CN114539455A - Preparation of polyvinyl ethers by cationic polymerization using continuous flow process and process - Google Patents

Preparation of polyvinyl ethers by cationic polymerization using continuous flow process and process Download PDF

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CN114539455A
CN114539455A CN202210264197.4A CN202210264197A CN114539455A CN 114539455 A CN114539455 A CN 114539455A CN 202210264197 A CN202210264197 A CN 202210264197A CN 114539455 A CN114539455 A CN 114539455A
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cationic polymerization
vinyl ether
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CN114539455B (en
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陈昶乐
巴舍尔
廖道鸿
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University of Science and Technology of China USTC
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    • C08F116/12—Homopolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical by an ether radical
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Abstract

The present disclosure provides a process for preparing polyvinyl ethers by cationic polymerization using a continuous flow process comprising: providing an injector A and an injector B, wherein the injector A is filled with a cationic polymerization catalyst solution, the injector B is filled with a vinyl ether monomer and an initiator solution, and additives are optionally included; connecting the syringe A and the syringe B to two syringe pumps respectively, controlling the liquid flow rate by the syringe pumps, injecting the solutions in the syringe A and the syringe B into a mixer, mixing in the mixer, flowing into a tubular reactor, and carrying out cationic polymerization while continuously flowing in the tubular reactor to obtain the product polyvinyl ether.

Description

Preparation of polyvinyl ethers by cationic polymerization using continuous flow process and process
Technical Field
The disclosure belongs to the field of synthesis of high polymer materials, and particularly relates to a method for preparing polyvinyl ether by cationic polymerization by adopting a continuous flow method.
Background
The stereoregularity of polymers has a very significant impact on the performance of polymeric materials, and therefore, stereoselective polymerization of various types of monomers has been extensively explored over the past several decades, for example, coordination-insertion polymerization of alpha-olefins using chiral metallocene catalysts. However, these metallocene catalysts are often easily poisoned by polar groups on the monomer and lead to catalyst deactivation. Subsequently, late transition metal catalysts have appeared to be used for polymerization of polar vinyl ether monomers, but these methods have difficulty in achieving good control of stereoselectivity. At present, many researchers have taken radical polymerization or cationic polymerization to polymerize vinyl ether monomers, which is a great advantage in controlling polymer composition, molecular weight and molecular weight distribution, but still faces great challenges in stereo selectivity.
Cationic polymerization of vinyl ethers at low temperatures using some catalysts has also been known in the art, but the resulting polymers have only about 70% isotacticity. Although some polymerization systems can produce polymers with isotacticity of about 90%, there are problems of inverse dependence of polymer stereoselectivity and monomer concentration. Based on these problems, the large-scale application of cationic polymerization of vinyl ethers is limited.
Disclosure of Invention
In view of the above technical problems, the present disclosure provides a method for preparing polyvinyl ether by cationic polymerization using a continuous flow method, which is intended to at least partially solve the above technical problems.
In order to solve the above technical problems, as one aspect of the present disclosure, there is provided a method for preparing polyvinyl ether by cationic polymerization using a continuous flow method, comprising:
providing a syringe A and a syringe B, wherein the syringe A is filled with a cationic polymerization catalyst solution, the syringe B is filled with a vinyl ether monomer solution, an initiator solution and an optional additive;
connecting the syringe A and the syringe B to two syringe pumps respectively, controlling the liquid flow rate by the syringe pumps, injecting the solution in the syringe A and the solution in the syringe B into a mixer, mixing in the mixer, flowing into a tubular reactor, and carrying out cationic polymerization while continuously flowing in the tubular reactor to obtain the product polyvinyl ether.
In one embodiment, the cationic polymerization catalyst comprises at least one of:
TiCl2(OAr)2、EtAlCl2、BF3Et2O、Et2AlCl、SnCl4wherein Ar is 2, 6-diisopropylphenyl.
In one embodiment, the solvents of the solutions in syringe a and syringe B are the same or different, and each comprises at least one of:
n-hexane, toluene, methylcyclohexane, and dichloromethane.
In one embodiment, the vinyl ether monomer comprises at least one of:
isobutyl vinyl ether, tert-butyl vinyl ether, trimethylvinyloxysilane, n-butyl vinyl ether, cyclohexyl vinyl ether.
In one embodiment, the initiator is an addition product obtained by reacting HCl with any one of the vinyl ether monomers described above.
In one embodiment, the additive comprises: 2, 6-di-tert-butyl-4-methylpyridine.
In one embodiment, the concentration of the cationic polymerization catalyst solution includes: 0.005-0.04M;
the concentrations of the above additives include: 0 to 0.006M;
the molar ratio of the above monomer to the above initiator comprises: 24-144: 1;
the reaction temperature of the tubular reactor comprises: -50 to-78 ℃;
the above cationic polymerization is carried out under an inert atmosphere.
In one embodiment, the mixer is a Y-mixer.
In one embodiment, the liquid flow rate controlled by the syringe pump comprises: 5-20 mL/h.
As another aspect of the present disclosure, there is provided a polyvinyl ether prepared by the above method.
