Composition as well as preparation method and application thereof in polyolefin compatibilization

Abstract

The invention discloses a composition as well as a preparation method and application thereof in polyolefin compatibilization. Relates to the technical field of compatibilizers. The composition comprises a cycloolefin copolymer and polyolefin, the cycloolefin copolymer is a compatibilizer of the polyolefin; the cycloolefin copolymer is prepared from the following raw materials: cycloolefin, a chain shuttling agent, a promoter, ethylene, a catalyst 1 and a catalyst 2, the structural formulas of the catalyst 1 and the catalyst 2 are as follows: # imgabs0. In the composition disclosed by the invention, the cycloolefin copolymer is used as a compatibilizer of polyolefin, so that the composition disclosed by the invention is a compatible composition, and the recovery of polyolefin plastic is realized.

Description

Technical Field

[0001] The invention relates to the technical field of compatibilizers, in particular to a composition and a preparation method thereof and application in polyolefin compatibilization. Background Art

[0002] In 2020, polypropylene (PP) and polyethylene (PE) accounted for a combined 64% of the global production of general-purpose plastics, but the recycling rate of these materials is extremely low. Due to their excellent chemical stability and difficult-to-degrade properties, PE and PP will cause serious white pollution problems once they enter the ecological environment. In addition, due to the similar density and appearance of PE and PP, it is difficult to effectively separate them during the recycling process, and mixing them further increases the difficulty of sorting. In order to solve this problem, recycling and reuse has become the most feasible solution. However, simple processing and blending often leads to a significant decrease in mechanical properties, and the elongation at break is usually only about 15%. This is mainly because PE and PP are generally incompatible, and these materials must be volume-enhanced to achieve effective material compounding and recycling.

[0003] At present, diblock or multiblock copolymers are widely used in the compatibilization strategy. For example, some research progress has been made in the application of PMMA / PS system, but the application in PE / iPP system is relatively small.

[0004] One of the compatibilization strategies is graft copolymerization, which has been studied by Geoffrey W. Coates's group and Carlos R. López-Barrón's team at ExxonMobil. They found that when the side chain polypropylene of the main chain polyethylene is longer, the compatibilization effect is better, and the increase in the molar number of the side chain will also improve the compatibilization effect. Random copolymer ethylene propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM) are also commonly used compatibilizers and compounding additives. Although EPDM has shown a good compatibilization effect in the composite of PE and iPP, it requires a higher addition amount, and too much addition will affect the overall mechanical properties.

[0005] Another compatibilization strategy is DOW. The multi-block OBC prepared by DOW chemistry using chain shuttling technology also shows good compatibilization and enhancement performance and has entered the commercial stage, so it is considered to be the most mature compatibilization strategy. However, the preparation methods of these copolymerization methods are still limited by catalysts. Although the choice of catalysts is very wide, it is still difficult to control the structure of grafted copolymers, and unreacted branched homopolymers often appear. If the branch chain is too long, the copolymerization efficiency will be reduced.

[0006] Based on this, there is an urgent need to develop a new type of compatibilizer that can exhibit excellent polypropylene (PP) and polyethylene (PE) compatibilization effect at a lower addition amount. Summary of the invention

[0007] The object of the present invention is to provide a composition comprising polyolefin and cycloolefin copolymer as a compatibilizer, thereby realizing the recycling of polyolefin plastics.

[0008] The first aspect of the present invention is:

[0009] A composition is provided.

[0010] The second aspect of the present invention is:

[0011] A method for preparing a composition is provided.

[0012] Specifically, the technical solution adopted according to the first aspect of the present invention is:

[0013] A composition comprising a cyclic olefin copolymer and a polyolefin;

[0014] The cyclic olefin copolymer is a compatibilizer for the polyolefin;

[0015] The raw materials of the cycloolefin copolymer include the following components:

[0016] Cyclic olefin, chain shuttling agent, cocatalyst, ethylene and catalyst 1 and catalyst 2;

[0017] The structural formulas of the catalyst 1 and the catalyst 2 are:

[0018] According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0019] The composition of the present invention comprises cyclic olefin copolymer and polyolefin, wherein the cyclic olefin copolymer is used as a compatibilizer of polyolefin, so that the composition of the present invention is a compatible composition, thereby realizing the recycling of polyolefin plastics.

