Bio-based polyester polyol based on hydroxy fatty acid / acid ester as well as preparation method and application of bio-based polyester polyol

Abstract

The invention belongs to the technical field of polyester polyol, and relates to bio-based polyester polyol based on hydroxy fatty acid / acid ester as well as a preparation method and application of the bio-based polyester polyol. The invention discloses a preparation method of bio-based polyester polyol based on hydroxy fatty acid / acid ester, which comprises the following steps: mixing hydroxy fatty acid / acid ester, polyol and a catalyst in inert gas, heating to a first reaction temperature of 90-120 DEG C, reacting for 0.1-3 hours, heating to a second reaction temperature of 110-180 DEG C, continuously reacting for 6-24 hours, vacuumizing to a vacuum degree of 0-400 Pa, reacting for 1-5 hours, cooling to room temperature, and filtering to obtain the bio-based polyester polyol based on hydroxy fatty acid / acid ester. The bio-based polyester polyol based on the hydroxy fatty acid ester is obtained. The invention also discloses a bio-based polyester material and a bio-based polyurethane material which take the bio-based polyester polyol based on the hydroxy fatty acid ester as a raw material. The bio-based polyester polyol based on hydroxy fatty acid / acid ester can be compounded with other polyols for use, is used for regulating and controlling the performance of high polymer materials, and effectively improves the mechanical properties of the materials.

Description

Technical Field

[0001] This invention belongs to the field of polyester polyol technology, and relates to a bio-based polyester polyol based on hydroxy fatty acids / esters, its preparation method and application. Background Technology

[0002] Polyester polyols, as key soft segment raw materials for biodegradable polyurethane elastomers, offer superior weather resistance, hydrolytic stability, low-temperature flexibility, resilience, abrasion resistance, oil resistance, and compression resistance compared to polyether polyols. Currently, the main source of biodegradable polyester polyols still relies on the ring-opening polymerization of cyclic monomers, including polylactic acid (PLA) polyols prepared from lactide and polycaprolactone (PCL) polyols prepared from caprolactone. For example, Chinese Patent Publication CN119552350 A prepares an in-situ catalyst by heating zinc salt, organic ammonium salt, and bis(ethylene carbonate) ether, then adds lactide monomer and polymerizes to obtain polylactic acid polyol. Chinese Patent Publication CN118079813A achieves continuous production through an inert environment-controlled raw material mixing, preparation, and purification system, allowing for flexible adjustment of the ratio and type of lactide and polyol to synthesize polylactic acid polyols of different molecular weights. Chinese patent publication CN115651171B describes a process where an initiator, ε-caprolactone, and catalyst are premixed and then continuously ring-opening polymerized in a tubular reactor after drying and dehydration to ultimately obtain a polycaprolactone polyol with low acid value and narrow molecular weight distribution.

[0003] Although polyhydroxy fatty acid esters (PHAs) have attracted widespread attention as an emerging class of biodegradable bio-based polyesters, their synthesis mainly relies on bio-fermentation. Attempts to prepare corresponding polyester polyols via direct polymerization using linear hydroxy fatty acids / esters as monomers still face significant technical bottlenecks. These bottlenecks primarily stem from the structural characteristics of linear hydroxy fatty acids (such as 3-hydroxybutyric acid): their secondary hydroxyl groups exhibit low reactivity and are prone to dehydration and other side reactions during polymerization, resulting in poor controllability of the polymerization process and difficulty in precisely controlling the molecular weight of the product. Consequently, no polyester polyols based on this type of monomer have been reported to date. Therefore, there is an urgent need to develop a novel bio-based polyester polyol using linear hydroxy fatty acids / esters as raw materials and to provide an efficient and controllable preparation method to further expand its application in bio-based polyester or polyurethane materials. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by proposing a simple and controllable method for preparing bio-based polyester polyols based on hydroxy fatty acids / esters, and to further improve the strength of bio-based polyester materials or bio-based polyurethane materials using this polyester polyol.