Based on the technical scheme, the method for preparing polyvinyl ether by cationic polymerization by adopting a continuous flow method and the continuous flow method have the beneficial effects that at least one of the following effects is realized:
(1) in the embodiment of the disclosure, a continuous flow method is adopted to facilitate the sufficient contact between the cationic polymerization catalyst and the vinyl ether monomer in the flow process, and the polyvinyl ether polymer with higher isotacticity can be synthesized.
(2) In the embodiment of the disclosure, the preparation method provided by the disclosure can be adjusted according to different vinyl ether monomers and different reaction conditions (such as cationic catalyst, reaction temperature, solvent, initiator and the like) to prepare different vinyl ether polymers with different isotacticities, and the method has certain universality.
(3) In the embodiment of the disclosure, the polyvinyl ether polymer with higher isotacticity is prepared by cationic polymerization by adopting a continuous flow method, and the polyvinyl alcohol with higher isotacticity obtained by hydrolyzing the polymer can be applied to the fields of liquid crystal display, polarizing films and the like, so that the development and innovation of the polyvinyl alcohol industry can be driven.
Drawings
FIG. 1 is a schematic illustration of the process of the present disclosure for making polyvinyl ethers by cationic polymerization using a continuous flow process;
FIG. 2 is a schematic illustration of the mechanism of the present disclosure for making polyvinyl ethers by cationic polymerization using a continuous flow process;
FIG. 3 is a depiction of the polyisobutyl vinyl ether polymer in example 1 of the present disclosure13C nuclear magnetic spectrum;
FIG. 4 is an X-ray diffraction pattern of a polyisobutyl vinyl ether polymer of example 1 of the present disclosure;
FIG. 5 is a differential scanning calorimetry test plot of the polymers of example 1 and example 13 of the present disclosure.
Detailed Description
For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.
The technical problems to be solved by the present disclosure are to improve the stereoselectivity in the polymerization process of vinyl ether monomers to obtain polyvinyl ethers with higher isotacticity, and to solve the problems of inverse correlation between polymer stereoselectivity and monomer concentration, and hopefully provide a new idea for large-scale controllable polymerization of vinyl ether monomers, and to explore the industrial production of high isotacticity polyvinyl ethers. Accordingly, the present disclosure provides a method for preparing polyvinyl ether by cationic polymerization using a continuous flow method, which realizes the synthesis of polyvinyl ether having a high isotacticity, wherein the isotacticity of the polyisobutyl vinyl ether prepared using isobutyl vinyl ether as a monomer is as high as 98%. The continuous flow method is adopted in the method, a plurality of experimental conditions can be simply adjusted in a flow chemical means, and thus, polyvinyl ether polymers with different isotacticities can be obtained.
FIG. 1 is a schematic illustration of the process of the present disclosure for making polyvinyl ethers by cationic polymerization using a continuous flow process.
According to an embodiment of the present disclosure, a syringe a containing a cationic polymerization catalyst solution and a syringe B containing a solution of a vinyl ether monomer, an initiator and optionally further including an additive are provided; connecting the syringe A and the syringe B to two syringe pumps respectively, controlling the liquid flow rate by the syringe pumps, injecting the solutions in the syringe A and the syringe B into a mixer, mixing in the mixer, flowing into a tubular reactor, and carrying out cationic polymerization while continuously flowing in the tubular reactor to obtain the product polyvinyl ether.
By the embodiment of the present disclosure, in the glove box, a solution of cationic polymerization catalyst with a certain concentration is prepared and sucked into one syringe a, a mixed solution of monomer, initiator and additive with a certain concentration is prepared and sucked into the other syringe B, and then the take-out syringe A, B is installed on a syringe pump which has been programmed to start flowing at a set temperature and a set flow rate for cationic polymerization. The product was collected at the end of the tubular reactor and quenched by addition of ethanol and filtered to give the polymer. The continuous flow method is adopted to realize the full contact of the cationic polymerization catalyst and the vinyl ether monomer in the flow process, which is beneficial to synthesizing the polyvinyl ether polymer with higher isotacticity.
According to embodiments of the present disclosure, the cationic polymerization catalyst comprises at least one of: TiCl (titanium dioxide)2(OAr)2、EtAlCl2、BF3Et2O、Et2AlCl、SnCl4Wherein Ar is 2, 6-diisopropylphenyl, preferred cationic catalysts are TiCl2(OAr)2The structural formula of (A) is as follows:
Figure BDA0003551004310000041
by way of example of the present disclosure, with TiCl2(OAr)2By way of example, the electron pair shared by the initiator is further dissociated by the titanium metal central atom deficient in electrons on the cationic polymerization catalyst during the polymerization reaction to give the ion pair CH+-Cl-And thus facilitates subsequent coordination insertion of the vinyl ether monomer. When the vinyl ether monomer is inserted in a coordinated manner, the titanium metal central atom of the catalyst can also be coordinated with the oxygen atom on the side group of the vinyl ether monomer to form a cyclic transition state, and the spatial orientation of the side group is determined by the coordination transition state when the vinyl ether monomer is inserted, so that the isotacticity of the polymer is improved. Similar mechanisms are true for other cationic polymerization catalysts, the only difference being the difference in the cationic catalyst and vinyl ether monomer, and the resulting polymers differing in isotacticity.
