CN114891147B - Methyl methacrylate copolymer and preparation method and application thereof - Google Patents
Methyl methacrylate copolymer and preparation method and application thereof Download PDFInfo
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- CN114891147B CN114891147B CN202210694622.3A CN202210694622A CN114891147B CN 114891147 B CN114891147 B CN 114891147B CN 202210694622 A CN202210694622 A CN 202210694622A CN 114891147 B CN114891147 B CN 114891147B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
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- C08F220/14—Methyl esters, e.g. methyl (meth)acrylate
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F212/00—Copolymers 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 aromatic carbocyclic ring
- C08F212/02—Monomers containing only one unsaturated aliphatic radical
- C08F212/04—Monomers containing only one unsaturated aliphatic radical containing one ring
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Abstract
The invention discloses a methyl methacrylate copolymer, a preparation method and application thereof, wherein the copolymer is prepared from the following raw material monomers in parts by mass through polymerization in the presence of a mercaptan chain transfer agent: 20-78 parts by mass of a) methyl methacrylate monomer, 0-20 parts by mass of b) other acrylate monomer different from the monomer a), 20-78 parts by mass of c) aromatic unsaturated hydrocarbon monomer, and 0.02-0.3 part by mass of thiol chain transfer agent; the mercaptan chain transfer agent comprises a chain length C based on 100% of the total mass 8 ‑C 11 1-30% of alkyl mercaptan of chain length C 12 65-98% of alkyl mercaptan of chain length C 13 ‑C 15 From 0.01 to 10% of an alkyl mercaptan. Because the chain transfer agent is a composition of mercaptan with various structures, the copolymer provided by the invention has narrow molecular weight distribution and obvious advantages in the aspects of mechanical strength and chemical resistance.
Description
Technical Field
The invention relates to a copolymer, in particular to a methyl methacrylate copolymer, a preparation method and application thereof.
Background
Methyl methacrylate-styrene copolymer (MS resin) is a commonly used transparent plastic, which is mainly obtained by free radical polymerization of two monomers, methyl methacrylate and styrene. In some application fields, the light-emitting material has more excellent properties such as good processability, low moisture absorption rate, solvent resistance and lower cost than polymethyl methacrylate (PMMA), and also has more excellent light transmittance, so that the light-emitting material is widely used in the application fields such as light guide plates, daily necessities, cosmetic packages and the like.
The MS resin can be prepared by general processes such as bulk polymerization, solution polymerization, suspension polymerization and the like, wherein the continuous bulk polymerization process in the presence of a small amount of solvent has the advantages of stable product quality, high purity, low production cost of unit products and the like, and is the most commonly used preparation method of the MS resin at present, for example, the continuous polymerization process with a small amount of ethylbenzene as the solvent is adopted to prepare methyl methacrylate-styrene copolymer resin in the patent US20160355625A1 and CN107250255A, CN107793512A, JP1992057810A, wherein the methyl methacrylate addition ratio is 20-70%, the outlet conversion rate is 60-85%, and the methyl methacrylate-styrene copolymer with excellent transparency is obtained after flash evaporation or extrusion devolatilization of slurry.
It is well known to those skilled in the art that in preparing MS resins, the molecular weight of the product is primarily controlled by the addition of chain transfer agents. However, as the two monomers of methyl methacrylate and styrene have large structural difference, the inventor discovers that the chain transfer constant of the same chain transfer agent for the two monomers has large difference, so that MS resin has larger difficulty in terms of molecular weight regulation compared with PMMA resin, and is not beneficial to preparing products with narrower molecular weight distribution. For MS polymers, the molecular weight distribution can affect the mechanical strength of the polymer, particularly when the MS polymers are extruded and molded, products with narrow molecular weight distribution have higher melt strength, and the molded plates have better dimensional stability.
Disclosure of Invention
In order to solve the above technical problems, the present invention firstly proposes a methyl methacrylate copolymer in one aspect. The methyl methacrylate copolymer has narrower molecular weight distribution, has obvious advantages in the aspects of mechanical strength such as stretching, bending and impact resistance of products, has better stress cracking resistance when used for cosmetic packaging, and has better dimensional stability when used for extruding a light guide plate.
Based on the second aspect of the invention, a preparation method of the methyl methacrylate copolymer is also provided.
