Thermoplastic elastomer preparation device and preparation method thereof

Abstract

The application belongs to the field of high polymer materials, and particularly relates to a plastic elastomer preparation device and a preparation method thereof. The application uses inexpensive and readily available commercial bulk chemicals such as propylene lactone, propylene oxide, carbon dioxide and succinic anhydride as raw materials to prepare high-performance thermoplastic elastomers under mild reaction conditions. Meanwhile, a complete set of equipment matched with the preparation method is designed, so that industrialized continuous production can be realized. The reaction condition is mild and controllable, the reaction equipment is safe, environmentally friendly, high-efficiency and energy-saving, and the production cost of the thermoplastic elastomer is greatly reduced. The solvent can be recycled and reused, so that resource waste and environmental pollution caused by waste liquid discharge are avoided. The thermoplastic elastomer granules obtained through the product forming device can be directly used for commercial processing and molding.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of high polymer materials, and particularly relates to a plastic elastomer preparation device and a preparation method thereof. BACKGROUND

[0002] In recent years, thermoplastic elastomers have developed rapidly. Thermoplastic elastomers have better processing performance and longer service life than rubber, and also have strength similar to that of engineering plastics and good flexibility and dynamic mechanical properties. However, traditional thermoplastic elastomers are prepared by condensation polymerization, which requires high temperature, high vacuum, high equipment requirements and high energy consumption, resulting in high production cost of traditional thermoplastic elastomers. Therefore, it has become a hot spot for people to synthesize thermoplastic elastomers by using other preparation strategies and preparing safe, environmentally friendly and energy-efficient preparation devices.

[0003] The application uses inexpensive and readily available commercial bulk chemicals such as lactide, propylene oxide, carbon dioxide and succinic anhydride as raw materials to prepare high-performance thermoplastic elastomers under mild reaction conditions. At the same time, a complete set of equipment matched with the preparation method is designed, which can realize industrialized continuous production. The reaction conditions are mild and controllable, the reaction equipment is safe, environmentally friendly and energy efficient, which greatly reduces the production cost of such thermoplastic elastomers. The solvent can be recycled and reused, avoiding resource waste and environmental pollution caused by waste liquid discharge. The thermoplastic elastomer pellets obtained through the product forming device can be directly used for commercial processing and molding. SUMMARY

[0004] The main content of the application is to provide a plastic elastomer preparation device and a preparation method thereof according to the deficiencies of the prior art.

[0005] The technical scheme of the application is as follows:

[0006] A thermoplastic elastomer preparation device mainly comprises a raw material storage device, a polymerization reaction device, a solvent recovery device and a product forming device.

[0007] The raw material storage device comprises a raw material inlet, a raw material outlet, an inert gas protection port, a temperature rising and falling jacket, a liquid delivery pump, a gas flow meter, a liquid flow meter and corresponding connecting pipelines.

[0008] The raw material storage device is used for anhydrous and anaerobic storage and quantitative conveying of raw materials.

[0009] The polymerization reaction device comprises a raw material inlet, an exhaust port, a polymer outlet, an inert gas protection port, a temperature rising and falling jacket, a liquid delivery pump, a gas flow meter, a liquid flow meter and corresponding connecting pipelines.

[0010] The solvent recovery device comprises a polymer stock solution inlet, a polymer outlet, a distillation device, a drying device, a liquid delivery pump, a liquid flow meter and corresponding connecting pipelines.

[0011] The solvent recovery device is used for recovering and quantitatively delivering the solvent to the raw material storage device.

[0012] The product forming device comprises a double-screw injection molding extrusion device and a product pelletizing device.

