Propenyl block polyolefin elastomer and preparation method thereof

Abstract

A catalyst A with isotactic selectivity and a catalyst B with random selectivity are selected to form a binary catalytic system, and the allyl block polyolefin elastomer is efficiently synthesized through chain shuttling polymerization. The melting point and the glass-transition temperature of the allyl block polyolefin elastomer can be conveniently regulated and controlled by changing the isotacticity and introducing the content of the comonomer, the melting point range is 100-160 DEG C, and the glass-transition temperature range is-50-0 DEG C. The prepared propenyl block polyolefin elastomer is novel in structure and excellent in performance and has original innovativeness.

Description

Technical Field

[0001] This invention relates to the application of coordination polymerization in the preparation of propylene-based block polyolefin elastomers. Background Technology

[0002] Block polymers are a special type of polymer prepared by linking two or more polymer segments with different properties together. They combine the excellent properties of multiple polymers to obtain high-performance functional polymer materials, which can be used as thermoplastic elastomers, drug carriers, membrane materials, etc. Block polymers have controllable molecular weight and distribution, and their molecular structure and composition can be designed, making them a highly significant and challenging research direction in the field of polymer science. A successful example is the successful application of pyridine-amine hafnium complexes developed by Dow Chemicals, synergistically using a phenoxy-imine zirconium catalyst, to the synthesis of olefin block copolymers via a chain shuttle polymerization mechanism (Science 2006, 312, 714-719).

[0003] Isotactic polypropylene (iPP) is a crystalline material with a high melting point (T). m = 165 °C), while atactic polypropylene (aPP) is an amorphous material with a glass transition temperature (T = 165 °C). g The temperature range is relatively low (-12 ~ 0 °C). By cleverly combining these two chain structures, stereoblock polypropylene elastomers with thermoplastic elastomer (TPE) properties can be obtained. As early as 1959, Natta et al. first synthesized polypropylene elastomers using a heterogeneous Ziegler–Natta catalyst and attributed their elastic behavior to the alternating isotactic and random block structures in the polymer chains. However, due to the heterogeneity of the polymer composition and the low activity of the catalytic system, the further development of this method in the field of propylene-based elastomers has been limited.

[0004] This invention employs an isotactic-selective catalyst A and a atactic-selective catalyst B to form a binary catalytic system, enabling the efficient synthesis of propylene-based block polyolefin elastomers via chain shuttle polymerization. By altering the isotacticity and introducing the content of comonomers, the melting point and glass transition temperature of the propylene-based block polyolefin elastomers can be easily controlled, with a melting point range of 100–160 °C and a glass transition temperature range of -50–0 °C. The propylene-based block polyolefin elastomers prepared by this invention exhibit novel structures, excellent performance, and original innovation. Summary of the Invention

[0005] The purpose of this invention is to provide a propylene-based block polyolefin elastomer and its preparation method.

[0006] The aforementioned propylene-based block polyolefin elastomer is produced by chain shuttle polymerization of propylene monomers and their comonomers (one or more of 1-butene, 1-hexene, 1-octene, 1-decene, etc.) using an isotactic-selective catalyst A and a atactic-selective catalyst B.

[0007] The aforementioned propylene-based block polyolefin elastomers include isotactic polypropylene hard segments and atactic polypropylene soft segments.

[0008] The isotacticity of the aforementioned isotactic polypropylene hard segments (measured as the percentage of isotactic pentatonic units [mmmm] in the propylene molecular chain) ranges from 80 to 99 mmmm.

[0009] The isotacticity of the above-mentioned atactic polypropylene soft segments (as a percentage of the propylene unit isotactic pentatonic group [mmmm] in the propylene molecular chain) ranges from 0 to 20 mmmm.

[0010] The melting point and glass transition temperature of the above-mentioned propylene-based block polyolefin elastomer can be controlled by changing the isotacticity and introducing one or more of the comonomers 1-butene, 1-hexene, 1-octene, and 1-decene. The melting point range is 100~160 ℃, and the glass transition temperature range is -50~0 ℃.