Based on the third aspect of the invention, there is also provided the use of a methyl methacrylate copolymer.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the methyl methacrylate copolymer is prepared by polymerization reaction of raw material monomers comprising the following mass parts in the presence of a mercaptan chain transfer agent:
a) 20 to 78 parts by mass, preferably 35 to 65 parts by mass, of methyl methacrylate monomer,
b) 0 to 20 parts by mass, preferably 0 to 10 parts by mass, of other acrylate monomers differing from the monomers a),
c) 20 to 78 parts by mass, preferably 30 to 60 parts by mass, of an aromatic unsaturated hydrocarbon monomer,
the addition amount of the thiol chain transfer agent is 0.02 to 0.3 part by mass, preferably 0.05 to 0.2 part by mass;
the thiol chain transfer agent used to prepare the methyl methacrylate copolymers of the present invention is a mixture of thiols of various structures. The mercaptan chain transfer agent comprises a chain length C based on 100% of the total mass 8 -C 11 1-30% of alkyl mercaptan of chain length C 12 65-98% of alkyl mercaptan of chain length C 13 -C 15 From 0.01 to 10% of an alkyl mercaptan.
In terms of the chemical structure of the thiols, the present invention provides medium chain length C 8 -C 11 Alkyl mercaptan of (C) and chain length C 13 -C 15 The thiol group on the molecular chain of the alkyl mercaptan may be connected with a primary carbon atom, a secondary carbon atom or a tertiary carbon atom. The present invention is not particularly limited, and the present invention can be generally achieved and completed. However, for chain length C 12 The mercapto group on the molecular chain of the alkyl mercaptan must be attached to a tertiary carbon atom, i.e. chain length C 12 The alkyl mercaptan of (2) is t-dodecyl mercaptan.
The inventors have unexpectedly found in continuous studies that by controlling the composition of the chain transfer agent within the ranges defined above, a methyl methacrylate copolymer having a narrow molecular weight distribution is more advantageously produced, thereby achieving effective control of the molecular weight of the methyl methacrylate copolymer, which has significant advantages in expanding the downstream applications of the methyl methacrylate copolymer.
Based on the progress of the above research, it is presumed that the carbon chain length of the different thiol chain transfer agents affects the diffusion speed in the reaction liquid, the chemical structure affects the collision probability of the thiol chain transfer agents with the monomer free radicals, and the adjustment performance of the thiol chain transfer agents on the molecular weight of the polymer is further affected. For the methyl methacrylate copolymer provided by the invention, because the chain transfer constants of the methyl methacrylate and the styrene monomer of the thiol with the same structure are very different, when the thiol chain transfer agent with a single structure is adopted, the effective regulation and control of the molecular weight of the copolymer cannot be realized. The invention specifically combines thiols of different carbon chain lengths and different chemical structures, wherein, C is adopted as the component 12 Tertiary-based thiols of chain length, predominantly C of other structure 8 -C 11 Alkyl mercaptan and C 13 -C 15 The alkyl mercaptan is taken as an auxiliary material, so that the effective regulation and control of the methyl methacrylate copolymer molecular chain can be realized. Compared with a single-structure mercaptan chain transfer agent, the methyl methacrylate copolymer prepared by the combined mercaptan chain transfer agent has lower molecular weight distribution, better mechanical strength, better chemical resistance and board dimensional stability.
In a preferred embodiment of the present invention, the thiol chain transfer agent comprises a chain length C, based on 100% of its total mass 8 -C 11 9-20% of alkyl mercaptan of chain length C 12 79-90% of alkyl mercaptan of chain length C 13 -C 15 0.1-8% of alkyl mercaptan.
Preparation of the methyl methacrylate resin copolymer of the present invention contains an aromatic unsaturated hydrocarbon monomer c) in addition to methyl methacrylate. The copolymerization of an aromatic unsaturated hydrocarbon monomer with methyl methacrylate can improve hygroscopicity, solvent resistance, injection molding processability, and the like of a methyl methacrylate polymer. The aromatic unsaturated hydrocarbon monomer is selected from one or more of styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, alpha-methylstyrene, alpha-ethylstyrene, dimethylstyrene and vinylnaphthalene, preferably styrene.
In the preparation of the methyl methacrylate resin copolymer of the present invention, other acrylate monomers b) than the monomers a) may be selected as required in addition to the methyl methacrylate and the aromatic unsaturated hydrocarbon monomers. It may be one or any combination of alkyl acrylates and their methyl substituents. In a preferred embodiment of the present invention, the monomer b) is selected from any one or more of methyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, isooctyl acrylate, cyclohexyl methacrylate, isobornyl methacrylate.
In a preferred embodiment of the present invention, the polymerization reaction may be carried out by any one of bulk polymerization, emulsion polymerization, solution polymerization, suspension polymerization, and bulk polymerization in the presence of no or a small amount of solvent is preferred.
