Preparation and application of poly (lactone-b-olefin) block copolymer

Abstract

The invention discloses an efficient synthesis method for preparing a poly (lactone-b-olefin) block copolymer. According to the method, a guanidyl iron complex is adopted as a catalyst, a bifunctional initiator is utilized, lactide ring-opening polymerization and olefin atom transfer radical polymerization are synchronously achieved through a one-pot one-step method under the solvent-free condition, operation is easy, and complex aftertreatment is not needed. The obtained block copolymer is used as an interfacial compatibilizer, and can realize multi-dimensional improvement of mechanical strength, toughness, thermal stability and processing fluidity of a blended material. The high-performance polylactic acid-based composite material developed by the method has both practicability and environmental friendliness, and provides technical support for large-scale replacement of biodegradable plastic with traditional materials.

Description

Technical Field

[0001] The present invention relates to the technical field of biodegradable polymer material synthesis, and in particular to a method and application for preparing a poly(lactone-b-olefin) block copolymer with a well-defined structure in a "one-pot, one-step" manner based on an iron complex / bifunctional initiator catalytic system. Background Art

[0002] With the deepening global adoption of sustainable development, the research and development of biodegradable polymer materials has become a key approach to addressing traditional plastic pollution and promoting resource recycling. Polyester materials, particularly polylactic acid (PLA), are considered an ideal alternative to petroleum-based plastics due to their similar mechanical properties to traditional plastics and excellent biodegradability. However, single PLA homopolymers face performance bottlenecks in practical applications, such as high brittleness and poor thermal stability, which restrict their large-scale application. Consequently, blending and modification technologies are widely adopted, introducing general-purpose plastics such as polyolefins to enhance the overall performance of the material.

[0003] However, the polarity difference between polylactic acid and polyolefin leads to poor interfacial compatibility between the two phases, and severe phase separation is prone to occur during the blending process, causing degradation of mechanical properties and processing defects. For this reason, block copolymers are introduced into polylactic acid-based blending systems as an efficient blending compatibilizer. By designing block copolymers, their structural characteristics enable them to construct a stable bonding layer at the interface between polylactic acid and polyolefin, significantly reducing the interfacial energy and inhibiting phase separation. In addition, traditional synthesis processes are limited by complex process flows and are difficult to meet the needs of industrial applications. Therefore, the development of new block compatibilizers that have both efficient interface stabilization functions, wide processing adaptability and economical synthesis processes remains the key to breaking through the bottleneck of industrialization of polyester / polyolefin high-performance blends. Summary of the Invention

[0004] In view of this, the present invention provides a preparation method and application of a poly(lactone-b-olefin) block copolymer, characterized by comprising the following steps:

[0005] A lactone monomer, an olefin monomer and a solvent are mixed and added into a reactor, and a polymerization reaction is carried out in the presence of a catalyst and a bifunctional initiator to form the poly(lactone-b-olefin) block copolymer.

[0006] According to the present invention, the catalyst is selected from formula (I-1), formula (I-2), formula (I-3) or formula (I-4), and the structural formula is:

[0007]

[0008] Preferably, the catalyst is as shown in formula (I-3).

[0009] According to the present invention, the lactone monomer includes one or more of D,L-lactide, D-lactide, L-lactide, and ε-caprolactone.

[0010] Preferably, the lactone monomer is selected from D,L-lactide and ε-caprolactone.

[0011] According to the present invention, the olefin monomer includes one or more of styrene, 4-chloromethylstyrene, methyl methacrylate, hydroxyethyl methacrylate, lauryl methacrylate, isooctyl methacrylate, N,N-dimethylacrylamide, N-isopropylacrylamide, N-acryloylmorpholine, N-vinylpyrrolidone, 4-vinylpyridine, allyl glycidyl ether, and glycidyl methacrylate.

[0012] Preferably, the olefin monomer is selected from styrene, methyl methacrylate, N,N-dimethylacrylamide, N-isopropylacrylamide, N-acryloylmorpholine, lauryl methacrylate and isooctyl methacrylate.