[0011] In the aforementioned propylene-based block polyolefin elastomer and its preparation method, the isotactic polypropylene hard segments are synthesized from an isotactic stereoselective catalyst A, the structure of which is shown in formula (I).

[0012] (I),

[0013] Wherein, R1 is selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R2 is selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R3 is selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R4 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen; R5 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen; R6 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen; R7 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen; R8 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen, substituted phenyl, substituted carbazole; R9 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen, substituted phenyl, substituted carbazole; M is selected from hafnium, zirconium, titanium.

[0014] The isotactic stereoselective catalyst A described above is characterized by being a compound represented by at least one of the following:

[0015] .

[0016] In the above-mentioned propylene-based block polyolefin elastomer and its preparation method, the atactic polypropylene soft segments are synthesized by a atactic stereoselective catalyst B, the structure of which is shown in formula (II).

[0017] (II)

[0018] Among them, R 10 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 11 Selected from hydrogen, methyl, isopropyl; R 12 Selected from hydrogen, methyl, isopropyl; R 13 Selected from hydrogen, methyl, isopropyl; R 14 Selected from hydrogen, methyl, isopropyl; R 15 Selected from hydrogen, methyl, isopropyl; R 16 Selected from hydrogen, methyl, isopropyl; R 17 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 18 Selected from hydrogen, methyl, isopropyl; R 19 Selected from hydrogen, methyl, isopropyl; R 20 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 21 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 22 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 23 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; M is selected from hafnium, zirconium, titanium.

[0019] The above-described atactic-selective catalyst B is characterized by being a compound represented by at least one of the following:

[0020] .

[0021] The isotactic-selective catalyst A and atactic-selective catalyst B of the aforementioned propylene-based block polyolefin elastomer and its preparation method require the use of a co-catalyst for catalysis. The co-catalyst is one or more of tris(pentafluorophenylboron), triphenylcarbamonite tetra(pentafluorophenyl)borate, aluminoxane, alkylaluminum, and alkylaluminum chloride. The aluminoxane is methylaluminoxane, ethylaluminoxane, or isobutylaluminoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum, or tri-n-hexylaluminum; and the alkylaluminum chloride is diethylaluminum chloride, sesqui-diethylaluminum chloride, or ethylaluminum dichloride.

[0022] In the above-mentioned propylene-based block polyolefin elastomer and its preparation method, the polymerization temperature is 0-200 °C, the polymerization pressure is 0.1-5 MPa, and the solvent used for polymerization is one or more of n-hexane, n-heptane, n-pentane, cyclohexane, and toluene.

[0023] The isotactic-selective catalyst A and atactic-selective catalyst B of the above-mentioned propylene-based block polyolefin elastomer and its preparation method require chain shuttle polymerization in conjunction with a chain shuttle agent to prepare the propylene-based block polyolefin elastomer; the chain shuttle agent is one or more of diethylzinc, dimethylzinc, triisobutylaluminum, trimethylaluminum, triethylaluminum and tri-n-hexylaluminum. Attached Figure Description

[0024] Figure 1 Example 9 has a molecular weight of 257 kg·mol⁻¹ -1 GPC diagram of a propylene-based block polyolefin elastomer with a molecular weight distribution of 1.6.

[0025] Figure 2 The image shows the DSC plot of the propylene-based block polyolefin elastomer of Example 9, which has a melting point of 138 °C and a glass transition temperature of -50 °C. Detailed Implementation

[0026] The present invention is further illustrated by examples, but is not limited thereto. These examples will enable those skilled in the art to gain a more comprehensive understanding of the invention.

