Performance-controllable polyether ester copolymer and preparation method thereof

Abstract

The invention discloses a performance-controllable polyether ester copolymer and a preparation method thereof, and belongs to the field of high polymer materials. An epoxy compound and a cyclic lactone compound are used as comonomers for ring opening polymerization, so that the polyether ester copolymer is synthesized through a one-pot method, and the performance of the copolymer can be regulated and controlled by adjusting the feeding amount of the comonomers. Meanwhile, a small amount of ester groups are introduced into the polyether structural unit to serve as ester exchange sites, so that the compatibility of the polyester structural unit and the polyether structural unit is improved, and the polyether ester copolymer with uniform and controllable performance can be prepared. The obtained polyether ester copolymer can be used as polyurethane polyol, and can also be independently used as a high polymer material.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a polyether ester copolymer with controllable performance and a preparation method thereof. Background Art

[0002] Aliphatic polyesters, as a biodegradable and biocompatible polymer material, have attracted widespread attention in the academic community in recent years, and there are a large number of literature reports on their synthesis and performance. However, existing aliphatic polyesters have disadvantages such as single structure, poor hydrophilicity and high brittleness, which limit their application in the fields of medicine and health. Moreover, due to their own properties, polyesters with a single structure cannot meet diversified needs. Therefore, efficiently realizing the modification of polyesters has important theoretical research significance and practical application value.

[0003] Combining ether functional groups with ester segments to obtain polyether-polyester copolymers is an effective modification method to improve the performance of polyester. Currently, there are three main methods for preparing polyether-ester copolymers: Method 1 is to physically blend polyether polyols and polyester polyols in a certain proportion, but due to the poor compatibility of polyether and polyester, the products prepared by this method have the problem of uneven performance. Moreover, the polyurethane materials prepared by using such polyether ester polyols often have poor performance (Chinese patent CN 116265506A); the second method is to prepare polyether ester copolymers by condensation polymerization of dibasic acid, diol and polyether polyol (Chinese patent CN106832307A). The advantage of this method is that the polyether ester components are controllable. Compared with the polyether ester copolymers prepared by physical blending, the homogeneity is better, but the terminal hydroxyl activity of polyether polyol is low, and the reaction temperature is high, which easily causes the dibasic acid to undergo side reactions such as decarboxylation and oxidation, affecting the product quality; the third method is to prepare polyether ester copolymers by ring-opening polymerization of epoxy compounds and cyclic lactones under the action of catalysts. The advantage of this method is that the reaction conditions are relatively mild and the material structure is controllable, but it often requires the development of new catalysts, the cost is high, and it is not suitable for industrial production. In addition, due to the large difference in ring tension between epoxy alkylene and cyclic lactone, the reactivity ratio is large, so it is often difficult to prepare polyether-polyester random copolymers (Chemical Reviews, 1959, 59(4): 737-799), which results in the stratification of the prepared polyetherester products, and the polymer properties of different layers are significantly different. In response to the above problems, researchers have developed a series of methods for the preparation of polyether-ester copolymers. For example, Pispas et al. (J. Polym. Sci., Part A: Polym. Chem., 2015, 53(7):846-853) used phosphazene base as a catalyst to prepare degradable polyether-ester copolymers through the ring-opening polymerization of caprolactone and tert-butyl glycidyl ether; Lynd et al. (Macromolecules, 2017, 50(7): 2714-2723) used Vandenberg catalyst to prepare a series of polyether-ester copolymers; Coates et al. (Chem. Commun., 2019, 55(48):6914-6917) developed a bimetallic catalytic system to synthesize hydrolyzable polyether-polyester copolymers using PO and lactones such as β-BL, γ-VL, and CL as raw materials; Ren et al. (Chinese J. Polym. Sci., 2020.) used heteronuclear bimetallic catalysts to achieve the copolymerization of lactones and alkylene oxides. They found that metal Co and Al complexes were active for the ring opening of epoxides and lactones, respectively.From the current research situation, although new catalysts have been developed for the preparation of polyether ester copolymers with uniform properties, they are often costly and have harsh reaction conditions. In addition, there is still the problem of poor uniformity of polyether ester products, which makes them unsuitable for industrial production. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the present invention provides a polyether ester copolymer with controllable properties and a preparation method thereof.