[0005] One objective of this invention is achieved through the following technical solution: A method for preparing a bio-based polyester polyol based on hydroxy fatty acids / esters, comprising: In an inert gas atmosphere, hydroxy fatty acid / ester, polyol and catalyst are mixed and heated to the first reaction temperature of 90~120℃ for 0.1~3h, then heated to the second reaction temperature of 110~180℃ for 6~24h, and then evacuated to a vacuum of 0~400 Pa for 1~5h to obtain bio-based polyester polyol based on hydroxy fatty acid ester. The molar ratio of the hydroxy fatty acid / ester and the polyol is (1~50):1; The amount of catalyst added is 0.001~1% of the molar amount of hydroxy fatty acid / ester; The hydroxy fatty acid / ester includes at least one of 3-hydroxybutyric acid, methyl 3-hydroxybutyrate, and ethyl 3-hydroxybutyrate; The polyols include chain polyols and / or cyclic polyols; The catalyst includes at least one of stannous octoate, dibutyltin dilaurate, tetrabutyl titanate, and tin dioxylate.

[0006] Preferably, the hydroxy fatty acid / ester includes at least one of 3-hydroxybutyric acid, methyl 3-hydroxybutyrate, and ethyl 3-hydroxybutyrate.

[0007] Preferably, the structural formula of the hydroxy fatty acid / ester is shown in formula (1) below:

[0008] Wherein, R includes at least one of H, -CH3, and -CH2CH3.

[0009] Preferably, the chain polyol includes at least one of ethylene glycol, polyethylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerol, pentaerythritol, and 3-hydroxymethylpropane. The cyclic polyols include at least one of 1,4-cyclohexanediol, isosorbide, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 4,4'-bicyclohexanol.

[0010] Further preferably, the polyol is a chain polyol.

[0011] Preferably, the molar ratio of the hydroxy fatty acid / ester and the polyol is (30~1):1.

[0012] More preferably, the molar ratio of the hydroxy fatty acid / ester and the polyol is (15~2.5):1.

[0013] Preferably, the molar amount of the catalyst is 0.1 to 5‰ of the molar amount of hydroxy fatty acid / ester.

[0014] More preferably, the molar amount of the catalyst is 0.4 to 5‰ of the molar amount of hydroxy fatty acid / ester.

[0015] Preferably, the molecular weight of the bio-based polyester polyol based on hydroxy fatty acids / esters is 300-5000.

[0016] Further preferably, the molecular weight distribution of the bio-based polyester polyol based on hydroxy fatty acids / esters is ≤1.5.

[0017] Preferably, the bio-based polyester polyol based on hydroxy fatty acids / esters is poly(3-hydroxybutyrate) polyol, and the end group of the polyol is a secondary hydroxyl group.

[0018] Preferably, the structural formula of the bio-based polyester polyol based on hydroxy fatty acids / esters includes at least one of formulas (21) to (210):

[0019]

[0020] Where n is 1 to 25.

[0021] The second objective of this invention is achieved through the following technical solution: A bio-based polyester polyol based on hydroxy fatty acid esters prepared by the above preparation method.

[0022] The third objective of this invention is achieved through the following technical solution: A bio-based polyester material, the raw materials of which include the above-mentioned bio-based polyester polyols based on hydroxy fatty acids / esters.

[0023] Preferably, the raw materials for the bio-based polyester material include bio-based polyester polyols based on hydroxy fatty acids / esters, dimethyl terephthalate, and polyols in a molar ratio of (0.05-0.9):1:(0.3-1.6). The polyols include at least one selected from ethylene glycol, polyethylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerol, pentaerythritol, 3-hydroxymethylpropane, 1,4-cyclohexanediol, isosorbide, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 4,4'-bicyclohexanol.

[0024] Preferably, the structure of the bio-based polyester material includes the following formula (31):

[0025] Where n is 1 to 25, and R includes at least one of the following formulas (51) to (55):

[0026] The fourth objective of this invention is achieved through the following technical solution: A method for preparing a bio-based polyester material includes: mixing a bio-based polyester polyol based on hydroxy fatty acids / esters with dimethyl terephthalate, a polyol, and a catalyst, and then carrying out a first reaction at 130~210℃ for 1~12h, followed by adding a polycondensation catalyst and a stabilizer, and then continuing to raise the temperature to 220~260℃ for a second reaction for 1~6h to obtain the bio-based polyester material.