According to an embodiment of the present disclosure, the solvent of the solution in syringe a and syringe B is the same or different, each comprising at least one of: n-hexane, toluene, methylcyclohexane, dichloromethane.
In this disclosureIn the examples, organic solvents of different polarity have a significant effect on the isotacticity of the polymer. In nonpolar solvents, e.g. n-hexane, the dissociation of the CH-Cl bond and the CH is favoured+-Cl-The stable existence of ion pairs. In polar solvents, polar solvent molecules may also interact with ion pairs, creating a competitive relationship with monomer coordination, disrupting the stable existence of ion pairs and cyclic transition states, and adversely affecting the steric orientation of the monomer pendant groups, so that isotacticity is reduced in polar solvents.
According to embodiments of the present disclosure, the vinyl ether monomer includes at least one of: isobutyl vinyl ether, tert-butyl vinyl ether, trimethylvinyloxysilane, n-butyl vinyl ether, cyclohexyl vinyl ether, wherein the vinyl ether monomer is preferably isobutyl vinyl ether (IBVE) and has the following structural formula:
Figure BDA0003551004310000051
according to the embodiment of the present disclosure, the initiator is an addition product obtained by reacting HCl with any one of vinyl ether monomers, wherein, taking the addition product obtained by reacting HCl with isobutyl vinyl ether monomer as an example, the structural formula of the obtained addition product is as follows:
Figure BDA0003551004310000052
according to the embodiments of the present disclosure, the initiator may have an interaction with the active species at the end of the growing chain during the polymerization process, which may stabilize the active species at the end of the chain and maintain the polymerization activity; and can assist the titanium catalyst to control the spatial orientation of the side group when the vinyl ether monomer is inserted, thereby improving the isotacticity.
According to an embodiment of the present disclosure, the additive comprises: 2, 6-di-tert-butyl-4-methylpyridine, wherein the structural formula of the 2, 6-di-tert-butyl-4-methylpyridine is as follows:
Figure BDA0003551004310000061
by way of example of the present disclosure, the lower isotacticity of the polyvinyl ethers produced without the addition of additives is due to the fact that the presence of some trace amounts of impurities in the polymerization system, such as water, oxygen, etc., both the initiation of the initiator and the subsequent stereoselective polymerization are affected in the absence of additives; after the additive is used, the initiation of the initiator is facilitated, and the influence of trace impurities on the polymerization reaction is reduced, so that the isotacticity of the polymer is improved.
According to an embodiment of the present disclosure, the concentration of the cationic polymerization catalyst solution includes: 0.005-0.04M, wherein 0.005, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04M and the like can be selected.
In the examples of the present disclosure, the polyvinyl ether polymer prepared using the cationic polymerization catalyst solution in this concentration range has a high isotacticity, and when the concentration of the cationic polymerization catalyst solution is further increased, the effect of further increasing the isotacticity of the polyvinyl ether polymer is insignificant, while the isotacticity of the polyvinyl ether polymer prepared below this concentration range is decreased.
According to an embodiment of the present disclosure, the concentration of the additive includes: 0 to 0.006M, wherein 0, 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, etc. can be selected.
According to embodiments of the present disclosure, the molar ratio of vinyl ether monomer to initiator comprises: 24-144: 1, wherein the ratio can be selected from 24:1, 48:1, 72:1, 144:1 and the like.
By limiting the molar ratio of vinyl ether monomer to initiator within this range by embodiments of the present disclosure, on the one hand, higher monomer conversion and isotacticity of the polymer may be achieved, and on the other hand, higher molecular weight of the polymer may be achieved.
According to an embodiment of the present disclosure, the reaction temperature of the tubular reactor includes: -50 to-78 ℃, wherein, the temperature can be selected from-50, -58, -68, 78 ℃ and the like.
By way of example of the present disclosure, when the reaction temperature for preparing the polyvinyl ether polymer by cationic polymerization is higher, it is not beneficial to stably exist the cationic active species and the above mentioned cyclic transition state on the one hand, and it is also not beneficial to control the spatial orientation of the pendant group by the catalyst when the vinyl ether monomer is coordinately inserted, and the vinyl ether monomer is inserted more disorderly, so that the obtained polymer has lower isotacticity. When the reaction temperature of the cationic polymerization is lower, the stable existence of the cationic polymerization catalyst is facilitated, and the prepared polyvinyl ether has higher isotacticity. Where experimental conditions permit, the reaction temperature of the cationic polymerization can be further reduced to increase the isotacticity of the polyvinyl ether polymer.
According to an embodiment of the present disclosure, the cationic polymerization reaction is performed under an inert atmosphere, wherein the inert gas may be selected from nitrogen or argon.
By embodiments of the present disclosure, the use of an inert gas can provide an anhydrous, oxygen-free environment for the cationic catalyst.
According to an embodiment of the present disclosure, the mixer is a Y-type mixer.
Through the embodiment of the disclosure, the Y-shaped mixer is selected to facilitate the mixing of the solutions in the syringe A and the syringe B, so that the solutions are fully and uniformly mixed. Other shapes of mixer may be chosen depending on the actual situation.