The methyl methacrylate copolymers of the present invention may be either thermally initiated or initiator initiated at the polymerization stage. In order to accelerate the polymerization reaction rate and facilitate the regulation of the conversion rate, an initiator is preferably used to initiate polymerization. For alternative initiators, an initiator half-life of 3 to 30 minutes, preferably 5 to 15 minutes, at the polymerization temperature is suitable. When the half-life is too short, the initiator decomposes too quickly, resulting in low initiation efficiency, and too fast a reaction rate may cause problems of local explosion. When the half-life period of the initiator is too long, the polymerization reaction rate is insufficient, and the production period is long; and a large amount of initiator always remains in the reaction liquid in the reaction process, and the reaction is easy to be out of control once the conditions of insufficient mixing or stirring failure and the like occur.
In a preferred embodiment of the present invention, the polymerization is optionally added with an initiator, which is an organic peroxide initiator or azo initiator, preferably an organic peroxide initiator, further preferably any one or more of 1, 1-bis- (t-butylperoxy) -3, 5-trimethylcyclohexane, 1-bis- (t-butylperoxy) cyclohexane, t-butyl peroxy-3, 5-trimethylhexanoate, 2-bis (t-butylperoxy) butane, t-butylperoxy-2-ethylhexyl carbonate, t-amyl peroxybenzoate, t-butyl peroxybenzoate, dicumyl peroxide, and di-t-butyl peroxide;
preferably, the initiator is added in an amount of from 10 to 1000ppm, preferably from 50 to 300ppm, based on the total mass of the monomers a), b), c). When the addition amount of the initiator is too low, the time required for reaching the same conversion rate is too long, which is unfavorable for the production efficiency; when the initiator addition amount is too high, the proportion of unstable terminal groups at the polymer terminals increases, which is detrimental to the thermal stability of the resin.
A process for the preparation of a methyl methacrylate copolymer as described hereinbefore, comprising: polymerizing monomers a), b), c) by means of a thiol chain transfer agent under initiation conditions, preferably in the absence of a solvent or in the presence of a small amount of a solvent; and devolatilizing after the reaction is finished to obtain the methyl methacrylate copolymer.
In a preferred embodiment of the present invention, the method for preparing the methyl methacrylate copolymer comprises the steps of:
1) Polymerization: continuously adding methyl methacrylate monomer a), other acrylic ester monomers b) different from the monomer a), aromatic unsaturated hydrocarbon monomers c) and mercaptan chain transfer agent into a polymerization reactor together, continuously adding an initiator, and reacting at 100-180 ℃ and preferably 130-160 ℃ for 1-6h and preferably 2-4h;
2) After the polymerization reaction is completed, the obtained reaction solution is sent to a devolatilizer to remove unreacted monomers and other volatile matters, extruded and granulated to obtain the methyl methacrylate copolymer.
In preparing the methyl methacrylate copolymers of the present invention, a solvent may be optionally added to reduce the viscosity of the material in the reactor, and alternative solvents include, but are not limited to, toluene, ethylbenzene, xylene, acetone, butanone, ethyl acetate, butyl acetate, tetrahydrofuran, N-dimethylformamide, preferably toluene or ethylbenzene. The solvent is added in an amount of 5 to 30%, preferably 10 to 20% of the total mass of the monomers a), b), c). When the solvent addition amount is too large, the solid content of the materials at the outlet of the reaction kettle is too low, which is unfavorable for the improvement of the yield, and a large amount of solvent needs to be removed, so that the energy consumption is not reduced. When the solvent addition amount is too low or no solvent is added, the viscosity of the reaction solution is high, and a certain problem may exist in terms of mass transfer and heat transfer.
In the aspect of a polymerization reactor, the methyl methacrylate polymer can be selected from a full mixed flow reactor, a plug flow reactor or a combination of the two, preferably the full mixed flow reactor, and more preferably a stirred reactor with a jacket for controlling the temperature. The polymerization reactor is provided with a supply port, a discharge port, and a stirring device, and the stirring device preferably has a mixing performance substantially throughout the entire reaction zone. Besides jacket temperature control, a flow guide pipe, a coil and the like can be arranged in the reactor, and further temperature control can be performed through heat carrier circulation.
In the polymerization reaction stage, the reaction temperature is 100-180 ℃, preferably 130-160 ℃, and when the reaction temperature is too low, the viscosity of the reaction solution is high, so that mass transfer and heat transfer are not facilitated; when the reaction temperature is too high, the proportion of the side-reaction oligomers increases, which is unfavorable for improving the quality of the product.