[0027] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0028] The synthesis of catalyst A-1 in this invention follows the method described in the literature (Polym. Chem. 2024, 15, 4141-4150). The synthesis of catalyst A-2 follows the method described in the literature (Angew. Chem., Int. Ed. 2006, 45, 3278-3283). The synthesis of catalyst A-3 follows the method described in the literature (CN 120842458 A). The synthesis of catalyst A-4 follows the method described in the literature (J. Am. Chem. Soc. 2010, 132, 5566–5567). The synthesis of catalyst B-1 follows the method described in the literature (CN 120842459 A). The synthesis of catalyst B-2 follows the method described in the literature (Organometallics 2012, 31, 6244-6251). Catalyst B-3 was synthesized according to the method described in the literature (Organometallics 2021, 40, 242-252). Catalyst B-4 was synthesized according to the method described in the literature (Organometallics 2024, 43, 2472-2479). Catalyst B-5 was synthesized according to the method described in the literature (CN 119529141 A). Catalyst B-6 was synthesized according to the method described in the literature (CN120842458 A).

[0029] The present invention is described below with reference to specific embodiments.

[0030] Example 1: Propylene polymerization catalyzed by catalysts A-3 and B-6

[0031] The high-pressure reactor was connected to a high-pressure pipeline to remove nitrogen and purge propylene three times. 100 mL of toluene and 100 μmol of diethylzinc were added under a propylene atmosphere at 25 °C. In a glove box, 2 μmol of catalyst A-3, 2 μmol of catalyst B-6, 4 μmol of triphenylmethyltetra(pentafluorophenyl)borate, and 100 μmol of methylaluminoxane were added to a sample vial. 5 mL of anhydrous toluene was added to the sample vial to dissolve the catalyst. The toluene solution was then injected into the main catalyst transition chamber using a syringe, and subsequently added to the reactor. The reaction was carried out at 25 °C with a propylene pressure of 5 atm and vigorous stirring for 10 min. The reaction solution was neutralized with 5 mL of hydrochloric acid-acidified ethanol solution to obtain a polymer precipitate. The precipitate was washed with ethanol, vacuum dried overnight, and weighed. Polymerization activity: 5.40 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 220 kg·mol -1 M w / M n = 2.3, T m = 148 °C, T g = -10 °C.

[0032] Example 2: Propylene polymerization catalyzed by catalysts A-3 and B-6

[0033] The polymerization process and conditions were the same as in Example 1, with a polymerization temperature of 120 °C. Polymerization activity: 12.0 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 180 kg·mol -1 M w / M n = 2.0, T m = 146 °C, T g = -8 °C.

[0034] Example 3: Propylene polymerization catalyzed by catalysts A-3 and B-6

[0035] The polymerization process and reaction conditions were the same as in Example 1, using n-hexane as the solvent. Polymerization activity: 6.1 × 10⁻⁶ 6g·mol -1 (Hf)·h -1 Polymer M w = 260 kg·mol -1 M w / M n = 2.1, T m = 146 °C, T g = -9 °C.

[0036] Example 4: Propylene polymerization catalyzed by catalysts A-3 and B-3

[0037] The polymerization process and reaction conditions were the same as in Example 1, with catalysts A-3 and B-3. Polymerization activity: 4.0 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 300 kg·mol -1 M w / M n = 2.4, T m = 138 °C, T g = -6 °C.

[0038] Example 5: Propylene polymerization catalyzed by catalysts A-3 and B-5

[0039] The polymerization process and reaction conditions were the same as in Example 1, with catalysts A-3 and B-5. Polymerization activity: 3.3 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 608 kg·mol -1 M w / M n = 2.6, T m = 126 °C, T g = -5 °C.

[0040] Example 6: Propylene polymerization catalyzed by catalysts A-1 and B-6

[0041] The polymerization process and reaction conditions were the same as in Example 1, with catalysts A-1 and B-6. Polymerization activity: 2.2 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 145 kg·mol -1 M w / M n= 2.1, T m = 130 °C, T g = -8 °C.

[0042] Example 7: Propylene polymerization catalyzed by catalysts A-2 and B-6

[0043] The polymerization process and reaction conditions were the same as in Example 1, with catalysts A-2 and B-6. Polymerization activity: 8.6 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 485 kg·mol -1 M w / M n = 2.1, T m = 120 °C, T g = -6 °C.