[0027] Preferably, the molar ratio of the bio-based polyester polyol based on hydroxy fatty acid / ester, dimethyl terephthalate, and polyol is (0.05-0.9):1:(0.3-1.6).

[0028] Preferably, the polyol includes at least one selected from ethylene glycol, polyethylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerol, pentaerythritol, 3-hydroxymethylpropane, 1,4-cyclohexanediol, isosorbide, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 4,4'-bicyclohexanol.

[0029] Preferably, the catalyst includes at least one of stannous octoate, dibutyltin dilaurate, tetrabutyl titanate, zinc acetate, and tin dioxygenate.

[0030] Preferably, the molar amount of the catalyst is 0.01 to 0.3% of the molar amount of the bio-based polyester polyol based on hydroxy fatty acids / esters.

[0031] Preferably, the polycondensation catalyst includes at least one of antimony trioxide, antimony glycolate, and tetrabutyl titanate.

[0032] Preferably, the molar amount of the polycondensation catalyst is 0.01 to 0.3% of the molar amount of the bio-based polyester polyol based on hydroxy fatty acids / esters.

[0033] Preferably, the stabilizer includes at least one of triphenyl phosphate, trimethyl phosphate, and triphenylphosphine.

[0034] Preferably, the molar amount of the stabilizer is 0.01 to 0.5% of the molar amount of the bio-based polyester polyol based on hydroxy fatty acids / esters.

[0035] The fifth objective of this invention is achieved through the following technical solution: A bio-based polyurethane material, the raw materials of which include the above-mentioned bio-based polyester polyol based on hydroxy fatty acids / esters.

[0036] Preferably, the raw materials of the bio-based amino polyester material include bio-based polyester polyols, polyols, and isocyanates based on hydroxy fatty acids / esters in a molar ratio of (0.1~10):1:(1~30).

[0037] Preferably, the bio-based amino polyester material includes at least one repeating unit from formulas (41) to (410) in its structural formula:

[0038]

[0039] Where n is 1~25, x≥10, and R includes at least one of the following formulas (51)~(55):

[0040] The sixth objective of this invention is achieved through the following technical solution: A method for preparing a bio-based polyurethane material includes: adding a bio-based polyester polyol based on hydroxy fatty acid / ester, a polyol, an isocyanate, and a catalyst to a solvent, heating to 70-120°C and reacting for 1-6 hours, adding a chain extender, and continuing the reaction for 1-12 hours to obtain the bio-based polyurethane material.

[0041] Preferably, the molar ratio of the bio-based polyester polyol, polyol, and isocyanate based on hydroxy fatty acid / ester is (0.1~10):1:(1~30).

[0042] Preferably, the polyol includes at least one selected from ethylene glycol, polyethylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerol, pentaerythritol, 3-hydroxymethylpropane, 1,4-cyclohexanediol, isosorbide, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 4,4'-bicyclohexanol.

[0043] Preferably, the isocyanate includes at least one of hexamethylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, pentamethylene diisocyanate, and diphenylmethane diisocyanate.

[0044] Preferably, the amount of catalyst added is 0.1-5% of the molar amount of the bio-based polyester polyol based on hydroxy fatty acids / esters.

[0045] Further preferably, the amount of catalyst added is 0.5% of the molar amount of the bio-based polyester polyol based on hydroxy fatty acids / esters.

[0046] Preferably, the catalyst includes at least one of stannous octoate, dibutyltin dilaurate, tetrabutyl titanate, zinc acetate, and tin dioxygenate.

[0047] Preferably, the chain extender includes at least one of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerol, pentaerythritol, and 3-hydroxymethylpropane.

[0048] Further preferably, the polyol is different from the chain extender.

[0049] Preferably, the molar amount of the added chain extender is the same as the molar amount of the bio-based polyester polyol based on hydroxy fatty acid / ester and the total molar amount of the polyol.

[0050] Preferably, the solvent is an organic solvent, including at least one of toluene, ethyl acetate, acetone, xylene, N-methylpyrrolidone, and tetrahydrofuran.

[0051] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention adopts a simple and controllable process route to successfully prepare bio-based polyester polyols based on hydroxy fatty acids / esters, avoiding the multi-step reactions and harsh conditions commonly found in the synthesis of traditional high molecular weight polymers. The process conditions are mild and easy to implement and promote on a large scale.