In the polymerization stage, the outlet conversion rate of the reactor is suitably controlled in the range of 50 to 80%, preferably in the range of 60 to 70%, and when the outlet conversion rate is too low, the improvement of the production efficiency is not facilitated, and when the outlet conversion rate is too high, the production control is not facilitated due to the large viscosity. In order to control the outlet conversion, the polymerization time is from 0.5 to 5 hours, preferably from 1 to 3 hours. The polymerization temperature and reactor residence time together determine the outlet conversion.
The devolatilizer used for producing the methyl methacrylate copolymer of the present invention may be one or a combination of a plurality of vented extruder, falling-strand devolatilizer, falling-film devolatilizer, thin film evaporator, single-shaft devolatilizer, double-shaft devolatilizer, preferably falling-strand devolatilizer, vented extruder or a combination thereof, more preferably vented extruder.
The screw devolatilizer preferably has a rear volatile component outlet, a reaction liquid supply port, a front volatile component outlet, and a polymer outlet arranged from the driving portion side of the screw toward the front end side. The reaction liquid supplied from the reaction liquid supply port rapidly evaporates the volatile component by releasing heat accumulated as latent heat at the reaction liquid supply port. In order to remove the vapor of the volatile component rapidly from the extruder, it is preferable to provide a rear volatile component outlet on the side opposite to the flow direction of the resin with respect to the reaction liquid supply port. Further, in order to suppress the generation of carbide and coloring of the resin, it is preferable to coat the cylinder inner wall portion, the screw surface, and the like with a metal other than iron such as chromium, titanium, and the like.
And a devolatilization stage for removing unreacted monomers and impurities in a devolatilizer. The devolatilizer melt temperature is controlled to be 210 ℃ to 280 ℃, preferably 220 ℃ to 240 ℃. The devolatilization pressure is below 5KPa, preferably below 3KPa. The residence time of the resin in the melt pool is not more than 15min, preferably 5-10min. When the devolatilization temperature is too low, the residence time is short, and volatiles are not easily removed sufficiently. When the devolatilization temperature is too high and the residence time is too long, the polymer is easily colored by heat.
From the viewpoint of economy, it is preferable that the volatile matters such as unreacted monomers are recovered by condensing them with a condenser and then reused. In this case, it is more preferable that the high boiling point components such as oligomers contained in the volatile matter are separated and removed by distillation and then reused as a monomer.
The invention further provides methyl methacrylate copolymers prepared by the process of the invention wherein the copolymer has a weight average molecular weight in the range of from 5 to 30 ten thousand, preferably from 8 to 15 ten thousand. When the molecular weight is too low, the improvement of the resin properties is not facilitated, and when the molecular weight is too high, the production and processing of the resin are not facilitated.
When the methyl methacrylate copolymer is produced by the above method, additives such as a mold release agent, an ultraviolet absorber, an antioxidant, a colorant, an antistatic agent and the like may be added as required, and the types and the amounts of these additives are known to those skilled in the art.
The invention also provides an application of the methyl methacrylate copolymer or the methyl methacrylate copolymer prepared by the method in automobile glass, aviation materials, building materials, agricultural materials, liquid crystal materials, optical materials, medical materials or packaging materials.
The methyl methacrylate copolymer provided by the invention is transparent resin, has relatively narrow molecular weight distribution and mechanical strength under the conditions of high transmittance and low haze, and has good application performance.
Detailed Description
The invention will now be further illustrated by means of specific examples which are given solely by way of illustration of the invention and do not limit the scope thereof.
The sources of the main raw materials involved in the following examples and comparative examples of the present invention are shown in Table 1:
TABLE 1 Main raw Material information
| Raw material name | Short for short | Level of | Suppliers (suppliers) |
| Methyl methacrylate | MMA | Industrial grade | Wanhua chemistry |
| Styrene | St | Industrial grade | Wanhua chemistry |
| Acrylic acid methyl ester | MMA | Industrial grade | Wanhua chemistry |
| Butyl methacrylate | BMA | Industrial grade | Mitsubishi chemistry |
| Tert-butyl peroxy-3, 5-trimethylhexanoate | TBPMH | Industrial grade | Ackersinobell |
| 1, 1-bis (t-butylperoxy) -3, 5-trimethylcyclohexane | TMCH | Industrial grade | Ackersinobell |
| Dicumyl peroxide | DCP | Industrial grade | Ackersinobell |
| Di-tert-butyl peroxide | DTBP | Industrial grade | Ackersinobell |
| Ethylbenzene (ethylbenzene) | EB | Reagent grade | Alatine |
| Toluene (toluene) | EB | Reagent grade | Alatine |
| Zhong Xin mercaptan | / | Reagent grade | TCI-ladder love |
| 1-nonylthiol | / | Reagent grade | TCI-ladder love |
| Tertiary nonylthiol | / | Reagent grade | TCI-ladder love |
| 1-decanethiol | / | Reagent grade | TCI-ladder love |
| 1-undecanethiol | / | Reagent grade | TCI-ladder love |
| Tert-dodecyl mercaptan | / | Reagent grade | TCI-ladder love |
| 1-tridecanethiol | / | Reagent grade | TCI-ladder love |
| N-tetradecylthiol | / | Reagent grade | TCI-ladder love |
| Tert-tetradecylthiol | / | Reagent grade | TCI-ladder love |
The polymer related structure and performance test method are as follows:
< molecular weight test >
Molecular weights were measured by liquid gel chromatography (GPC), mobile phase Tetrahydrofuran (THF), and a parallax refractive detector was used for the detector. Monodisperse PMMA was used as standard.