[0020] The glass transition temperatures (Tg) of polyolefins (such as polyethylene and polypropylene) are -120°C and -30°C respectively. At such low Tg, their interfaces are basically in an amorphous state, showing a soft and lacking mechanical strength. Therefore, the olefin copolymer of the present invention not only serves as a compatibilizer that is compatible with polyolefins (such as polyethylene and polypropylene), but also contains a high glass transition temperature (Tg). g ) is greater than 25°C, the Tg is relatively high, so that it can fix these amorphous segments, reduce the mobility of the interfacial polyolefin polymer chains, achieve the enhancement of mechanical properties, and ultimately make the composition have extremely excellent mechanical tensile properties.

[0021] According to one embodiment of the present invention, the mass ratio of the cycloolefin copolymer to the polyolefin is 0.1-10:1-1.2.

[0022] According to one embodiment of the present invention, the mass ratio of the cycloolefin copolymer to the polyolefin is 0.14-0.2:1-1.2.

[0023] According to one embodiment of the present invention, the polyolefin is a mixture of multiple polyolefins.

[0024] According to one embodiment of the present invention, the polyolefin includes a first polyolefin and a second polyolefin.

[0025] According to one embodiment of the present invention, in the composition, the mass content of the first polyolefin is 5%-95%, and the mass content of the second polyolefin is 5%-95%.

[0026] According to one embodiment of the present invention, in the composition, the mass ratio of the first polyolefin to the second polyolefin is 30-40:60-70.

[0027] According to one embodiment of the present invention, in the composition, the mass ratio of the first polyolefin to the second polyolefin is 30-35:65-70.

[0028] According to one embodiment of the present invention, the polyolefin includes at least one of polypropylene and polyethylene.

[0029] Polypropylene and polyethylene have poor compatibility themselves. By adding the cyclic olefin copolymer of the present invention as a compatibilizer for polypropylene and polyethylene, the composition containing polypropylene, polyethylene and the cyclic olefin copolymer has extremely excellent mechanical tensile properties.

[0030] According to one embodiment of the present invention, the polypropylene includes at least one of isotactic polypropylene, atactic polypropylene and syndiotactic polypropylene.

[0031] According to one embodiment of the present invention, the polyethylene includes at least one of high-density polyethylene, low-density polyethylene, linear low-density polyethylene and polyethylene fiber.

[0032] According to one embodiment of the present invention, the cyclic olefin includes at least one of bornene, ethylidene norbornene, dicyclopentadiene, cyclopentene and cyclooctene.

[0033] According to one embodiment of the present invention, the chain shuttling agent includes at least one of an alkyl zinc compound and an alkyl aluminum compound.

[0034] According to some embodiments of the present invention, the alkyl zinc compound includes at least one of dimethyl zinc (Me2Zn), diethyl zinc (Et2Zn) and diphenyl zinc (Ph2Zn).

[0035] According to some embodiments of the present invention, the alkyl aluminum compound includes at least one of trimethyl aluminum (Me3Al), triethyl aluminum (Et3Al), triisobutyl aluminum (Bui3Al) and tri-tert-butyl aluminum (But3Al).

[0036] According to some embodiments of the present invention, the co-catalyst includes at least one of methylaluminoxane, alkylaluminum and organic boron.

[0037] According to some embodiments of the present invention, the molar ratio of the co-catalyst to the catalyst is 500-3000.

[0038] According to some embodiments of the present invention, the amount of ethylene used includes but is not limited to 0.5 atmospheres to 20 atmospheres.

[0039] According to some embodiments of the present invention, the solvent includes at least one of hexane, cyclohexane, heptane, toluene and xylene.

[0040] According to one embodiment of the present invention, in the composition, the raw material components further include auxiliary agents.

[0041] According to one embodiment of the present invention, in the composition, the auxiliary agent includes an antioxidant.

[0042] According to one embodiment of the present invention, in the composition, the amount of the antioxidant is 0.2-0.5% of the mass of the polyolefin.