According to an embodiment of the present disclosure, a liquid flow rate controlled by an injection pump includes: 5-20 mL/h, wherein 5, 10, 15, 20mL/h and the like can be selected, and corresponding adjustment can be performed according to actual requirements.
According to the embodiment of the disclosure, the flow rate of the liquid is controlled within 5-20 mL/h by using an injection pump, so that higher polymer molecular weight and monomer conversion rate can be obtained, but the isotacticity of the polyvinyl ether polymers obtained at different flow rates is not obviously different.
To make the process of the present disclosure for preparing polyvinyl ethers by cationic polymerization using a continuous flow process clearer, the following explanation is made in conjunction with the mechanism of the cationic polymerization process.
FIG. 2 is a schematic illustration of the mechanism of the present disclosure for making polyvinyl ethers by cationic polymerization using a continuous flow process.
The initiator is the addition product of the reaction of HCl with any one of the vinyl ether monomers. As shown in FIG. 2, firstly, the common electron pair of CH-Cl bond in the initiator is further dissociated to generate positive and negative ion pair CH with the help of the catalyst+----Cl-Or alternatively Cl-Anion radical formed with the catalyst, subsequently, from CH+Cationic polymerization of vinyl ether monomers is initiated cationically, the chain ends remaining CH after the monomer coordination insertion+---Cl-The active species is a cation. Then repeating the monomer coordination insertion process to obtain polymer molecular chains, and finally carrying out chain termination reaction to finish polymerization. In the polymerization process, the cationic polymerization catalyst also plays a role in controlling the spatial orientation of the side group when the vinyl ether monomer is coordinately inserted, so that the inserted side group of the vinyl ether monomer basically faces to one spatial direction, and further the polymer with high stereoregularity is obtained.
The invention discloses a method for preparing polyvinyl ether by cationic polymerization by adopting a continuous flow method, which comprises the following specific operation steps:
in the glove box, a cationic polymerization catalyst solution with a certain concentration is prepared and sucked into one syringe A, a mixed solution of a monomer, an initiator and an additive with a certain concentration is prepared and sucked into the other syringe B, then the syringe A, B is taken out and installed on a programmed syringe pump, and the flow is started at a set temperature and a set flow rate for cationic polymerization. Collecting the product at the end of the tubular reactor, adding ethanol to quench the reaction, filtering to obtain a polymer, drying, and performing test analysis such as nuclear magnetism, DSC, GPC and the like. Wherein, GPC is gel permeation chromatography test, which is used to test the molecular weight and molecular weight distribution of the obtained polymer; DSC is differential scanning calorimetry, a thermal analysis method that measures the power difference (e.g., as heat) input to a sample and reference versus temperature at a programmed temperature to test the melting point of a polymer.
In order to make the objects, technical solutions and advantages of the present disclosure more clear, the technical solutions and principles of the present disclosure are further illustrated by the following specific embodiments in combination with the accompanying drawings. It should be noted that the following specific examples are given by way of illustration only, and the scope of the disclosure is not limited thereto.
Test materials, reagents and the like used in the following examples are commercially available unless otherwise specified.
The specific techniques or conditions not specified in the examples can be performed according to the techniques or conditions described in the literature in the field or according to the product specification.
It should be noted that the synthesis of the catalyst and the polymerization process in the following examples were carried out in the absence of water and oxygen, all sensitive materials were stored in a glove box, and all solvents were strictly dried to remove water. All raw materials were purchased and used as received, unless otherwise specified.
Performing nuclear magnetic testing at room temperature by adopting a Bruker 400MHz nuclear magnetic instrument and using a deuterated reagent of deuterated chloroform; the element analysis is determined by the physicochemical center of Chinese science and technology university; molecular weight and molecular weight distribution were determined by GPC (polystyrene type columns, HR2 and HR4, tank temperature 45 ℃ C., using Water 1515 and Water 2414 pumps; tetrahydrofuran as the mobile phase, flow rate 1.0 ml per minute, polydispersed polystyrene as standard); the melting point was measured using a TA2000 type DSC instrument at a temperature rise rate of 10 deg.C/min and analyzed using the results of the second temperature rise test.
Example 1
In the embodiment, n-hexane is used as a solvent, the flow rate of the solution in the injection pump is 10mL/h, and the cationic polymerization reaction is carried out at-78 ℃, and the specific process is as follows:
in a glove box, 20mL of 0.02M TiCl was prepared2(OAr)2(Ar is 2, 6-diisopropylphenyl) catalyst in n-hexane solution and was sucked into a20 mL syringe A, and then 20mL of a mixed solution of isobutyl vinyl ether monomer of 0.72M concentration, initiator of 0.01M concentration and additive of 0.004M in n-hexane was prepared and sucked into another 20ML syringe B. The syringe A, B was taken out from the glove box, connected to a line having an inner diameter of 2mm, and fixed to syringe pumps, respectively, and the syringe pumps were programmed to have a liquid flow rate of 10mL/h, and then the line was placed in a low-temperature ethanol bath which had been cooled to-78 ℃ and the solution in the syringe A, B at a low temperature of-78 ℃ was mixed in a Y-type mixer and flowed into a tubular reactor to start the cationic polymerization. It should be noted that a nitrogen atmosphere is maintained throughout the process. Continuously flowing for a period of time at a set temperature and flow rate, receiving a product at the tail end of the tubular reactor, quenching with ethanol to terminate the reaction, separating out a solid polymer, filtering, and drying in vacuum to constant weight. The polyvinyl ether polymers prepared were tested and the results are shown in table 1.