[0013] According to the present invention, the bifunctional initiator includes one of 4-bromomethylbenzyl alcohol, 2-bromoethanol, 3-bromo-1-propanol, 1,3-diiodoisopropanol, 6-bromohexanol, 11-bromo-1-undecanol, 4-bromo-1-butanol, 2-bromo-2-methyl-1-propanol, and 2-bromocyclopentanol.

[0014] Preferably, the bifunctional initiator is selected from 4-bromomethylbenzyl alcohol.

[0015] According to the present invention, the polymerization reaction temperature is 100 to 210° C., the polymerization reaction time is 0.1 to 24 hours, the molar ratio of the lactone monomer to the olefin monomer is 1:0.5 to 1:10, the molar ratio of the catalyst to the lactone monomer is 1:50 to 1:1000, the molar ratio of the catalyst to the bifunctional initiator is 1:0.5 to 1:5, and the solvent is one of tetrahydrofuran, toluene, dichloromethane, ethyl acetate, and dimethyl sulfoxide or is not added.

[0016] Preferably, the polymerization reaction temperature is 130-150° C., the polymerization reaction time is 0.2-10 h, the molar ratio of lactone monomer to olefin monomer is 1:1-1:5, the molar ratio of catalyst to lactone monomer is 1:100-1:500, the molar ratio of catalyst to bifunctional initiator is 1:1-1:2, and no solvent is added.

[0017] According to the present invention, the poly(lactone-b-olefin) block copolymer has a number average molecular weight of 5 kg / mol-200 kg / mol and a molecular weight distribution of 1.2-2.0.

[0018] Preferably, the poly(lactone-b-olefin) block copolymer has a number average molecular weight of 10 kg / mol to 150 kg / mol and a molecular weight distribution of 1.3 to 1.9.

[0019] According to the present invention, the obtained poly(lactone-b-olefin) block copolymer can be used as an interfacial compatibilizer without complicated post-processing. With a small amount of addition, the mechanical strength, toughness, thermal stability and processing fluidity of the blended material can be improved in multiple dimensions.

[0020] According to the present invention, the block copolymer is added as an interfacial compatibilizer in an amount of 0.1 wt% to 5 wt%.

[0021] Preferably, the block copolymer is added in an amount of 2.0 wt% to 2.2 wt% as an interfacial compatibilizer.

[0022] According to the present invention, the blended material includes one or more of polylactide (also known as polylactic acid, PLA) / low-density polyethylene (LDPE), polylactide / linear low-density polyethylene, polylactide / high-density polyethylene (HDPE), polylactide / polyolefin elastomer, polylactide / polystyrene, polylactide / polymethyl methacrylate, polylactide / polyoctadecyl methacrylate, and polycaprolactone / high-density polyethylene.

[0023] Preferably, the blended material is selected from polylactide / linear low-density polyethylene, polylactide / high-density polyethylene, polylactide / polyolefin elastomer, polylactide / polystyrene, polylactide / polymethyl methacrylate, polylactide / polyoctadecyl methacrylate, and polycaprolactone / high-density polyethylene.

[0024] The beneficial effects of the present invention are:

[0025] The present invention provides an efficient synthesis method for preparing poly(lactone-b-olefin) block copolymers and their application. Using an iron complex / bifunctional initiator as a catalytic system, the ring-opening polymerization of lactones and the atom transfer radical polymerization of olefins are simultaneously achieved in a one-pot, one-step process under solvent-free conditions. Experimental results show that the catalytic system exhibits excellent polymerization efficiency: the monomer conversion rate can reach over 90% within 3 hours, and the molecular weight distribution index is It can be precisely controlled at around 1.5, achieving efficient regulation of the two-block structure.

[0026] The prepared block copolymer serves as a highly efficient interfacial compatibilizer. Its structural characteristics enable it to construct a stable bonding layer at the interface between polyester and polyolefin phases, significantly reducing the interfacial energy and inhibiting phase separation, thereby enhancing the comprehensive performance of polyester / polyolefin blends.

[0027] Taking a PLA / HDPE (40 / 60) blend as an example, adding the block copolymer prepared in this invention significantly increased the tensile strength of the composite material from 11 MPa to 25 MPa (a 127% increase), and the elongation at break also increased significantly from 14% to 115%, demonstrating a significant synergistic strengthening and toughening effect. The high-performance polylactic acid-based composite system constructed on this basis provides a theoretical breakthrough for the development of environmentally friendly materials that meet diverse application needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The ligand prepared in Example 1 of the present invention was analyzed by hydrogen nuclear magnetic resonance spectrum in CDCl3.

