Methyl methacrylate terpolymer, process for its preparation and use thereof

Abstract

The application belongs to the technical field of polymer material preparation, relates to the field of organic glass research, and discloses a methyl methacrylate terpolymer as well as a preparation method and application thereof. The methyl methacrylate terpolymer contains structural unit I as shown in formula (1), structural unit II as shown in formula (2) and structural unit III as shown in formula (3), wherein R and R' in formula (3) are the same or different, and each is C4-C 10 alkyl. The application introduces two specific functional structural units into the macromolecular chain of polymethyl methacrylate, and prepares a novel methyl methacrylate terpolymer. The novel methyl methacrylate terpolymer has more excellent light transmission performance and heat resistance, and has high impact strength and good light transmission.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polymer material preparation, relates to the field of organic glass, and in particular relates to a methyl methacrylate terpolymer, a preparation method and application thereof. BACKGROUND

[0002] Poly methyl methacrylate is a transparent material with excellent comprehensive performance, which has excellent light transmittance, the highest full-spectrum light transmittance, and the light transmittance can reach 92%. The apparent glossiness is good. The poly methyl methacrylate also has good dielectricity and electrical insulation, excellent arc resistance, good chemical reagent resistance, solvent resistance, weather resistance and certain heat resistance and cold resistance, can be processed by casting, injection molding, extrusion, thermoforming and the like, and has good post-processing performance, and is widely used in the fields of automobile, advertising, medicine, communication and building.

[0003] The domestic engineering plastic market is in a situation of overcapacity of low-end materials and dependence on imports of high-end materials, and PMMA is also the same. PMMA is mainly used in the electronic industry and the building industry. Although the production capacity of PMMA in China is not small, the product structure is not very reasonable, only ordinary varieties can be produced, and high value-added products are lacking. The varieties and quality of high-end products are difficult to meet the domestic demand, and the dependence on foreign countries is high. In recent years, due to the sharp increase in the production of flat panel televisions and the rapid growth in the demand for vehicle-mounted liquid crystal displays, optical-grade PMMA has become the most growth-oriented field, and the potential market is large.

[0004] At present, the production technology of PMMA mainly includes bulk polymerization, suspension polymerization, solution polymerization, emulsion polymerization and copolymerization modification and the like. The suspension polymerization and solution polymerization technologies are mature and belong to traditional production technologies, and most enterprises adopt these two production technologies. However, high-end PMMA materials have strict requirements on light transmittance, thermal stability and product purity, and foreign factories generally adopt continuous bulk polymerization process technology. This technology has strict requirements on equipment and process, and at present only a few production enterprises in Germany, the United States and Japan master this technology.

[0005] The bulk polymerization process can realize continuous production, high equipment utilization, and low energy consumption in colloid post-processing, and is a green and environmentally friendly process meeting industrial and environmental requirements. The optical grade PMMA on the market is mostly MMA homopolymer, and the microstructure of its macromolecular chain is amorphous random structure, and its product performance is poor, so it is limited to the application in high-end material field. In addition, because the process uses homogeneous free radical polymerization, no solvent is added in the system, and the relative molecular mass distribution of the obtained product is narrow, and the bulk is uniform. However, in the polymerization process, when the monomer conversion rate is >20%, the viscosity of the polymerization system increases sharply, the mass transfer and heat transfer are seriously affected, the heat generated by polymerization is difficult to transfer in time, and local overheating occurs, even gelation occurs, which leads to increased operation difficulty and decreased product comprehensive performance. SUMMARY

[0006] In view of the defects in the prior art that the comprehensive performance such as heat resistance, impact resistance and light transmission of the existing methyl methacrylate terpolymer cannot meet the high-end demand, the processing operation is difficult, and the product comprehensive performance is decreased, the purpose of the present application is to provide a methyl methacrylate terpolymer, a preparation method and application thereof. The present application introduces two specific functional structural units into the macromolecular chain of polymethyl methacrylate to prepare a new type of methyl methacrylate terpolymer. The new type of methyl methacrylate terpolymer has more excellent light transmission and heat resistance, and high impact strength and good light transmission.

[0007] In order to achieve the above-mentioned purpose of the application, the first aspect of the present application provides a methyl methacrylate terpolymer containing structural unit I as shown in formula (1), structural unit II as shown in formula (2) and structural unit III as shown in formula (3),

[0008]

[0009]

[0010] In formula (3), R and R' are the same or different, and each is C4-C 10 alkyl.

