Recyclable polyolefin polyester and method for preparing the same
By designing recyclable polyolefin-like polyesters with triblock or multiblock structures, the problem of inefficient recycling of polyolefin plastics has been solved, achieving high melting point, high tensile strength and complete chemical recyclability, and constructing a closed-loop circular material system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN UNIV OF TECH
- Filing Date
- 2026-04-29
- Publication Date
- 2026-07-07
AI Technical Summary
The chemical inertness of existing polyolefin plastics leads to large-scale accumulation pollution, and existing recycling methods are difficult to achieve efficient reuse, especially for recyclable materials that combine high melting point, high tensile strength, and complete chemical recyclability.
A class of recyclable polyolefin polyesters with triblock or multiblock structures was designed. Polymers with excellent thermal and mechanical properties were synthesized by using specific catalysts and controlling polymerization reactions. The polymers were then completely degraded into the initial monomers by pyrolysis or chemical depolymerization.
It achieves complete chemical recycling of polymers, with a monomer recovery rate of over 98%. The material has excellent upper limit temperature for use, tensile strength, and complete chemical recyclability. Its performance is adjustable and surpasses that of traditional polyolefin materials.
Smart Images
Figure CN122344313A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer materials technology and relates to a recyclable polyolefin polyester and its preparation method. Background Technology
[0002] Polyolefins are highly valued for their excellent heat resistance and good mechanical properties, accounting for more than 50% of global plastic production. However, their chemical inertness leads to the massive accumulation of plastic waste, causing significant pollution problems. Although physical recycling methods can treat some polyolefin plastic waste, the difficulty of separation and the complex chemical reactions involved in the separation process mean that only about 9% of polyolefins can be effectively recycled and reused. The large-scale use of polyolefin materials and the extremely low recycling rate have caused serious pollution problems, and the development of a new generation of recyclable polyolefin polyesters with fully chemically recyclable and biodegradable properties provides an important way to solve these problems.
[0003] Polyester derivatives have attracted much attention due to their biodegradability and reversibility. By controlling the thermodynamics and kinetics of their polymerization-depolymerization reactions, they can be efficiently reduced to polymer precursors, thereby achieving chemical recycling and reuse. Polyethylene-like materials containing polyester fragments can be generated through the condensation reaction of diesters and glycols. These materials can be depolymerized back to polymer precursors and used for repolymerization. Nature 2021, 590 , 423-427; Angew. Chem. Int. Ed. 2022, 135 ,e202213438; Angew. Chem. Int. Ed. 2023, 135 (e202310729). However, this method is limited by the high degree of matching of stoichiometry between the small condensation molecules. When a slight imbalance occurs, the molecular weight and physical properties of the polymer will drop sharply. Therefore, it is difficult to achieve a diverse range of polymer properties through this small molecule condensation method. In addition, recyclable polyesters with properties similar to polyolefin plastics can also be constructed through the ring-opening polymerization of lactones. For example, gem-dialkyl-substituted... d -Valactone (VL) R2 It not only boasts a high melting point of 123 °C and an elongation at break of 322%, but also achieves complete chemical cycling. Nat. Chem. 2022, 15 , 278-285). Besides designing monomer structures, stereoselective polymerization strategies can also harmonize the thermal and mechanical properties of polymers with their recyclability. Nat. Catal. 2023, 6(720-728), but its stereoselectivity control depends on specific catalysts, and it is difficult to simultaneously achieve both polymerization activity and high selectivity. Furthermore, copolymerizing lactone monomers with closed-ring recovery characteristics is also an effective way to obtain polyethylene-like polyesters with performance superior to their homopolymers. Dioxane and... (The sentence is incomplete and ends abruptly.) d Random copolyesters derived from caprolactone have been reported ( Macromolecules 2025, 58 (4183-4193). This material has a tensile strength of 25 MPa and an elongation at break of 246%, and can be completely chemically recycled. Although copolymerization lowers the melting point to below 100 °C, it still creates a new material system that combines high tensile strength with a relatively good melting point. Therefore, obtaining a recyclable polyolefin polyester material that combines high melting point (>100 °C), high tensile strength (>15 MPa), and complete chemical recyclability is a very challenging task. Summary of the Invention
[0004] The purpose of this invention is to disclose a class of polyolefin-like polyesters that can achieve chemical recycling. The polyolefin-like polyester material involved in this invention is a recyclable polymer whose polymer as a whole can be completely degraded into polymerization precursors through thermal or catalytic degradation, and this polyester material possesses excellent thermal and mechanical properties comparable to commercially available polyolefin materials.
[0005] The technical solution of this invention: A recyclable polyolefin polyester, with the following structural formula: In the formula, x, y, and z are 1 to 10. 6 Integers; When z=1, the recyclable polyolefin polyester is a triblock polyolefin polyester; When z>1, the recyclable polyolefin polyester is a multi-block polyolefin polyester; The structure of A is shown in equation (Ⅰ), and the structure of B is shown in equation (Ⅱ): Equation (I) Equation (II) In formula (II), R 1 It is an alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 12 carbon atoms, or an alkenyl group with 2 to 20 carbon atoms; The structure of C is one of the structures shown in equation (Ⅲ): ; Formula (III) In formula (Ⅲ), R 2The corresponding C is selected from one of the structures shown in (Ⅳ): ; Equation (Ⅳ) In equation (Ⅳ), R 5 The alkyl group is selected from 1 to 20 carbon atoms, m is selected from 1 to 3 integers, and n is selected from 1 to 3 integers; In formula (Ⅲ), R 3 The corresponding C is selected from one of the structures shown in (V): ; Formula (V) In formula (Ⅲ), R 4 The corresponding C is the structure shown in (VI): .