[0044] Example 8: Propylene polymerization catalyzed by catalysts A-4 and B-6

[0045] The polymerization process and reaction conditions were the same as in Example 1, with catalysts A-4 and B-6. Polymerization activity: 8.6 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 710 kg·mol -1 M w / M n = 2.6, T m = 145 °C, T g = -5 °C.

[0046] Example 9: Copolymerization of propylene and 1-octene catalyzed by catalysts A-3 and B-6

[0047] The high-pressure reactor was connected to a high-pressure pipeline to remove nitrogen and purge propylene three times. Under a propylene atmosphere, 100 mL of toluene, 20 mL of 1-octene, and 100 μmol of diethylzinc were added, and the temperature was raised to 120 °C. In a glove box, 2 μmol of catalyst A-3, 2 μmol of catalyst B-6, 4 μmol of triphenylmethyltetra(pentafluorophenyl)borate, and 100 μmol of methylaluminoxane were added to a sample vial. 5 mL of anhydrous toluene was added to the sample vial to dissolve the catalyst. The toluene solution was then injected into the main catalyst transition chamber using a syringe, and subsequently added to the reactor. The reaction was carried out at 120 °C with a propylene pressure of 10 atm and vigorous stirring for 10 min. The reaction solution was neutralized with 5 mL of hydrochloric acid-acidified ethanol solution to obtain a polymer precipitate. The precipitate was washed with ethanol, vacuum dried overnight, and weighed. Polymerization activity: 20.0 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 257kg·mol -1 M w / M n = 1.6, T m = 138 °C, T g = -50 °C.

[0048] Example 10: Copolymerization of propylene and 1-hexene catalyzed by catalysts A-3 and B-6

[0049] The polymerization process and reaction conditions were the same as in Example 9, with 1-hexene as the comonomer. Polymerization activity: 22.5 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 185 kg·mol -1 M w / M n = 2.2, T m = 140 °C, T g = -44 °C.

[0050] Example 11: Copolymerization of propylene and 1-octene catalyzed by catalysts A-3 and B-3

[0051] The polymerization process and reaction conditions were the same as in Example 9, with catalysts A-3 and B-3. Polymerization activity: 8.5 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w= 305 kg·mol -1 M w / M n = 2.6, T m = 130 °C, T g = -25 °C.

[0052] Example 12: Copolymerization of propylene and 1-octene catalyzed by catalysts A-3 and B-5

[0053] The polymerization process and reaction conditions were the same as in Example 9, with catalysts A-3 and B-5. Polymerization activity: 5.2 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 550 kg·mol -1 M w / M n = 2.8, T m = 132 °C, T g = -22 °C.

[0054] Example 13: Copolymerization of propylene and 1-octene catalyzed by catalysts A-2 and B-6

[0055] The polymerization process and reaction conditions were the same as in Example 9, with catalysts A-2 and B-6. Polymerization activity: 38.5 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 120 kg·mol -1 M w / M n = 1.9, T m = 145 °C, T g = -43 °C.

[0056] Example 14: Copolymerization of propylene and 1-octene catalyzed by catalysts A-4 and B-6

[0057] The polymerization process and reaction conditions were the same as in Example 9, with catalysts A-2 and B-6. Polymerization activity: 50.8 × 10⁻⁶ 6 g·mol -1 (Hf)·h -1 Polymer M w = 440 kg·mol -1 M w / M n = 1.9, T m = 150 °C, Tg = -37 °C。

Claims

1. A propylene-based block polyolefin elastomer and its preparation method, characterized in that, The propylene-based block polyolefin elastomer is synthesized by chain shuttle polymerization of propylene monomers and their comonomers (one or more of 1-butene, 1-hexene, 1-octene, 1-decene, etc.) using an isotactic-selective catalyst A and a atactic-selective catalyst B.

2. The propylene-based block polyolefin elastomer and its preparation method according to claim 1, characterized in that, The propylene-based block polyolefin elastomer includes isotactic polypropylene hard segments and atactic polypropylene soft segments.