[0011] According to the present application, R and R' are the same or different, and each is C4-C 10 alkyl. The alkyl group can be a straight-chain alkyl group or a branched-chain alkyl group, and is preferably a C5-C8 branched-chain alkyl group.

[0012] According to the present application, the content of each structural unit can be selected within a wide range, and in a preferred embodiment of the present application, the content of the structural unit I is 83.8-96 wt%, the content of the structural unit II is 3.9-16 wt%, and the content of the structural unit III is 0.05-0.5 wt%, based on the total weight of the methyl methacrylate terpolymer being 100 wt%; more preferably,

[0013] The content of the structural unit I is 85.9-95 wt%, for example 85.9 wt%, 87 wt%, 89 wt%, 91 wt%, 95 wt%, 95 wt%, and any two values or any range of any two values; the content of the structural unit II is 4.9-14 wt%, for example 4.9 wt%, 7 wt%, 9 wt%, 11 wt%, 13 wt%, 14 wt%, and any two values or any range of any two values; and the content of the structural unit III is 0.08-0.4 wt%, for example 0.08 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, and any two values or any range of any two values, based on the total weight of the methyl methacrylate terpolymer being 100 wt%.

[0014] In a preferred embodiment of the present application, the glass transition temperature of the methyl methacrylate terpolymer is 128-154°C, preferably 146-154°C.

[0015] In a preferred embodiment of the present application, the impact strength of the methyl methacrylate terpolymer is 22.1-24.9 KJ / m 2 , preferably 23.3-24.9 KJ / m 2 .

[0016] In a preferred embodiment of the present application, the weight average molecular weight of the methyl methacrylate terpolymer is 11.7-16.2 million, preferably 14.5-16.2 million.

[0017] In a preferred embodiment of the present application, the PDI of the methyl methacrylate terpolymer is 1.43-1.61, preferably 1.43-1.55.

[0018] In a preferred embodiment of the present application, the haze of the methyl methacrylate terpolymer is not higher than 0.3%, preferably not higher than 0.2%.

[0019] In a preferred embodiment of the present application, the light transmittance of the methyl methacrylate terpolymer is 92.5%-93.3%, preferably 92.8%-93.3%.

[0020] According to the present application, the content of each structural unit, the weight average molecular weight, the PDI, the glass transition temperature, the impact strength, the light transmittance, the haze and other parameters of the methyl methacrylate terpolymer can be detected by the methods known in the art, including but not limited to the methods described in the present application.

[0021] The second aspect of the present application is to provide a preparation method of the methyl methacrylate terpolymer of the first aspect, comprising polymerizing methyl methacrylate, functional monomer II represented by formula (4) and functional monomer III represented by formula (5) in the presence of an initiator, a chain transfer agent and an accelerator in a protective atmosphere to obtain the methyl methacrylate terpolymer.

[0022]

[0023] In formula (5), R and R' are the same or different, and each is a C4-C 10 alkyl group.

[0024] According to the present application, R and R' are the same or different, and each is a C4-C 10 alkyl group. The alkyl group can be a linear alkyl group or a branched alkyl group, and is preferably a C5-C8 branched alkyl group.

[0025] According to the present application, the specific process steps can be selected within a wide range. In a preferred embodiment of the present application, the preparation method comprises the following steps:

[0026] Step 1: mixing methyl methacrylate, functional monomer II and functional monomer III to obtain a monomer solution;

[0027] Step 2: adding an accelerator and a chain transfer agent to the monomer solution to obtain a reaction solution;

[0028] Step 3: adding an initiator to the reaction solution under a protective atmosphere to perform a first-stage polymerization reaction to obtain a prepolymer solution;

[0029] Step 4: performing a second-stage polymerization reaction on the prepolymer solution to obtain the methyl methacrylate terpolymer.

[0030] In a preferred embodiment of the present application, Step 1 further comprises a step of cooling the methyl methacrylate, and preferably the temperature of the methyl methacrylate before being mixed with the functional monomer II and the functional monomer III is 0-10°C.

[0031] In a preferred embodiment of the present application, in Step 3, the conditions of the first-stage polymerization reaction include a temperature of 100-130°C and / or a time of 20-60 minutes.

