A tetra-chloro-phthalic anhydride / epoxide / carbon dioxide terpolymer and a method for its preparation

Abstract

The application discloses a trichlorophthalic anhydride / epoxide / carbon dioxide ternary block copolymer and a preparation method thereof. The application initiates catalysis of epoxide, carbon dioxide and high-activity trichlorophthalic anhydride through a Lewis acid-base pair to obtain a polyester-polycarbonate copolymer with a two-block or three-block structure. Since the polyester segment formed by trichlorophthalic anhydride and epoxide has a high glass transition temperature, and the polycarbonate segment formed by epoxide and carbon dioxide has a low glass transition temperature, the block copolymer has two glass transition temperatures, and the unique block structure guarantees the heat resistance, mechanical strength and toughness of the copolymer, and widens the application field of the copolymer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a tetra-chloro-phthalic anhydride / epoxide / carbon dioxide ternary block copolymer and a preparation method thereof. BACKGROUND

[0002] Biodegradable polypropylene carbonate (PPC) prepared from the copolymerization of propylene oxide and carbon dioxide has high transparency and barrier properties, but its low glass transition temperature (38-42℃) limits its application in the packaging field. Recently, a ternary copolymer (PPC-P) prepared from the copolymerization of propylene oxide, phthalic anhydride and carbon dioxide (CO2) maintains the high light transmission and high barrier properties of traditional PPC materials, while showing improved glass transition temperature (47℃-53℃) and mechanical properties (~40MPa), but the elongation at break is low (<10%), showing low toughness (~3MJ / m 3 )(CN 111378101A, J.CO2 Util.2021, 49, 101558). Therefore, it is necessary to find new methods to improve the toughness of PPC-P materials and further improve their glass transition temperature and gas barrier properties. SUMMARY

[0003] The present application overcomes the deficiencies of the prior art and provides a carbon dioxide-based polyester-polycarbonate material with high molecular weight, high glass transition temperature, excellent mechanical properties and high barrier property, and a preparation method thereof. The present application is characterized by introducing tetrachlorophthalic anhydride into an epoxide and CO2 copolymerization system, using an inexpensive, readily available, simple and efficient non-metallic Lewis acid and organic amine or organic ammonium salt two-component catalyst system to catalyze the ternary copolymerization of carbon dioxide, epoxide and tetrachlorophthalic anhydride to prepare a polyester-polycarbonate copolymer with a block structure. Since the reaction activity of tetrachlorophthalic anhydride in the catalyst system is very high, the polymer synthesized by one-pot one-step method has a very perfect block structure. In addition, the polyester formed by tetrachlorophthalic anhydride and epoxide has a very high glass transition temperature, and the polycarbonate copolymerized by CO2 and epoxide has a lower glass transition temperature. The block structure causes the polyester segment and the polycarbonate segment to form a two-phase separation structure, so that the polyester-polycarbonate block copolymer exhibits two glass transition temperatures, the polyester segment with a high glass transition temperature endows the polymer with excellent heat resistance and strength, and the polycarbonate segment with a low glass transition temperature endows the polymer with good flexibility. Therefore, compared with existing carbon dioxide-based copolymers, the tetrachlorophthalic anhydride / epoxide / carbon dioxide ternary block copolymer of the present application has excellent heat resistance and mechanical properties. In addition, due to the introduction of chlorine atoms, the intermolecular forces are further enhanced, so that the tetrachlorophthalic anhydride / epoxide / carbon dioxide ternary block copolymer has more excellent gas barrier property than other carbon dioxide copolymers. Since it is an amorphous structure and does not contain metal components in the catalyst system, the tetrachlorophthalic anhydride / epoxide / carbon dioxide ternary block copolymer has extremely high light transmittance. It can be seen that the present application provides a carbon dioxide-based polymer material with excellent heat resistance, mechanical properties, barrier property and complete transparency, which expands the application range of carbon dioxide-based polymer materials.