[0005] To achieve the above object, the present invention adopts the following technical solution: A polyether-ester copolymer with controllable properties is a copolymer having polyether and polyester structural units; the preparation method thereof comprises the following steps: adding an epoxy compound, a cyclic lactone compound, an acid anhydride compound, a catalyst 1, a catalyst 2 and an initiator into a reactor to carry out a primary ring-opening polymerization reaction of the epoxy compound and the acid anhydride compound; after the pressure in the reactor is reduced to 0, the temperature is raised to carry out a secondary ring-opening polymerization reaction of the cyclic lactone and an ester exchange reaction to obtain the polyether-ester copolymer; the reaction formula thereof is as follows: , Among them, R1=-H, -CH3, -CH2CH3, -Cl; R2=-(CH2)3-, -(CH2)4-, -CH2COOCH2-, -CH3CHCOOCHCH3-; R3=-CH2-, -CH2CH2-, -CH3CHCH2-; m=1~2000; n=1~2000; p=1~2000.

[0006] Furthermore, the epoxy compound is any one of ethylene oxide, propylene oxide, epichlorohydrin and butylene oxide; its specific structural formula is as follows: .

[0007] Further, the cyclic lactone compound is any one of glycolide, levorotatory lactide, dextrorotatory lactide, racemic lactide, valerolactone or caprolactone, and its specific structural formula is as follows; .

[0008] Furthermore, the acid anhydride compound is any one of succinic anhydride, methylsuccinic anhydride or glutaric anhydride.

[0009] Furthermore, the catalyst 1 is zinc-cobalt double metal cyanide complex (DMCC).

[0010] Furthermore, the catalyst 2 is an organic carboxylate or oxide containing any one of metal titanium, tin, antimony and germanium.

[0011] Furthermore, the initiator is any one of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, glycerol, pentaerythritol, polyethylene glycol, and polypropylene glycol.

[0012] Furthermore, the molar ratio of the cyclic lactone compound to the epoxy compound is 1:0.1-9.

[0013] Furthermore, the molar ratio of the anhydride compound to the epoxy compound is 1:10-100.

[0014] Furthermore, the mass ratio of the catalyst 1 to the epoxy compound is 1:100-10000.

[0015] Furthermore, the mass ratio of the catalyst 2 to the cyclic lactone compound is 1:100-1000.

[0016] Furthermore, the molar ratio of the initiator to the epoxy compound is 1:1-2000.

[0017] Furthermore, the temperature of the primary reaction is 70-120° C., and the time is 0.5-2 h.

[0018] Furthermore, the temperature of the secondary reaction is 100-180°C, and the time is 2-12 h.

[0019] Furthermore, the properties of the obtained polyetherester copolymer can be controlled by adjusting the amount of comonomer fed, and the molecular weight can be controlled in the range of 1000-100000 g / mol, wherein the molar content of the polyether structural unit is 5-95 mol%; and the glass transition temperature or melting point can be controlled in the range of -60-50 °C.

[0020] Beneficial effects of the present invention (1) The present invention uses epoxy compounds and cyclic lactone compounds as raw materials. By adjusting the feed ratio, the glass transition temperature or melting point of the obtained polyether ester copolymer can be adjusted within a range of -60 to 50 °C.

[0021] (2) The present invention improves the compatibility of the polyester structural unit and the polyether structural unit by introducing a small amount of ester groups as ester exchange sites into the polyether structural unit, thereby being able to prepare a random polyether ester copolymer with uniform and controllable properties, which can be used as a polyol for preparing polyurethane materials, and can also be used alone as a polymer material.

[0022] (3) The polyether ester copolymer of the present invention is prepared by a "one-pot method" which does not require a solvent, has a simple route, is low in cost, and has the prospect and potential for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is the GPC spectrum of the propylene oxide-lactide copolymer prepared in Example 1. As can be seen from the figure, the GPC spectrum of the obtained copolymer presents a single peak distribution and a narrow molecular weight distribution.