[0032] In a preferred embodiment of the present application, in the fourth step, the conditions of the second-stage polymerization reaction include a temperature of 170-260°C and / or a time of 50-100 minutes; more preferably,

[0033] The second-stage polymerization reaction is carried out in an extruder, preferably including a front-stage extrusion, a middle-stage extrusion and a final-stage extrusion; further more preferably, the temperature of the front-stage extrusion is 170-210°C, the temperature of the middle-stage extrusion is 200-240°C, the temperature of the final-stage extrusion is 230-260°C, and / or the residence time of the gel in the extruder is 50-100 minutes.

[0034] In a preferred embodiment of the present application, the preparation method further includes granulating, cooling and drying the obtained methyl methacrylate terpolymer after the second-stage polymerization reaction.

[0035] In a more preferred embodiment of the preparation method of the methyl methacrylate terpolymer according to the present application, the preparation method includes the following steps:

[0036] In the first step, the purified methyl methacrylate is cooled to 0-10°C, pumped and metered into a specially-made polymerization kettle, and the functional monomer II and the functional monomer III are added into the polymerization kettle, and stirred to completely dissolve;

[0037] In the second step, the chain transfer agent and the promoter are added into the polymerization kettle, stirred and dissolved to form a stable solution;

[0038] In the third step, after nitrogen is blown into the polymerization kettle for 30 minutes, the initiator is added, stirred to uniformly mix, and the polymerization kettle is heated to 100-130°C, and the reaction time is 20-60 minutes;

[0039] In the fourth step, the prepolymer gel in the polymerization kettle is extruded from the bottom of the kettle and sent to a screw devolatilization extruder, the temperature of the front-stage extruder is 170-210°C, the temperature of the middle-stage extruder is 200-240°C, the temperature of the final-stage extruder is 230-260°C, and the reaction time of the gel in the extruder is 50-100 minutes;

[0040] In the fifth step, after the cutting head at the front end of the extruder is started to granulate, cool and dry, the polymethyl methacrylate molding material is obtained.

[0041] In a more preferred embodiment of the present application, in the first step, the specially-made polymerization kettle is provided with a strong torque stirring paddle to strengthen the mass transfer and heat transfer, avoid coking and yellowing, and ensure smooth discharge of the material; and a gas phase condenser is mounted on the upper end of the polymerization kettle to realize precise temperature control of the bulk polymerization.

[0042] In a more preferred embodiment of the present application, a devolatilization port is provided at the upper end of the terminal extruder in the fourth step, and unreacted monomers are removed at high temperature, and are recovered and reused after condensation.

[0043] According to the present application, the amount of each monomer can be selected within a wide range. In a preferred embodiment of the present application, the amount of methyl methacrylate is 83.8-96 wt%, the amount of functional monomer II is 3.9-16 wt%, and the amount of functional monomer III is 0.05-0.5 wt%, based on 100 wt% of the total weight of methyl methacrylate, functional monomer II and functional monomer III.

[0044] In a preferred embodiment of the present application, the amount of methyl methacrylate is 85.9-95 wt%, for example 85.9 wt%, 87 wt%, 89 wt%, 91 wt%, 95 wt%, 95 wt%, and any two values or any range between any two values; the amount of functional monomer II is 4.9-14 wt%, for example 4.9 wt%, 7 wt%, 9 wt%, 11 wt%, 13 wt%, 14 wt%, and any two values or any range between any two values; and the amount of functional monomer III is 0.08-0.4 wt%, for example 0.08 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, and any two values or any range between any two values.

[0045] According to the present application, the chain transfer agent can be selected within a wide range. In a preferred embodiment of the present application, the chain transfer agent is C 10 -C 18 alkyl mercaptan, preferably at least one of hexadecyl mercaptan, tetradecyl mercaptan, tert-tetradecyl mercaptan, dodecyl mercaptan and tert-dodecyl mercaptan.

[0046] According to the present application, the amount of the chain transfer agent can be selected within a wide range. In a preferred embodiment of the present application, the amount of the chain transfer agent is 0.05%-0.5% based on the total weight of methyl methacrylate, functional monomer II and functional monomer III.

[0047] In a preferred embodiment of the present application, the accelerator is 1-phenyl-3-(2-hydroxyethyl)thiourea.

[0048] The accelerator is a compound represented by formula (6):

[0049]

[0050] According to the present application, the amount of the promoter can be selected within a wide range, and in a preferred embodiment of the present application, the amount of the promoter is 0.02% to 0.1% based on the total weight of methyl methacrylate, functional monomer II and functional monomer III.