[0004] To achieve the above-mentioned object, the present application adopts the following technical solutions:

[0005] A tetrachlorophthalic anhydride / epoxide / carbon dioxide ternary block copolymer has an AB two-block structure, an ABA three-block structure or a BAB three-block structure, and its structure is shown in the following formula

[0006]

[0007] As preferred, in the above-mentioned tetrachlorophthalic anhydride / epoxide / carbon dioxide ternary block copolymer, the molar content of the polyester segment is 10%-40%, and the molar content of the polycarbonate segment is 90-60%.

[0008] As preferred, in the above-mentioned tetrachlorophthalic anhydride / epoxide / carbon dioxide ternary block copolymer, the epoxide is propylene oxide, epichlorohydrin or butylene oxide.

[0009] The preparation method of the above-mentioned trichloro phthalic anhydride / epoxide / carbon dioxide ternary block copolymer comprises the following steps:

[0010] (1) For the preparation of AB two-block copolymer and ABA three-block copolymer, a one-pot one-step method is adopted: the epoxide, trichloro phthalic anhydride, and catalyst are added into a high-pressure reactor, carbon dioxide is introduced, and the polymerization reaction is carried out by heating; after a period of reaction, the purified ternary block copolymer with block structure is directly obtained by precipitation and drying; (2) For the preparation of BAB three-block copolymer, a one-pot two-step method is adopted: the epoxide, part of the trichloro phthalic anhydride, and catalyst are added into a high-pressure reactor, carbon dioxide is introduced, and the polymerization reaction is carried out by heating; after a period of reaction, the same amount of the remaining trichloro phthalic anhydride is added (the addition ratio before and after is 1:1), and the reaction is continued for a period of time; then, the purified ternary block copolymer is obtained by precipitation and drying.

[0011] As a preferred, in the above-mentioned preparation method, the catalyst is a Lewis acid and an organic amine or an organic ammonium salt two-component catalyst.

[0012] As a preferred, in the above-mentioned preparation method, the Lewis acid is an organic boride, and a typical representative is triethyl boron; the organic amine or the organic ammonium salt is triethylamine, tributylamine, bis(triphenylphosphine)ammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium chloride, tetra-butylamide succinic acid, tetra-butylamide terephthalic acid, or 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0013] As a preferred, in the above-mentioned preparation method, the molar ratio of the epoxide and the trichloro phthalic anhydride is 10:1-40:1; the molar ratio of the trichloro phthalic anhydride and the organic amine or the organic amine salt is 50:1-300:1; and the molar ratio of the triethyl boron and the organic amine or the organic amine salt is 1.5:1-0.5:1.

[0014] As a preferred, in the above-mentioned preparation method, the remaining trichloro phthalic anhydride in step (2) is pumped into by dissolving the trichloro phthalic anhydride in toluene and using a high-pressure pump.

[0015] As a preferred, in the above-mentioned preparation method, the temperature of the polymerization reaction is 50-70℃, the reaction pressure is 0.5-2 MPa, and the total reaction time is 4-10 hours.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] (1) Trichloro phthalic anhydride is a cheap and readily available raw material with very high reactivity, and by using its copolymerization reaction with propylene oxide and carbon dioxide, a polyester-polycarbonate copolymer with block structure can be directly obtained by a one-pot one-step method.

[0018] (2) The present application initiates the catalytic copolymerization of epoxide, carbon dioxide and highly active chloranil by Lewis acid-base pair to obtain polyester-polycarbonate copolymer with diblock or triblock structure. Since the polyester segment formed by chloranil and epoxide has high glass transition temperature, the main chain is introduced with 10-40% of the polyester segment, and the thermal performance and strength of the material are significantly improved, while the polycarbonate segment formed by epoxide and carbon dioxide has a lower glass transition temperature, which ensures the toughness of the material, so that the unique block structure of the carbon dioxide-based polyester-polycarbonate copolymer has excellent heat resistance, mechanical strength and toughness, and widens the application field of carbon dioxide-based copolymer.