[0029] Figure 2 This is the infrared absorption spectrum of the ligand and catalyst prepared in Example 1 of the present invention.

[0030] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the poly(lactide-b-styrene) block copolymer prepared in Example 4 of the present invention in CDCl3.

[0031] Figure 4 Proton nuclear magnetic resonance spectrum of the poly(lactide-b-lauryl methacrylate) block copolymer prepared in Example 14 of the present invention in CDCl3. DETAILED DESCRIPTION

[0032] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content of the present invention being recorded, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the limited scope of the present invention equally.

[0033] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0034] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0035] Unless otherwise specified, the concentrations in the following examples are all molar concentrations.

[0036] The molecular weight and molecular weight distribution of the polymers obtained in the following copolymerization examples were determined by conventional room temperature GPC methods.

[0037] All synthesized compounds and polymers described below were confirmed by NMR.

[0038] Example 1: Preparation of Catalyst Formula (I-3)

[0039] Add (1R, 2R) cyclohexanediamine (30mmol), triethylamine (60mmol), and 60mL of acetonitrile to the flask in sequence, and then place the above mixture under zero-degree reaction conditions during stirring, and add 60mmol of 2-chloro-1,3-dimethylimidazoline chloride in acetonitrile (60mL) dropwise, heat to reflux and react overnight. After the reaction is completed, cool to room temperature, add sodium hydroxide (60mmol) to the above reaction solution, and distill under reduced pressure to remove the solvent. Add 30mL of a 50% mass fraction of potassium hydroxide aqueous solution to the obtained mixture, and extract three times with 50mL of acetonitrile respectively. Collect the obtained organic phase and dry it with anhydrous sodium sulfate. Then distill under reduced pressure to remove the solvent to obtain the ligand. The ligand 1 H-NMR Figure 1 As shown, the infrared absorption spectrum is Figure 2 shown.

[0040] Under heating conditions, the obtained ferrous chloride (1 mmol) was dissolved in 4 mL of tetrahydrofuran solution. Then, the heated tetrahydrofuran solution containing the ligand (1.2 mmol) was added to the above mixture to obtain a gray solid. Yield: 72%. The infrared absorption spectrum of the catalyst represented by formula (I-3) is shown as follows: Figure 2 shown.

[0041] Example 2: Preparation of blended strips

[0042] Taking polylactic acid and high-density polyethylene as an example, prepare the components according to the following proportions:

[0043] 40 parts by mass of polylactic acid

[0044] 60 parts by mass of high-density polyethylene

[0045] PLA and high-density polyethylene (HDPE) were blended in the aforementioned proportions in an internal mixer at 180°C and a rotor speed of 100 rpm for 10 minutes. The uniformly mixed sample was then transferred to a flat-plate vulcanizer and hot-pressed at 180°C to form a sheet of uniform thickness. After the sheet cooled to room temperature, tensile test specimens were punched out using a standard dumbbell cutter.

[0046] Example 3: Preparation of blended strips with added compatibilizer

[0047] Taking polylactic acid and high-density polyethylene as an example, prepare the components according to the following proportions:

[0048] 40 parts by mass of polylactic acid

[0049] 60 parts by mass of high-density polyethylene

[0050] 2 parts by mass of the prepared block copolymer

[0051] PLA, high-density polyethylene, and the prepared block copolymer were blended in the aforementioned proportions in an internal mixer at 180°C and a rotor speed of 100 rpm for 10 minutes. The uniformly mixed sample was then transferred to a flat-plate vulcanizer and hot-pressed at 180°C to form a sheet of uniform thickness. After the sheet cooled to room temperature, tensile test specimens were punched out using a standard dumbbell cutter.