[0006] Formula (VI) A method for preparing a recyclable polyolefin polyester, comprising the following steps: Synthesis of triblock polyolefin polyesters: The polymerization reaction was carried out in a glove box filled with an inert atmosphere; first, monomer M and initiator were dissolved in solvent S1, followed by rapid addition of catalyst to initiate the reaction; through 1 After confirming the polymerization reaction had reached equilibrium by ¹H NMR, a solution of monomeric N in S²⁻ was added. After the reaction reached equilibrium a second time, water or an acidic substance was added to terminate the polymerization reaction. Subsequently, the polymerization was... 1 The monomer conversion data were obtained by H NMR analysis; the terminated mixture was poured into cold methanol under vigorous stirring to precipitate, filtered and washed with cold methanol to remove unreacted monomers and residual catalyst, and then the obtained polymer was dried in a vacuum oven at 50 °C to constant weight, finally yielding a triblock polyolefin polyester.
[0007] Synthesis of multi-block polyolefin polyesters: After the second equilibrium was reached during the synthesis of tri-block polyolefin polyesters, the reaction system was diluted by half with toluene, and diphenyl phosphate (DPP, equivalent to the catalyst) was added to neutralize the catalyst. The mixture was then equilibrated at 50 °C for 20 min in an oil bath. Subsequently, stannous octoate (Sn(Oct)2, 0.2 equivalents relative to the initiator) and isocyanate I (1.1 equivalents relative to the initiator) were added. The reaction was continued at 50 °C for 1 h for stepwise growth polymerization. The resulting mixture was diluted by half with dichloromethane, poured into cold methanol to precipitate and remove unreacted monomers and residual catalyst. The resulting polymer was then filtered and dried to constant weight in a vacuum oven at 50 °C to finally obtain the multi-block polyolefin polyester.
[0008] The structure of monomer M is shown in equation (VII), and the structure of monomer N is shown in equation (VIII): Formula (VII) Formula (VIII) The initiator is one or more of the structures shown in (VIII): ; Formula (VIII) The catalysts used include, but are not limited to, one of the structures shown in (IX). Any metal catalyst, organic catalyst, or inorganic catalyst with similar catalytic activity or structure can be used for the synthesis of the polyolefin polyesters shown in this invention. ; Formula (IX) The reaction temperature range for the entire process of synthesizing triblock polyolefin polyester is -70 ~ 80 ℃, and the reaction pressure is 1 ~ 10 atmospheres; the concentration range of monomer M is 0.1 ~ 10 mol / L, the concentration range of monomer N is 0.1 ~ 10 mol / L, the ratio of the amount of catalyst to the sum of the amounts of monomer M and monomer N is 1:5 ~ 1:1000000, the molar ratio of monomer M to monomer N is 1:1000 ~ 1000:1, and the molar ratio of initiator to catalyst is 1:1000 ~ 1000:1.
[0009] When water or acidic substances are added to terminate the polymerization reaction, the amount of water or acidic substances added is 1 to 10 times the equivalent of the catalyst.
[0010] Furthermore, acidic substances include one or more combinations of acetic acid, benzoic acid, hydrochloric acid, sulfuric acid, and phosphoric acid.
[0011] Solvent S1 includes one or more of the following: benzene, toluene, ethylbenzene, hexane, heptane, octane, tetrahydrofuran, diethyl ether, petroleum ether, chloroform, dichloromethane, and N,N-dimethylformamide.
[0012] Furthermore, solvent S2 includes one or more of benzene, toluene, ethylbenzene, tetrahydrofuran, chloroform, dichloromethane, and N,N-dimethylformamide.
[0013] The temperature range for cold methanol is -30 ~ 0 ℃.
[0014] Wherein, isocyanate I is one or more of the structures shown in (X): ; Formula (X) A chemical recycling method for recyclable polyolefin polyesters, comprising: Thermal depolymerization involves heating recyclable polyolefin polyesters directly at 200-350 °C and obtaining monomers as shown in formulas (VII) and (VIII) through atmospheric distillation, vacuum sublimation, or vacuum distillation.
[0015] Chemical depolymerization involves mixing a recyclable polyolefin polyester with an acidic catalyst, followed by heating at 50–250 °C, and obtaining monomers as shown in (VII) and (VIII) by atmospheric distillation, vacuum sublimation, or vacuum distillation.
[0016] Formula (VII) Formula (VIII) Furthermore, the acidic catalyst is one or a combination of two or more of zinc chloride, ferrous chloride, ferric chloride, zinc acetate, stannous octoate, and phosphomolybdic acid.