[0019] (3) Due to the introduction of chlorine atoms, the intermolecular force is further enhanced, so that the chloranil / epoxide / carbon dioxide ternary block copolymer has more excellent gas barrier property than other carbon dioxide copolymers, and the amorphous state ensures its high light transmittance.

[0020] The present application can be further explained and illustrated in combination with the following specific embodiments, but the specific embodiments do not have any form of limitation on the present application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The drawings are used to further clearly illustrate and explain the technical solutions and embodiments of the present application, and do not constitute a limitation on the present application, in which:

[0022] Figure 1 The nuclear magnetic hydrogen spectrum of the chloranil / epoxy propane / carbon dioxide ternary block copolymer obtained in Example 1 of the present application.

[0023] Figure 2 The nuclear magnetic hydrogen spectrum of the phthalic anhydride / epoxy propane / carbon dioxide ternary random copolymer obtained in Comparative Example 1 of the present application.

[0024] Figure 3 The DSC spectrum of the chloranil / epoxy propane / carbon dioxide ternary block copolymer obtained in Example 1 of the present application.

[0025] Figure 4 The DSC spectrum of the phthalic anhydride / epoxy propane / carbon dioxide ternary random copolymer obtained in Comparative Example 1 of the present application.

[0026] Figure 5 The ultraviolet-visible absorption spectrum curve of the chloranil / epoxy propane / carbon dioxide ternary block copolymer obtained in Example 1 of the present application.

[0027] Figure 6TG curves of the terpolymers of chloroendomethylene tetrahydrophthalic anhydride / propylene oxide / carbon dioxide and the terpolymers of phthalic anhydride / propylene oxide / carbon dioxide obtained in Example 1 and Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0028] Example 1

[0029] In anhydrous and anaerobic environment, 3.9 g of chloroendomethylene tetrahydrophthalic anhydride, 16 g of propylene oxide, 80 mg of bis(triphenylphosphine)amine chloride, 200 μL of triethyl boron solution were sequentially added into a 50 mL autoclave, 2.0 MPa of carbon dioxide was filled, and the reaction was carried out at 50°C for 10 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved in dichloromethane, and the BAB triblock polymer was precipitated in ethanol. The polymer was vacuum dried and then subjected to molecular weight test, nuclear magnetic resonance, thermal performance and mechanical performance analysis. Mn = 54.9 kDa, PDI = 1.37; polyester content = 16.7%, polycarbonate content = 81.2%, polyether content = 2.1%; T g1 = 38°C, T g2 = 100°C; tensile strength = 39 MPa, elongation at break = 35%. The nuclear magnetic resonance spectrum of the obtained chloroendomethylene tetrahydrophthalic anhydride / epoxide / carbon dioxide terpolymer is shown in FIG. 1; the DSC spectrum of the obtained chloroendomethylene tetrahydrophthalic anhydride / epoxide / carbon dioxide terpolymer is shown in FIG. 2; the light transmittance of the obtained chloroendomethylene tetrahydrophthalic anhydride / epoxide / carbon dioxide terpolymer is shown in FIG. 3; the TG curve of the obtained chloroendomethylene tetrahydrophthalic anhydride / epoxide / carbon dioxide terpolymer is shown in FIG. 4; and the barrier property parameters of the obtained chloroendomethylene tetrahydrophthalic anhydride / epoxide / carbon dioxide terpolymer are shown in Table 1. Figure 1 Figure 3 Figure 5 Figure 6

[0030] Example 2

[0031] In anhydrous and anaerobic environment, 2.5 g of chloroendomethylene tetrahydrophthalic anhydride, 16 g of propylene oxide, 14 mg of triethylamine, 200 μL of triethyl boron solution were sequentially added into a 50 mL autoclave, 1.0 MPa of carbon dioxide was filled, and the reaction was carried out at 60°C for 5 h. 2.5 g of chloroendomethylene tetrahydrophthalic anhydride in toluene was pumped into the reaction system by using a high-pressure pump, and the reaction was continued for 2 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved in dichloromethane, and the BAB triblock polymer was precipitated in ethanol. The polymer was vacuum dried and then subjected to molecular weight test, nuclear magnetic resonance, thermal performance and mechanical performance analysis. Mn = 56.2 kDa, PDI = 1.31; polyester content = 22.2%, polycarbonate content = 72.5%, polyether content = 5.3%; T g1 = 38°C, T g2 ​​​​= 37 °C, T = 100 °C; tensile strength 42 MPa, elongation at break 40%.