[0052] Example 4: Preparation of block copolymer P1

[0053] The general reaction formula is shown below:

[0054]

[0055] Prepare the components in the following proportions:

[0056]

[0057] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and styrene were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above ratio, and stirred at 130°C for 1 hour. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0058] pass 1 The product obtained in Example 4 was detected by H-NMR. The results showed that the conversion rate of D, L-lactide was 87%, the conversion rate of styrene was 76%, and the product structure was shown in P1. The product after purification was 1 H-NMR Figure 3 As shown; the number average molecular weight of the prepared poly (lactide -b-styrene) block copolymer was measured by GPC to be 23.8 kg / mol, and the molecular weight distribution was 1.58.

[0059]

[0060] Example 5: Preparation of block copolymer P2

[0061] Prepare the components in the following proportions:

[0062]

[0063] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and styrene were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above proportions, and stirred at 130°C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0064] pass 1 The product obtained in Example 5 was analyzed by H-NMR. The results showed that the conversion rate of D,L-lactide was 96%, and the conversion rate of styrene was 91%. GPC analysis showed that the number average molecular weight of the prepared poly(lactide-b-styrene) block copolymer was 30.7 kg / mol, and the molecular weight distribution was 1.63.

[0065] Example 6: Preparation of block copolymer P3

[0066] Prepare the components in the following proportions:

[0067]

[0068] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and styrene were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above proportions, and stirred at 130°C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0069] pass 1 The product obtained in Example 6 was analyzed by H-NMR. The results showed that the conversion rate of D,L-lactide was 91%, and the conversion rate of styrene was 81%. GPC analysis showed that the number average molecular weight of the prepared poly(lactide-b-styrene) block copolymer was 50.4 kg / mol, and the molecular weight distribution was 1.64.

[0070] Example 7: Preparation of block copolymer P4

[0071] Prepare the components in the following proportions:

[0072]

[0073] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and styrene were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above proportions, and stirred at 130°C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0074] pass 1 The product obtained in Example 7 was analyzed by H-NMR. The results showed that the conversion of D,L-lactide was 79%, and the conversion of styrene was 70%. GPC analysis showed that the number average molecular weight of the prepared poly(lactide-b-styrene) block copolymer was 72.3 kg / mol, and the molecular weight distribution was 1.58.

[0075] Example 8: Preparation of block copolymer P5

[0076] Prepare the components in the following proportions:

[0077]

[0078] Under anhydrous and oxygen-free conditions, the catalyst shown in formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and styrene were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above proportions, and stirred at 130°C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0079] pass 1 The product obtained in Example 8 was analyzed by H-NMR. The results showed that the conversion rate of D,L-lactide was 85%, and the conversion rate of styrene was 96%. GPC analysis showed that the number average molecular weight of the prepared poly(lactide-b-styrene) block copolymer was 44.8 kg / mol, and the molecular weight distribution was 1.58.

[0080] Example 9: Preparation of block copolymer P6

[0081] Prepare the components in the following proportions:

[0082]

[0083] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and styrene were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above proportions, and stirred at 130°C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0084] pass 1The product obtained in Example 9 was analyzed by H-NMR. The results showed that the conversion of D,L-lactide was 97%, and the conversion of styrene was 61%. GPC analysis showed that the number average molecular weight of the prepared poly(lactide-styrene) block copolymer was 72.6 kg / mol, and the molecular weight distribution was 1.77.

[0085] Example 10: Preparation of block copolymer P7

[0086] Prepare the components in the following proportions:

[0087]

[0088] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and styrene were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above ratio, and stirred at 130°C for 5 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0089] pass 1 The product obtained in Example 10 was analyzed by H-NMR. The results showed that the conversion rate of D,L-lactide was 92%, and the conversion rate of styrene was 95%. GPC analysis showed that the number average molecular weight of the prepared poly(lactide-b-styrene) block copolymer was 96.4 kg / mol, and the molecular weight distribution was 1.62.

[0090] Example 11: Preparation of block copolymer P8

[0091] Prepare the components in the following proportions:

[0092]

[0093] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and N-acryloylmorpholine were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above ratio, and stirred at 130°C for 4 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0094] pass 1The product obtained in Example 11 was analyzed by H-NMR. The results showed that the conversion rate of D,L-lactide was 85%, the conversion rate of N-acryloylmorpholine was 65%, and the structure was shown in P8. GPC measurement showed that the number average molecular weight of the prepared poly(lactide-bN-acryloylmorpholine) was 28.3 kg / mol, and the molecular weight distribution was 1.57.