[0013] A thermoplastic elastomer preparation method using a preparation device, specifically comprising the following steps:

[0014] Step 1: Preparation of soft segment polymer: Propylene oxide, succinic anhydride, solvent and catalyst are added to the raw material storage device, and are dissolved by heating. The soft segment polymer is quantitatively added to the polymerization reaction device through the liquid delivery pump and the liquid flow meter. Carbon dioxide is introduced into the polymerization reaction device through the gas inlet, and the temperature is raised to 80-130℃. The soft segment polymerization reaction is carried out for 4-6 hours. After the reaction is completed, the excess carbon dioxide is released through the exhaust port. The soft segment polymer stock solution is added to the two triblock polymerization reaction devices in equal amounts. The molar ratio of propylene oxide to succinic anhydride is 1:0.1-0.3. The mass ratio of propylene oxide to catalyst is 10000:1-5. The mass ratio of propylene oxide to solvent is 1:1-2. The carbon dioxide pressure is 0.5-1.5 MPa.

[0015] Step 2: Preparation of triblock polymer: After the equal amount of soft segment polymer is added to the two triblock polymerization reaction devices, equal amounts of catalyst, solvent and D-lactide or L-lactide are added through the raw material storage device. The temperature is raised to 110-150℃, and the reaction is carried out for 4-8 hours to obtain the triblock polymer stock solution. The triblock polymer stock solution is delivered to the multi-block polymerization reaction kettle through the liquid delivery pump and the liquid flow meter. The mass ratio of D-lactide or L-lactide to soft segment polymer is 1:0.5-2. The mass ratio of catalyst to D-lactide or L-lactide is 1:500-1000. The mass ratio of solvent to D-lactide or L-lactide is 0.5-1.5:1.

[0016] Step 3: Preparation of multi-block polymer: Equal amounts of solvent and hexamethylene diisocyanate are added to the multi-block polymerization reaction kettle, and the temperature is raised to 60-80℃. The reaction is carried out for 0.5-3 hours to obtain the multi-block polymer stock solution. The multi-block polymer stock solution is delivered to the same stereocomplex polymerization reaction kettle through the liquid delivery pump and the liquid flow meter. The molar ratio of hexamethylene diisocyanate to triblock polymer is 1.1-1.3:1. The mass ratio of solvent to triblock polymer is 1-1.5:1.

[0017] Step 4: preparation of stereocomplex polymer: equal amounts of two multi-block polymers are added to a stereocomplex polymerization reactor, and the temperature is raised to 50-120℃, and the reaction is carried out for 3-10 hours to obtain a stereocomplex polymer. The stereocomplex polymer is transported to a solvent recovery device, and the temperature is raised to 70-130℃, and after distillation, cooling and drying, the recovered solvent is obtained, stored in a raw material storage device, and quantitatively transported to other raw material storage devices through a liquid transport device and a liquid flow meter for reuse.

[0018] Step 5: preparation of elastomer pellets: the solvent-removed stereocomplex polymer is transferred to a twin-screw injection molding machine for extrusion, and combined with a pelletizer to obtain thermoplastic elastomer pellets.

[0019] The solvent is one of tetrahydrofuran, 1,4-dioxane, toluene, dichloroethane or n-hexane.

[0020] The general structure of the thermoplastic elastomer is as follows:

[0021]

[0022] In the formula:

[0023] x is a real number from 1 to 10;

[0024] y is a real number from 1 to 10;

[0025] z is a real number from 1 to 10;

[0026] m is a natural number other than 0;

[0027] n is a natural number other than 0;

[0028] p is a natural number other than 0.

[0029] Advantages of the present application:

[0030] (1) The present application uses propylene oxide, carbon dioxide, succinic anhydride and lactide as raw materials to prepare high-performance thermoplastic elastomers. The cost is low, the waste is less, the reaction conditions are mild, and it has good industrialization prospect.

[0031] (2) The present application provides a preparation device matched with the thermoplastic elastomer, which is safe, environmentally friendly, low-energy and high-efficiency, and can realize the continuous preparation of such thermoplastic elastomers. BRIEF DESCRIPTION OF DRAWINGS

[0032] The schematic diagram is only used to illustrate the specific reaction process in combination with the embodiments, and the material, model and size of the reaction device, transport device and connecting pipeline are not limited. Those skilled in the art can design the reaction device according to the actual situation under the guidance of the present application.

