Synthesis of bio-based lauryl vinyl ether vinyl ester copolymer

Abstract

The application discloses synthesis of a bio-based vinyl laurate vinyl ether copolymer. The synthesis method of the bio-based vinyl laurate vinyl ether copolymer comprises the following steps: mixing a first monomer and a second monomer, adding an initiator and a solvent, and performing solution polymerization to generate a bio-based copolymer; the first monomer is vinyl laurate; and the second monomer comprises n-propyl vinyl ether. In the application, the bio-based vinyl laurate is a rigid unit, the n-propyl vinyl ether regulates the rigidity and flexibility of a molecular chain and reduces the viscosity of a system, an addition polymerization reaction is realized through solution polymerization, and a bio-based vinyl laurate / n-propyl vinyl ether copolymer is prepared through a heat curing process; TG testing shows that the thermal decomposition temperature of the polymer is above 310 DEG C, indicating that the polymer has good high-temperature resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of synthesis of copolymers, in particular to the synthesis of bio-based lauryl vinyl ether vinyl ether copolymer. BACKGROUND

[0002] In order to reduce the dependence of high molecular materials on petrochemical resources, bio-based materials have emerged. Therefore, the development of bio-based and environmentally friendly elastomers to replace traditional petroleum chemical products is of great significance. With the continuous development of biotechnology and catalytic chemistry, in-depth research on bio-based elastomers has become possible.

[0003] Although there has been great progress in the research of bio-based materials, there are still many challenges to achieve their industrial production, the most important of which is to achieve the preparation of bio-based elastomers with high strength, high modulus and good heat resistance. At present, the main use of bio-based elastomers is still as the matrix of composite materials such as glass steel, which puts forward higher requirements for its mechanical properties and heat resistance. In order to replace petroleum-based resins, the corresponding properties of bio-based elastomers need to meet the requirements. From the perspective of molecular structure design, it is undoubtedly a good choice to introduce rigid structure into the molecular structure of linear polymers and diluents.

[0004] Lauryl vinyl ether is a monomer that can achieve a main chain of saturated carbon chain and a side group of polar ester group by addition polymerization, which is a kind of acrylate polymer. The high polarity and complete saturation of the structure make it have oxidation resistance and ozone resistance, and outstanding resistance to hydrocarbon oil swelling. The number of alkyl carbon atoms in the lauryl vinyl ether side chain is more, which shields the polarity of the ester group. The increase of this hydrophobicity improves the water stability and moisture resistance of the copolymer, so that the material has better performance in humid or underwater applications. At the same time, due to the shielding effect, the intermolecular force is weakened, which leads to an increase in internal plasticity, thereby reducing the brittleness temperature and improving the cold resistance. The long-chain lauryl vinyl ether also forms more physical entanglements in the polymer matrix due to the longer side chain, which is introduced into the copolymer. The long side chain saturated alkane provides a certain rigid structure, thereby affecting the mechanical properties, improving the tensile strength, elongation, toughness, wear resistance, etc. of the material.

[0005] Vinyl ether is a kind of unsaturated carbon-carbon double bond monomer, containing CH2==CH2—CH—O— structural unit. The lone pair of electrons of oxygen atom forms a conjugated structure with carbon-carbon double bond, so that the electron cloud density of double bond increases, so the carbon-carbon double bond of vinyl ether is an electron-rich double bond, which has different reaction characteristics from general olefin monomers, that is, higher reactivity, which can easily realize free radical polymerization, cationic polymerization, charge transfer complex alternating copolymerization and the like. At the same time, vinyl ether can be used as a general active diluent in various radiation curing systems (for example, in free radical systems, cationic systems and hybrid systems). During the polymerization process, n-propyl vinyl ether can affect the viscosity, and during the polymerization reaction process of n-propyl vinyl ether, the addition of low-polarity oxygen-containing side chains in the main chain can reduce the structure of the source homopolymer with high molecular regularity and orientation, reduce the internal crystallization ability, and reduce the hindering effect of the lattice force after crystallization, thereby improving the activity of the molecular chain. Therefore, vinyl ether as an active diluent has very excellent dilution, which can significantly reduce the viscosity of the system. By adjusting the proportion of n-propyl vinyl ether and other monomers, as well as the polymerization conditions, bio-based elastomers with different physical and chemical properties can be obtained to meet the needs of different application fields. At the same time, its toxicity and odor are relatively low, and it can be applied to the preparation reaction of bio-based elastomers. SUMMARY

[0006] The application provides a synthesis method of a bio-based vinyl laurate vinyl ether copolymer, the bio-based vinyl laurate is a rigid unit, the n-propyl vinyl ether regulates the rigidity and flexibility of the molecular chain and reduces the viscosity of the system, and the addition polymerization reaction is realized through solution polymerization, and then the bio-based vinyl laurate / n-propyl vinyl ether copolymer is prepared through a thermal curing process.