The monomer conversion was 86%, the polymer molecular weight was 26400g/mol, the melting point was 136 ℃ and the isotacticity was 98%.
FIG. 3 is a depiction of the polyisobutyl vinyl ether polymer in example 1 of the present disclosure13C nuclear magnetic spectrum.
As shown in fig. 3, the isotacticity of the polymer is calculated by integrating the carbon peaks of the polyisobutyl vinyl ether polymer, wherein m is rmr + mmr + mmm is 98%, which is much higher than the isotacticity of the polyisobutyl vinyl ether obtained by other systems at present.
FIG. 4 is an X-ray diffraction pattern of a polyisobutyl vinyl ether polymer of example 1 of the present disclosure.
As shown in fig. 4, the X-ray diffraction pattern (XRD) indicates that the polymer is a semicrystalline polymer, indicating a crystalline state of the polymer.
Example 2
The same preparation as in example 1 was carried out, except that the monomer in example 2 was n-butyl vinyl ether, and the results of the relevant tests are shown in Table 1.
Example 3
The same preparation process as in example 1 was employed, except that the vinyl ether monomer in example 3 was cyclohexyl vinyl ether, and the results of the relevant tests are shown in Table 1.
Example 4
The same preparation as in example 1 was carried out, except that the vinyl ether monomer in example 4 was 2-vinyloxytetrahydrofuran, and the results of the tests are shown in Table 1.
Example 5
The same preparation as in example 1 was carried out, except that the monomer in example 5 was trimethylvinyloxysilane, and the results of the relevant tests are shown in Table 1.
Example 6
The same preparation process as in example 1 was employed, except that the vinyl ether monomer in example 6 was t-butyl vinyl ether, and the results of the relevant tests are shown in Table 1.
TABLE 1 Effect of Using different vinyl Ether monomers on cationic polymerization to prepare polyvinyl ethers
Figure BDA0003551004310000101
As can be seen from Table 1, the isotacticity of the polymer prepared using isobutyl vinyl ether is highest, up to 98%. The polyvinyl ether polymers prepared by cationic polymerization by using other vinyl ether monomers by using a continuous flow method also have different high isotacticity, which shows that the method for preparing the polyvinyl ether by using the continuous flow method provided by the disclosure has certain universality and potential for further large-scale production. In the case of 2-vinyloxytetrahydrofuran and trimethylvinyloxysilanes, the possible heteroatom-containing groups present on the monomer side groups poison cationic polymerization catalysts, such as TiCl2(OAr)2The catalyst is deactivated, resulting in no polymerization activity.
Example 7
In this example, a cationic polymerization was carried out at-78 ℃ using methylene chloride as a solvent and a solution flow rate of 10 mL/h.
In a glove box, 20mL of 0.02M TiCl was prepared2(OAr)2(Ar is 2, 6-diisopropylphenyl) in dichloromethaneThen, the mixture was sucked into a20 mL syringe A, and a20 mL dichloromethane mixed solution containing isobutyl vinyl ether monomer at a concentration of 0.72M, initiator at a concentration of 0.01M, and additive at a concentration of 0.004M was prepared and sucked into another 20mL syringe B. The syringe A, B was taken out from the glove box, connected to a line having an inner diameter of 2mm, and fixed to syringe pumps, respectively, and the syringe pumps were programmed to have a liquid flow rate of 10mL/h, and then the line was placed in a low-temperature ethanol bath which had been cooled to-78 ℃ and the solutions in the two syringes were mixed in a Y-type mixer at a low temperature of-78 ℃ and flowed into a tubular reactor to start the cationic polymerization. It should be noted that a nitrogen atmosphere is maintained throughout the process. Continuously flowing for a period of time at a set temperature and flow rate, receiving a product at the tail end of the tubular reactor, quenching with ethanol to terminate the reaction, separating out a solid polymer, filtering, and drying in vacuum to constant weight.
It was found that the monomer conversion was 27%, the polymer molecular weight was 6300g/mol, the melting point was 97 ℃ and the isotacticity was 88%.
Example 8
The same preparation as in example 7 was used except that the organic solvent in example 8 was toluene. The polyvinyl ether polymers prepared were tested and the results are shown in table 2.
Example 9
The same preparation process as in example 7 was employed except that the organic solvent in example 9 was methylcyclohexane. The polyvinyl ether polymers prepared were tested and the results are shown in table 2.