[0017] The beneficial effects of this invention are as follows: The polyolefin-like polyester of this invention can be degraded into initial polymerizable monomers through thermal and chemical degradation methods, with a monomer recovery rate greater than 98%. Simultaneously, the polyolefin-like polyesters of this invention all possess good upper limit operating temperature (melting point > 100 ℃), excellent mechanical properties (tensile strength > 15 MPa), and complete chemical recyclability. Furthermore, the mechanical properties of the resulting recyclable polymer can be effectively adjusted by changing the ratio of the two monomers, achieving the successful preparation of recyclable polyester materials with properties similar to or exceeding those of commercially available polyolefin thermoplastic elastomers and commercially available polyolefin plastics, thus constructing a complete closed-loop cycle of "monomer-polymer-monomer". Attached Figure Description
[0018] Figure 1 The image shows the two monomers recovered from the triblock polyolefin polyester in Example 10 of this invention through thermal degradation, and their comparison with the polymer and the initial monomer using nuclear magnetic resonance imaging. Figure 2 The image shows the two monomers recovered from the multi-block polyolefin polyester in Example 14 of this invention through chemical degradation, and their comparison with the polymer and the initial monomer using nuclear magnetic resonance imaging. Figure 3 The mechanical property test diagrams are shown for comparing the triblock polyolefin polyesters in Examples 1, 5, 9, 10, 11, 12 and 13 of this invention with SBS and LDPE.
[0019] Figure 4 The mechanical property test diagrams are comparisons between multi-block polyolefin polyesters and LDPE in Examples 14, 23, 24 and 25 of this invention. Detailed Implementation
[0020] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.
[0021] Example 1 The polymerization reaction was carried out at 20 °C in a glove box filled with an inert atmosphere, using a 20 mL serum bottle that had been dried in an oven. First, 3 mmol of monomer was weighed... α -methyl- d -Velolactone and 0.01 mmol of the initiator 1,4-terephthalic acid were dissolved in 1 ml of toluene, followed by the rapid addition of 0.02 mmol of catalyst Mg1 to initiate the reaction. 1 After confirming that the polymerization reaction had reached equilibrium by 1H NMR, 7 mmol was added. α , α -Spirocyclohexyl- d - A 5 mol / L toluene solution of valproic acid was prepared. After the predetermined reaction time was reached, a certain amount of benzoic acid / CDCl3 solution (10 mg / mL) was immediately added to terminate the reaction, followed by... 1 Monomer conversion data were obtained by ¹H NMR analysis. The terminated mixture was poured into cold methanol at -30 °C with stirring to precipitate the product. After filtration and washing with cold methanol at -30 °C to remove unreacted monomers, the product was finally dried to constant weight in a vacuum oven at 50 °C. 1.2 g of a white solid triblock polyolefin polyester was obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.66. The average molecular weight of the polymer determined by gel permeation chromatography is 143 kg / mol, the molecular weight distribution is 1.56, the melting point is 129 ℃ and the glass transition temperature is -52 ℃, and the tensile strength is 20.9 MPa.
[0022] Example 2 The polymerization reaction was carried out at 20 °C in a glove box filled with an inert atmosphere, using a 20 mL serum bottle that had been dried in an oven. First, 3 mmol of monomer was weighed... α -Eicosyl- d -Velolactone and 0.01 mmol of the initiator 1,4-terephthalic acid were dissolved in 1 ml of toluene, followed by the rapid addition of 0.02 mmol of catalyst Mg1 to initiate the reaction. 1 After confirming that the polymerization reaction had reached equilibrium by 1H NMR, 7 mmol was added. α , α -Spirocyclohexyl- d- A 5 mol / L toluene solution of valproic acid was prepared. After the predetermined reaction time was reached, a certain amount of benzoic acid / CDCl3 solution (10 mg / mL) was immediately added to terminate the reaction, followed by... 1 Monomer conversion data were obtained by HNMR analysis. The terminated mixture was poured into cold methanol at -30 °C with stirring to precipitate the product. After filtration and washing with cold methanol at -30 °C to remove unreacted monomers, the product was finally dried to constant weight in a vacuum oven at 50 °C. 1.3 g of a white solid triblock polyolefin polyester was obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.68. The average molecular weight of the polymer determined by gel permeation chromatography is 153 kg / mol, the molecular weight distribution is 1.55, the melting point is 130 °C, the glass transition temperature is -53 °C, and the tensile strength is 20.1 MPa.
[0023] Example 3 The polymerization reaction was carried out at 20 °C in a glove box filled with an inert atmosphere, using a 20 mL serum bottle that had been dried in an oven. First, 3 mmol of monomer was weighed... α -phenyl- d -Velolactone and 0.01 mmol of the initiator 1,4-terephthalic acid were dissolved in 1 ml of toluene, followed by the rapid addition of 0.02 mmol of catalyst Mg1 to initiate the reaction. 1 After confirming that the polymerization reaction had reached equilibrium by 1H NMR, 7 mmol was added. α , α -Spirocyclohexyl- d - A 5 mol / L toluene solution of valproic acid was prepared. After the predetermined reaction time was reached, a certain amount of benzoic acid / CDCl3 solution (10 mg / mL) was immediately added to terminate the reaction, followed by... 1 Monomer conversion data were obtained by ¹H NMR analysis. The terminated mixture was poured into cold methanol at -30 °C with stirring to precipitate the product. After filtration and washing with cold methanol at -30 °C to remove unreacted monomers, the product was finally dried to constant weight in a vacuum oven at 50 °C. 1.2 g of a white solid triblock polyolefin polyester was obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- dThe molar content of valproic acid is 0.70. The average molecular weight of the polymer determined by gel permeation chromatography is 165 kg / mol, the molecular weight distribution is 1.63, the melting point is 131 °C, the glass transition temperature is -52 °C, and the tensile strength is 22.2 MPa.