[0051] According to the present application, the initiator can be any initiator commonly used in the art, and in a preferred embodiment of the present application, the initiator is at least one of azobisisobutyronitrile, azobisisoheptyl nitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, dibenzoyl peroxide, t-butyl peroxybenzoate and dicumyl peroxide.

[0052] According to the present application, the amount of the initiator can be selected within a wide range, and in a preferred embodiment of the present application, the amount of the initiator is 0.06% to 0.6% based on the total weight of methyl methacrylate, functional monomer II and functional monomer III.

[0053] In a preferred embodiment of the present application, the protective atmosphere is nitrogen and / or inert gas.

[0054] According to the present application, "and / or" means that either one condition alone or both conditions can exist.

[0055] A third aspect of the present application is to provide use of the methyl methacrylate terpolymer of the first aspect or the methyl methacrylate terpolymer prepared by the preparation method of the second aspect in aviation materials, optical materials, agricultural materials, building materials, liquid crystal materials or medical materials.

[0056] According to the present application, the methyl methacrylate terpolymer contains structural unit I as shown in formula (1), structural unit II as shown in formula (2) and structural unit III as shown in formula (3),

[0057]

[0058] In formula (3), R and R' are the same or different, and each is C4-C 10 The preparation method of the methyl methacrylate terpolymer comprises polymerizing methyl methacrylate, functional monomer II as shown in formula (4) and functional monomer III as shown in formula (5) in the presence of an initiator, a chain transfer agent and a promoter in a protective atmosphere to obtain the methyl methacrylate terpolymer. In formula (5), R and R' are the same or different, and each is C4-C 10alkyl group. The present application uses a copolymerization method to copolymerize methyl methacrylate with specific functional monomers in the present application, so that the organic glass not only has excellent light transmittance, but more importantly has excellent temperature resistance, thereby improving the temperature resistance and thermal decomposition temperature of the organic glass.

[0059] The methyl methacrylate terpolymer and the preparation method thereof have the following advantages and effects in molecular structure and performance compared with the prior art.

[0060] In the polymer macromolecular chain, the introduction of the large side group styryl group in the structural unit II enhances the rigidity of the molecular chain and the intermolecular force, and further improves the temperature resistance of the polymer; the double ester structure in the structural unit III further improves the entanglement ability of the molecular chain, so that the thermal decomposition temperature of the polymer is higher, and the application field of the polymethyl methacrylate product is further widened. The present application introduces the large side group styryl group functional monomer II and the maleate functional monomer III into the macromolecular structure of polymethyl methacrylate, and introduces a polymerization promoter into the polymerization system, which can improve the activity of the two functional monomers in the free radical polymerization, and can improve the randomness of the three structural units on the macromolecular chain, that is, under the condition of ensuring the high light transmittance of polymethyl methacrylate, the heat resistance of the polymer product is further improved. DETAILED DESCRIPTION

[0061] The following embodiments are described in detail, and it is necessary to point out that the following embodiments are only used to further illustrate the present application, and cannot be understood as limiting the protection scope of the present application. Some non-essential improvements and adjustments of the present application made by those skilled in the art according to the content of the present application still belong to the protection scope of the present application.

[0062] The following are several specific embodiments.

[0063] The gel permeation chromatography (PL-gPC20) is used to measure the molecular weight and molecular weight distribution (i.e. PDI) of the polymer; the differential scanning calorimeter (DSC8500) is used to test the glass transition temperature Tg of the polymer; the water absorption rate of the sample is tested according to ISO62-2008 Plastics Determination of Water Absorption; the light transmittance and haze of the polymer are tested according to the national standard gB / T2410; and the impact strength of the polymer is tested according to ISO179-1-2010.

[0064] In the following embodiments, the mass content of methyl methacrylate, functional monomer II and functional monomer III in the brackets refers to the proportion of methyl methacrylate, functional monomer II and functional monomer III based on the total mass of all monomers being 100%, that is, the total mass of methyl methacrylate, functional monomer II and functional monomer III.

[0065] In the following examples, the functional monomer II is as shown in formula (4) and the functional monomer III is as shown in formula (5).

[0066] In formula (5), R and R' are the same and are described in the corresponding examples.