TABLE 2 Effect of different organic solvents on cationic polymerization for the preparation of polyvinyl ethers
Figure BDA0003551004310000121
As can be seen from Table 2, cationic polymerization using organic solvents of different polarities has a significant effect on the isotacticity of the polymer, with the highest isotacticity of 96. + -. 2% for the polymer obtained in a non-polar olefinic solvent such as n-hexane, and 91. + -. 1% for the polyisobutyl vinyl ether obtained using toluene as the solvent, and only 88. + -. 1% for the polymer obtained in a polar solvent such as dichloromethane. The non-polar organic solvent is favorable for dissociation of CH-Cl bonds and stable existence of ion pairs, and the existence of the polar solvent can cause polar solvent molecules to have interaction with the ion pairs and generate a competitive relationship with coordination of monomers, so that the stable existence of the ion pairs and a cyclic transition state is damaged, and the spatial orientation of monomer side groups is also not favorably controlled, so that the isotacticity is reduced in the polar solvent.
Example 10
In this example, a cationic polymerization was carried out at-78 ℃ using n-hexane as a solvent at a solution flow rate of 5 mL/h:
in a glove box, 20mL of 0.02M TiCl was prepared2(OAr)2(Ar is 2, 6-diisopropylphenyl) was sucked into one 20mL syringe A, and 20mL of a mixed solution of isobutyl vinyl ether monomer of 0.72M concentration, initiator of 0.01M concentration and additive of 0.004M concentration in n-hexane was prepared and sucked into the other 20mL syringe B. The syringe A, B was taken out from the glove box, connected to a line having an inner diameter of 2mm, and fixed to syringe pumps, respectively, and the syringe pumps were programmed to have a liquid flow rate of 5mL/h, and then the line was placed in a low-temperature ethanol bath which had been cooled to-78 ℃ and the solutions in the two syringes were mixed in a Y-type mixer at a low temperature of-78 ℃ and flowed into a tubular reactor to start the cationic polymerization. It should be noted that a nitrogen atmosphere is maintained throughout the process. Continuously flowing for a period of time at a set temperature and flow rate, receiving a product at the tail end of the tubular reactor, quenching with ethanol to terminate the reaction, separating out a solid polymer, filtering, and drying in vacuum to constant weight.
Example 11
The same preparation method as in example 10 was employed except that the solution flow rate in example 11 was 20 mL/h. The polyvinyl ether polymers prepared were tested and the results are shown in table 3.
Example 12
In this example, n-hexane was used as a solvent, and cationic polymerization was carried out by a discontinuous flow method at a reaction temperature of-78 ℃.
Preparing 20mL of a mixed solution of isobutyl vinyl ether monomer with the concentration of 0.72M, initiator with the concentration of 0.01M and additive with the concentration of 0.004M in a glove box, adding the mixed solution into a 100mLSchlenck bottle, taking out the bottle, putting the bottle into a low temperature of-78 ℃, and then preparing 20mL of TiCl with the concentration of 0.02M2(OAr)2(Ar is 2, 6-diisopropylphenyl) was added to a Schlenck flask, followed by initiation of cationic polymerization. The process also requires maintaining a nitrogen atmosphere, anhydrous and oxygen free. After the same time as that under the flowing condition, adding ethanol to quench and terminate the reaction, filtering the polymer, and drying in vacuum to constant weight. The polyvinyl ether polymers prepared were tested and the results are shown in table 3.
TABLE 3 Effect of different flow rates of the solutions on the preparation of polyvinyl ethers by cationic polymerization
Figure BDA0003551004310000131
As can be seen from Table 3, when the flow rate of the solution in syringe A, B was 5mL/h, the conversion of isobutyl vinyl ether monomer was > 97% and the molecular weight of the resulting polymer was higher (38200 g/mol); when the flow rate of the solution in syringe A, B was 20mL/h, the conversion of isobutyl vinyl ether monomer was 73%, and the molecular weight of the resulting polymer was lower (22200g/mol), but the flow rate of the solution in syringe had no significant effect on the isotacticity of the polyvinyl ether polymer. At a flow rate of 10mL/h, the obtained polyisobutyl vinyl ether has the highest isotacticity, which reaches 96 +/-2%.
It can also be found from Table 3 that the isotacticity of the polyvinyl ether polymer prepared by cationic polymerization using the continuous flow method can reach 96. + -. 2% under the same reaction conditions, while the isotacticity of the polyvinyl ether polymer prepared by the conventional polymerization method (i.e., non-flow method) is only 91. + -. 1%, which indicates that the cationic catalyst and the monomer are more sufficiently contacted in the cationic polymerization using the continuous flow method, which is a continuous reaction process, and the isotacticity of the polymer is further improved. In addition, the polyisobutyl vinyl ethers obtained by the continuous flow process have a higher melting point and a greater enthalpy of fusion than polyisobutyl vinyl ethers obtained by conventional (non-flowing) polymerization processes
FIG. 5 is a differential scanning calorimetry test plot of polymers of example 11 and example 13 of the present disclosure.
As shown in fig. 5, the polyisobutyl vinyl ether prepared by the continuous flow method (flow chemistry method) has a higher melting point of 136 deg.c, compared to the polyisobutyl vinyl ether prepared by the conventional method (non-flow method).