[0052] 2. The bio-based polyester polyol based on hydroxy fatty acids / esters of the present invention has the characteristics of precise molecular weight control, low acid value and flexible structural design, showing good application prospects and development potential.

[0053] 3. The hydroxy fatty acid / ester-based bio-based polyester polyol of the present invention can be compounded with other polyols for the performance regulation of polymer materials, and can effectively improve the mechanical properties of the materials. Attached Figure Description

[0054] Figure 1 This is the 1H NMR spectrum of the poly(3-hydroxybutyric acid) polyol in Example 1 of the present invention.

[0055] Figure 2 This is a graph showing the molecular weight and molecular weight distribution of the poly(3-hydroxybutyric acid) polyol in Example 1 of the present invention.

[0056] Figure 3 The infrared spectrum of the poly(3-hydroxybutyric acid) polyol in Example 1 of this invention is shown. Detailed Implementation

[0057] The technical solution of the present invention will be further described and illustrated below through specific embodiments. It should be understood that the specific embodiments described herein are only for the purpose of helping to understand the present invention and are not intended to limit the present invention.

[0058] Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commonly used in the art, and the methods used in the embodiments are all conventional methods in the art.

[0059] In this article, hydroxy fatty acids / esters refer to hydroxy fatty acids or hydroxy fatty acid esters.

[0060] Example 1 In this embodiment, the bio-based polyester polyol based on hydroxy fatty acids / esters is poly(3-hydroxybutyric acid) polyol, and its preparation method includes: After nitrogen gas was introduced into the reaction vessel for 10 min, 0.25 mol of 3-hydroxybutyric acid and 0.1 mol of ethylene glycol (molar ratio 2.5:1) were added, followed by 0.1 mmol of tetrabutyl titanate catalyst. The mixture was slowly heated to 110 °C at a rate of 20 °C / min under normal pressure and reacted for 1 h. The temperature was then increased to 120 °C and reacted for 15 h. The system was then evacuated to a vacuum of 150 Pa to remove unreacted monomers, yielding a poly(3-hydroxybutyric acid) polyol with a molecular weight of 300 g / mol.

[0061] The molecular weight and molecular weight distribution of the poly(3-hydroxybutyric acid) polyol in this embodiment are shown in Table 1.

[0062] Figure 1 The 1H NMR spectrum of poly(3-hydroxybutyric acid) polyol was obtained. The molecular weight was calculated based on the ratio of the number of methylene groups in the terminal groups and the number of 3-hydroxybutyric acid units in the molecular chain. The results showed that the theoretical and experimental values ​​were consistent, proving that the molecular weight of the polyol is controllable.

[0063] Figure 2 The graph shows the molecular weight and molecular weight distribution of poly(3-hydroxybutyric acid) polyol, indicating that the molecular weight distribution is relatively narrow.

[0064] Figure 3 The image shows the infrared spectrum of poly(3-hydroxybutyric acid) polyol. The vibration at 3450 cm⁻¹ is attributed to the stretching vibration of -OH, the vibration around 2930–2980 cm⁻¹ is attributed to the stretching vibrations of methyl and methylene groups, the vibration at 1736 cm⁻¹ is the stretching vibration of -C=O, the vibration at 1457 cm⁻¹ is the in-plane bending vibration of -OH, the vibration at 1381 cm⁻¹ is attributed to the in-plane bending vibration of -CH, and the vibration at 1000–1300 cm⁻¹ is attributed to the stretching vibration of -CO. This confirms the successful preparation of the oligomeric polyol.

[0065] Example 2 In this embodiment, the bio-based polyester polyol based on hydroxy fatty acids / esters is poly(3-hydroxybutyric acid) polyol, and its preparation method includes: After nitrogen gas was introduced into the reaction vessel for 10 min, 0.5 mol of 3-hydroxybutyric acid and 0.1 mol of 1,3-propanediol (molar ratio 5:1) were added, followed by 0.2 mmol of butyltin dioxide catalyst. The mixture was slowly heated to 110 °C at a rate of 20 °C / min under normal pressure and reacted for 1 h. The temperature was then increased to 130 °C and reacted for 12 h. The system was then evacuated to a vacuum of 150 Pa to remove unreacted monomers, yielding a poly(3-hydroxybutyric acid) polyol with a molecular weight of 500 g / mol.