[0024] Figure 2 The propylene oxide-lactide copolymer prepared in Example 1 1 H NMR spectrum. This spectrum proves the successful synthesis of propylene oxide-lactide copolymer.

[0025] Figure 3 This is the GPC spectrum of the propylene oxide-lactide copolymer prepared in Example 2. As can be seen from the figure, the GPC spectrum of the obtained copolymer presents a single peak distribution and a narrow molecular weight distribution.

[0026] Figure 4 The propylene oxide-lactide copolymer prepared in Example 2 1 H NMR spectrum. This spectrum proves the successful synthesis of propylene oxide-lactide copolymer.

[0027] Figure 5 This is the GPC spectrum of the propylene oxide-caprolactone copolymer prepared in Example 3. As can be seen from the figure, the GPC spectrum of the obtained copolymer presents a single peak distribution and a narrow molecular weight distribution.

[0028] Figure 6 The propylene oxide-caprolactone copolymer prepared in Example 3 1 H NMR spectrum. This spectrum proves the successful synthesis of propylene oxide-caprolactone copolymer.

[0029] Figure 7 This is the GPC spectrum of the propylene oxide-caprolactone copolymer prepared in Example 4. As can be seen from the figure, the GPC spectrum of the obtained copolymer presents a single peak distribution and a narrow molecular weight distribution.

[0030] Figure 8 The propylene oxide-caprolactone copolymer prepared in Example 4 1 H NMR spectrum. This spectrum proves the successful synthesis of propylene oxide-caprolactone copolymer.

[0031] Fig. 9 This is the GPC spectrum of the polylactic acid prepared in Comparative Example 1. As can be seen from the figure, the GPC spectrum of the obtained polylactic acid homopolymer presents a single peak distribution and a narrow molecular weight distribution.

[0032] Fig.10 The polylactic acid prepared in Comparative Example 1 1 H NMR spectrum. This figure proves the successful synthesis of polylactic acid homopolymer.

[0033] Fig.11This is the GPC spectrum of the polycaprolactone prepared in Comparative Example 2. As can be seen from the figure, the GPC spectrum of the obtained polycaprolactone homopolymer presents a single peak distribution and a narrow molecular weight distribution.

[0034] Fig.12 The polycaprolactone prepared in Comparative Example 2 1 H NMR spectrum. This spectrum proves the successful synthesis of polycaprolactone homopolymer.

[0035] Fig.13 This is the GPC spectrum of the product prepared in Comparative Example 3. As can be seen from the figure, the GPC spectrum of the obtained copolymer presents a bimodal distribution and a wide molecular weight distribution.

[0036] Fig.14 The product prepared in Comparative Example 3 1 H NMR spectrum. As can be seen from the figure, the upper product and the lower product are not the same, the upper product is mainly polypropylene oxide, and the lower product is mainly polycaprolactone.

[0037] Fig.15 The secondary temperature rise DSC curves of the samples obtained in Example 1, Example 2 and Comparative Example 1 are shown. As can be seen from the figure, compared with the polylactic acid homopolymer, the glass transition temperature of the propylene oxide-lactide copolymer is lower and presents a single glass transition temperature, which proves that the thermal properties of the product can be regulated by regulating the copolymer composition, and the product has good uniformity.

[0038] Fig.16 The secondary temperature rise DSC curves of the samples obtained in Example 3, Example 4 and Comparative Example 2 are shown in FIG. As can be seen from the figure, compared with the polycaprolactone homopolymer, the melting point and melting peak intensity of the propylene oxide-caprolactone copolymer are reduced, which proves that the thermal properties of the product can be regulated by regulating the copolymer composition, and the product has good uniformity.

[0039] Fig.17 This is the secondary heating DSC curve of the product prepared in Comparative Example 3. As can be seen from the figure, the secondary heating DSC curve of the upper product has no melting peak, which is an amorphous polymer, and the secondary heating DSC curve of the lower product has double melting peaks, which is a crystalline polymer, proving that the properties of the two phases are significantly different. DETAILED DESCRIPTION

[0040] A preparation method for a polyether ester copolymer with controllable properties is as follows: an epoxy compound, a cyclic lactone compound, an acid anhydride compound, a catalyst 1, a catalyst 2 and an initiator are added into a reactor, and reacted at 70-120° C. for 0.5-2 h; after the pressure in the reactor drops to 0, the temperature is raised to 100-180° C., and the reaction is continued for 2-12 h to obtain the polyether ester copolymer.