[0033] Figure 1 NMR spectrum of hydrogen of thermoplastic elastomer with L-polylactic acid as hard segment before stereocomplexation.

[0034] Figure 2 Schematic diagram of device for preparing thermoplastic elastomer.

[0035] Representative signs in the figure are explained as follows:

[0036] R-1 is a soft segment polymerization device, V-1 is a soft segment raw material storage device, S1 is a solvent, S2 is propylene oxide, succinic anhydride and a catalyst, CO2 is a carbon dioxide gas source, and P is a liquid delivery pump and a liquid flow meter, which are the same below.

[0037] R-2 is a triblock polymerization device with D-polylactic acid as hard segment, V-2 is a triblock raw material storage device, S3 is a solvent, and S4 is D-lactide and a catalyst.

[0038] R-3 is a triblock polymerization device with L-polylactic acid as hard segment, V-4 is a triblock raw material storage device, S7 is a solvent, and S4 is L-lactide and a catalyst.

[0039] R-4 is a multi-block polymerization device with D-polylactic acid as hard segment, V-3 is a multi-block raw material storage device, S5 is a solvent, and S6 is hexamethylene diisocyanate.

[0040] R-5 is a multi-block polymerization device with L-polylactic acid as hard segment, V-5 is a multi-block raw material storage device, S9 is a solvent, and S10 is hexamethylene diisocyanate.

[0041] R-6 is a stereocomplex polymerization device,

[0042] T-1 is a solvent recovery device, which is provided with a distillation device, a cooling device and a drying device, and V-6 is a recovered solvent storage device.

[0043] The product forming device includes a double-screw injection molding extrusion and product pelletization. DETAILED DESCRIPTION

[0044] The technical solutions of the present application are further described below through examples.

[0045] The terms used in the present application have meanings generally understood by those of ordinary skill in the art, unless otherwise specified.

[0046] In the following examples, various processes and methods not described in detail are conventional methods known in the art. Meanwhile, since the structure of polymers is diverse, all preparation methods are not described in detail, and typical examples are used to illustrate the specific process steps of the present application.

[0047] Examples:

[0048] Step 1: Preparation of soft segment polymer: After removing water, toluene was added to V-1 (1 kg, mass ratio of toluene to propylene oxide was 1:1), propylene oxide (1 kg), succinic anhydride (172 g, molar ratio of succinic anhydride to propylene oxide was 0.1:1) and catalyst (0.5 g, mass ratio of catalyst to propylene oxide was 5:1000) were added to V-1, and the temperature was raised to 50°C for dissolution. After uniform mixing, S-1 was added at a constant speed for 5 h through a liquid delivery pump and a liquid flow meter. Carbon dioxide (0.6 MPa) was introduced into R-1 through a gas inlet, and the temperature was raised to 80°C. The reaction was carried out until the addition of raw materials in V-1 was completed, and then the reaction was maintained for 30 min. After the reaction was completed, the excess carbon dioxide was released through an exhaust port, and a soft segment polymer stock solution of 2320 g was obtained.

[0049] Step 2: Preparation of triblock polymer with D-polylactic acid as hard segment: The soft segment polymer stock solution in R-1 was evenly divided into two parts and delivered to R-2 and R-3, respectively, through a liquid delivery pump and a liquid flow meter. After removing water, toluene (660 g) was added to V-2, and D-lactide (660 g, mass ratio of D-lactide to soft segment polymer was 1:1, i.e., hard segment content was 50%) and catalyst (0.66 g, mass ratio of catalyst to D-lactide was 1:1000) were added to V-2. The temperature was raised to 50°C for dissolution, and the mixture was uniformly mixed. The raw materials in V-2 were added to R-2 at one time through a liquid delivery pump. The temperature was raised to 130°C, and the reaction was carried out for 6 h to obtain a triblock polymer stock solution of 2480 g (of which, triblock polymer with D-polylactic acid as hard segment was 1320 g).