[0032] Example 3

[0033] In anhydrous and anaerobic environment, 3.9 g of pyromellitic anhydride, 16 g of propylene oxide, 80 mg of bis(triphenylphosphine)amine chloride, 140 μL of triethyl boron solution, were sequentially added into a 50 mL autoclave, 1.0 MPa of carbon dioxide was filled, and the reaction was carried out at 70 °C for 4 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved with dichloromethane, and the two-block polymers were precipitated in ethanol. After the polymers were vacuum dried, molecular weight test, nuclear magnetic resonance, thermal performance and mechanical performance analysis were carried out. Mn = 59.8 kDa, PDI = 1.28; polyester content 15.9%, polycarbonate content 77.9%, polyether content 6.2%; T g1 = 37 °C, T g2 = 100 °C; tensile strength 42 MPa, elongation at break 40%.

[0034] Example 4

[0035] In anhydrous and anaerobic environment, 5.1 g of pyromellitic anhydride, 16 g of propylene oxide, 40 mg of bis(triphenylphosphine)amine chloride, 100 μL of triethyl boron solution, were sequentially added into a 50 mL autoclave, 1.0 MPa of carbon dioxide was filled, and the reaction was carried out at 60 °C for 9 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved with dichloromethane, and the two-block polymers were precipitated in ethanol. After the polymers were vacuum dried, molecular weight test, nuclear magnetic resonance, thermal performance and mechanical performance analysis were carried out. Mn = 62.5 kDa, PDI = 1.28; polyester content 25.6%, polycarbonate content 70.5%, polyether content 3.9%; T g1 = 37 °C, T g2 = 100 °C; tensile strength 42 MPa, elongation at break 40%.

[0036] Example 5

[0037] In anhydrous and anaerobic environment, 5.9 g of pyromellitic anhydride, 16 g of propylene oxide, 84 mg of succinic acid tetrabutylamine, 150 μL of triethyl boron solution, were sequentially added into a 50 mL autoclave, 1.0 MPa of carbon dioxide was filled, and the reaction was carried out at 60 °C for 6 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved with dichloromethane, and the two-block polymers were precipitated in ethanol. After the polymers were vacuum dried, molecular weight test, nuclear magnetic resonance, thermal performance and mechanical performance analysis were carried out. Mn = 67.3 kDa, PDI = 1.28; polyester content 32.1%, polycarbonate content 63.9%, polyether content 4.0%; T g1 = 37 °C, T g2= 100 °C; tensile strength 48 MPa, elongation at break 15%.

[0038] Example 6

[0039] In anhydrous and anaerobic environment, 3.9 g of chloranil, 26 g of epichlorohydrin, 31 mg of tetra-n-butylammonium chloride, 200 μL of triethylboron solution were sequentially added into a 50 mL high-pressure reactor, 1.0 MPa of carbon dioxide was filled, and the reaction was carried out at 60 °C for 6 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved with dichloromethane, and the diblock polymer was precipitated in ethanol. After the polymer was vacuum dried, molecular weight test, nuclear magnetic resonance, thermal performance and mechanical property analysis were performed. Mn=65.7 kDa, PDI=1.69; polyester content 15.9%, polycarbonate content 75.3%, polyether content 2.2%; T g1 = 42 °C, T g2 = 106 °C; tensile strength 42 MPa, elongation at break 31%.