[0041] Wherein, the epoxy compound is any one of ethylene oxide, propylene oxide, epichlorohydrin, and butylene oxide. The cyclic lactone compound is any one of glycolide, levorotatory lactide, dextrorotatory lactide, racemic lactide, valerolactone, or caprolactone. The acid anhydride compound is any one of succinic anhydride, methylsuccinic anhydride, or glutaric anhydride. The catalyst 1 is zinc-cobalt double metal cyanide complex (DMCC). The catalyst 2 is an organic carboxylate or oxide containing any one of metal titanium, tin, antimony, and germanium. The initiator is any one of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, glycerol, pentaerythritol, polyethylene glycol, and polypropylene glycol.

[0042] The molar ratio of the cyclic lactone compound to the epoxy compound is 1:0.1 to 9. The molar ratio of the acid anhydride compound to the epoxy compound is 1:10 to 100. The mass ratio of the catalyst 1 to the epoxy compound is 1:100 to 10000. The mass ratio of the catalyst 2 to the cyclic lactone compound is 1:100 to 1000. The molar ratio of the initiator to the epoxy compound is 1:1 to 2000.

[0043] The technical solution of the present invention is further described below through embodiments.

[0044] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art.

[0045] In the following examples, various processes and methods not described in detail are conventional methods known in the art. At the same time, due to the diverse proportions of polymer structures, not all preparation methods are described in detail, and typical examples are taken to illustrate the specific process steps of the present invention.

[0046] Example 1 A 50 mL autoclave equipped with mechanical stirring was dried at 120 °C for more than 12 h, evacuated and cooled to room temperature, and filled with nitrogen for use. Under nitrogen protection, propylene oxide (1.83 g, 31.5 mmol), L-lactide (18.2 g, 126.2 mmol), and succinic anhydride (0.158 g, 1.58 mmol) were weighed and added to the reactor at room temperature, and zinc-cobalt double metal cyanide complex (Zn-Co DMCC, 6.1 mg) with a mass ratio of 1:300 to propylene oxide, stannous octoate (18.2 mg) with a mass ratio of 1:1000 to L-lactide, and polypropylene glycol 200 (0.72 g, 3.6 mmol) were added. After the reactor was sealed, the temperature was set to 80 °C and the reaction was allowed to proceed for 2 hours. After the pressure in the reactor dropped to zero, the temperature was raised to 130° C. and the reaction was continued for 6 hours to obtain a polyether ester copolymer.

[0047] Thermal properties test showed that the glass transition temperature of the obtained polyether ester copolymer was 17.5 ℃. GPC test results showed that its number average molecular weight was 6.6 kg / mol and molecular weight distribution was 1.43. Nuclear magnetic resonance hydrogen spectrum results showed that the molar content of polyether structural units in the copolymer was 17.8%.

[0048] Example 2 A 50 mL autoclave equipped with mechanical stirring was dried at 120 °C for more than 12 h, evacuated and cooled to room temperature, and filled with nitrogen for use. Under nitrogen protection, propylene oxide (7.32 g, 126.0 mmol), L-lactide (18.2 g, 126.2 mmol), succinic anhydride (0.126 g, 1.26 mmol) were weighed and added to the reactor at room temperature, and zinc-cobalt double metal cyanide complex (Zn-Co DMCC, 24.4 mg) with a mass ratio of 1:300 to propylene oxide, stannous octoate (18.2 mg) with a mass ratio of 1:1000 to L-lactide, and polypropylene glycol 200 (0.082 g, 0.41 mmol) were added. After the reactor was sealed, the temperature was set to 80 °C and the reaction was allowed to proceed for 2 hours. After the pressure in the reactor dropped to zero, the temperature was raised to 130° C. and the reaction was continued for 6 hours to obtain a polyether ester copolymer.