[0007] In order to achieve the above-mentioned purpose, the technical scheme adopted by the application is:

[0008] The first aspect of the application provides a synthesis method of a bio-based vinyl laurate vinyl ether copolymer, comprising the following steps:

[0009] The first monomer and the second monomer are mixed, an initiator and a solvent are added, and solution polymerization is carried out, so as to generate a bio-based copolymer;

[0010] The first monomer is vinyl laurate; and the second monomer comprises n-propyl vinyl ether.

[0011] Preferably, the molar ratio of the vinyl laurate and the n-propyl vinyl ether is (3-10):1.

[0012] Preferably, the reaction time is 5-12 h.

[0013] Preferably, the reaction temperature is 50-90 DEG C.

[0014] Preferably, the amount of the initiator added is 1-3wt% of the total mass of the monomers.

[0015] Preferably, the initiator comprises azobisisobutyronitrile, and the solvent comprises methanol.

[0016] Preferably, the second monomer comprises n-propyl vinyl ether and vinyl acetate.

[0017] In view of the fact that the excessively long side chain of vinyl laurate and the poor polymerization characteristics of n-propyl vinyl ether make the final curing effect difficult to form a film and the mechanical properties are poor, an improved scheme is provided on this basis.

[0018] The raw material vinyl acetate in the synthesis of vinyl laurate is selected as the raw material. On the one hand, the monomer structure of the small molecule vinyl group meets the monomer requirements of ethylene propylene acrylate rubber (AEM), and at the same time, the influence of the conjugation effect, steric effect and polarity effect of the substituent group on the activity of the monomer and free radical is considered. The monomer activity is reacted through the Q value. The Q value of n-propyl vinyl ether is about 0.048, which is relatively close to the Q value 0.026 of vinyl acetate, and is easy to polymerize. At the same time, block copolymer can be generated between vinyl acetate and vinyl laurate. Therefore, vinyl acetate can further improve the polymerization degree of vinyl laurate and n-propyl vinyl ether by acting as a bridge, and the addition of vinyl acetate can reduce the steric effect of the side chain of vinyl laurate and n-propyl vinyl ether.

[0019] Further preferably, the molar ratio of the vinyl laurate, vinyl acetate and n-propyl vinyl ether is (4-6):(4-6):1.

[0020] The second aspect of the present application provides a bio-based vinyl laurate vinyl ether copolymer, which is prepared by the synthesis method of the bio-based vinyl laurate vinyl ether copolymer.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] In the present application, the bio-based vinyl laurate is a rigid unit, the n-propyl vinyl ether regulates the rigidity and flexibility of the molecular chain and reduces the viscosity of the system, and the addition polymerization reaction is realized through solution polymerization, and then the bio-based vinyl laurate / n-propyl vinyl ether copolymer is prepared through a thermal curing process. TG test shows that the thermal decomposition temperature of the polymer is above 310℃, indicating that it has good high temperature resistance. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The reaction device for the examples is shown in the schematic diagram.

[0024] Figure 2 The infrared spectra of P5:1-0.9, P pure laurate and P10:1 solid samples are shown in the infrared spectra.

[0025] Figure 3 Infrared spectra of solid samples of P5:1-0.9, P10:1 with underlayer liquid copolymer;

[0026] Figure 4 NMR hydrogen spectrum of solid samples of P5:1-0.9, P10:1, P5:1-12h, P pure month after curing;

[0027] Figure 5 (a) TG and (b) DTG curves of solid samples of P5:1-0.9, P10:1, P5:1-12h, P pure month after curing;

[0028] Figure 6 Rheological property diagram of bio-based vinyl laurate / propoxyethylene primary copolymer;

[0029] Figure 7 Infrared spectra of solid samples of P5:5:1 with P5:5:1 underlayer liquid copolymer;

[0030] Figure 8 NMR hydrogen spectrum of solid samples of P5:1-0.9 and P5:5:1;

[0031] Figure 9 (a) TG and (b) DTG curves of samples P5:1-0.9 and P5:5:1 after curing;

[0032] Figure 10 Rheological property diagram of P5:1-0.9 and P5:5:1 rheological property primary copolymer. DETAILED DESCRIPTION

[0033] The specific embodiments of the present application are described below. It should be noted that the description of these embodiments is intended to help understand the present application, but does not constitute a limitation on the present application. In addition, the technical features involved in each of the embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0034] The experimental methods in the following examples are all conventional methods unless otherwise specified. The test materials used in the following examples are all commercially available unless otherwise specified.