[0067] Example 1

[0068] 1. Purified methyl methacrylate was cooled to 3°C and then pumped into a specially designed polymerization kettle at a metered amount of 575.7 g (mass content 95.95%). 24.0 g (mass content 4.0%) of functional monomer II and 0.3 g (mass content 0.05%) of functional monomer III (R is a linear alkyl group with n = 4) were added to the polymerization kettle, and the mixture was thoroughly stirred to completely dissolve and form a uniform solution;

[0069] 2. 0.3 g of tert-dodecyl mercaptan and 0.6 g of 1-phenyl-3-(2-hydroxyethyl)thiourea were added to the above polymerization kettle, and the mixture was stirred and dissolved to form a stable and uniform solution;

[0070] 3. After the polymerization kettle was purged with nitrogen for 30 minutes, 3.6 g of dimethyl azobis isobutyrate was added, and the mixture was stirred to mix uniformly. The polymerization kettle was heated to 130°C to initiate polymerization, and a high-torque stirring paddle was started to react for 20 minutes;

[0071] 4. The pre-3-polymerized glue solution in the above polymerization kettle was extruded from the bottom of the kettle and sent to a screw devolatilization extruder. The temperature of the front section of the extruder was 210°C, the temperature of the middle section was 240°C, and the temperature of the end section was 260°C. The residence time of the glue in the extruder was 50 minutes;

[0072] 5. The cutting machine head at the front end of the extruder was started to perform granulation. After vacuum drying at 110°C to a constant weight, a polymethyl methacrylate terpolymer molding compound was obtained. The performance test results are shown in Table 1.

[0073] Example 2

[0074] 1. Purified methyl methacrylate was cooled to 5°C and then pumped into a specially designed polymerization kettle at a metered amount of 569.52 g (mass content 94.92%). 30 g (mass content 5%) of functional monomer II and 0.48 g (mass content 0.08%) of functional monomer III (n = 6, structural formula ) were added to the polymerization kettle, and the mixture was thoroughly stirred to completely dissolve and form a uniform solution;

[0075] 2. 1.2 g of dodecyl mercaptan and 0.24 g of 1-phenyl-3-(2-hydroxyethyl)thiourea were added to the above polymerization kettle, and the mixture was stirred and dissolved to form a stable and uniform solution;

[0076] 3. After bubbling nitrogen into the polymerizer for 30 minutes, 1.2 g of dibenzoyl peroxide is added, and the mixture is stirred until uniform. The polymerizer is heated to 100°C to initiate polymerization, and a high-torque stirring paddle is started for 30 minutes;

[0077] 4. The prepolymer solution in the polymerizer is extruded from the bottom of the polymerizer and fed into a screw devolatilizing extruder. The temperature of the front section of the extruder is 180°C, the temperature of the middle section is 210°C, and the temperature of the end section is 235°C. The residence time of the gel in the extruder is 60 minutes;

[0078] 5. A cutting head at the front of the extruder is started to pelletize the product. After vacuum drying at 110°C until a constant weight is obtained, a polymethyl methacrylate terpolymer molding compound is obtained. The performance test results are shown in Table 1.

[0079] Example 3

[0080] 1. Purified methyl methacrylate is cooled to 8°C, and then pumped and metered into a specially designed polymerizer at 549.6 g (mass content 91.6%). 48 g (mass content 8%) of functional monomer II and 2.4 g (mass content 0.4%) of functional monomer III (n = 6, structural formula ) are added to the polymerizer, and the mixture is stirred until uniform.

[0081] 2. 1.8 g of dodecyl mercaptan and 0.48 g of 1-phenyl-3-(2-hydroxyethyl)thiourea are added to the polymerizer, and the mixture is stirred until uniform.

[0082] 3. After bubbling nitrogen into the polymerizer for 30 minutes, 2.4 g of dibenzoyl peroxide is added, and the mixture is stirred until uniform. The polymerizer is heated to 110°C to initiate polymerization, and a high-torque stirring paddle is started for 50 minutes.

[0083] 4. The prepolymer solution in the polymerizer is extruded from the bottom of the polymerizer and fed into a screw devolatilizing extruder. The temperature of the front section of the extruder is 190°C, the temperature of the middle section is 220°C, and the temperature of the end section is 250°C. The residence time of the gel in the extruder is 80 minutes.

[0084] 5. A cutting head at the front of the extruder is started to pelletize the product. After vacuum drying at 110°C until a constant weight is obtained, a polymethyl methacrylate terpolymer molding compound is obtained. The performance test results are shown in Table 1.