< test of conversion >
In the continuous polymerization process, the ratio of the mass of the polymer at the outlet of the extruder to the feeding amount of the reaction liquid in unit time is calculated.
< test for chemical resistance >
Sheets of 250mm x 25.4mm x 3mm size (injection temperature 230-250 ℃) were prepared by injection molding. The obtained sheet was dried in a vacuum dryer for 5 hours, and tested in a constant temperature and humidity room at 23 ℃ and 50% humidity. The test was performed as follows:
(1) The sample was held horizontally by holding the sample with one end thereof sandwiched by the fixed base and holding the sample from below at a position 146mm away from the fixed position.
(2) A load was applied to the other end of the sample so as to create a surface stress of 18.9MPa in the sample.
(3) Ethanol is applied to the sheet surface and is applied periodically to avoid evaporation and disappearance of the ethanol.
(4) The time from the start of ethanol application until the appearance of a crack on the sample was determined.
The chemical resistance of the article was evaluated by the time at which the crack occurred. The longer the crack occurs, the better the chemical resistance.
Other relevant performance test methods are shown in table 2:
TABLE 2 Polymer Performance test criteria and conditions
| Test item | Test standard | Experimental conditions |
| Transmittance of light | ISO 13486 | 3mm |
| Haze degree | ISO 14782 | 3mm |
| Tensile Strength | ISO 527 | 1A/5 |
| Flexural Strength | ISO 178 | / |
| Non-notched impact strength of cantilever beam | ISO 179 | 1eU, no gap |
[ example 1 ]
60 parts by mass of methyl methacrylate, 40 parts by mass of styrene, 0.018 part by mass of t-butylperoxy-3, 5-trimethylhexanoate, 15 parts by mass of toluene, and 0.15 part by mass of a thiol composition (wherein 1-nonylthiol accounts for 10%, t-dodecylthiol accounts for 85%, and n-tetradecylthiol accounts for 5%) were charged into a batch tank, and the reaction mixture was prepared by thoroughly mixing. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at a flow rate of 10KG/h, the temperature in the reactor is controlled to be 135 ℃ (the half-life period of an initiator is 8 min), the average residence time is 2h, and the outlet conversion rate is 65%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 2 ]
50 parts by mass of methyl methacrylate, 50 parts by mass of styrene, 0.02 part by mass of t-butyl peroxy-3, 5-trimethylhexanoate, 15 parts by mass of ethylbenzene, and 0.13 part by mass of a thiol composition (wherein 1-undecanethiol accounts for 13%, t-dodecylthiol accounts for 82%, and n-tetradecanethiol accounts for 5%) were charged into a batch tank, and the reaction mixture was prepared by thorough mixing. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at a flow rate of 10KG/h, the temperature in the reactor is controlled to be 135 ℃ (the half-life period of an initiator is 8 min), the average residence time is 2h, and the outlet conversion rate is 65%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 3 ]
40 parts by mass of methyl methacrylate, 60 parts by mass of styrene, 0.022 part by mass of t-butyl peroxy-3, 5-trimethylhexanoate, 15 parts by mass of toluene, and 0.1 part by mass of a thiol composition (wherein Zhong Xin thiol accounts for 9.9%, t-dodecyl thiol accounts for 90%, and t-tetradecyl thiol accounts for 0.1%) were added to the formulation tank, and the mixture was thoroughly mixed to prepare a reaction solution. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at a flow rate of 10KG/h, the temperature in the reactor is controlled to be 135 ℃ (the half-life period of an initiator is 8 min), the average residence time is 2h, and the outlet conversion rate is 65%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 4 ]
Into the mixing tank were added 20 parts by mass of methyl methacrylate, 2 parts by mass of methyl acrylate, 78 parts by mass of styrene, 0.025 parts by mass of t-butylperoxy-3, 5-trimethylhexanoate, 15 parts by mass of toluene, and 0.02 parts by mass of a thiol composition (wherein 1-nonylthiol accounts for 9%, t-dodecylmercaptan accounts for 83%, and t-tetradecylthiol accounts for 8%) and the mixture was thoroughly mixed to prepare a reaction solution. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at the flow rate of 10KG/h, the temperature in the reactor is controlled to be 135 ℃ (the half-life period of the initiator is 8 min), the average residence time is 2h, and the outlet conversion rate is 62%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 5 ]