[0066] The molecular weight and molecular weight distribution of the poly(3-hydroxybutyric acid) polyol in this embodiment are shown in Table 1.

[0067] Example 3 In this embodiment, the bio-based polyester polyol based on hydroxy fatty acids / esters is poly(3-hydroxybutyric acid) polyol, and its preparation method includes: After nitrogen gas was introduced into the reaction vessel for 10 min, 1 mol of 3-hydroxybutyric acid and 0.1 mol of 1,4-butanediol (molar ratio 10:1) were added, followed by 0.5 mmol of tetrabutyl titanate catalyst. The mixture was slowly heated to 110 °C at a rate of 20 °C / min under normal pressure and reacted for 1 h. The temperature was then increased to 145 °C and reacted for 7 h. The system was then evacuated to a vacuum of 150 Pa to remove unreacted monomers, yielding poly(3-hydroxybutyric acid) polyol with a molecular weight of 1000 g / mol.

[0068] The molecular weight and molecular weight distribution of the poly(3-hydroxybutyric acid) polyol in this embodiment are shown in Table 1.

[0069] Example 4 In this embodiment, the bio-based polyester polyol based on hydroxy fatty acids / esters is poly(3-hydroxybutyric acid) polyol, and its preparation method includes: After nitrogen gas was introduced into the reaction vessel for 10 min, 1.5 mol of 3-hydroxybutyric acid and 0.1 mol of pentanediol (molar ratio 15:1) were added, followed by 1 mmol of tetrabutyl titanate catalyst. The mixture was slowly heated to 110 °C at a rate of 20 °C / min under normal pressure and reacted for 1 h. The temperature was then increased to 130 °C and reacted for 7 h. The system was then evacuated to a vacuum of 150 Pa to remove unreacted monomers, yielding poly(3-hydroxybutyric acid) polyol with a molecular weight of 1500 g / mol.

[0070] The molecular weight and molecular weight distribution of the poly(3-hydroxybutyric acid) polyol in this embodiment are shown in Table 1.

[0071] Example 5 In this embodiment, the bio-based polyester polyol based on hydroxy fatty acids / esters is poly(3-hydroxybutyric acid) polyol, and its preparation method includes: After nitrogen gas was introduced into the reaction vessel for 10 min, 1.5 mol of methyl 3-hydroxybutyrate and 0.1 mol of 1,4-cyclohexanediethanol (molar ratio 15:1) were added, followed by 5 mmol of tetrabutyl titanate catalyst. The mixture was slowly heated to 110 °C at a rate of 20 °C / min under normal pressure and reacted for 1 h. The temperature was then increased to 130 °C and reacted for 7 h. The system was then evacuated to a vacuum of 150 Pa to remove unreacted monomers, yielding poly(3-hydroxybutyrate) polyol with a molecular weight of 1500 g / mol.

[0072] The molecular weight and molecular weight distribution of the poly(3-hydroxybutyric acid) polyol in this embodiment are shown in Table 1.

[0073] Example 6 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: After purging nitrogen gas into the reaction vessel for 10 min, 0.05 mol of poly(3-hydroxybutyric acid) polyol from Example 1, 0.05 mol of polyethylene glycol, and 0.21 mol of hexamethylene diisocyanate (molar ratio 1:1:4.2) were added, along with 50 ml of toluene and 0.25 mmol of stannous octoate catalyst. The mixture was slowly heated to 90 °C at a rate of 20 °C / min under normal pressure and reacted for 3 h. Then, 0.1 mol of chain extender 1,4-butanediol was added, and the reaction was continued for another 2 h to obtain poly(3-hydroxybutyric acid) polyurethane.

[0074] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0075] Example 7 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: After purging nitrogen into the reaction vessel for 10 min, 0.06 mol of poly(3-hydroxybutyric acid) polyol from Example 2, 0.04 mol of polypropylene glycol, and 0.21 mol of diphenylmethane diisocyanate (molar ratio 1.5:1:5.25) were added, followed by 80 ml of tetrahydrofuran and 0.3 mmol of stannous octoate catalyst. The mixture was slowly heated to 90 °C at a rate of 20 °C / min under normal pressure and reacted for 3 h. Then, 0.1 mol of chain extender 1,3-propanediol was added, and the reaction was continued for another 3 h to obtain poly(3-hydroxybutyric acid) polyurethane.