[0085] Example 4

[0086] 1. The purified methyl methacrylate is cooled to 10°C, then pumped into a special polymerization kettle in a metered amount of 520.8 g (mass content 86.8%) and 78 g (mass content 13%) of functional monomer II and 1.2 g (mass content 0.2%) of functional monomer III (n = 6, structural formula ) are added to the polymerization kettle, and it is stirred thoroughly to form a uniform solution;

[0087] 2. 2.4 g of dodecyl mercaptan and 0.36 g of 1-phenyl-3-(2-hydroxyethyl)thiourea are added to the polymerization kettle, stirred and dissolved to form a stable uniform solution;

[0088] 3. After the polymerization kettle is purged with nitrogen for 30 minutes, 3.0 g of azobisisobutyronitrile is added, stirred to mix uniformly, and the polymerization kettle is heated to 120°C to initiate polymerization, and a high-torque stirring paddle is started to react for 40 minutes;

[0089] 4. The prepolymer solution in the polymerization kettle is extruded from the bottom of the kettle and fed into a screw devolatilizing extruder, the temperature of the front section of the extruder is 200°C, the temperature of the middle section is 230°C, and the temperature of the end section is 255°C; the residence time of the colloid in the extruder is 70 minutes;

[0090] 5. The cutting head at the front end of the extruder is started to granulate, and the poly(methyl methacrylate) terpolymer molding compound is obtained after vacuum drying at 110°C to a constant weight, and the performance test results are shown in Table 1.

[0091] Example 5

[0092] 1. The purified methyl methacrylate is cooled to 0°C, then pumped into a special polymerization kettle in a metered amount of 504 g (mass content 84%) and 93 g (mass content 15.5%) of functional monomer II and 3 g (mass content 0.5%) of functional monomer III (R is an alkyl group with a methyl branch, n = 10, which is -(CH2)7-CH(CH3)2), are added to the polymerization kettle, and it is stirred thoroughly to form a uniform solution;

[0093] 2. 3 g of n-octyl mercaptan and 0.12 g of 1-phenyl-3-(2-hydroxyethyl)thiourea are added to the polymerization kettle, stirred and dissolved to form a stable uniform solution;

[0094] 3. After the polymerization kettle is purged with nitrogen for 30 minutes, 0.36 g of tert-butyl peroxybenzoate is added, stirred to mix uniformly, and the polymerization kettle is heated to 100°C to initiate polymerization, and a high-torque stirring paddle is started to react for 60 minutes;

[0095] 4. The prepolymerization glue solution in the polymerization kettle is extruded from the kettle bottom and sent to the screw devolatilization extruder, the temperature of the front section of the extruder is 170℃, the temperature of the middle section is 200℃, and the temperature of the last section is 240℃; the residence time of the glue in the extruder is 100 minutes;

[0096] 5. The cutting head at the front end of the extruder is started to granulate, and the poly(methyl methacrylate) terpolymer molding material is obtained after vacuum drying at 110℃ to constant weight, and the performance test results are shown in Table 1.

[0097] Comparative Example 1

[0098] The poly(methyl methacrylate) copolymer molding material is prepared according to the method of Example 3, except that the accelerator is replaced by 1-(2-hydroxypropyl)-3-phenylthiourea

[0099] Comparative Example 2

[0100] The copolymer is prepared according to the method of Example 3, except that 4-ethoxystyrene is used instead of functional monomer II in Example 3.

[0101] Comparative Example

[0102] The copolymer is prepared according to the method of Example 3, except that only functional monomer II is added, and functional monomer III is not added.

[0103] Comparative Example

[0104] The copolymer is prepared according to the method of Example 3, except that only functional monomer III is added, and functional monomer II is not added.

[0105] Table 1

[0106]

[0107]

[0108] As can be seen from the comparison of Examples 1-5 and Comparative Examples 1-4 in the above table, the weight average molecular weight, PDI, glass transition temperature, impact strength, light transmittance, and haze of the poly(methyl methacrylate) terpolymer prepared by copolymerizing the specific functional monomer with methyl methacrylate according to the present application are unexpectedly superior to those of Comparative Examples 1-4, and the performance is excellent, which can meet the high-end requirements and has significant technical progress.

[0109] It should be noted that the above-mentioned examples serve only to illustrate the application and are not to be construed as limiting the application in any way. The application has been described in great detail in the foregoing disclosure with reference to certain embodiments. It should be understood that the words which have been used are words of description and illustration, and are not to be construed as limiting the application in any way. Modifications and alterations of the application will occur to those skilled in the art upon reading the preceding disclosure and it is intended to include all such modifications and alterations insofar as they come within the scope of the claims. Although the application has been described in connection with specific embodiments thereof, it will be understood that the application is not limited to the specific embodiments disclosed, but rather, it will be understood to be broadly within the appended claims, as well as within the further scope of equivalents thereof.