[0095]

[0096] Example 12: Preparation of block copolymer P9

[0097] Prepare the components in the following proportions:

[0098]

[0099] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and N-vinyl pyrrolidone were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above ratio, and stirred at 130°C for 6 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0100] pass 1 The product obtained in Example 12 was tested by H-NMR. The results showed that the conversion rate of D,L-lactide was 93%, the conversion rate of N-vinyl pyrrolidone was 37%, and the structure was shown in P9. GPC measured the number average molecular weight of the prepared poly(lactide-bN-vinyl pyrrolidone) to be 19.7 kg / mol, and the molecular weight distribution was 1.29.

[0101]

[0102] Example 13: Preparation of block copolymer P10

[0103] Prepare the components in the following proportions:

[0104]

[0105] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and N-isopropylacrylamide were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above ratio, and stirred at 130°C for 4 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0106] pass 1 The product obtained in Example 13 was analyzed by H-NMR. The results showed that the conversion rate of D,L-lactide was 89%, the conversion rate of N-isopropylacrylamide was 46%, and the structure was shown in P10. GPC measurement showed that the number average molecular weight of the prepared poly(lactide-bN-isopropylacrylamide) was 35.7 kg / mol, and the molecular weight distribution was 1.25.

[0107]

[0108] Example 14: Preparation of block copolymer P11

[0109] Prepare the components in the following proportions:

[0110]

[0111] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 10 mmol 4-bromomethylbenzyl alcohol, purified D, L-lactide, and lauryl methacrylate were added to a 1 L polymerization reaction bottle after dehydration and deoxygenation according to the above ratio, and stirred at 130 ° C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0112] pass 1 The product obtained in Example 14 was detected by H-NMR. The results showed that the conversion rate of D, L-lactide was 67%, the conversion rate of lauryl methacrylate was 95%, and the structure was shown in P11. The product after purification was 1 H-NMR Figure 4 As shown; the number average molecular weight of the prepared poly (lactide-b-lauryl methacrylate) was measured by GPC to be 125.7 kg / mol, and the molecular weight distribution was 1.47.

[0113]

[0114] Example 15: Preparation of block copolymer P12

[0115] Prepare the components in the following proportions:

[0116]

[0117] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and isooctyl methacrylate were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above proportions, and stirred at 130°C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0118] pass 1 The product obtained in Example 15 was tested by H-NMR. The results showed that the conversion rate of D,L-lactide was 59%, the conversion rate of isooctyl methacrylate was 97%, and the structure was shown in P12. GPC was used to measure the number average molecular weight of the prepared poly(lactide-b-isooctyl methacrylate) to be 131.4 kg / mol, and the molecular weight distribution was 1.52.

[0119]

[0120] Example 16: Preparation of block copolymer P13

[0121] Prepare the components in the following proportions:

[0122]

[0123] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified D,L-lactide, and methyl methacrylate were added to a 1L polymerization reaction bottle after dehydration and deoxygenation, and stirred at 130°C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0124] pass 1 The product obtained in Example 16 was tested by H-NMR. The results showed that the conversion rate of D,L-lactide was 82%, the conversion rate of methyl methacrylate was 86%, and the structure was shown in P13. GPC measurement showed that the number average molecular weight of the prepared poly(lactide-b-methyl methacrylate) was 51.7 kg / mol, and the molecular weight distribution was 1.56.

[0125]

[0126] Example 17: Preparation of block copolymer P14

[0127] Prepare the components in the following proportions:

[0128]

[0129] Under anhydrous and oxygen-free conditions, the catalyst represented by formula (I-3), 4-bromomethylbenzyl alcohol, purified ε-caprolactone, and styrene were added to a 1L polymerization reaction bottle after dehydration and deoxygenation according to the above ratio, and stirred at 130°C for 3 hours. After cooling to room temperature, the polymerization reaction bottle was opened and the first step was to take 1 The remaining sample was dissolved in a small amount of dichloromethane, and then precipitated by adding a large amount of ethanol, filtered, dried, and weighed.