[0024] Example 4 The polymerization reaction was carried out at 20 °C in a glove box filled with an inert atmosphere, using a 20 mL serum bottle that had been dried in an oven. First, 3 mmol of monomer was weighed... α -allyl- d -Velolactone and 0.01 mmol of the initiator 1,4-terephthalic acid were dissolved in 1 ml of toluene, followed by the rapid addition of 0.02 mmol of catalyst Mg1 to initiate the reaction. 1 After confirming that the polymerization reaction had reached equilibrium by 1H NMR, 7 mmol was added. α , α -Spirocyclohexyl- d - A 5 mol / L toluene solution of valproic acid was prepared. After the predetermined reaction time was reached, a certain amount of benzoic acid / CDCl3 solution (10 mg / mL) was immediately added to terminate the reaction, followed by... 1 Monomer conversion data were obtained by ¹H NMR analysis. The terminated mixture was poured into cold methanol at -30 °C with stirring to precipitate the product. After filtration and washing with cold methanol at -30 °C to remove unreacted monomers, the product was finally dried to constant weight in a vacuum oven at 50 °C. 1.2 g of a white solid triblock polyolefin polyester was obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.68. The average molecular weight of the polymer determined by gel permeation chromatography is 155 kg / mol, the molecular weight distribution is 1.53, the melting point is 128 ℃ and the glass transition temperature is -53 ℃, and the tensile strength is 21.2 MPa.
[0025] Example 5 Using the same experimental apparatus and conditions as in Example 1, except the reaction temperature was lowered to -10 °C, 1.0 g of a white solid triblock polyolefin polyester was finally obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- dThe molar content of valproic acid is 0.58. The average molecular weight of the polymer determined by gel permeation chromatography is 134 kg / mol, the molecular weight distribution is 1.35, the melting point is 126 ℃ and the glass transition temperature is -49 ℃, and the tensile strength is 23.7 MPa.
[0026] Example 6 Using the same experimental apparatus and conditions as in Example 1, except that all reaction solvents were replaced with tetrahydrofuran, 1.3 g of a white solid triblock polyolefin polyester was finally obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid was 0.70. The average molecular weight of the polymer was determined to be 153 kg / mol by gel permeation chromatography, and the molecular weight distribution was 1.36. DSC test showed that its melting point was 131 ℃ and its glass transition temperature was -53 ℃. Mechanical property test showed that its tensile strength was 21.3 MPa.
[0027] Example 7 Using the same experimental apparatus and conditions as in Example 1, except that the initiator was replaced with ethylene glycol, 1.0 g of a white solid triblock polyolefin polyester was finally obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.65. The average molecular weight of the polymer determined by gel permeation chromatography is 113 kg / mol, the molecular weight distribution is 1.76, the melting point is 128 °C, the glass transition temperature is -51 °C, and the tensile strength is 19.8 MPa.
[0028] Example 8 Using the same experimental apparatus and under the same conditions as in Example 1, only the catalyst was changed to t Bu-P4. Finally, 1.2 g of a white solid triblock polyolefin polyester was obtained, which was then processed... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.69. The average molecular weight of the polymer determined by gel permeation chromatography is 123 kg / mol, and the molecular weight distribution is 1.69. DSC test shows that its melting point is 119 ℃, glass transition temperature is -49 ℃, and mechanical property test shows that its tensile strength is 18.8 MPa.
[0029] Example 9 Using the same experimental apparatus and under the same conditions as in Example 1, only... α , α -Spirocyclohexyl- d -Velolactone was replaced with 4 mmol. The final product was 0.8 g of a white solid triblock polyolefin polyester, obtained by... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.53. The average molecular weight of the polymer, determined by gel permeation chromatography, is 102 kg / mol, with a molecular weight distribution of 1.33. DSC testing shows that its melting point is 127 ℃, its glass transition temperature is -46 ℃, and mechanical property testing shows that its tensile strength is 24.9 MPa.
[0030] Example 10 Using the same experimental equipment and under the same conditions as in Example 1, only the monomer was changed. α -methyl- d The amount of β-valproic acid was 6 mmol. α , α -Spirocyclohexyl- d The amount of valproic acid lactone was 5 mmol. The final product was 1.3 g of a white solid triblock polyolefin polyester, obtained by... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.38. The average molecular weight of the polymer determined by gel permeation chromatography is 163 kg / mol, the molecular weight distribution is 1.21, the melting point is 124 ℃ and the glass transition temperature is -48 ℃, and the tensile strength is 25.0 MPa.
[0031] Example 11 Using the same experimental equipment and under the same conditions as in Example 1, only the monomer was changed. α -methyl- d The amount of β-valproic acid was 6 mmol. α , α -Spirocyclohexyl- d The amount of valproic acid was 4 mmol. A final product of 1.2 g was obtained as a white solid triblock polyolefin polyester, which was then analyzed by... 1 H NMR determination of polymers α , α -Spirocyclohexyl- dThe molar content of valproic acid is 0.34. The average molecular weight of the polymer determined by gel permeation chromatography is 132 kg / mol, the molecular weight distribution is 1.44, the melting point is 119 ℃ and the glass transition temperature is -49 ℃, and the tensile strength is 22.2 MPa.