[0035] Example 1

[0036] Bio-based copolymer was synthesized by solution polymerization using bio-based vinyl laurate and propoxyethylene as monomers, methanol as solvent and azobisisobutyronitrile (AIBN) as initiator. The specific steps are as follows:

[0037] With 39.4 g of lauric acid vinyl ester as the standard, two monomers were mixed according to the molar ratio of the table 1 and 10 g of methanol was added into a four-necked flask, connected with a mechanical stirrer, a four-necked flask, a gas pump, a gas meter, a condensing device, and N2 was introduced at 20 mL / min for about 40 min to exhaust air, then the initiator azobisisobutyronitrile (AIBN) was dissolved in 20 ml of methanol according to the grams in table 1, and then the initiator solution was connected to the injection instrument, and the reaction device was as shown in Figure 1 The injection time was set to 6 h, and the final solution was reacted at 60 ℃ oil bath for 6 h, and after the reaction was completed, it was kept for 30 min and then cooled to room temperature to obtain the bottom layer of the initial polymer. The bottom layer of the initial polymer was added dropwise to the glass substrate, heated to 200 ℃ on a constant temperature heating table for about 30 min, then the solidified part was taken out and cooled to obtain the preliminary product.

[0038]

[0039] Table 1

[0040]

[0041] The curing conditions of different samples are shown in table 2.

[0042] Table 2

[0043]

[0044] According to the curing condition analysis, combined with the curing time of the samples with 0.5, 0.7 and 0.9 g of initiator content and the changes of the objects after curing, and considering that the initiator content exceeding 2% of the mass of the monomer will reduce the polymerization degree of the polymer, it is preliminarily judged that the content of the initiator is 0.9 g. At the same time, comparing the final curing time and curing conditions of different raw material ratios, it can be seen that the degree of participation of n-propyl vinyl ether in the polymerization reaction is not high, and increasing the content of lauric acid vinyl ester can improve the molecular weight. At the same time, under the condition of 0.9 g of initiator, prolonging the reaction time does not have a great improvement on the curing effect, and too long reaction time in the system can easily cause the chain growth stage, and at the same time, the system is easy to have side reactions at high temperature, which affects the polymerization effect of the product, therefore, it is preliminarily determined that the final reaction time is 6 h after adding the initiator dropwise and standing for half an hour.

[0045] In addition, in order to improve the reaction temperature, isopropanol and n-butyl vinyl ether were used to replace methanol solvent (boiling point 64.7°C) and n-propyl vinyl ether (boiling point 64.5°C) (corresponding to sample P5: 1-80°C), but the dissolution effect of lauryl vinyl ester and initiator in isopropanol was poor, the concentration of monomer and initiator in isopropanol solvent system was large, the reaction chain grew too fast, the substances in the system were not uniformly heated, and then the gel effect increased, which led to uneven polymerization of monomer molecules. In addition, the long side chain of n-butyl vinyl ether hindered the polymerization effect, so the final preliminary polymer solidification degree did not have a great improvement.

[0046] The infrared spectra of P5: 1-0.9, P pure lauryl vinyl ester and P10: 1 solid samples are shown in FIG. 1. Figure 2 As can be seen from the figure, in the infrared spectrum of the cured bio-based lauryl vinyl ester / n-propyl vinyl ether polymer, the characteristic peak at 1737 cm -1 is the stretching vibration of C=O, the characteristic peak at 1173 cm -1 is the symmetric stretching vibration of ester group C-O-C (compared with the ester group of lauryl vinyl ester monomer), and the characteristic peak at 1112 cm -1 is the symmetric stretching vibration of ether bond C-O-C, indicating that the lauryl vinyl ester and n-propyl vinyl ether in the system undergo polyaddition reaction. The peaks at 2926 cm -1 and 2850 cm -1 are the symmetric stretching vibrations of CH3 and CH2, the characteristic peak at 1468 cm -1 belongs to the scissors deformation vibration of -CH2-, and the characteristic peak at 722 cm -1 is the in-plane rocking vibration of C-C with n>4, which indicates the structure of the long carbon chain of lauryl vinyl ester side chain. In addition, the characteristic peak intensities of the three samples are almost the same, and it can be preliminarily judged from the infrared spectrum that the bio-based lauryl vinyl ester / n-propyl vinyl ether polymer is successfully prepared.