[0130] pass 1 The product obtained in Example 17 was tested by H-NMR. The results showed that the conversion rate of ε-caprolactone was 87%, the conversion rate of styrene was 82%, and the structure was shown in P14. GPC was used to measure the number average molecular weight of the prepared poly(caprolactone-b-styrene) block copolymer to be 142.8 kg / mol, and the molecular weight distribution was 1.68.

[0131]

[0132] Example 18

[0133] Tensile properties of the prepared polylactide / low-density polyethylene (LDPE) blend and those incorporating 2 wt% of an interfacial compatibilizer were tested using a universal testing machine (UTM 4103) at room temperature at a constant rate of 30 mm / min. Each sample was tested at least three times to obtain reliable data. The interfacial compatibilizer used was block copolymer P5. The results showed that the addition of 2 wt% of the interfacial compatibilizer increased the tensile strength from 5 MPa to 12 MPa, while the elongation at break increased from 8% to 96%.

[0134] Example 19

[0135] Tensile properties of the prepared polylactide / linear low-density polyethylene (LLDPE) blend and those incorporating 2 wt% of an interfacial compatibilizer were tested using a universal testing machine (UTM 4103) at room temperature at a constant rate of 30 mm / min. Each sample was tested in triplicate to obtain reliable data. The interfacial compatibilizer used was block copolymer P5. The results showed that the addition of 2 wt% of the interfacial compatibilizer increased the tensile strength from 6 MPa to 15 MPa, while the elongation at break increased from 10% to 102%.

[0136] Example 20

[0137] Tensile properties of the prepared polylactide / high-density polyethylene (HDPE) blend and those incorporating 2 wt% of an interfacial compatibilizer were tested using a universal testing machine (UTM 4103) at room temperature at a constant rate of 30 mm / min. Each sample was tested at least three times to obtain reliable data. The interfacial compatibilizer used was block copolymer P5. The results showed that the addition of 2 wt% of the interfacial compatibilizer increased the tensile strength from 11 MPa to 25 MPa, while the elongation at break increased from 14% to 115%.

[0138] Example 21

[0139] Tensile properties of the prepared polylactide / polyolefin elastomer blends and those containing 2 wt% of an interfacial compatibilizer were tested using a universal testing machine (UTM 4103) at room temperature at a constant rate of 30 mm / min. Each sample was tested in triplicate to obtain reliable data. The interfacial compatibilizer used was block copolymer P5. The results showed that the addition of 2 wt% of the interfacial compatibilizer increased the tensile strength from 3 MPa to 13 MPa, while the elongation at break increased from 47% to 368%.

[0140] Example 22

[0141] Tensile properties of the prepared polylactide / polystyrene blend bars and bars containing 2 wt% of an interfacial compatibilizer were tested using a universal testing machine (UTM 4103) at room temperature at a constant rate of 30 mm / min. Each sample was tested in triplicate to obtain reliable data. The interfacial compatibilizer used was block copolymer P2. The results showed that the addition of 2 wt% of the interfacial compatibilizer increased the tensile strength from 11 MPa to 28 MPa, while the elongation at break increased from 5% to 82%.

[0142] Example 23

[0143] Tensile properties of the prepared polylactide / polymethyl methacrylate (PLMA) blends and those containing 2 wt% of an interfacial compatibilizer were tested using a universal testing machine (UTM 4103) at room temperature at a constant rate of 30 mm / min. Each sample was tested in triplicate to obtain reliable data. The interfacial compatibilizer used was the block copolymer P13. The results showed that the addition of 2 wt% of the interfacial compatibilizer increased the tensile strength from 18 MPa to 32 MPa, while the elongation at break increased from 4% to 67%.

[0144] Example 24

[0145] Tensile properties of the prepared blend (polylactide / polyoctadecyl methacrylate) and those incorporating 2 wt% of an interfacial compatibilizer were tested using a universal testing machine (UTM 4103) at room temperature at a constant rate of 30 mm / min. Each sample was tested in triplicate to obtain reliable data. The interfacial compatibilizer used was the block copolymer P13. The results showed that the addition of 2 wt% of the interfacial compatibilizer increased the tensile strength from 2 MPa to 10 MPa, while the elongation at break increased from 2% to 31%.

