product, which was purified by column chromatography to obtain 14 g butyl 2-butylsulfonamido benzoate, in a yield of 70%.

    [0122] Step (3): 1.52 g NaH was dissolved in 30 mL DMF, and 13 g butyl 2-butylsulfonamido benzoate dissolved in 60 mL DMF was added to a Schlenk bottle, following by stirring for about 2 h. After H.sub.2 was completely released, 18 g iodomethane dissolved in 150 mL THE was added dropwise to the reaction solution, which was stirred for 36 h at room temperature, and then an appropriate amount of concentrated hydrochloric acid was slowly added dropwise to the reaction solution to neutralize excess NaH until the pH was 7 or lower. Afterwards, the reaction solution was transferred to a 1000 mL separatory funnel and 200 ml water was added to carry out hydrolysis, followed by extraction with methyl t-butyl ether. The organic phase from the extraction was concentrated to obtain a crude product, which was purified by column chromatography to obtain 10 g butyl 2-(N-methylbutylsulfonamido)benzoate as a yellow oil, in a yield of 71%.

    [0123] The .sup.1H and .sup.13C NMR spectra of the butyl 2-(N-methylbutylsulfonamido)benzoate are shown in FIGS. 1 and 2.

    [0124] .sup.1H NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 7.88 (d, 1H, J=8.0 Hz), 7.54 (t, 1H, J=8.8 Hz), 7.42 (q, 2H, J=9.6 Hz), 4.33 (t, 2H, J=6.8 Hz), 3.35 (d, 3H, J=2.8 Hz), 3.07 (t, 2H, J=8.0 Hz), 1.86-1.73 (m, 4H), 1.53-1.39 (m, 4H), 1.01-0.91 (m, 6H).

    [0125] .sup.13C NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 166.22, 140.37, 132.58, 131.20, 130.64, 130.61, 128.16, 65.32, 51.61, 39.37, 30.60, 25.27, 21.69, 19.22, 13.59.

    Example 2

    Methyl 2-(N-methylphenylsulfonamido)benzoate

    [0126] ##STR00031##

    [0127] The reaction steps were the same as those in Example 1, except that in Step (1), the raw material n-butanol was replaced with methanol to synthesize methyl 2-aminobenzoate first; then in Step (2) the butyl sulfonyl chloride was replaced with phenyl sulfonyl chloride to obtain methyl 2-phenylsulfonamido benzoate; then in Step (3) the butyl 2-butylsulfonamido benzoate was replaced with methyl 2-phenylsulfonamido benzoate to obtain methyl 2-(N-methylphenylsulfonamido)benzoate as white solid particles with a melting point of 97° C., in a yield of 59%.

    [0128] The .sup.1H and .sup.13C NMR spectra of the methyl 2-(N-methylphenylsulfonamido)benzoate are shown in FIGS. 3 and 4.

    [0129] .sup.1H NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 7.88-7.86 (dd, 1H, J.sub.1=8.0 Hz, J.sub.2=2.8 Hz), 7.67 (d, 2H, J=8.0 Hz), 7.60 (t, 1H, J=8.0 Hz), 7.52-7.39 (m, 4H), 6.96-6.94 (dd, 1H, J.sub.1=8.0 Hz, J.sub.2=2.0 Hz), 3.85 (s, 3H), 3.13 (s, 3H).

    [0130] .sup.13C NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 166.72, 140.04, 138.75, 132.53, 132.23, 132.14, 131.14, 128.98, 128.82, 128.18, 127.54, 52.35, 38.98.

    Example 3

    Methyl 2-(N-methylbutylsulfonamido)benzoate

    [0131] ##STR00032##

    [0132] The reaction steps were the same as those in Example 1, except that in Step (1) the raw material n-butanol was replaced with methanol to synthesize methyl 2-aminobenzoate first; then in Step (2) methyl 2-butylsulfonamido benzoate was obtained; and in Step (3) the butyl 2-butylsulfonamido benzoate was replaced with methyl 2-butylsulfonamido benzoate to obtain methyl 2-(N-methylbutylsulfonamido)benzoate as reddish brown powder with a melting point of 42° C., in a yield of 53%.