[0049] Thermal properties test showed that the glass transition temperature of the obtained polyether ester copolymer was -1.7 ℃. GPC test results showed that its number average molecular weight was 60.1 kg / mol and molecular weight distribution was 1.73. Nuclear magnetic resonance hydrogen spectrum results showed that the molar content of polyether structural units in the copolymer was 47.9%.

[0050] Example 3 A 50 mL autoclave equipped with mechanical stirring was dried at 120 °C for more than 12 h, evacuated and cooled to room temperature, and filled with nitrogen for use. Under nitrogen protection, propylene oxide (2.26 g, 39.0 mmol), ε-caprolactone (17.74 g, 155.6 mmol), and succinic anhydride (0.195 g, 1.95 mmol) were weighed and added to the reactor at room temperature, and zinc-cobalt double metal cyanide complex (Zn-Co DMCC, 7.53 mg) with a mass ratio of 1:300 to propylene oxide, stannous octoate (17.7 mg) with a mass ratio of 1:1000 to ε-caprolactone, and polypropylene glycol 200 (2.0 g, 10 mmol) were added. After the reactor was sealed, the temperature was set to 80 °C and the reaction was allowed to proceed for 2 hours. After the pressure in the reactor dropped to zero, the temperature was raised to 130° C. and the reaction was continued for 6 hours to obtain a polyether ester copolymer.

[0051] Thermal properties test showed that the melting point of the obtained polyether ester copolymer was 31.7 ℃. GPC test results showed that its number average molecular weight was 2.6 kg / mol and molecular weight distribution was 1.96. Nuclear magnetic resonance hydrogen spectrum results showed that the molar content of polyether structural units in the copolymer was 22.2%.

[0052] Example 4 A 100 mL autoclave equipped with mechanical stirring was dried at 120 °C for more than 12 h, evacuated and cooled to room temperature, and filled with nitrogen for use. Under nitrogen protection, propylene oxide (2.9 g, 0.05 mol), ε-caprolactone (51.3 g, 0.45 mol), and succinic anhydride (0.5 g, 5 mmol) were weighed and added to the reactor at room temperature. Zinc-cobalt double metal cyanide complex (Zn-Co DMCC, 5.8 mg) with a mass ratio of 1:500 to propylene oxide, stannous octoate (51.3 mg) with a mass ratio of 1:1000 to ε-caprolactone, and polypropylene glycol 200 (1.72 g, 8.6 mmol) were added. After the reactor was sealed, the temperature was set to 80 °C and the reaction was carried out for 2 hours. After that, when the pressure in the reactor dropped to zero, the temperature was raised to 130 °C and the reaction was continued for 6 hours to obtain a polyether ester copolymer.

[0053] Thermal properties test showed that the melting point of the obtained polyether ester copolymer was 49.7 ℃. GPC test results showed that its number average molecular weight was 35.0 kg / mol and molecular weight distribution was 1.75. Nuclear magnetic resonance hydrogen spectrum results showed that the molar content of polyether structural units in the copolymer was 12.7%.

[0054] Comparative Example 1 A 50 mL autoclave equipped with mechanical stirring was dried at 120 °C for more than 12 h, evacuated and cooled to room temperature, and filled with nitrogen for use. Under nitrogen protection, L-lactide (14.4 g, 0.1 mol), stannous octoate (14.4 mg) and polypropylene glycol 200 (0.48 g, 2.4 mmol) were weighed and added to the autoclave at room temperature. After the autoclave was sealed, the temperature was set to 130 °C and the reaction was carried out for 6 hours to obtain polylactic acid.

[0055] Thermal properties test showed that the glass transition temperature of the obtained polylactic acid was 44.9 ℃; GPC test results showed that its number average molecular weight was 6.1 kg / mol and the molecular weight distribution was 1.49.

[0056] Comparative Example 2 A 50 mL autoclave equipped with mechanical stirring was dried at 120 °C for more than 12 h, evacuated, cooled to room temperature, and filled with nitrogen for use. Under nitrogen protection, ε-caprolactone (11.4 g, 0.1 mol), stannous octoate (11.4 mg) and polypropylene glycol 200 (1.14 g, 5.7 mmol) were weighed and added to the autoclave at room temperature. After the autoclave was sealed, the temperature was set to 130 °C and the reaction was carried out for 6 hours to obtain polycaprolactone.