[0050] Step 2: Preparation of triblock polymer with L-polylactic acid as hard segment: The soft segment polymer stock solution in R-1 was evenly divided into two parts and delivered to R-2 and R-3, respectively, through a liquid delivery pump and a liquid flow meter. After removing water, toluene (660 g) was added to V-4, and L-lactide (660 g, mass ratio of L-lactide to soft segment polymer was 1:1, i.e., hard segment content was 50%) and catalyst (0.66 g, mass ratio of catalyst to L-lactide was 1:1000) were added to V-4. The temperature was raised to 50°C for dissolution, and the mixture was uniformly mixed. The raw materials in V-4 were added to R-3 at one time through a liquid delivery pump. The temperature was raised to 130°C, and the reaction was carried out for 6 h to obtain a triblock polymer stock solution of 2480 g (of which, triblock polymer with L-polylactic acid as hard segment was 1320 g).

[0051] R-2 and R-3 were carried out in parallel.

[0052] Step 3: Preparation of the multi-block polymer with D-polylactic acid as the hard segment: transfer all the polymer stock solution in R-2 to R-4, add hexamethylene diisocyanate (6.1 g, molar ratio to the tri-block polymer 1.1:1) and toluene (1320 g, mass ratio to the tri-block polymer 1:1) after water removal to V-3, add the raw materials in V-3 to R-4 at one time, and heat to 60°C for 2 h to obtain a multi-block polymer stock solution with D-polylactic acid as the hard segment 3806 g (of which the multi-block polymer with D-polylactic acid as the hard segment is 1326 g, and toluene is 2480 g).

[0053] Step 3: Preparation of the multi-block polymer with D-polylactic acid as the hard segment: transfer all the polymer stock solution in R-2 to R-4, add hexamethylene diisocyanate (6.1 g, molar ratio to the tri-block polymer 1.1:1) and toluene (1320 g, mass ratio to the tri-block polymer 1:1) after water removal to V-3, add the raw materials in V-3 to R-4 at one time, and heat to 60°C for 2 h to obtain a multi-block polymer stock solution with D-polylactic acid as the hard segment 3806 g (of which the multi-block polymer with D-polylactic acid as the hard segment is 1326 g, and toluene is 2480 g).

[0054] R-4 and R-5 are carried out in parallel.

[0055] Step 4: Preparation of the stereocomplex polymer: transfer the multi-block polymer in R-4 and R-5 to R-6, 100°C, and react for 6 h to obtain a stereocomplex polymer 7612 g (of which the stereocomplex polymer is 2652 g, and toluene is 4960 g). Transfer the polymer stock solution in R-6 to T-1, heat to 130°C, and perform atmospheric distillation. After cooling the distillate, dry it through a dryer, and collect it in a toluene storage device V-6. A total of 3620 g of toluene is recovered, with a recovery rate of 73%. The toluene in V-6 is quantitatively transported to V-1, V-2, and V-3 through a flow meter and a delivery pump for recycling and reuse.

[0056] Step 5: Preparation of the elastomer granules: transfer the solvent-removed stereocomplex polymer to a twin-screw injection molding machine for extrusion, and use a pelletizer to obtain thermoplastic elastomer granules 2572 g, with a total yield of 97%. The schematic diagram of the thermoplastic elastomer preparation device is shown in Figure 2 .

[0057] Using the above reaction device and preparation steps, a series of elastomer granules with different hard segment mass contents are prepared by only changing the amount of hard segment feed. After molding the granules, the thermodynamic properties are tested, and the following performance results are obtained.

[0058] Thermodynamic properties of the series of elastomers

[0059]

[0060] Note: Hard segment content is mass content, NY = No Yield

[0061] Comparative Example:

[0062] The thermoplastic elastomer was prepared by using a batch reactor.