[0110] All publications, patents, patent applications and other references mentioned in this specification are herein incorporated by reference. Unless otherwise defined, all technical and scientific terms used in this specification are to be taken as commonly understood terms within the skill of the art. In the case of conflict between the present specification and the definitions of terms, the present specification controls.

[0111] When the specification states a genus of elements with disclosure of examples, it is intended to convey that the genus can be limited to the disclosed examples, or that the genus can encompass other examples that can not have been literally disclosed, but which other examples can be a substitution of a disclosed example. When the specification states that a genus of elements includes the disclosure of one or more examples, it is intended to convey that the genus can be limited to the disclosed examples, or that the genus can encompass other examples that can not have been literally disclosed, but which other examples can be a substitution of a disclosed example.

[0112] The endpoints of the ranges and any values described in this application document are not to be understood as being limited to the exact values recited as the desired endpoints can necessarily be a small range around the recited values. For values which are less than one, or the endpoint is a process, such as washing, the ranges of from the lower limit of zero up to any other stated limit, and desired ranges are encompassed; that is, for values which are less than one, or the endpoint is a process, such as washing, the lower limit of the range is always zero or one, or the lower limit of the process, respectively. For values which are greater than one, or the endpoint is a process, such as washing, the ranges of from any other stated limit up to the upper limit of 100 are encompassed; that is, for values which are greater than one, or the endpoint is a process, such as washing, the upper limit of the range is always 100 or one, or the upper limit of the process, respectively. These are only examples of what is specifically asserted to be the new and non-obvious aspects of the claimed application. Now that the above has been presented, certain embodiments of the application will be further explained with reference to the figures attached hereto.

[0113] In the context of this specification, unless otherwise indicated, any aspects or items not specifically excluded or identified as being expressly stated terms are to be understood as directly applicable without any modification from those known in the art.

[0114] Furthermore, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or technical ideas formed thereby are all considered to be part of the original disclosure or original description of the present application, and should not be considered as new content that has not been disclosed or anticipated herein, unless the combination is deemed to be obviously unreasonable by those skilled in the art.

Claims

1. A methyl methacrylate terpolymer comprising structural unit I as shown in formula (1), structural unit II as shown in formula (2), and structural unit III as shown in formula (3), Equation (1); Equation (2); Equation (3), where R and R' are the same or different, each is C4-C 10 The alkyl group; based on the total weight of the methyl methacrylate terpolymer as 100wt%, the content of structural unit I is 83.8-96wt%, the content of structural unit II is 3.9-16wt%, and the content of structural unit III is 0.05-0.5wt%.

2. The methyl methacrylate terpolymer according to claim 1, characterized in that: Based on the total weight of the methyl methacrylate terpolymer as 100wt%, the content of structural unit I is 85.9-95wt%, the content of structural unit II is 4.9-14wt%, and the content of structural unit III is 0.08-0.4wt%.

3. The methyl methacrylate terpolymer according to claim 1 or 2, characterized in that: The glass transition temperature of the methyl methacrylate terpolymer is 128-154°C; and / or, The impact strength of the methyl methacrylate terpolymer is 22.1-24.9 KJ / m. 2 ; and / or, The weight-average molecular weight of the methyl methacrylate terpolymer is 117,000-162,000; and / or, The PDI of the methyl methacrylate terpolymer is 1.43-1.61; and / or, The haze of the methyl methacrylate terpolymer is not higher than 0.3%; and / or, The light transmittance of the methyl methacrylate terpolymer is 92.5%-93.3%.

4. The methyl methacrylate terpolymer according to claim 1 or 2, characterized in that: The glass transition temperature of the methyl methacrylate terpolymer is 146-154°C; and / or, The impact strength of the methyl methacrylate terpolymer is 23.3-24.9 KJ / m. 2 ; and / or, The weight-average molecular weight of the methyl methacrylate terpolymer is 145,000-162,000; and / or, The PDI of the methyl methacrylate terpolymer is 1.43-1.55; and / or, The haze of the methyl methacrylate terpolymer is not higher than 0.2%; and / or, The light transmittance of the methyl methacrylate terpolymer is 92.8%-93.3%.