    [0133] The .sup.1H and .sup.13C NMR spectra of the methyl 2-(N-methylbutylsulfonamido)benzoate are shown in FIGS. 5 and 6.

    [0134] .sup.1H NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 7.90-7.87 (dq, 1H, J.sub.1=1.6 Hz, J.sub.2=7.6 Hz), 7.56 (t, 1H, J=8.4 Hz), 7.41 (q, 2H, J=8.4 Hz), 3.93 (t, 3H, J=1.6 Hz), 3.34 (t, 3H, J=1.2 Hz), 3.07 (t, 2H, J=8.0 Hz), 1.86-1.78 (m, 2H), 1.44 (q, 2H, J=7.6 Hz), 0.94 (t, 3H, J=7.6 Hz).

    [0135] .sup.13C NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 166.57, 140.46, 132.74, 131.24, 131.02, 130.60, 128.16, 52.39, 51.65, 39.36, 25.27, 21.69, 13.59.

    Example 4

    Isopropyl 2-(N-methylphenylsulfonamido)benzoate

    [0136] ##STR00033##

    [0137] The reaction steps were the same as those in Example 1, except that in step (1) the raw material n-butanol was replaced with isopropanol to synthesize isopropyl 2-aminobenzoate first; then in Step (2) the butyl sulfonyl chloride was replaced with phenyl sulfonyl chloride to obtain isopropyl 2-phenylsulfonamido benzoate; and in Step (3) the butyl 2-butylsulfonamido benzoate was replaced with isopropyl 2-phenylsulfonamido benzoate to obtain isopropyl 2-(N-methylphenylsulfonamido)benzoate as white flocculent needle crystals with a melting point of 118° C., in a yield of 68%.

    [0138] The .sup.1H and .sup.13C NMR spectra of the isopropyl 2-(N-methylphenylsulfonamido)benzoate are shown in FIGS. 7 and 8.

    [0139] .sup.1H NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 7.87-7.85 (m, 1H), 7.67 (d, 2H, J=8.4 Hz), 7.60 (t, 1H, J=7.2 Hz), 7.49 (t, 2H, J=8.0 Hz), 7.42-7.35 (m, 2H), 6.80-6.78 (m, 1H), 5.30-5.21 (m, 1H), 3.31 (s, 3H), 1.42 (d, 6H, J=6.4 Hz).

    [0140] .sup.13C NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 165.98, 139.82, 138.70, 133.52, 132.53, 131.80, 130.99, 128.82, 128.38, 128.20, 127.53, 69.12, 38.98, 21.82.

    Example 5

    Propyl 2-(N-methylbutylsulfonamido)benzoate

    [0141] ##STR00034##

    [0142] The reaction steps were the same as those in Example 1, except that in step (1) the raw material n-butanol was replaced with n-propanol to synthesize propyl 2-aminobenzoate first; then in Step (2) propyl 2-butylsulfonamido benzoate was obtained; and in Step (3) the butyl 2-butylsulfonamido benzoate was replaced with propyl 2-butylsulfonamido benzoate to obtain propyl 2-(N-methylbutylsulfonamido)benzoate as a golden yellow oily liquid, in a yield of 73%.

    [0143] The .sup.1H and .sup.13C NMR spectra of the propyl 2-(N-methylbutylsulfonamido)benzoate are shown in FIGS. 9 and 10.

    [0144] .sup.1H NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 7.89 (t, 1H, J=4.0 Hz), 7.55 (q, 1H, J=5.6 Hz), 7.46-7.40 (m, 2H), 4.32-4.27 (m, 2H), 3.36 (s, 3H), 3.09-3.05 (m, 2H), 1.87-1.79 (m, 4H), 1.50-1.43 (m, 2H), 1.06-0.93 (dt, 6H, J.sub.1=7.6 Hz, J.sub.2=40 Hz).

    [0145] .sup.13C NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 166.23, 140.36, 132.58, 131.22, 131.20, 130.58, 128.16, 67.06, 51.58, 39.38, 25.27, 21.95, 13.59, 10.49.