[0047] In order to analyze the structure and composition of the bottom liquid preliminary copolymer and the product after curing, Fourier infrared spectrum was used for characterization. P5: 1-0.9 and P10: 1 were taken as examples, and the results are shown in FIG. 2. Figure 3 The characteristic peaks of the bottom liquid and the product after curing are the same at 2926, 2850, 1737, 1468, 1173, 1112, 722 cm -1 . The characteristic peak at 3710 cm -1 in the infrared spectrum of the bottom liquid preliminary copolymer is the -OH stretching vibration of residual solvent methanol. In addition, compared with the solid product, it has additional characteristic peaks at 1647, 1033 cm -1 and 871 cm -1 , and the corresponding characteristic peaks are 1674 cm -1 .C=C double bond stretching vibration at 1033 cm -1 C-H deformation vibration at 871 cm -1 C-H substitution vibration at 871 cm, based on which, it can be preliminarily determined that there is still a small amount of monomer residue in the bottom layer liquid, and after heating and curing treatment, the monomer is removed to leave high degree of polymerization macromolecules to achieve curing.

[0048] To further analyze the chemical structure of the cured bio-based ethylene laurate / n-propyl vinyl ether polymer, solid nuclear magnetic resonance instrument was used for characterization, and the results are shown in Figure 4 The signals at 0.98, 1.39, 1.66, 2.32, 2.94 and 4.92 ppm in the binary copolymer nuclear magnetic hydrogen spectrum correspond to H1, H2, H3, H4, H5 and H6 in the binary copolymer respectively. Among them, the obvious characteristic peak at 1.39 ppm is due to the -CH2- of the side carbon long chain of ethylene laurate, and the obvious characteristic peak at 0.98 ppm is from the -CH3 outer end of n-propyl vinyl ether and ethylene laurate monomer. By comparing the binary polymer with the homopolymer, it is found that the characteristic peak of 2.94 ppm appears in the binary polymer nuclear magnetic resonance hydrogen spectrum, while the homopolymer does not have the corresponding characteristic peak, which is due to the C-O-C of n-propyl vinyl ether in the polymer. Combined with infrared and other characterization, it can be known that the binary copolymer is successfully prepared.

[0049] The thermal stability of the cured bio-based ethylene laurate / n-propyl vinyl ether copolymer was analyzed under N2 atmosphere, and the results are shown in Figure 5 Table 3. From Table 3, it can be seen that the cured bio-based ethylene laurate / n-propyl vinyl ether copolymer has good thermal stability, and the thermal decomposition temperature (T d5％ ) is between 310.0-320℃. The thermal decomposition temperature (T d5％ ) and the maximum thermal decomposition rate temperature (T max ) of the copolymer with different proportions and different times are not much different, among which the maximum thermal decomposition temperature (T d5％ ) and the maximum thermal decomposition rate temperature (T max ) are 274.3℃ and 403.1℃ respectively for pure ethylene laurate polymer. Compared with pure ethylene laurate polymer, the introduction of n-propyl vinyl ether in the system makes the thermal stability of the bio-based ethylene laurate / n-propyl vinyl ether copolymer decrease, which is closely related to the curing degree. Specifically, the addition of n-propyl vinyl ether makes the copolymer molecule not conducive to the chain growth reaction in the polymerization reaction, resulting in a slight decrease in the curing degree, but the overall influence is very small, which is not obvious in the figure.

[0050] Table 3

[0051]

[0052] Rheological properties of the primary polymer of bio-based vinyl laurate / n-propyl vinyl ether, such as Figure 6 As shown in the figure, all samples did not exhibit significant shear thinning with increasing shear rate, exhibiting Newtonian fluid behavior and no entanglement between molecular chains. The viscosity of the uncured copolymer with 0.7 g initiator was 250–270 mPa·s, while the viscosity of the uncured copolymer with 0.9 g initiator significantly increased to approximately 2000 mPa·s, preliminarily indicating that the efficiency was optimal at 0.9 g initiator, the polymerization reaction was relatively complete, and the resulting molecular weight should be relatively large. Furthermore, the comparison revealed that as the molar ratio of vinyl laurate to n-propyl vinyl ether monomers gradually increased, the viscosity of the uncured primary polymer also increased, corroborating the effect of n-propyl vinyl ether on the polymer molecular chain conformation—that is, adding low-polarity oxygen-containing side chains to reduce orientation, thereby increasing molecular chain mobility and thus reducing overall viscosity.