[0057] Thermal properties test showed that the melting point of the obtained polycaprolactone was 54.8 ℃; GPC test results showed that its number average molecular weight was 3.8 kg / mol and the molecular weight distribution was 1.70.

[0058] Comparative Example 3 A 100 mL autoclave equipped with mechanical stirring was dried at 120 °C for more than 12 h, evacuated and cooled to room temperature, and filled with nitrogen for use. Under nitrogen protection, propylene oxide (2.9 g, 0.05 mol) and ε-caprolactone (51.3 g, 0.45 mol) were weighed at room temperature and added to the reactor, and zinc-cobalt double metal cyanide complex (Zn-Co DMCC, 5.8 mg) with a mass ratio of 1:500 to propylene oxide, stannous octoate (51.3 mg) with a mass ratio of 1:1000 to ε-caprolactone and polypropylene glycol 200 (1.72 g, 8.6 mmol) were added. After the reactor was sealed, the temperature was set to 80 °C and the reaction was carried out for 2 hours. After that, when the pressure in the reactor dropped to zero, the temperature was raised to 130 °C and the reaction was continued for 6 hours to obtain the product.

[0059] The product was clearly phase-separated, and the GPC test showed a bimodal distribution. The number average molecular weight was 69.7 kg / mol, and the molecular weight distribution was 4.78. The thermal performance test showed that the glass transition temperature of the upper layer product was -63.7 °C, and the melting points of the lower layer product were 47.4 and 52.9 °C. The results of hydrogen nuclear magnetic resonance spectrum showed that the upper layer product was polypropylene oxide and the lower layer product was polycaprolactone, which proved that the introduction of ester groups could improve the compatibility of polyester structural units and polyether structural units.

[0060] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for preparing a polyetherester copolymer with controllable properties, characterized in that: The epoxy compound, the cyclic lactone compound, the acid anhydride compound, the catalyst 1, the catalyst 2 and the initiator are added into the reactor for a primary reaction; after the pressure in the reactor drops to zero, the temperature is raised for a secondary reaction to obtain the polyether ester copolymer.

2. The method for preparing a polyetherester copolymer according to claim 1, characterized in that: The epoxy compound is any one of ethylene oxide, propylene oxide, epichlorohydrin and butylene oxide.

3. The method for preparing the polyetherester copolymer according to claim 1, characterized in that: The cyclic lactone compound is any one of glycolide, levorotatory lactide, dextrorotatory lactide, racemic lactide, valerolactone or caprolactone; and the molar ratio of the cyclic lactone compound to the epoxy compound is 1:0.1-9.

4. The method for preparing a polyetherester copolymer according to claim 1, characterized in that: The acid anhydride compound is any one of succinic anhydride, methylsuccinic anhydride or glutaric anhydride, and the molar ratio of the acid anhydride compound to the epoxy compound is 1:10-100.

5. The method for preparing a polyetherester copolymer according to claim 1, characterized in that: The catalyst 1 is a zinc-cobalt double metal cyanide complex, and the mass ratio of the zinc-cobalt double metal cyanide complex to the epoxy compound is 1:100-10000.

6. The method for preparing a polyetherester copolymer according to claim 1, characterized in that: The catalyst 2 is an organic carboxylate or oxide containing any one of metal titanium, tin, antimony and germanium, and the mass ratio of the organic carboxylate or oxide to the cyclic lactone compound is 1:100-1000.

7. The method for preparing a polyetherester copolymer according to claim 1, characterized in that: The initiator is any one of ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, glycerol, pentaerythritol, polyethylene glycol, and polypropylene glycol, and the molar ratio of the initiator to the epoxy compound is 1:1-2000.

8. The method for preparing a polyetherester copolymer according to claim 1, characterized in that: The temperature of the primary reaction is 70-120°C and the time is 0.5-2 h.

9. The method for preparing a polyetherester copolymer according to claim 1, characterized in that: The temperature of the secondary reaction is 100-180°C and the time is 2-12 h.

10. A polyetherester copolymer with controllable properties prepared by the method of any one of claims 1 to 9.

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