[0063] Step 1: Preparation of soft segment polymer: After water removal, toluene was added to the reactor (1 kg, mass ratio of toluene to propylene oxide was 1:1), and after water removal, propylene oxide (1 kg), succinic anhydride (172 g, molar ratio of succinic anhydride to propylene oxide was 0.1:1) and catalyst (0.5 g, mass ratio of catalyst to propylene oxide was 5:1000) were added to the feeding kettle, carbon dioxide (0.6 MPa) was introduced into the reactor, the reactor was heated to 80°C, and after the acid anhydride was dissolved by heating the feeding kettle to 50°C, the solution in the feeding kettle was added to the reactor at a constant pressure and a speed of 5h, and the reaction was kept for 30 min after the reaction was completed. Excess carbon dioxide was released, and a soft segment polymer stock solution of 2320 g was obtained.

[0064] Step 2: Preparation of triblock polymer with D-polylactic acid as hard segment: After water removal, toluene (660 g) and D-lactide (660 g, mass ratio of soft segment polymer to D-lactide was 1:1, i.e. hard segment content was 50%) were added to the feeding kettle with catalyst (0.66 g, mass ratio of catalyst to D-lactide was 1:1000), and the temperature was raised to 50°C for dissolution, and then added to the reactor at one time. The temperature was raised to 130°C and the reaction was carried out for 6h to obtain a triblock polymer stock solution of 2480 g (of which the triblock polymer with D-polylactic acid as hard segment was 1320 g).

[0065] Step 3: Preparation of multi-block polymer with D-polylactic acid as hard segment: Hexamethylene diisocyanate (6.1 g, molar ratio of hexamethylene diisocyanate to triblock polymer was 1.1:1) and toluene (1320 g, mass ratio of toluene to triblock polymer was 1:1) were added to the reactor at one time after water removal, and the temperature was raised to 60°C for 2h to obtain a multi-block polymer stock solution of 3806 g (of which the multi-block polymer with D-polylactic acid as hard segment was 1326 g, and toluene was 2480 g).

[0066] According to the above operation steps, a multi-block polymer with L-polylactic acid as hard segment was prepared, and the difference was that the raw material D-lactide was replaced by L-lactide to obtain a multi-block polymer stock solution of 3806 g (of which the multi-block polymer with L-polylactic acid as hard segment was 1326 g, and toluene was 2480 g).

[0067] Step 4: Preparation of stereocomplex polymer: The two-pot prepared multi-block polymers were mixed at 100°C for 6h to obtain stereocomplex polymer 7612g (of which stereocomplex polymer 2652g, toluene 4960g). The product was precipitated by adding the stock solution into a large amount of ethanol, the product was collected and dried.

[0068] Step 5: Preparation of elastomer pellets: The dried stereocomplex polymer was transferred to a twin-screw injection molding machine for extrusion, and was combined with a pelletizer to obtain thermoplastic elastomer pellets 2254g, with a total yield of 85%.

[0069] Table 1 Comparison of Examples and Comparative Examples

[0070] Preparation apparatus Preparation mode Yield Solvent recovery Example Complete continuous apparatus Continuous 97％ 73％ Comparative example Charge tank + reaction tank Batch 85％ No recovery

[0071] The above description is only the preferred embodiment of the present application, and any equivalent changes and modifications made within the scope of the patent application of the present application shall be included in the scope of the present application.

Claims

1. An apparatus for preparing thermoplastic elastomers, characterized in that, The preparation device comprises raw material storage device, polymerization device, solvent recovery device and product forming device. The raw material storage device comprises raw material inlet, raw material outlet, inert gas protection port, temperature rising jacket, liquid delivery pump, gas flow meter, liquid flow meter and corresponding connecting pipelines; the raw material storage device is used for anhydrous and anaerobic preservation and quantitative transmission of raw materials; The polymerization device comprises soft segment polymerization device (R-1), triblock polymerization device with D-polylactic acid as hard segment (R-2), triblock polymerization device with L-polylactic acid as hard segment (R-3), multi-block polymerization device with D-polylactic acid as hard segment (R-4), multi-block polymerization device with L-polylactic acid as hard segment (R-5) and stereocomplex polymerization device (R-6); the soft segment polymer is prepared by using propylene oxide, succinic anhydride, solvent and catalyst; The solvent recovery device comprises polymer crude liquid inlet, polymer outlet, distillation device, drying device, liquid delivery pump, liquid flow meter and corresponding connecting pipelines; the solvent recovery device is used for recovering solvent and quantitatively delivering the solvent to the raw material storage device; The product forming device comprises double screw injection extrusion device and product pelletizing device.