Example 13
In this example, n-hexane was used as a solvent, the solution flow rate was 10mL/h, and the cationic polymerization was carried out at-50 ℃:
in a glove box, 20mL of 0.02M TiCl was prepared2(OAr)2(Ar is 2, 6-diisopropylphenyl) in n-hexane, was sucked into a20 mL syringe, and then 20mL of a mixed solution of isobutyl vinyl ether (IBVE) monomer at 0.72M, initiator at 0.01M, and additive at 0.004M in n-hexane was prepared and sucked into another 20mL syringe. The syringe was taken out from the glove box, connected to a line having an inner diameter of 2mm, fixed to the syringe pump, programmed to have a liquid flow rate of 10mL/h, and then the line was placed in a low-temperature ethanol bath which had been cooled to-50 ℃ and the solutions in the two syringes were mixed in a Y-type mixer at a low temperature of-50 ℃ and flowed into the tubular reactor to start the cationic polymerization. It should be noted that a nitrogen atmosphere is maintained throughout the process. Continuously flowing for a period of time at a set temperature and flow rate, receiving a product at the tail end of the tubular reactor, quenching with ethanol to terminate the reaction, separating out a solid polymer, filtering, and drying in vacuum to constant weight. The polyvinyl ether polymer thus prepared was subjected to measurementThe results of the tests are shown in Table 4.
TABLE 4 influence of different cationic polymerization temperatures on the preparation of polyvinyl ethers by cationic polymerization
Figure BDA0003551004310000151
As can be seen from Table 4, the isotacticity of the polymer decreases with increasing temperature of the cationic polymerization. The isotacticity of the polyisobutyl vinyl ether polymer obtained by cationic polymerization at-78 ℃ reaches up to 96 +/-2%, and when the temperature is increased to-50 ℃, the isotacticity of the polymer is only 79 +/-2%. It is shown that at higher temperatures, this is not conducive to the stable presence of cationic active species and cyclic transition states, and is not conducive to the steric orientation of pendant groups controlled by the catalyst during monomer coordination insertion, and the monomer insertion is more disordered, resulting in lower isotacticity of the resulting polymer.
Example 14
The same procedure as in example 1 was followed, except that in example 14, no additive was used, and the results of the tests are shown in Table 5.
TABLE 5 Effect of additives on the cationic polymerization for the preparation of polyvinyl ethers
Figure BDA0003551004310000152
As is clear from Table 5, under otherwise identical conditions, the addition of the additive 2, 6-di-tert-butyl-4-methylpyridine (DTBMP) gave a polymer isotacticity of 96. + -. 2%, whereas the polymer isotacticity without the addition of the additive was only 85. + -. 2%. The reason for this is that, after the use of additives, the initiator is advantageously initiated, while the effect of trace impurities on the polymerization is minimized, thereby increasing the isotacticity of the polymer.
Example 15
The same preparation method as that of example 1 was used except that the concentration of the cationic polymerization catalyst solution in example 15 was 0.005, and the results of the relevant tests are shown in Table 6.
Example 16
The same preparation method as that in example 1 was used except that the concentration of the cationic polymerization catalyst solution in example 16 was 0.03, and the results of the relevant tests are shown in Table 6.
Example 17
The same preparation method as that of example 1 was used except that the concentration of the cationic polymerization catalyst solution in example 17 was 0.04, and the results of the relevant tests are shown in Table 6.
TABLE 6 Effect of different cationic polymerization catalysts on the cationic polymerization for the preparation of polyvinyl ethers
Figure BDA0003551004310000161
As can be seen from Table 6, the isotacticity of the polyvinyl ether polymer prepared by the cationic polymerization catalyst in the range of 0.005-0.04M can reach more than 95%, even 98%, and the isotacticity of the polymer is not obviously reduced with the increase of the concentration of the cationic polymerization catalyst.
Example 18
The same procedure as in example 1 was followed, except that in example 18 the vinyl ether monomer to initiator molar ratio was 24:1, and the results of the tests are shown in Table 7.
Example 19
The same procedure as in example 1 was followed, except that in example 19 the vinyl ether monomer to initiator molar ratio was 48:1, and the results of the relevant tests are shown in Table 7.
Example 20
The same procedure as in example 1 was followed, except that in example 20 the vinyl ether monomer to initiator molar ratio was 144:1, and the results of the tests are shown in Table 7.
TABLE 7 influence of vinyl ether monomer to initiator molar ratio on preparation of polyvinyl ethers by cationic polymerization
Figure BDA0003551004310000171
As can be seen from Table 7, the isotacticity of the polymer can reach 98% at a molar ratio of the monomer to the initiator of 72, and as the concentration of the monomer to the initiator is further increased, the isotacticity of the polymer is still maintained at 92% or more, which is still higher than that of the polymer prepared by the conventional method (non-flow method).
In view of the foregoing, the present disclosure provides a method for preparing polyvinyl ether by cationic polymerization using a continuous flow process, wherein the polymer has an isotacticity of up to 98% under preferred conditions. In addition, the continuous flow method can be easily adjusted for various monomers, various solvents, cationic polymerization reaction temperature and other parameter conditions, and shows that the method has certain universality. And due to the unique advantages of the flow chemical means in industrial production, the continuous controllable synthesis of the high-isotacticity polyvinyl ether in a large scale is hopefully realized, and a new thought is provided for obtaining the high-isotacticity polyvinyl ether through the large-scale continuous controllable polymerization of the vinyl ether monomer.