78 parts by mass of methyl methacrylate, 2 parts by mass of butyl methacrylate, 20 parts by mass of styrene, 0.015 part by mass of t-butylperoxy-3, 5-trimethylhexanoate, 15 parts by mass of toluene, and 0.3 part by mass of a thiol composition (wherein 1-decanethiol accounts for 20%, t-dodecanethiol accounts for 79%, and n-tetradecylthiol accounts for 1%) were added to the formulation tank, and the reaction mixture was prepared by thoroughly mixing. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at a flow rate of 10KG/h, the temperature in the reactor is controlled to be 135 ℃ (the half-life period of an initiator is 8 min), the average residence time is 2h, and the outlet conversion rate is 65%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 6 ]
40 parts by mass of methyl methacrylate, 20 parts by mass of t-butyl methacrylate, 40 parts by mass of styrene, 0.015 part by mass of t-butylperoxy-3, 5-trimethylhexanoate, 15 parts by mass of toluene, and 0.15 part by mass of a thiol composition (wherein t-nonylthiol accounts for 10%, t-dodecylmercaptan accounts for 85%, and n-tetradecylthiol accounts for 5%) were added to the formulation tank, and the reaction mixture was prepared by thoroughly mixing. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at the flow rate of 10KG/h, the temperature in the reactor is controlled to be 135 ℃ (the half-life period of the initiator is 8 min), the average residence time is 1.5h, and the outlet conversion rate is 60%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 7 ]
40 parts by mass of methyl methacrylate, 10 parts by mass of t-butyl methacrylate, 50 parts by mass of styrene, 0.015 part by mass of t-butylperoxy-3, 5-trimethylhexanoate, 15 parts by mass of toluene, and 0.15 part by mass of a thiol composition (wherein 1-decanethiol accounts for 6%, 1-undecanethiol accounts for 6%, t-dodecyl thiol accounts for 83%, and 1-tridecyl thiol accounts for 5%) were added to the formulation tank, and the reaction mixture was prepared by thoroughly mixing. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at the flow rate of 10KG/h, the temperature in the reactor is controlled to be 135 ℃ (the half-life period of the initiator is 8 min), the average residence time is 1.5h, and the outlet conversion rate is 60%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 8 ]
50 parts by mass of methyl methacrylate, 50 parts by mass of styrene, 0.02 part by mass of 1, 1-bis- (t-butylperoxy) -3, 5-trimethylcyclohexane), 30 parts by mass of toluene, and 0.18 part by mass of a thiol composition (wherein 1-undecanethiol accounts for 13%, t-dodecylthiol accounts for 82%, and 1-tridecanethiol accounts for 5%) were charged into a batch tank, and the reaction mixture was prepared by thorough mixing. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at the flow rate of 10KG/h, the temperature in the reactor is controlled to 130 ℃ (the half-life period of the initiator is 3 min), the average residence time is 3h, and the outlet conversion rate is 70%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 9 ]
50 parts by mass of methyl methacrylate, 50 parts by mass of styrene, 0.02 part by mass of di-t-butyl peroxide, 5 parts by mass of ethylbenzene and 0.10 part by mass of a thiol composition (wherein 1-undecanethiol accounts for 13%, t-dodecyl thiol accounts for 82% and n-tetradecanethiol accounts for 5%) were charged into a batch tank, and the reaction mixture was prepared by thorough mixing. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at the flow rate of 10KG/h, the temperature in the reactor is controlled to 160 ℃ (the half-life period of the initiator is 15 min), the average residence time is 1h, and the outlet conversion rate is 68%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
[ example 10 ]
50 parts by mass of methyl methacrylate, 50 parts by mass of styrene, 0.015 part by mass of dicumyl peroxide, 15 parts by mass of ethylbenzene and 0.12 part by mass of a thiol composition (wherein Zhong Xin thiol accounts for 10%, 1-nonylthiol accounts for 10%, t-dodecyl thiol accounts for 70%, 1-tridecyl thiol accounts for 5% and t-tetradecylthiol accounts for 5%) were charged into a batch tank, and the reaction mixture was prepared by thoroughly mixing. And (5) introducing nitrogen and fully removing oxygen.