[0043] According to one embodiment of the present invention, the method for preparing the cycloolefin copolymer comprises the following steps:

[0044] S1, in a negative pressure environment, mixes cycloolefin, chain shuttling agent and co-catalyst in a solvent to obtain a mixed solution, and then introduces ethylene;

[0045] S2, adding catalyst 1 and catalyst 2 into step S1 to carry out polymerization reaction to obtain the cycloolefin copolymer.

[0046] The cyclic olefin copolymer used in the present invention is a compatibilizer for polyolefins. The cyclic olefin copolymer is a vinyl copolymer (including block, gradient, and random) and is prepared by polymerizing ethylene and at least one comonomer.

[0047] The cycloolefin copolymer used in the present invention is prepared by selecting catalyst 1 and catalyst 2 of specific structure, and the prepared cycloolefin multi-block copolymer not only has a cycloolefin / olefin chain soft segment with a low insertion rate (low Tg1), but also has a cycloolefin / olefin chain hard segment with a high insertion rate (high Tg2).

[0048] According to some embodiments of the present invention, the cyclic olefin copolymer is used as a compatibilizer in incompatible polyolefins.

[0049] According to some embodiments of the present invention, the molar ratio of catalyst 1 to catalyst 2 is 1-10:10-1. By changing the molar ratio of the two catalysts, the ratio of the cycloolefin / olefin chain soft segment with low insertion rate and the cycloolefin / olefin chain hard segment with high insertion rate is changed, thereby achieving the regulation of the mechanical properties of the cycloolefin block copolymer material.

[0050] According to one embodiment of the present invention, the molar content of ethylene in the raw material components of the cycloolefin copolymer is 10%-90%.

[0051] According to one embodiment of the present invention, the molar content of cycloolefin in the raw material components of the cycloolefin copolymer is 10%-90%.

[0052] Specifically, the technical solution adopted according to the second aspect of the present invention is:

[0053] A method for preparing the composition comprises the following steps:

[0054] The cycloolefin copolymer and the polyolefin are mixed and kneaded to obtain the composition.

[0055] According to one embodiment of the present invention, during the mixing process, the temperature is 170°C-200°C.

[0056] According to one embodiment of the present invention, during the mixing process, the temperature is 170°C-190°C.

[0057] According to one embodiment of the present invention, during the mixing process, the mixing time is 1-10 minutes.

[0058] According to one embodiment of the present invention, during the mixing process, the mixing time is 1-5 minutes.

[0059] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0061] Figure 1 This is a test graph of the glass transition temperature of the cycloolefin copolymer prepared in Example 1 of the present invention;

[0062] Figure 2 The tensile test diagram of the homopolymer or composition prepared in Example 1 and Comparative Examples 1-3 of the present invention;

[0063] Figure 3 The tensile test results of the composition prepared in Comparative Example 4;

[0064] Figure 4 The tensile test results of the composition prepared in Example 2 are shown. DETAILED DESCRIPTION

[0065] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0066] The words "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that may provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0067] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0068] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0069] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0070] The catalyst 1 of the present invention is prepared by the following method:

[0071] 4.5 g of pentafluoroaniline and 5.56 g of 3,5-di-tert-butyl salicylaldehyde were dissolved in 20 ml of methanol and reacted for 24 hours under the catalysis of 10 mg of p-toluenesulfonic acid. After the reaction, the reaction solution was crystallized at low temperature to obtain 8.36 g of ligand; 1.92 g of ligand was dissolved in 20 ml of ether, cooled to -78°C, and the same amount of n-butyl lithium was added dropwise, and the temperature was raised to room temperature for reaction for 2 hours; then half an equivalent of titanium tetrachloride was added to the reaction solution at low temperature, and the temperature was raised to room temperature for reaction overnight. After the reaction was completed, the solvent was removed, the solid was washed with dichloromethane, the obtained liquid was concentrated and then washed with ether and n-hexane, and the remaining solid was dried to obtain the final catalyst 1;

[0072] Catalyst 1 NMR data: 1 H NMR (CDCl3) δ1.32 (s, 18H, tBu), 1.36 (s, 18H, tBu), 7.20 (d, J=2.4Hz, 2H, aromatic-H), 7.67 (d, J=2.4Hz, 2H, aromatic-H), 8.21 (s, 2H, CH=N).