[0053] Furthermore, changing the reaction time and temperature reduced the viscosity of the uncured primary polymer. This is presumably due to side reactions occurring during prolonged reaction times, or the poor solubility of isopropanol solvent combined with higher temperatures leading to excessively rapid reaction rates, uneven heating of the system, and increased gelation effect, all ultimately resulting in lower molecular weight and decreased viscosity. Rotational rheometer testing showed that adjusting the monomer feed ratio and temperature in the solution polymerization system can effectively control the viscosity of the bio-based vinyl laurate / n-propyl vinyl ether primary polymer.

[0054] Example 2

[0055] Given that the excessively long side chains of vinyl lauryl ester and the poor polymerization properties of n-propyl vinyl ether make it difficult to form a film after final curing and result in poor mechanical properties, an improved solution is provided.

[0056] A solution polymerization method was used to synthesize a bio-based copolymer using vinyl laurate, vinyl acetate, and propoxyethylene as monomers, with methanol as the solvent and azobisisobutyronitrile (AIBN) as the initiator. The specific steps included:

[0057] With 39.4g of vinyl laurate as a standard, three monomers were mixed according to a 5:5:1 (vinyl laurate: vinyl acetate: n-propyl vinyl ether) molar ratio and 10g of methanol was added into a four-necked flask, a mechanical stirrer, a four-necked flask, a gas pump, a gas meter, and a condensing device were connected, N2was introduced at 20mL / min for about 40min to exhaust air, 0.9g of initiator azobisisobutyronitrile (AIBN) was dissolved in 20ml of methanol, the initiator solution was connected to a syringe pump, and the injection time was set to 6h, and finally the solution was reacted at 60°C in an oil bath for 6h, after the reaction was completed, the solution was kept for 30min, and then cooled to room temperature to obtain the bottom layer of the primary copolymer. The bottom layer of the primary copolymer was added dropwise to a glass substrate, and after being placed in a vacuum oven at 70°C for about 72h, it was cooled to room temperature and taken out to obtain a solid film.

[0058]

[0059] The infrared spectrum of the solid sample and the bottom layer of the liquid copolymer is shown in FIG. 1. Figure 7 As can be seen from the figure, the characteristic peak of the bio-based vinyl laurate / vinyl acetate / n-propyl vinyl ether polymer after curing is 1737cm-1, which is the stretching vibration of C=O, 1148cm-1, which is the symmetric stretching vibration of ester group C-O-C, and 1116cm-1, which is the symmetric stretching vibration of ether bond C-O-C, indicating that the vinyl laurate, vinyl acetate, and n-propyl vinyl ether in the system have undergone polyaddition reaction. -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 ​​​​​​​​​​​​​​​​The characteristic peak, corresponding to 1679 cm⁻¹, is... -1 The C=C double bond stretching vibration at 1039 cm⁻¹ -1 Deformation vibration of =CH at 875cm and -1 Based on the =CH substitution vibration, it can be preliminarily determined that there are still a small amount of monomer residues in the bottom liquid. After heating and curing, the monomers are removed, leaving high-polymerization macromolecules to achieve solidification.

[0060] The 1H NMR spectra of sample P5:1-0.9 from Example 1 and sample P5:5:1 from Example 2 are as follows: Figure 8 As shown in the 1H NMR spectrum of the terpolymer, the signals at 0.98, 1.39, 1.66, 1.82, 2.02, 2.32, 2.94, and 4.92 ppm correspond to H1, H2, H3, H8, H7, H4, H5, and H6 in the terpolymer, respectively. The binary and terpolymers simultaneously exhibit characteristic peaks at H1, H2, H3, H4, H5, and H6, indicating successful polymerization of n-propyl vinyl ether. Unlike the binary copolymer, the ternary copolymer with added vinyl acetate exhibited two characteristic peaks, H7 and H8. The 2.02 ppm peak at H7 corresponds to the -CH2- group linked to the ester group of vinyl acetate's side chain, indicating successful polymerization of vinyl acetate with vinyl laurate and n-propyl vinyl ether. Furthermore, the 1.82 ppm H8 peak, distinct from the H3 peak on the main chain, corresponds to the main chain peak resulting from the bridging effect of vinyl acetate and vinyl laurate with n-propyl vinyl ether. This suggests that the ternary copolymer is not entirely block copolymerized, but rather exhibits alternating polymerization with a significant proportion of vinyl acetate acting as a bridge. Combined with infrared spectroscopy and other characterization methods, the ternary copolymer was successfully prepared.