[0032] Example 12 Using the same experimental equipment and under the same conditions as in Example 1, only the monomer was changed. α -methyl- d The amount of β-valproic acid was 6 mmol. α , α -Spirocyclohexyl- d The amount of β-valerol was 3 mmol. A final product of 1.1 g was obtained as a white solid triblock polyolefin polyester, which was then analyzed by... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid was 0.32. The average molecular weight of the polymer was determined to be 109 kg / mol by gel permeation chromatography, and the molecular weight distribution was 1.22. DSC test showed that its melting point was 122 ℃ and its glass transition temperature was -47 ℃. Mechanical property test showed that its tensile strength was 14.8 MPa.
[0033] Example 13 Using the same experimental equipment and under the same conditions as in Example 1, only the monomer was changed. α -methyl- d The amount of β-valproic acid was 1 mmol. α , α -Spirocyclohexyl- d The amount of valproic acid was 5 mmol. The final product was 0.8 g of a white solid triblock polyolefin polyester, obtained by... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid was 0.81. The average molecular weight of the polymer was determined to be 75.6 kg / mol by gel permeation chromatography, and the molecular weight distribution was 1.56. DSC test showed that its melting point was 134 ℃, and mechanical property test showed that its tensile strength was 29.4 MPa.
[0034] Example 14 The polymerization reaction was carried out at 20 °C in a glove box filled with an inert atmosphere, using a 20 mL serum bottle that had been dried in an oven. First, 3 mmol of monomer was weighed... α -methyl- d-Velolactone and 0.1 mmol of the initiator 1,4-terephthalic acid were dissolved in 1 ml of toluene, followed by the rapid addition of 0.2 mmol of catalyst Mg1 to initiate the reaction. 1 After confirming that the polymerization reaction had reached equilibrium by 1H NMR, 7 mmol was added. α , α -Spirocyclohexyl- d A 5 mol / L toluene solution of valproic acid was prepared. After the reaction reached the predetermined time, a multi-block copolymer precursor was obtained. The system was then diluted by half with toluene, and diphenyl phosphate (DPP, 0.2 mmol) was added to the serum vial to neutralize Mg1. The reactor was immersed in an oil bath and equilibrated at 50 °C for 20 min. Stannous octoate (Sn(Oct)2, 0.02 mmol) and 4,4'-methylene diphenyl diisocyanate (MDI, 0.11 mmol) were then added. The reaction was continued at 50 °C for 1 h for stepwise growth polymerization. The resulting mixture was diluted by half with dichloromethane and then poured into cold methanol at -30 °C to precipitate and remove unreacted monomers and residual catalyst. Finally, the obtained polymer was filtered and dried to constant weight in a vacuum oven at 50 °C. 1.2 g of a white solid multi-block polyolefin polyester was obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.67. The average molecular weight of the polymer determined by gel permeation chromatography is 246 kg / mol, and the molecular weight distribution is 2.37. DSC test shows that its melting point is 110 ℃, glass transition temperature is -36 ℃, and mechanical property test shows that its tensile strength is 19.8 MPa.
[0035] Example 15 Using the same experimental apparatus and under the same conditions as in Example 14, only the reaction monomers were... α -methyl- d -Velolactone replaced with α -Ethyl- d -Velolactone. The final product was 1.3 g of a white solid multi-block polyolefin polyester, obtained through... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid was 0.69. The average molecular weight of the polymer was determined to be 266 kg / mol by gel permeation chromatography, with a molecular weight distribution of 2.27. DSC test showed that its melting point was 111 ℃ and its glass transition temperature was -35 ℃. Mechanical property test showed that its tensile strength was 20.6 MPa.
[0036] Example 16 Using the same experimental apparatus and under the same conditions as in Example 14, only the reaction monomers were... α -methyl- d -Velolactone replaced with α -pentyl- d -Velolactone. The final product was 1.4 g of a white solid multi-block polyolefin polyester, obtained through... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid was 0.68. The average molecular weight of the polymer was determined to be 261 kg / mol by gel permeation chromatography, with a molecular weight distribution of 2.33. DSC test showed that its melting point was 113 ℃ and its glass transition temperature was -33 ℃. Mechanical property test showed that its tensile strength was 21.2 MPa.
[0037] Example 17 Using the same experimental apparatus and under the same conditions as in Example 14, only the reaction monomers were... α -methyl- d -Velolactone replaced with α -phenyl- d -Velolactone. The final product was 1.4 g of a white solid multi-block polyolefin polyester, obtained through... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid was 0.70. The average molecular weight of the polymer was determined to be 267 kg / mol by gel permeation chromatography, with a molecular weight distribution of 2.53. DSC test showed that its melting point was 115 ℃ and its glass transition temperature was -28 ℃. Mechanical property test showed that its tensile strength was 22.4 MPa.
[0038] Example 18 Using the same experimental apparatus and under the same conditions as in Example 14, only the reaction monomers were... α -methyl- d -Velolactone replaced with α -allyl- d -Velolactone. The final product was 1.2 g of a white solid multi-block polyolefin polyester, obtained through... 1 H NMR determination of polymers α , α -Spirocyclohexyl- dThe molar content of valproic acid was 0.68. The average molecular weight of the polymer was determined to be 247 kg / mol by gel permeation chromatography, with a molecular weight distribution of 2.42. DSC test showed that its melting point was 105 ℃ and its glass transition temperature was -33 ℃. Mechanical property test showed that its tensile strength was 19.4 MPa.