[0040] Example 7

[0041] In anhydrous and anaerobic environment, 4.5 g of chloranil, 20 g of butylene oxide, 80 mg of bis(triphenylphosphine)ammonium chloride, 200 μL of triethylboron solution were sequentially added into a 50 mL high-pressure reactor, 1.0 MPa of carbon dioxide was filled, and the reaction was carried out at 60 °C for 7 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved with dichloromethane, and the diblock polymer was precipitated in ethanol. After the polymer was vacuum dried, molecular weight test, nuclear magnetic resonance, thermal performance and mechanical property analysis were performed. Mn=70.8 kDa, PDI=1.69; polyester content 19.5%, polycarbonate content 79.3%, polyether content 1.2%; T g1 = 14 °C, T g2 = 80 °C; tensile strength 30 MPa, elongation at break 150%.

[0042] Comparative Example 1

[0043] In anhydrous and anaerobic environment, 8.2 g of phthalic anhydride (PA), 16 g of propylene oxide, 80 mg of bis(triphenylphosphine)ammonium chloride, 200 μL of triethylboron solution were sequentially added into a 50 mL high-pressure reactor, 1.0 MPa of carbon dioxide was filled, and the reaction was carried out at 65 °C for 8 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved with dichloromethane, and the random polymer was precipitated in ethanol. After the polymer was vacuum dried, molecular weight test, nuclear magnetic resonance, thermal performance and mechanical property analysis were performed. Mn=62.1 kDa, PDI=1.31; polyester content 33.1%, polycarbonate content 61.0%, polyether content 5.9%; T g= 45.6°C; tensile strength 36 MPa, elongation at break 8%. The1H NMR spectrum of the obtained phthalic anhydride / propylene oxide / carbon dioxide terpolymer (PPC-P) is shown in Figure 1; the DSC spectrum and the TG plot are shown in Figures 2 and 3, respectively. Figure 2 As can be seen from Comparative Example 1, the difference from Example 1 is that the phthalic anhydride is replaced by tetrachlorophthalic anhydride, and the strength and elongation at break, heat resistance, and barrier property (see Table 1) of the obtained polymer are all lower than those of Example 1. This is because the polyester segment of Example 1 contains chlorine, and the intermolecular force is strong, so it has better thermal stability and barrier property. In addition, the terpolymer obtained in Example 1 has a perfect block structure, with two glass transition temperatures, a high glass transition temperature of 100°C, which ensures the strength and heat deformation resistance of the material, and a low glass transition temperature, which endows the material with toughness. The polymer obtained in Comparative Example 1 has a random structure, only one glass transition temperature at 45.6°C, and is a brittle material at room temperature, and loses mechanical strength above 50°C. Figure 4 , Figure 6 Table 1 is the gas barrier property parameter of the tetrachlorophthalic anhydride / propylene oxide / carbon dioxide terblock copolymer obtained in Example 1 and the phthalic anhydride / propylene oxide / carbon dioxide terpolymer obtained in Comparative Example 1.

[0044] Table 1 is the gas barrier property parameter of the tetrachlorophthalic anhydride / propylene oxide / carbon dioxide terblock copolymer obtained in Example 1 and the phthalic anhydride / propylene oxide / carbon dioxide terpolymer obtained in Comparative Example 1.

[0045] Table 1

[0046]

[0047] Comparative Example 2:

[0048] In an anhydrous and anaerobic environment, 0.5Zn-Co DMC catalyst, 3.9 g of tetrachlorophthalic anhydride, 16 g of propylene oxide, were sequentially added into a 50 mL high-pressure reactor, 5.0 MPa of carbon dioxide was filled, and the reaction was carried out at 60°C for 10 h. After the reaction was completed, the carbon dioxide pressure was released, the product was dissolved in dichloromethane, and the polymer was precipitated in ethanol. After vacuum drying of the polymer, molecular weight test, nuclear magnetic, thermal performance and mechanical property analysis were carried out. Mn=5.8 kDa, PDI=1.89; polyester content 15.5%, polycarbonate content 76.7%, polyether content 7.8%; T g = 40°C. As can be seen from Comparative Example 2, the main difference from Example 1 is the catalyst, and the obtained polymer has too low molecular weight to be formed, and has no mechanical properties.