    Example 6

    Isobutyl 2-(N-methylethylsulfonamido)benzoate

    [0146] ##STR00035##

    [0147] The reaction steps were the same as those in Example 1, except that the raw material n-butanol was replaced with isobutanol to synthesize isobutyl 2-aminobenzoate first; then in Step (2) the butyl sulfonyl chloride was replaced with ethyl sulfonyl chloride to obtain isobutyl 2-ethylsulfonamido benzoate; and in Step (3) the butyl 2-butylsulfonamido benzoate was replaced with isobutyl 2-ethylsulfonamido benzoate to obtain isobutyl 2-(N-methylethylsulfonamido)benzoate as off-white powder with a melting point of 78° C., in a yield of 53%.

    [0148] The .sup.1H and .sup.13C NMR spectra of the isobutyl 2-(N-methylethylsulfonamido)benzoate are shown in FIGS. 11 and 12.

    [0149] .sup.1H NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 7.90 (d, 1H, J=7.6 Hz), 7.56 (t, 1H, J=7.6 Hz), 7.48-7.40 (m, 2H), 7.29 (s, 1H), 4.12 (d, 2H, J=6.8 Hz), 3.36 (d, 3H, J=0.8 Hz), 3.11 (q, 2H, J=7.2 Hz), 2.16-2.06 (m, 1H), 1.39 (t, 3H, J=7.2 Hz), 1.04-1.02 (dd, 6H, J.sub.1=1.2 Hz, J.sub.2=6.8 Hz).

    [0150] .sup.13C NMR (400 MHz, CDCl.sub.3, 25° C., TMS): δ (ppm) 166.12, 140.45, 132.62, 131.15, 130.79, 130.77, 128.18, 71.56, 46.30, 39.53, 27.75, 19.23, 8.01.

    Part II. Preparation and Evaluation of Catalysts

    Example 7

    [0151] This example provides a catalyst for propylene polymerization, which was prepared by the process as follows.

    [0152] To a reaction flask containing 250 mL TiCl.sub.4 and precooled to −30° C., 7.8 g spherical MgCl.sub.2.Math.2.65C.sub.2H.sub.5OH as a support was added slowly, and gradually heated to 80° C. Then 5 mmol methyl 2-(N-methylphenylsulfonamido)benzoate as an internal electron donor was added, and the above temperature was maintained for 30 minutes and then elevated to 130° C. to allow a reaction to proceed for 2 h, followed by filtration. Then 250 mL TiCl.sub.4 was added to allow a reaction to proceed at 130° C. for 2 h. The resultant was washed with n-hexane 6 times, and dried under vacuum to obtain 3.6 g catalyst having a titanium content of 2.2%.

    [0153] The above catalyst for propylene polymerization was used for a propylene polymerization experiment, which was carried out in a 2 L stainless steel autoclave.

    [0154] The pressure in the polymerization autoclave was released first until the gauge pressure was 0, and the autoclave was fully purged with high-purity nitrogen and then vacuumized for 1 h under heating. After the autoclave was cooled to room temperature, high-purity hydrogen gas at 0.1 MPa and 300 g propylene were fed into the autoclave under low-speed stirring. Via a catalyst dosing hopper protected in nitrogen, 10 mg of the catalyst of this example, 2 mL triethylaluminum (2.4 mol/L), and 2.5 mL methylcyclohexyldimethoxysilane (0.18 mol/L) were briefly pre-complexed and then added to the autoclave. Then 300 g propylene was further added, and the temperature was raised to 70° C. to allow a reaction to proceed for 1 h. At the end of the reaction, stirring was stopped, the resultant was cooled, the pressure was released, and the product was discharged to obtain a solid propylene polymer.

    [0155] For a one-hour polymerization reaction, the catalyst showed a polymerization activity of 38.3 kg PP/g cat, and the resultant polypropylene had an isotacticity of 98.2%.

    Example 8

    [0156] This example provides a catalyst for propylene polymerization, which was prepared by the same process as that in Example 7, except that propyl 2-(N-methylbutylsulfonamido)benzoate was used as the electron donor to obtain 0.87 g solid catalyst having a titanium content of 2.85%.

    [0157] The above catalyst for propylene polymerization was used for a propylene polymerization experiment according to the same procedure as in Example 7.