[0146] Example 25

[0147] Tensile properties of the prepared polycaprolactone / high-density polyethylene (HDPE) blend and those incorporating 2 wt% of an interfacial compatibilizer were tested using a universal testing machine (UTM 4103) at room temperature at a constant rate of 30 mm / min. Each sample was tested in triplicate to obtain reliable data. The interfacial compatibilizer used was the block copolymer P14. The results showed that the addition of 2 wt% of the interfacial compatibilizer increased the tensile strength from 9 MPa to 22 MPa, while the elongation at break increased from 19% to 142%.

Claims

1. A method for preparing a poly(lactone-b-olefin) block copolymer, characterized in that: The following steps are involved: The lactone monomer, olefin monomer and solvent are mixed and added into a reactor, and a polymerization reaction is carried out in the presence of a catalyst and a bifunctional initiator. After the polymerization is completed, the poly(lactone-b-olefin) block copolymer is obtained by ethanol precipitation and drying.

2. The method for preparing a poly(lactone-b-olefin) block copolymer according to claim 1, wherein The catalyst structure is shown in formula (I-1), formula (I-2), formula (I-3) or formula (I-4):

3. The method for preparing a poly(lactone-b-olefin) block copolymer according to claim 1, wherein: The lactone monomer includes one or more of D,L-lactide, D-lactide, L-lactide, and ε-caprolactone.

4. The method for preparing a poly(lactone-b-olefin) block copolymer according to claim 1, wherein The olefin monomers include one or more of styrene, 4-chloromethylstyrene, methyl methacrylate, hydroxyethyl methacrylate, lauryl methacrylate, isooctyl methacrylate, N,N-dimethylacrylamide, N-isopropylacrylamide, N-acryloylmorpholine, N-vinylpyrrolidone, 4-vinylpyridine, allyl glycidyl ether, and glycidyl methacrylate.

5. The method for preparing a poly(lactone-b-olefin) block copolymer according to claim 1, wherein: The bifunctional initiator includes one of 4-bromomethylbenzyl alcohol, 2-bromoethanol, 3-bromo-1-propanol, 1,3-diiodoisopropanol, 6-bromohexanol, 11-bromo-1-undecanol, 4-bromo-1-butanol, 2-bromo-2-methyl-1-propanol, and 2-bromocyclopentanol.

6. The method for preparing a poly(lactone-b-olefin) block copolymer according to claim 1, wherein: The polymerization reaction temperature is 100-210°C; The polymerization reaction time is 0.1 to 24 hours; The molar ratio of the lactone monomer to the olefin monomer is 1:0.5 to 1:10; The molar ratio of the catalyst to the lactone monomer is 1:50 to 1:1000; The molar ratio of the catalyst to the bifunctional initiator is 1:0.5 to 1:5; The solvent is one of tetrahydrofuran, toluene, dichloromethane, ethyl acetate, and dimethyl sulfoxide, or no solvent is added.

7. The poly(lactone-b-olefin) block copolymer prepared by the preparation method according to claims 1-6, characterized in that: As shown in formula (II), the poly(lactone-b-olefin) block copolymer has a number average molecular weight of 5 kg / mol-200 kg / mol and a molecular weight distribution of 1.2-2.

0.

8. Use of the poly(lactone-b-olefin) block copolymer according to claim 7, characterized in that Without the need for complex post-processing, the resulting block copolymer can be used as an interfacial compatibilizer to achieve multi-dimensional improvements in the mechanical strength, toughness, thermal stability and processing fluidity of the blended material.

9. Use of the poly(lactone-b-olefin) block copolymer according to claim 8, characterized in that The block copolymer is added as an interfacial compatibilizer in an amount of 0.1 wt% to 5 wt%.

10. The use of the poly(lactone-b-olefin) block copolymer according to claim 8, characterized in that The blended material includes one or more of polylactide / low-density polyethylene, polylactide / linear low-density polyethylene, polylactide / high-density polyethylene, polylactide / polyolefin elastomer, polylactide / polystyrene, polylactide / polymethyl methacrylate, polylactide / polyoctadecyl methacrylate, and polycaprolactone / high-density polyethylene.

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