[0039] Example 19 Using the same experimental apparatus and conditions as in Example 14, except that the initiator was replaced with pentaerythritol, 1.1 g of a white solid multi-block polyolefin polyester was finally obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.66. The average molecular weight of the polymer determined by gel permeation chromatography is 275 kg / mol, the molecular weight distribution is 2.53, the melting point is 101 °C, the glass transition temperature is -36 °C, and the tensile strength is 21.0 MPa.
[0040] Example 20 Using the same experimental apparatus and conditions as in Example 14, except that all reaction solvents were replaced with tetrahydrofuran, 1.2 g of a white solid multi-block polyolefin polyester was finally obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.68. The average molecular weight of the polymer determined by gel permeation chromatography is 245 kg / mol, the molecular weight distribution is 2.62, the melting point is 103 °C, the glass transition temperature is -34 °C, and the tensile strength is 20.2 MPa.
[0041] Example 21 Using the same experimental apparatus and under the same conditions as in Example 14, only the catalyst was changed to t Bu-P4. Finally, 1.2 g of a white solid multi-block polyolefin polyester was obtained, which was then processed... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.68. The average molecular weight of the polymer determined by gel permeation chromatography is 235 kg / mol, the molecular weight distribution is 2.52, the melting point is 103 °C, the glass transition temperature is -33 °C, and the tensile strength is 19.8 MPa.
[0042] Example 22 Using the same experimental apparatus and conditions as in Example 14, except that 4,4'-methylene diphenyl diisocyanate was replaced with toluene diisocyanate, 1.1 g of a white solid multi-block polyolefin polyester was finally obtained. 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.68. The average molecular weight of the polymer determined by gel permeation chromatography is 202 kg / mol, the molecular weight distribution is 2.62, the melting point is 107 °C, the glass transition temperature is -35 °C, and the tensile strength is 19.5 MPa.
[0043] Example 23 Using the same experimental apparatus and under the same conditions as in Example 14, only... α -methyl- d The amount of valproic acid becomes 4 mmol. α , α -Spirocyclohexyl- d The amount of valproic acid lactone became 6 mmol. A final product of 1.2 g was obtained as a white solid multi-block polyolefin polyester, which was then processed... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid is 0.59. The average molecular weight of the polymer determined by gel permeation chromatography is 270 kg / mol, the molecular weight distribution is 2.17, the melting point is 106 °C, the glass transition temperature is -30 °C, and the tensile strength is 17.4 MPa.
[0044] Example 24 Using the same experimental apparatus and under the same conditions as in Example 14, only... α -methyl- d The amount of valproic acid becomes 5 mmol. α , α -Spirocyclohexyl- d The amount of valproic acid lactone was reduced to 5 mmol. A final product of 1.1 g was obtained as a white solid multi-block polyolefin polyester. 1 H NMR determination of polymers α , α -Spirocyclohexyl- dThe molar content of valproic acid is 0.50. The average molecular weight of the polymer determined by gel permeation chromatography is 199 kg / mol, the molecular weight distribution is 2.43, the melting point is 96 ℃ and the glass transition temperature is -27 ℃, and the tensile strength is 18.3 MPa.
[0045] Example 25 Using the same experimental apparatus and under the same conditions as in Example 14, only... α -methyl- d The amount of valproic acid becomes 2 mmol. α , α -Spirocyclohexyl- d The amount of valproic acid lactone became 8 mmol. Finally, 1.3 g of a white solid multi-block polyolefin polyester was obtained, which was then processed... 1 H NMR determination of polymers α , α -Spirocyclohexyl- d The molar content of valproic acid was 0.76. The average molecular weight of the polymer was determined to be 285 kg / mol by gel permeation chromatography, with a molecular weight distribution of 2.47. DSC test showed that its melting point was 113 ℃ and its glass transition temperature was -7 ℃. Mechanical property test showed that its tensile strength was 17.5 MPa.
[0046] Example 26 1g of the polyolefin-like polyester obtained in Example 2 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 280 °C. After 3 hours, the autoclave was removed to obtain the desired product. α -Eicosyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.98 g of a mixture of monomers containing valproic acid. Gas chromatography determined the purity of all monomers to be greater than 99%.
[0047] Example 27 1g of the polyolefin-like polyester obtained in Example 3 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 280 °C. After 3 hours, the autoclave was removed to obtain... α -phenyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.99 g of a mixture of monomers containing valproic acid. Gas chromatography determined the purity of all monomers to be greater than 99%.
[0048] Example 28 1g of the polyolefin-like polyester obtained in Example 4 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 280 °C. After 3 hours, the autoclave was removed to obtain the desired product.α -allyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.97 g of a mixture of valproic acid monomers. Gas chromatography analysis determined the purity of all monomers to be greater than 99%.
[0049] Example 29 1g of the polyolefin-like polyester obtained in Example 10 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 260°C. After 3 hours, the autoclave was removed to obtain the desired product. α -methyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.99 g of a mixture of monomers containing valproic acid. Gas chromatography determined the purity of all monomers to be greater than 99%. Figure 1 The image shows the two monomers recovered from the triblock polyolefin polyester in Example 10 of the present invention through thermal degradation, and their NMR comparison with the polymer and the initial monomer.