In addition, a means of introducing a flow chemistry into a fixed bed reactor may be considered, and a catalyst or the like is supported on a carrier and fixed on the fixed bed, and then a flow chemistry reaction is performed, which is more favorable for the exploration of industrial production.
The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.

Claims (10)

1. A process for preparing polyvinyl ethers by cationic polymerization using a continuous flow process comprising:
providing a syringe A and a syringe B, wherein the syringe A is filled with a cationic polymerization catalyst solution, and the syringe B is filled with a vinyl ether monomer, an initiator solution and an optional additive;
connecting a syringe A and a syringe B to two syringe pumps respectively, controlling the liquid flow rate by the syringe pumps, injecting the solutions in the syringe A and the syringe B into a mixer, mixing in the mixer, flowing into a tubular reactor, and carrying out cationic polymerization while continuously flowing in the tubular reactor to obtain the product polyvinyl ether.
2. The method of claim 1, wherein the cationic polymerization catalyst comprises at least one of:
TiCl2(OAr)2、EtAlCl2、BF3Et2O、Et2AlCl、SnCl4wherein Ar is 2, 6-diisopropylphenyl.
3. The method of claim 1, wherein the solvent of the solution in syringe a and syringe B is the same or different, each comprising at least one of:
n-hexane, toluene, methylcyclohexane, dichloromethane.
4. The method of claim 1, wherein the vinyl ether monomer comprises at least one of:
isobutyl vinyl ether, tert-butyl vinyl ether, trimethylvinyloxysilane, n-butyl vinyl ether, cyclohexyl vinyl ether.
5. The method of claim 1, wherein said initiator is an addition product obtained by reacting HCl with any one of said vinyl ether monomers.
6. The method of claim 1, wherein the additive comprises: 2, 6-di-tert-butyl-4-methylpyridine.
7. The method of claim 1, wherein the concentration of the cationic polymerization catalyst solution comprises: 0.005-0.04M;
the concentrations of the additives include: 0 to 0.006M;
the molar ratio of the vinyl ether monomer to the initiator comprises: 24-144: 1;
the reaction temperature of the tubular reactor comprises: -50 to-78 ℃;
the cationic polymerization is carried out under an inert atmosphere.
8. The method of claim 1, wherein the mixer is a Y-mixer.
9. The method of claim 1, wherein the syringe pump controlled fluid flow rate comprises: 5-20 mL/h.
10. A polyvinyl ether produced by the method of any one of claims 1 to 9.
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0406977A1 (en) * 1989-07-06 1991-01-09 Stamicarbon B.V. Initiator and process for cationic polymerization
KR100538012B1 (en) * 2004-09-21 2005-12-21 인하대학교 산학협력단 Process for living cationic polymerization of tert-butyl vinyl ether initiated by iodine and pva having pre-determined molecular weight with narrow molecular weight distribution derived therefrom
US20130165360A1 (en) * 2011-12-21 2013-06-27 Exxonmobil Research And Engineering Company Polyvinyl ether based high performance synthetic fluids prepared using cationic polymerizwation
CN110078852A (en) * 2019-05-05 2019-08-02 苏州大学 The method that light initiation polymerization prepares vinyl ethers polymer
CN110092849A (en) * 2019-04-30 2019-08-06 南京工业大学 A kind of cation chain-transferring agent and its application
CN111961150A (en) * 2020-07-22 2020-11-20 福州大学 Method for preparing vinyl ether polymer by photo-controlled cationic polymerization

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0406977A1 (en) * 1989-07-06 1991-01-09 Stamicarbon B.V. Initiator and process for cationic polymerization
KR100538012B1 (en) * 2004-09-21 2005-12-21 인하대학교 산학협력단 Process for living cationic polymerization of tert-butyl vinyl ether initiated by iodine and pva having pre-determined molecular weight with narrow molecular weight distribution derived therefrom
US20130165360A1 (en) * 2011-12-21 2013-06-27 Exxonmobil Research And Engineering Company Polyvinyl ether based high performance synthetic fluids prepared using cationic polymerizwation
CN110092849A (en) * 2019-04-30 2019-08-06 南京工业大学 A kind of cation chain-transferring agent and its application
CN110078852A (en) * 2019-05-05 2019-08-02 苏州大学 The method that light initiation polymerization prepares vinyl ethers polymer
CN111961150A (en) * 2020-07-22 2020-11-20 福州大学 Method for preparing vinyl ether polymer by photo-controlled cationic polymerization

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
H.WANG ET AL.: "Continuous flow cationic polymerizations", 《CHEMICAL ENGINEERING JOURNAL》 *
J. LI ET AL.: "Controlled microflow cationic polymerization of vinyl ethers under ambient conditions", 《CHEMICAL ENGINEERING JOURNAL》 *
MAKOTO OUCHI，ET AL.: "Stereoregulation in Cationic Polymerization by Designed Lewis Acids. 1. Highly Isotactic Poly(isobutyl vinyl ether) with Titanium-Based Lewis Acids", 《MACROMOLECULES》 *

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