[0073] The catalyst 2 of the present invention is prepared by the following method:

[0074] 4.5 g of pentafluoroaniline and 3.23 g of 3-methyl salicylaldehyde were dissolved in 20 ml of methanol and reacted for 24 hours under the catalysis of 10 mg of p-toluenesulfonic acid. After the reaction, the reaction solution was crystallized at low temperature to obtain 6.06 g of ligand; 1.44 g of ligand was dissolved in 20 ml of ether, cooled to -78°C, and the same amount of n-butyl lithium was added dropwise, and the temperature was raised to room temperature for reaction for 2 hours; then half an equivalent of titanium tetrachloride was added to the reaction solution at low temperature, and the temperature was raised to room temperature for reaction overnight. After the reaction was completed, the solvent was removed, the solid was washed with dichloromethane, the obtained liquid was concentrated and then washed with ether and n-hexane, and the remaining solid was dried to obtain the final catalyst 2;

[0075] Catalyst 2 NMR data: 1 H NMR (CDCl3) δ2.08 (s, 6H, Me), 6.99 (t, J=7.6Hz, 2H, aromatic-H), 7.26 (dd, J=7.3, 1.5Hz, 2H, aromatic-H), 7.48 (dd, J=7.3, 1.5Hz, 2H, aromatic-H), 8.24 (s, 2H, CH=N).

[0076] Example 1

[0077] A composition comprising a cycloolefin copolymer and a polyolefin in a mass ratio of 0.1:1;

[0078] The cycloolefin copolymer is a compatibilizer for the polyolefin;

[0079] The polyolefin includes polypropylene (iPP) and high-density polyethylene (HDPE) in a mass ratio of 30:70.

[0080] The raw materials of the above-mentioned cycloolefin copolymer include the following components:

[0081] Cyclic olefin, chain shuttling agent, cocatalyst, ethylene and catalyst 1 and catalyst 2;

[0082] The structural formulas of the above catalyst 1 and catalyst 2 are:

[0083] Wherein, the co-catalyst is methylaluminoxane.

[0084] Among them, the cyclic olefin is norbornene.

[0085] Wherein, the chain shuttling agent is diethyl zinc.

[0086] The method for preparing the above-mentioned cycloolefin copolymer comprises the following steps:

[0087] S1: pre-bake a 1000mL reactor at 130°C for 2h, during which nitrogen and vacuum are replaced several times. After baking, cool to room temperature and place under negative pressure, and add 450ml toluene into the reactor.

[0088] S2: Weigh 44 g of norbornene in a glove box, dissolve it in toluene, add 1000 times the catalyst equivalent of methylaluminoxane MAO and 50 times the catalyst equivalent of diethylzinc Et2Zn to the solution, mix well, add the mixed solution to the reactor through a syringe, control the total volume of the mixed solution in the reactor to 500 mL, stir well by mechanical stirring, and then introduce ethylene gas until the reaction solution is dissolved saturated;

[0089] S3: Control the temperature of the reactor at room temperature, add catalyst 1 and catalyst 2 (50 μmol, catalyst 1 / catalyst 2=3 / 1) dissolved in toluene into the reactor through a syringe, start the polymerization reaction, and stop introducing ethylene after 20 minutes. Pour the mixture in the reactor into acidified ethanol for precipitation, stir until the polymer is completely precipitated, filter, and wash the polymer with ethanol for multiple times. Transfer the polymer to a vacuum drying oven, and dry it in a vacuum drying oven at 70°C to constant weight to obtain the above-mentioned cycloolefin copolymer.

[0090] The method for preparing the above composition comprises the following steps:

[0091] iPP, PE, cycloolefin copolymer and antioxidant were mixed in a mixer at a mixing temperature of 190° C. and a mixing time t of 5 minutes to obtain a composition.

[0092] The weight of the antioxidant is 0.5% of the total weight of iPP and PE.

[0093] Example 2

[0094] The difference between Example 2 and Example 1 is that in Example 2, the polyolefin is polypropylene (iPP) and high-density polyethylene (HDPE) in a mass ratio of 30:70.

[0095] Comparative Example 1

[0096] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 is a homopolymer containing only iPP.

[0097] Comparative Example 2

[0098] The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 is a homopolymer containing only PE.