[0049] It can be seen that the carbon dioxide-based polyester-polycarbonate ter-block copolymer prepared by the application has two obvious glass transition temperatures compared to other carbon dioxide copolymers, the polyester segment glass transition temperature is as high as 80-106 DEG C, the polycarbonate segment glass transition temperature is between 14-40 DEG C, the phase-separated block structure endows the carbon dioxide copolymer with more excellent heat resistance and mechanical properties, and can expand the application field of the carbon dioxide copolymer.

Claims

1. A tricopolymer of chloranilic acid / epoxide / carbon dioxide, characterized by The two-block structure, ABA three-block structure or BAB three-block structure is shown in the following formula: The mole content of the polyester segment is 10%-40%, and the mole content of the polycarbonate segment is 90-60%; The three-block copolymer is prepared from tetrachlorophthalic anhydride, epoxide and carbon dioxide, and a two-component catalyst of organoboride and organic amine or organic ammonium salt.

2. The tris-block copolymer of chloranilic acid / epoxide / carbon dioxide according to claim 1, characterized in that The epoxide is propylene oxide, epichlorohydrin or butylene oxide.

3. A process for the preparation of the trilinear block copolymer of chloranilic acid / epoxide / carbon dioxide of claim 1, characterized in that The method comprises the following steps: (1) For the preparation of AB two-block copolymer and ABA three-block copolymer, a one-pot one-step method is adopted: the epoxide, tetrachlorophthalic anhydride and catalyst are added into a high-pressure reactor, carbon dioxide is introduced, and the polymerization reaction is carried out under heating, and after a period of reaction, the purified three-block copolymer is obtained by precipitation and drying; (2) For the preparation of BAB three-block copolymer, a one-pot two-step method is adopted: the epoxide, part of the tetrachlorophthalic anhydride and the catalyst are added into a high-pressure reactor, carbon dioxide is introduced, and the polymerization reaction is carried out under heating, and after a period of reaction, the remaining same amount of tetrachlorophthalic anhydride is added, and the reaction is continued for a period of time, and then the purified three-block copolymer is obtained by precipitation and drying.

4. The process for the preparation of a trilinear block copolymer of chloranilic acid / epoxide / carbon dioxide according to claim 3, characterized in that: The organic amine or organic ammonium salt is triethylamine, tributylamine, bis(triphenylphosphine)ammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium chloride, tetrabutylammonium terephthalate or 1,8-diazabicyclo[5.4.0]undec-7-ene.

5. The process for the preparation of a trilinear block copolymer of chloranilic acid / epoxide / carbon dioxide according to claim 4, characterized in that: The mole ratio of the epoxide to the tetrachlorophthalic anhydride is 10:1-40:1; the mole ratio of the tetrachlorophthalic anhydride to the organic amine or organic ammonium salt is 50:1-300:1; and the mole ratio of the organoboride to the organic amine or organic ammonium salt is 1.5:1-0.5:

1.

6. The process for the preparation of a trilinear block copolymer of chloranilic acid / epoxide / carbon dioxide according to claim 3, characterized in that The remaining tetrachlorophthalic anhydride in step (2) is pumped into by a high-pressure pump after dissolving the tetrachlorophthalic anhydride in toluene.

7. The process for the preparation of a trithiophenic anhydride / epoxide / carbon dioxide terpolymer according to claim 3, characterized in that: The temperature of the polymerization reaction is 50-70°C, the reaction pressure is 0.5-2 MPa, and the total reaction time is 4-10 hours.

8. The process for the preparation of a trithiophene / carbon dioxide / epoxide terpolymer according to claim 3, characterized in that: The organoboride is triethylboron.

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