The reaction solution after the ingredients is continuously added into a fully mixed flow reaction kettle (effective volume is 30L) at the flow rate of 10KG/h, the temperature in the reactor is controlled to be 155 ℃, the average residence time is 1.2h, and the outlet conversion rate is 70%.
Continuously feeding the obtained slurry into a devolatilizing twin-screw extruder, and removing unreacted monomers and other volatile matters under the conditions of vacuum degree of-0.097 MPa, temperature of 230 ℃ and residence time of 10min. And extruding and granulating the devolatilized material to obtain the final product methyl methacrylate copolymer.
Comparative example 1
Methyl methacrylate copolymers were prepared in substantially the same manner as in example 2 except that: the thiol composition was replaced with the same parts by mass of t-dodecyl mercaptan.
Comparative example 2
Methyl methacrylate copolymers were prepared in substantially the same manner as in example 2 except that: the thiol composition was replaced with a mixture of t-dodecyl mercaptan and t-tetradecyl mercaptan (mass ratio: 95:5) in the same parts by mass.
[ comparative example 3 ]
Methyl methacrylate copolymers were prepared in substantially the same manner as in example 2 except that: the thiol composition was replaced with 1-undecanethiol and t-dodecyl mercaptan (mass ratio: 13:87) in the same parts by mass.
[ comparative example 4 ]
Methyl methacrylate copolymers were prepared in substantially the same manner as in example 1 except that: replacement of the thiol composition with: 1-nonylthiol accounting for 0.5 percent, tertiary dodecyl mercaptan accounting for 94.5 percent and n-tetradecylthiol accounting for 5 percent, and the total mass is unchanged.
Comparative example 5
Methyl methacrylate copolymers were prepared in substantially the same manner as in example 1 except that: replacement of the thiol composition with: 1-nonylthiol accounts for 10%, tert-dodecyl mercaptan accounts for 75%, n-tetradecylthiol accounts for 15%, and the total mass is unchanged.
The methyl methacrylate copolymers produced in each of the examples and comparative examples were subjected to the performance test shown in Table 3, and the results are shown in Table 3. As can be seen from comparison of examples and comparative examples, when the thiol composition of the present invention is used as a chain transfer agent, the molecular weight distribution of the prepared methyl methacrylate copolymer is narrower, and the polymer has obvious advantages in terms of mechanical strength and chemical resistance, thus showing that the thiol chain transfer agent of the present invention has more effective regulation effect on the molecular weight of the methyl methacrylate copolymer.
TABLE 3 Performance test results
Claims (24)
1. The methyl methacrylate copolymer is characterized by being prepared by polymerization reaction of raw material monomers comprising the following parts by mass in the presence of a mercaptan chain transfer agent:
a) 20-78 parts by mass of methyl methacrylate monomer,
b) 0 to 20 parts by mass of other acrylate monomers different from the monomer a),
c) 20-78 parts by mass of an aromatic unsaturated hydrocarbon monomer,
the addition amount of the mercaptan chain transfer agent is 0.02-0.3 part by mass;
the mercaptan chain transfer agent comprises a chain length C based on 100% of the total mass 8 -C 11 1-30% of alkyl mercaptan of chain length C 12 65-98% of alkyl mercaptan of chain length C 13 -C 15 0.01-10% of alkyl mercaptan; the chain length C 12 The alkyl mercaptan of (2) is t-dodecyl mercaptan.
2. The methyl methacrylate copolymer according to claim 1, which is produced by polymerization in the presence of a thiol chain transfer agent from a raw material monomer comprising the following parts by mass:
a) 35-65 parts by mass of methyl methacrylate monomer,
b) 0 to 10 parts by mass of other acrylate monomers different from the monomer a),
c) 30-60 parts by mass of an aromatic unsaturated hydrocarbon monomer,
the addition amount of the thiol chain transfer agent is 0.05 to 0.2 parts by mass.
3. The methyl methacrylate copolymer according to claim 1, wherein the thiol chain transfer agent comprises a chain length C based on 100% of the total mass thereof 8 -C 11 9-20% of alkyl mercaptan of chain length C 12 79-90% of alkyl mercaptan of chain length C 13 -C 15 0.1-8% of alkyl mercaptan.
4. The methyl methacrylate copolymer according to claim 1, wherein the other acrylic monomer(s) in monomer b) different from monomer a) is selected from any one or more of methyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, isooctyl acrylate, cyclohexyl methacrylate, and isobornyl methacrylate.
5. The methyl methacrylate copolymer according to any one of claims 1 to 4, wherein the aromatic unsaturated hydrocarbon monomer in the monomer c) is one or more selected from the group consisting of styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, α -methylstyrene, α -ethylstyrene, dimethylstyrene and vinylnaphthalene.