[0099] Comparative Example 3

[0100] The difference between Comparative Example 3 and Example 1 is that the composition of Comparative Example 3 contains only PE and iPP.

[0101] Comparative Example 4

[0102] The difference between Comparative Example 4 and Example 1 is that in the composition of Comparative Example 4, the cycloolefin copolymer of the present invention is not used, but the conventional compatibilizer ethylene propylene diene monomer rubber EPDM is used.

[0103] Performance Test:

[0104] The glass transition temperature of the cycloolefin copolymer prepared in Example 1 was tested using a differential scanning calorimeter. The test results are as follows: Figure 1 ,from Figure 1 It is known that the above-mentioned cycloolefin copolymer contains not only a high glass transition temperature (T g ) is greater than 25°C, and the chain segments simultaneously have a cycloolefin / olefin chain soft segment with a low insertion rate (low Tg1), and a cycloolefin / olefin chain hard segment with a high insertion rate (high Tg2), so that the above-mentioned cycloolefin copolymer is distributed at the phase interface during the process of compatibilizing polyolefin, thereby reducing the mobility of the interfacial polyolefin polymer chain, so that the above-mentioned composition has extremely excellent mechanical tensile properties.

[0105] The composition prepared in Example 1 and the homopolymers or compositions prepared in Comparative Examples 1-3 were subjected to tensile tests using a universal mechanical testing machine. The test results are shown in FIG. Figure 2 .from Figure 2It is known that PE and iPP have poor compatibility by themselves. By adding the cyclic olefin copolymer of the present invention as a compatibilizer for PE and iPP, the composition containing PE, iPP and the cyclic olefin copolymer has extremely excellent mechanical tensile properties.

[0106] The composition prepared in Comparative Example 4 was subjected to a tensile test using a universal mechanical testing machine. The test results are shown in FIG. Figure 3 .from Figure 3 It is known that conventional compatibilizers cannot achieve the compatibilization of PE and iPP, resulting in poor mechanical tensile properties of the composition.

[0107] The composition prepared in Example 2 was subjected to a tensile test using a universal mechanical testing machine. The test results are shown in FIG. Figure 4 .from Figure 4 It is known that the cyclic olefin copolymer of the present invention can also achieve the compatibilization of iPP and HDPE, but the effect is slightly lower than that of Example 1.

[0108] The above are only embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A composition, characterized in that: The components include cyclic olefin copolymer and polyolefin; The cyclic olefin copolymer is a compatibilizer for the polyolefin; The raw materials of the cycloolefin copolymer include the following components: Cyclic olefin, chain shuttling agent, cocatalyst, ethylene and catalyst 1 and catalyst 2; The structural formulas of the catalyst 1 and the catalyst 2 are:

2. The composition according to claim 1, characterized in that: The mass of the cycloolefin copolymer is 0.1%-10% of the mass of the polyolefin.

3. A composition according to claim 1, characterized in that: The polyolefin includes at least one of polypropylene and polyethylene.

4. A composition according to claim 3, characterized in that: The polypropylene includes at least one of isotactic polypropylene, atactic polypropylene and syndiotactic polypropylene.

5. A composition according to claim 3, characterized in that: The polyethylene includes at least one of high-density polyethylene, low-density polyethylene, linear low-density polyethylene and polyethylene fiber.

6. A composition according to claim 1, characterized in that: The cyclic olefin includes at least one of bornene, ethylidene norbornene, dicyclopentadiene, cyclopentene and cyclooctene.

7. A composition according to claim 1, characterized in that: The chain shuttling agent includes at least one of an alkyl zinc compound and an alkyl aluminum compound.

8. A composition according to claim 1, characterized in that: The preparation method of the cycloolefin copolymer comprises the following steps: S1, in a negative pressure environment, mixes cycloolefin, chain shuttling agent and co-catalyst in a solvent to obtain a mixed solution, and then introduces ethylene; S2, adding catalyst 1 and catalyst 2 into step S1 to carry out polymerization reaction to obtain the cycloolefin copolymer.

9. A composition according to any one of claims 1 to 8, characterized in that: The cyclic olefin copolymer is used as a compatibilizer in incompatible polyolefins.

10. A method for preparing a composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: The cycloolefin copolymer and the polyolefin are mixed and kneaded to obtain the composition.

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