[0050] Example 30 1g of the polyolefin-like polyester obtained in Example 14 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 290 °C. After 6 hours, the autoclave was removed to obtain the desired product. α -methyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.99 g of a mixture of monomers containing valproic acid. Gas chromatography determined the purity of all monomers to be greater than 99%.
[0051] Example 31 1g of the polyolefin-like polyester obtained in Example 15 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 290°C. After 6 hours, the autoclave was removed to obtain the desired product. α -Ethyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.99 g of a mixture of monomers containing valproic acid. Gas chromatography determined the purity of all monomers to be greater than 99%.
[0052] Example 32 1g of the polyolefin-like polyester obtained in Example 16 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 290 °C. After 6 hours, the autoclave was removed to obtain... α -pentyl- d -Velolactone and α , α -Spirocyclohexyl- d0.98 g of a mixture of monomers containing valproic acid. Gas chromatography determined the purity of all monomers to be greater than 99%.
[0053] Example 33 1g of the polyolefin-like polyester obtained in Example 17 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 320°C. After 6 hours, the autoclave was removed to obtain the desired product. α -phenyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.97 g of a mixture of monomers containing valproic acid. Gas chromatography determined the purity of all monomers to be greater than 99%.
[0054] Example 34 1g of the polyolefin-like polyester obtained in Example 18 was added to a stainless steel autoclave, which was then placed in a muffle furnace preheated to 320°C. After 6 hours, the autoclave was removed to obtain the desired product. α -allyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.99 g of a mixture of monomers containing valproic acid. Gas chromatography analysis determined the purity of all monomers to be greater than 99%.
[0055] Example 35 1 g of the polyolefin polyester obtained in Example 1 was added to a sublimator, followed by 10 mg of zinc chloride. The mixture was kept under vacuum of 0.06 Torr at 160 °C for 2 hours to obtain the desired product. α -methyl- d -Velolactone and α , α -Spirocyclohexyl- d - 0.99 g of a mixture of valproic acid monomers. Gas chromatography analysis determined the purity of all monomers to be greater than 99%.
[0056] Example 36 1 g of the polyolefin-like polyester obtained in Example 2 was added to a sublimator, followed by 10 mg of zinc chloride. The mixture was kept under vacuum of 0.06 Torr at 160 °C for 2 hours to obtain the desired product. α -Eicosyl- d -Velolactone and α , α -Spirocyclohexyl- d -Velolactone mixed monomers 0.98 g. Gas chromatography determined the purity to be greater than 99%.
[0057] Example 37 1 g of the polyolefin-like polyester obtained in Example 3 was added to a sublimator, along with 10 mg of zinc chloride. The temperature was maintained at 170 °C under a vacuum of 0.06 Torr for 2 hours to obtain the desired product.α -phenyl- d -Velolactone and α , α -Spirocyclohexyl- d - 0.99 g of a mixture of valproic acid monomers. Gas chromatography analysis determined the purity of all monomers to be greater than 99%.
[0058] Example 38 1 g of the polyolefin polyester obtained in Example 4 was added to a sublimator, followed by 10 mg of zinc chloride. The mixture was kept under vacuum of 0.06 Torr at 170 °C for 2 hours to obtain the desired product. α -allyl- d -Velolactone and α , α -Spirocyclohexyl- d -Velolactone mixed monomers 0.98 g. Gas chromatography determined the purity to be greater than 99%.
[0059] Example 39 1 g of the polyolefin-like polyester obtained in Example 14 was added to a sublimator, followed by 10 mg of zinc chloride. The mixture was kept under vacuum of 0.07 Torr at 160 °C for 6 hours to obtain the desired product. α -methyl- d -Velolactone and α , α -Spirocyclohexyl- d 0.99 g of a mixture of monomers containing valproic acid. Gas chromatography determined the purity of all monomers to be greater than 99%. Figure 2 The image shows the two monomers recovered from the multi-block polyolefin polyester in Example 14 of the present invention through chemical degradation, and their NMR comparison with the polymer and the initial monomer.
[0060] Example 40 1 g of the polyolefin-like polyester obtained in Example 16 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.06 Torr at 170 °C for 6 hours to obtain the desired product. α -pentyl- d -Velolactone and α , α -Spirocyclohexyl- d -Velolactone mixed monomers 0.98 g. Gas chromatography determined the purity to be greater than 99%.
[0061] Example 41 1 g of the polyolefin-like polyester obtained in Example 18 was added to a sublimator, along with 10 mg of zinc chloride. The mixture was kept under vacuum of 0.06 Torr at 170 °C for 6 hours to obtain the desired product. α -allyl- d -Velolactone and α ,α -Spirocyclohexyl- d - 0.99 g of a mixture of valproic acid monomers. Gas chromatography analysis determined the purity of all monomers to be greater than 99%.