6. The methyl methacrylate copolymer according to claim 5, wherein the aromatic unsaturated hydrocarbon monomer in the monomer c) is styrene.
7. The methyl methacrylate copolymer according to any one of claims 1 to 4, wherein the polymerization reaction is performed by any one of bulk polymerization, emulsion polymerization, solution polymerization, and suspension polymerization.
8. The methyl methacrylate copolymer according to claim 7, wherein the polymerization is performed by a bulk polymerization method in the absence of a solvent or in the presence of a small amount of a solvent.
9. The methyl methacrylate copolymer according to claim 7, wherein an initiator is added to the polymerization reaction as required, and the initiator is an organic peroxide-based initiator or an azo-based initiator.
10. The methyl methacrylate copolymer according to claim 9, wherein the initiator is an organic peroxide-based initiator.
11. The methyl methacrylate copolymer according to claim 10, wherein the initiator is any one or more of 1, 1-bis- (t-butylperoxy) -3, 5-trimethylcyclohexane, 1-bis- (t-butylperoxy) cyclohexane, t-butyl peroxy-3, 5-trimethylhexanoate, 2-bis (t-butylperoxy) butane, t-butylperoxy-2-ethylhexyl carbonate, t-amyl peroxybenzoate, t-butyl peroxybenzoate, dicumyl peroxide, and di-t-butyl peroxide.
12. Methyl methacrylate copolymer according to claim 9, characterized in that the initiator is added in an amount of 10 to 1000ppm based on the total mass of the monomers a), b), c).
13. Methyl methacrylate copolymer according to claim 12, characterized in that the initiator is added in an amount of 50-300ppm based on the total mass of monomers a), b), c).
14. A process for the preparation of a methyl methacrylate copolymer according to any one of claims 1 to 13, wherein monomers a), b), c) are polymerized by means of a thiol chain transfer agent under initiation conditions; and devolatilizing after the reaction is finished to obtain the methyl methacrylate copolymer.
15. The process for producing a methyl methacrylate copolymer according to claim 14, wherein the monomers a), b) and c) are polymerized by a thiol chain transfer agent under initiation conditions in the absence of a solvent or in the presence of a small amount of a solvent.
16. The method for producing a methyl methacrylate copolymer according to claim 14, comprising the steps of:
1) Polymerization: continuously adding methyl methacrylate monomer a), other acrylic ester monomers b) different from the monomer a), aromatic unsaturated hydrocarbon monomers c) and mercaptan chain transfer agent into a polymerization reactor together, continuously adding an initiator, and reacting for 1-6h at 100-180 ℃;
2) After the polymerization reaction is completed, the obtained reaction solution is sent to a devolatilizer to remove unreacted monomers and other volatile matters, extruded and granulated to obtain the methyl methacrylate copolymer.
17. The process for preparing a methyl methacrylate copolymer according to claim 16, wherein in step 1), the reaction is carried out at 130 to 160℃for 2 to 4 hours.
18. The process for producing a methyl methacrylate copolymer according to claim 16, wherein a solvent is added in an amount of 5 to 30% by mass based on the total mass of the monomers a), b) and c) during the polymerization reaction in step 1).
19. The process for preparing a methyl methacrylate copolymer according to claim 18, wherein the solvent is added in an amount of 10 to 20% based on the total mass of the monomers a), b) and c) during the polymerization reaction in step 1).
20. The method for producing a methyl methacrylate copolymer according to claim 18, wherein the solvent is one or more of toluene, ethylbenzene, xylene, acetone, butanone, ethyl acetate, butyl acetate, tetrahydrofuran, N-dimethylformamide.
21. The method for producing a methyl methacrylate copolymer according to claim 18, wherein the devolatilizer is selected from one or a combination of a plurality of vented extruders, falling-strand devolatilizers, falling-film devolatilizers, thin film evaporators, single-shaft devolatilizers, and double-shaft devolatilizers.
22. The method of producing a methyl methacrylate copolymer according to claim 21, wherein the devolatilizer is selected from a falling strand devolatilizer, a vented extruder, or a combination thereof.
23. The method for producing a methyl methacrylate copolymer according to claim 21, wherein the devolatilizer is a vented extruder.
24. Use of a methyl methacrylate copolymer according to any one of claims 1 to 13 or a methyl methacrylate copolymer obtained by a process according to any one of claims 14 to 23 in automotive glass, aerospace material, construction material, agricultural material, liquid crystal material, optical material, medical material or packaging material.
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| CN1106026A (en) * | 1993-11-09 | 1995-08-02 | 三菱瓦斯化学株式会社 | Process for preparing methyl methacrylate polymer |
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