[0061] The TG and DTG curves of sample P5:1-0.9 (shown as P5:1 in the figure) from Example 1 and sample P5:5:1 from Example 2 are shown below. Figure 9 As shown in Table 4, the specific thermal decomposition data are as follows. The data indicates that the bio-based vinyl laurate / vinyl acetate / n-propyl vinyl ether terpolymer exhibits good thermal stability after curing, with a thermal decomposition temperature (T0). d5％ At 318.5℃, it is close to the thermal decomposition temperature of polyvinyl laurate (319.8℃). The maximum thermal decomposition rate temperature (T0) is... max) respectively, which are almost the same. The mass change before 300 degrees is 1.78%, which removes the methanol solvent and the physically adsorbed water on the surface. Compared with the binary lauryl vinyl ether / n-propyl vinyl ether polymer, the introduction of vinyl acetate in the system makes the thermal stability of the bio-based lauryl vinyl ether / vinyl acetate / n-propyl vinyl ether copolymer have certain improvement, which has great relationship with the curing degree. Specifically, the addition of vinyl acetate makes the copolymer molecule conducive to the chain growth reaction in the polymerization reaction, the molecular weight has certain improvement, and the main chain rigid structure is improved, which leads to the increase of the curing degree and finally improves the thermal stability.

[0062] Table 4

[0063]

[0064] The rheological properties of sample P5:1-0.9 and P5:5:1 are shown in Figure 10 As can be seen from the figure, with the increase of shear rate, the primary copolymer of the ternary sample does not appear obvious shear thinning phenomenon, and presents Newtonian fluid behavior, and it is speculated that the reason is that the addition of ethylene acetate monomer reduces the side chain of lauryl vinyl ether carbon side long chain, and there is no entanglement between molecular chains. The results show that the viscosity of the uncured copolymer of the ternary bio-based lauryl vinyl ether / vinyl acetate / n-propyl vinyl ether (molar ratio of 5:5:1) primary copolymer at 25℃ is about 2770 mPa·s, which is obviously enhanced compared with the viscosity of the binary copolymer. Since the viscosity of the polymer is proportional to the molecular weight, it can be preliminarily judged that the addition of vinyl acetate can connect lauryl vinyl ether and n-propyl vinyl ether as a bridge to make the final polymerization degree increase.

[0065] The embodiments of the present application are described in detail above, but the present application is not limited to the described embodiments. For those skilled in the art, various changes, modifications, replacements and variations of the embodiments can be made without departing from the principles and spirits of the present application, and still fall within the protection scope of the present application.

Claims

1. A method for synthesizing a bio-based vinyl laurate copolymer, characterized in that, Includes the following steps: The first monomer and the second monomer are mixed, and an initiator and a solvent are added to carry out solution polymerization to generate a bio-based copolymer. The first monomer is vinyl lauryl ester; the second monomer is n-propyl vinyl ether; the initiator includes azobisisobutyronitrile; and the solvent includes methanol. The molar ratio of vinyl lauryl ester to n-propyl vinyl ether is (3-10):1; the amount of initiator added is 1-3 wt% of the total monomer mass; the reaction time is 5-12 h; and the reaction temperature is 50-90 °C.

2. A method for synthesizing a bio-based vinyl laurate copolymer, characterized in that, Includes the following steps: The first monomer and the second monomer are mixed, and an initiator and a solvent are added to carry out solution polymerization to generate a bio-based copolymer. The first monomer is vinyl lauryl ester; the second monomer is n-propyl vinyl ether and vinyl acetate; the initiator includes azobisisobutyronitrile; and the solvent includes methanol. The molar ratio of vinyl lauryl ester, vinyl acetate, and n-propyl vinyl ether is (4-6):(4-6):1; the amount of initiator added is 1-3 wt% of the total mass of the monomers; the reaction time is 5-12 h; and the reaction temperature is 50-90 °C.

3. A bio-based vinyl laurate copolymer, characterized in that, It is prepared by the method for synthesizing the bio-based vinyl laurate copolymer as described in claim 1 or 2.

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