3. The propylene-based block polyolefin elastomer and its preparation method according to claims 1 and 2, characterized in that, The isotacticity of the isotactic polypropylene hard segment (based on the percentage content of the propylene unit isotactic pentatonic [mmmm] in the propylene molecular chain) ranges from 80 to 99 mmmm; the isotacticity of the atactic polypropylene soft segment (based on the percentage content of the propylene unit isotactic pentatonic [mmmm] in the propylene molecular chain) ranges from 0 to 20 mmmm.

4. The propylene-based block polyolefin elastomer and its preparation method according to claims 1 and 2, characterized in that, The propylene-based block polyolefin elastomer can have its melting point and glass transition temperature controlled by changing its isotacticity and introducing one or more of the comonomers 1-butene, 1-hexene, 1-octene, and 1-decene. The melting point range is 100~160 ℃, and the glass transition temperature range is -50~0 ℃.

5. The propylene-based block polyolefin elastomer and its preparation method according to claims 1 and 2, characterized in that, The isotactic polypropylene hard segments are synthesized from an isotactic stereoselective catalyst A, the structure of which is shown in formula (I). （I）， Wherein, R1 is selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R2 is selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R3 is selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R4 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen; R5 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen; R6 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen; R7 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen; R8 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen, substituted phenyl, substituted carbazole; R9 is selected from hydrogen, methyl, ethyl, tert-butyl, methoxy, halogen, substituted phenyl, substituted carbazole; M is selected from hafnium, zirconium, titanium.

6. The propylene-based block polyolefin elastomer and its preparation method according to claims 1 and 2, characterized in that, The atactic polypropylene soft segments are synthesized from atactic stereoselective catalyst B, the structure of which is shown in formula (II). (II), Among them, R 10 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 11 Selected from hydrogen, methyl, isopropyl; R 12 Selected from hydrogen, methyl, isopropyl; R 13 Selected from hydrogen, methyl, isopropyl; R 14 Selected from hydrogen, methyl, isopropyl; R 15 Selected from hydrogen, methyl, isopropyl; R 16 Selected from hydrogen, methyl, isopropyl; R 17 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 18 Selected from hydrogen, methyl, isopropyl; R 19 Selected from hydrogen, methyl, isopropyl; R 20 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 21 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 22 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; R 23 Selected from hydrogen, methyl, phenyl, 2-isopropylphenyl; M is selected from hafnium, zirconium, titanium.

7. The propylene-based block polyolefin elastomer and its preparation method according to claims 1 and 2, characterized in that, The isotactic-selective catalyst A and atactic-selective catalyst B require the use of a co-catalyst for catalysis. The co-catalyst is one or more of tris(pentafluorophenylboron), triphenylcarbamonite tetra(pentafluorophenyl)borate, aluminoxane, alkylaluminum, and alkylaluminum chloride. The aluminoxane is methylaluminoxane, ethylaluminoxane, or isobutylaluminoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum, or tri-n-hexylaluminum; and the alkylaluminum chloride is diethylaluminum chloride, sesqui-diethylaluminum chloride, or ethylaluminum dichloride.

8. The propylene-based block polyolefin elastomer and its preparation method according to claims 1 and 2, characterized in that: The polymerization temperature is 0-200 °C, the polymerization pressure is 0.1-5 MPa, and the solvent used for polymerization is one or more of n-hexane, n-heptane, n-pentane, cyclohexane, and toluene.

9. The propylene-based block polyolefin elastomer and its preparation method according to claims 1 and 2, characterized in that: The isotactic stereoselective catalyst A and atactic stereoselective catalyst B need to be used in conjunction with a chain shuttle agent for chain shuttle polymerization to prepare a propylene-based block polyolefin elastomer; the chain shuttle agent is one or more of diethylzinc, dimethylzinc, triisobutylaluminum, trimethylaluminum, triethylaluminum and tri-n-hexylaluminum.

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