Claims
1. A recyclable polyolefin polyester, characterized in that, The structural formula of this recyclable polyolefin polyester is: In the formula, x, y, and z are 1 to 10. 6 Integers; When z=1, the recyclable polyolefin polyester is a triblock polyolefin polyester; When z>1, the recyclable polyolefin polyester is a multi-block polyolefin polyester; The structure of A is shown in equation (Ⅰ), and the structure of B is shown in equation (Ⅱ): Equation (I) Equation (II) In formula (II), R 1 It is an alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 12 carbon atoms, or an alkenyl group with 2 to 20 carbon atoms; The structure of C is one of the structures shown in equation (Ⅲ): ； Formula (III) In formula (Ⅲ), R 2 The corresponding C is selected from one of the structures shown in (Ⅳ): ； Equation (Ⅳ) In equation (Ⅳ), R 5 The alkyl group is selected from 1 to 20 carbon atoms, m is selected from 1 to 3 integers, and n is selected from 1 to 3 integers; In formula (Ⅲ), R 3 The corresponding C is selected from one of the structures shown in (V): ； Formula (V) In formula (Ⅲ), R 4 The corresponding C is the structure shown in (VI): Formula (VI).
2. A method for preparing the recyclable polyolefin polyester according to claim 1, characterized in that, The steps are as follows: Synthesis of triblock polyolefin polyesters: The polymerization reaction was carried out in a glove box filled with an inert atmosphere; first, monomer M and initiator were dissolved in solvent S1, followed by rapid addition of catalyst to initiate the reaction; through 1 After H NMR confirms that the polymerization reaction has reached equilibrium, an S2 solution of monomer N is added; after the reaction reaches equilibrium for the second time, water or an acidic substance is added to terminate the polymerization reaction; the terminated mixture is poured into cold methanol under vigorous stirring to precipitate, filtered, and washed with cold methanol to remove unreacted monomers and residual catalyst, and then the obtained polymer is filtered and dried in a vacuum oven at 50 °C to constant weight to obtain a triblock polyolefin polyester. Synthesis of multi-block polyolefin polyester: After the second equilibrium was reached in the synthesis of tri-block polyolefin polyester, the reaction system was diluted by half with toluene, and diphenyl phosphate of equal amount to the catalyst was added to neutralize the catalyst; the reaction was equilibrated at 50 °C for 20 min in an oil bath; then stannous octoate of 0.2 equivalents relative to the initiator and isocyanate I of 1.1 equivalents relative to the initiator were added; the reaction was continued at 50 °C for 1 h for stepwise growth polymerization; the resulting mixture was diluted by half with dichloromethane, poured into cold methanol to precipitate and remove unreacted monomers and residual catalyst, and then the obtained polymer was filtered and dried to constant weight in a vacuum oven at 50 °C to obtain multi-block polyolefin polyester; The structure of monomer M is shown in equation (VII), and the structure of monomer N is shown in equation (VIII): Formula (VII) Formula (VIII) The initiator is one or more of the structures shown in (VIII): ； Formula (VIII).
3. The method for preparing recyclable polyolefin polyester according to claim 2, characterized in that, The catalyst includes one of the structures shown in (IX): ； Formula (IX) The reaction temperature range for the entire process of synthesizing triblock polyolefin polyesters is -70 ~ 80 ℃, and the reaction pressure is 1 ~ 10 atmospheres; the monomer M ranges from 0.1 ~ 10 mol / L, the monomer N concentration is 0.1 ~ 10 mol / L, the ratio of the amount of catalyst to the sum of the amounts of monomer M and monomer N is 1:5 ~ 1:1000000, the ratio of the amount of monomer M to monomer N is 1:1000 ~ 1000:1, and the ratio of the amount of initiator to catalyst is 1:1000 ~ 1000:
1.
4. The method for preparing recyclable polyolefin polyester according to claim 2, characterized in that, When water or acidic substances are added to terminate the polymerization reaction, the amount of water or acidic substances added is 1 to 10 times the equivalent of the catalyst.
5. The method for preparing recyclable polyolefin polyester according to claim 2, characterized in that, Acidic substances include one or more of acetic acid, benzoic acid, hydrochloric acid, sulfuric acid, and phosphoric acid.
6. The method for preparing recyclable polyolefin polyester according to claim 2, characterized in that, Solvent S1 includes one or more of the following: benzene, toluene, ethylbenzene, hexane, heptane, octane, tetrahydrofuran, diethyl ether, petroleum ether, chloroform, dichloromethane, and N,N-dimethylformamide. Solvent S2 includes one or more of benzene, toluene, ethylbenzene, tetrahydrofuran, chloroform, dichloromethane, and N,N-dimethylformamide.
7. The method for preparing recyclable polyolefin polyester according to claim 2, characterized in that, The temperature range for cold methanol is -30 ~ 0 ℃.
8. The method for preparing recyclable polyolefin polyester according to claim 2, characterized in that, Isocyanate I is one or more of the structures shown in (X): ； Formula (X).
9. A chemical recycling method for the recyclable polyolefin polyester of claim 1, characterized in that, include: Thermal depolymerization involves heating recyclable polyolefin polyesters directly at 200-350 °C and obtaining monomers as shown in (VII) and (VIII) by atmospheric distillation, vacuum sublimation, or vacuum distillation. Chemical depolymerization involves mixing a recyclable polyolefin polyester with an acidic catalyst, followed by heating at 50-250 °C, and obtaining monomers as shown in (Ⅶ) and (Ⅷ) by atmospheric distillation, vacuum sublimation, or vacuum distillation. Formula (VII) Formula (VIII).
10. The chemical recycling method according to claim 9, characterized in that, The acid catalyst is one or a combination of two or more of zinc chloride, ferrous chloride, ferric chloride, zinc acetate, stannous octoate, and phosphomolybdic acid.