    [0158] For a one-hour polymerization reaction, the catalyst showed a polymerization activity of 36.3 kg PP/g cat, and the resultant polypropylene had an isotacticity of 97.9%.

    Example 9

    [0159] This example provides a catalyst for propylene polymerization, which was prepared by the same process as that in Example 7, except that isopropyl 2-(N-methylphenylsulfonamido)benzoate was used as the electron donor to obtain 0.78 g solid catalyst having a titanium content of 3.2%.

    [0160] For a one-hour polymerization reaction, the catalyst showed a polymerization activity of 35.0 kg PP/g cat, and the resultant polypropylene had an isotacticity of 97.3%.

    Example 10

    [0161] This example provides a catalyst for propylene polymerization, which was prepared by the same process as that in Example 7, except that butyl 2-(N-methylbutylsulfonamido)benzoate was used as the electron donor to obtain 0.78 g solid catalyst having a titanium content of 3.2%.

    [0162] The above catalyst for propylene polymerization was used for a propylene polymerization experiment according to the same procedure as in Example 7.

    [0163] For a one-hour polymerization reaction, the catalyst showed a polymerization activity of 35.0 kg PP/g cat, and the resultant polypropylene had an isotacticity of 97.3%.

    Example 11

    [0164] This example provides a catalyst for propylene polymerization, which was prepared by the same process as that in Example 7, except that methyl 2-(N-methylbutylsulfonamido)benzoate was used as the electron donor to obtain 3.6 g catalyst having a titanium content of 2.2%.

    [0165] The above catalyst for propylene polymerization was used for a propylene polymerization experiment according to the same procedure as in Example 7.

    [0166] For a one-hour polymerization reaction, the catalyst showed a polymerization activity of 37.6 kg PP/g cat, and the resultant polypropylene had an isotacticity of 96.0%.

    Example 12

    [0167] This example provides a catalyst for propylene polymerization, which was prepared by the same process as that in Example 7, except that isobutyl 2-(N-methylethylsulfonamido)benzoate was used as the electron donor to obtain 3.2 g spherical catalyst having a titanium content of 2.8%.

    [0168] The above catalyst for propylene polymerization was used for a propylene polymerization experiment according to the same procedure as in Example 7.

    [0169] For a one-hour polymerization reaction, the catalyst showed a polymerization activity of 38.2 kg PP/g cat, and the resultant polypropylene had an isotacticity of 96.8%.

    Example 13

    [0170] This example provides a catalyst for propylene polymerization, which was prepared by the same process that in Example 7, except that isopropyl 2-(N-methylcyclohexylsulfonamido)benzoate was used as the electron donor to obtain 3.0 g spherical catalyst having a titanium content of 3.0%.

    [0171] The above catalyst for propylene polymerization was used for a propylene polymerization experiment according to the same procedure as in Example 7.

    [0172] For a one-hour polymerization reaction, the catalyst showed a polymerization activity of 38.9 kg PP/g cat, and the resultant polypropylene had an isotacticity of 95.8%.

    Example 14

    [0173] This example provides a catalyst for propylene polymerization, which was prepared by the same process as that in Example 7, except that ethyl 2-(N-methylethylsulfonamido)benzoate was used as the electron donor to obtain 3.4 g spherical catalyst having a titanium content of 2.9%.

    [0174] The above catalyst for propylene polymerization was used for a propylene polymerization experiment according to the same procedure as in Example 7.

    [0175] For a one-hour polymerization reaction, the catalyst showed a polymerization activity of 35.3 kg PP/g cat, and the resultant polypropylene had an isotacticity of 96.5%.

    [0176] As can be seen through the above data, the use of the compound according to the present invention as the electron donor in a catalyst for a polypropylene results in a higher catalyst activity and better stereospecificity.

    [0177] Obviously, the above embodiments of the present invention are only examples to clearly illustrate the present invention, and not to limit the way of implementation of the present invention, and other different forms of variations or changes can be made on the basis of the above description by those of ordinary skill in the field. It is not possible to exhaust all the embodiments here, but all obvious variations or changes derived from the technical solutions of the present invention are still within the scope of protection of the present invention.