2. A thermoplastic elastomer characterized by, The thermoplastic elastomer is prepared by the preparation device of claim 1, and the structure of the thermoplastic elastomer has a general formula as follows: In the formula, x is a real number of 1-10; y is a real number of 1-10; z is a real number of 1-10; m is a natural number other than 0; n is a natural number other than 0; and p is a natural number other than 0. The preparation method utilizes the preparation device of claim 1 and specifically comprises the following steps: Step 1: preparation of soft segment polymer: propylene oxide, succinic anhydride, solvent and catalyst are added to the raw material storage device, dissolved by heating, quantitatively added to the polymerization device by the liquid delivery pump and liquid flow meter, carbon dioxide is introduced into the polymerization device through the gas inlet, heated to 80-130℃, and the soft segment polymerization reaction is carried out for 4-6h; after the reaction is completed, the excess carbon dioxide is released through the exhaust port, and the soft segment polymer crude liquid is equally added to two triblock polymerization devices; the molar ratio of propylene oxide to succinic anhydride is 1:0.1-0.3, the mass ratio of propylene oxide to catalyst is 10000:1-5, the mass ratio of propylene oxide to solvent is 1:1-2, and the carbon dioxide pressure is 0.5-1.5MPa. ​ ​ ​ ​ 3. A process for the preparation of a thermoplastic elastomer, characterized in that, ​ ​ Step 2: Preparation of the triblock polymer: after the same amount of soft segment polymer is added into two triblock polymerization reaction devices, the same amount of catalyst, solvent and D-lactide or L-lactide is added through the raw material storage device; the temperature is raised to 110-150℃, and the reaction is carried out for 4-8h to obtain a triblock polymer stock solution; the triblock polymer stock solution is transported to the multi-block polymerization reaction kettle through the liquid delivery pump and the liquid flow meter; the mass ratio of the D-lactide or L-lactide to the soft segment polymer is 1:0.5-2, the mass ratio of the catalyst to the D-lactide or L-lactide is 1:500-1000, and the mass ratio of the solvent to the D-lactide or L-lactide is 0.5-1.5:1; Step 3: Preparation of the multi-block polymer: the same amount of solvent and hexamethylene diisocyanate is added into the multi-block polymerization reaction kettle, the temperature is raised to 60-80℃, and the reaction is carried out for 0.5-3h to obtain a multi-block polymer stock solution; the multi-block polymer stock solution is transported to the same stereocomplex polymerization reaction kettle through the liquid delivery pump and the liquid flow meter; the molar ratio of the hexamethylene diisocyanate to the triblock polymer is 1.1-1.3:1, and the mass ratio of the solvent to the triblock polymer is 1-1.5:1; Step 4: Preparation of the stereocomplex polymer: the same amount of two multi-block polymers is added into the stereocomplex polymerization reaction kettle, the temperature is raised to 50-120℃, and the reaction is carried out for 3-10h to obtain a stereocomplex polymer; the stereocomplex polymer and the solvent are transported to the solvent recovery device, the temperature is raised to 70-130℃, and after distillation, cooling and drying, the recovered solvent is obtained and stored in the raw material storage device for quantitative transportation to other raw material storage devices through the liquid delivery device and the liquid flow meter for reuse; Step 5: Preparation of the elastomer granules: the stereocomplex polymer after removing the solvent is transferred to a twin-screw injection molding machine for extrusion, and the thermoplastic elastomer granules are obtained by using a pelletizer.

4. The production method according to claim 3, characterized by, The solvent in step 1 is any one of tetrahydrofuran, 1,4-dioxane, toluene, dichloroethane or n-hexane.

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