5. A method for preparing a methyl methacrylate terpolymer according to any one of claims 1-4, comprising, in a protective atmosphere, in the presence of an initiator, a chain transfer agent and a accelerator, performing a polymerization reaction on methyl methacrylate, functional monomer II of formula (4) and functional monomer III of formula (5) to obtain the methyl methacrylate terpolymer; Equation (4); Equation (5), where R and R' are the same or different, each is C4-C 10 The alkyl group; the accelerator is 1-phenyl-3-(2-hydroxyethyl)thiourea.

6. The preparation method according to claim 5, characterized in that... Includes the following steps: Step 1: Mix methyl methacrylate, functional monomer II and functional monomer III to obtain a monomer solution; Step 2: Add an accelerator and a chain transfer agent to the monomer solution to obtain a reaction solution; Step 3: Under a protective atmosphere, an initiator is added to the reaction solution to carry out the first stage of polymerization reaction, and a prepolymerized adhesive is obtained. Step 4: The prepolymerized adhesive solution is subjected to a second-stage polymerization reaction to obtain a methyl methacrylate terpolymer.

7. The preparation method according to claim 6, characterized in that: Step 1 also includes a step of cooling methyl methacrylate; and / or, In step 3, the conditions for the first stage of polymerization reaction include: a temperature of 100-130°C and / or a time of 20-60 minutes.

8. The preparation method according to claim 6, characterized in that: Step 1 also includes a step of cooling methyl methacrylate, which is at a temperature of 0-10°C before being mixed with functional monomers II and III.

9. The preparation method according to claim 6, characterized in that: In step 4, the conditions for the second stage of polymerization reaction include: a temperature of 170-260°C and / or a time of 50-100 minutes.

10. The preparation method according to claim 6, characterized in that: The second stage of polymerization is carried out in an extruder.

11. The preparation method according to claim 10, characterized in that: The second stage of polymerization is carried out in an extruder, including front extrusion, middle extrusion and back extrusion.

12. The preparation method according to claim 11, characterized in that: The extrusion temperature is 170-210℃ for the first stage, 200-240℃ for the middle stage, and 230-260℃ for the last stage, and / or the residence time of the colloid in the extruder is 50-100 minutes.

13. The preparation method according to claim 6, characterized in that: The preparation method further includes granulating, cooling and drying the obtained methyl methacrylate terpolymer after the second-stage polymerization reaction.

14. The preparation method according to any one of claims 5-13, characterized in that: Based on a total weight of 100wt% for methyl methacrylate, functional monomer II, and functional monomer III, the amount of methyl methacrylate is 83.8-96wt%, the amount of functional monomer II is 3.9-16wt%, and the amount of functional monomer III is 0.05-0.5wt%.

15. The preparation method according to any one of claims 5-13, characterized in that: Based on a total weight of 100wt% for methyl methacrylate, functional monomer II, and functional monomer III, the amount of methyl methacrylate is 85.9-95wt%, the amount of functional monomer II is 4.9-14wt%, and the amount of functional monomer III is 0.08-0.4wt%.

16. The preparation method according to any one of claims 5-13, characterized in that: The chain transfer agent is C. 10 -C 18 Alkyl thiols; and / or, The chain transfer agent is used in an amount of 0.05%-0.5% of the total weight of methyl methacrylate, functional monomer II, and functional monomer III; and / or, The amount of the accelerator is 0.02%-0.1% of the total weight of methyl methacrylate, functional monomer II and functional monomer III.

17. The preparation method according to any one of claims 5-13, characterized in that: The chain transfer agent is at least one of hexadecyl mercaptan, tetradecyl mercaptan, tert-tetradecyl mercaptan, dodecyl mercaptan, and tert-dodecyl mercaptan.

18. The preparation method according to any one of claims 5-13, characterized in that: The initiator is at least one selected from azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, benzoyl peroxide, tert-butyl peroxide, and dicumyl peroxide; and / or, The amount of the initiator is 0.06%-0.6% of the total weight of methyl methacrylate, functional monomer II, and functional monomer III; And / or, the protective atmosphere is nitrogen and / or an inert gas.

19. The application of the methyl methacrylate terpolymer according to any one of claims 1-4 or the methyl methacrylate terpolymer prepared by the preparation method according to any one of claims 5-18 in optical materials, aerospace materials, building materials, agricultural materials, liquid crystal materials, or medical materials.

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