[0076] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0077] Example 8 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: After purging nitrogen gas into the reaction vessel for 10 min, 0.07 mol of poly(3-hydroxybutyric acid) polyol from Example 3, 0.03 mol of polytetrahydrofuran diol, and 0.21 mol of toluene diisocyanate (molar ratio 2.3:1:7) were added, followed by 100 ml of toluene and 0.35 mmol of stannous octoate catalyst. The mixture was slowly heated to 90 °C at a rate of 20 °C / min under normal pressure and reacted for 3 h. Then, 0.1 mol of chain extender 1,4-butanediol was added, and the reaction was continued for another 5 h to obtain poly(3-hydroxybutyric acid) polyurethane.

[0078] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0079] Example 9 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: After purging nitrogen gas into the reaction vessel for 10 min, 0.09 mol of poly(3-hydroxybutyric acid) polyol from Example 4, 0.01 mol of cyclohexanediol, and 0.21 mol of diisophorone diisocyanate (molar ratio 9:1:21) were added, followed by 120 ml of tetrahydrofuran and 0.45 mmol of stannous octoate catalyst. The mixture was slowly heated to 90 °C at a rate of 20 °C / min under normal pressure and reacted for 3 h. Then, 0.1 mol of chain extender 1,4-butanediol was added, and the reaction was continued for another 6 h to obtain poly(3-hydroxybutyric acid) polyurethane.

[0080] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0081] Example 10 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: After purging nitrogen gas into the reaction vessel for 10 min, 0.04 mol of poly(3-hydroxybutyric acid) polyol from Example 5, 0.06 mol of polytetrahydrofuran glycol, and 0.21 mol of diphenylmethane diisocyanate (molar ratio 0.67:1:3.5) were added, followed by 60 ml of toluene and 0.2 mmol of stannous octoate catalyst. The mixture was slowly heated to 90 °C at a rate of 20 °C / min under normal pressure and reacted for 3 h. Then, 0.1 mol of chain extender ethylene glycol was added, and the reaction was continued for another 10 h to obtain poly(3-hydroxybutyric acid) polyurethane.

[0082] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0083] Example 11 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: The difference between Example 6 and Example 2 is that the poly-3-hydroxybutyrate polyol in Example 2 is used instead of the poly-3-hydroxybutyrate polyol in Example 1.

[0084] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0085] Example 12 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: The difference between Example 6 and Example 3 is that the poly-3-hydroxybutyrate polyol in Example 3 is used instead of the poly-3-hydroxybutyrate polyol in Example 1.

[0086] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0087] Example 13 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: The difference between Example 6 and Example 4 is that the poly-3-hydroxybutyrate polyol from Example 4 is used instead of the poly-3-hydroxybutyrate polyol from Example 1.

[0088] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0089] Example 14 In this embodiment, the bio-based polyurethane material is poly(3-hydroxybutyrate) polyurethane, and its preparation method includes: The difference between Example 6 and Example 5 is that the poly-3-hydroxybutyrate polyol in Example 5 is used instead of the poly-3-hydroxybutyrate polyol in Example 1.

[0090] The properties of the bio-based polyurethane material in this embodiment are shown in Table 2.

[0091] Example 15 In this embodiment, the bio-based polyester material is poly(3-hydroxybutyrate) polybutylene terephthalate, and its preparation method includes: After purging nitrogen into the reaction vessel for 10 min, 0.08 mol of poly(3-hydroxybutyric acid) polyol from Example 1, 0.1 mol of dimethyl terephthalate, and 0.03 mol of 1,4-butanediol (molar ratio 0.8:1:0.3) were added, followed by 0.08 mmol of tetrabutyl titanate catalyst. The mixture was slowly heated to 180 °C at a rate of 20 °C / min under normal pressure and reacted for 4 h. Then, 0.08 mmol of antimony trioxide condensation catalyst and 0.08 mmol of triphenyl phosphate stabilizer were added, and the mixture was further heated to 240 °C. The vacuum was then evacuated to a vacuum degree of 10 Pa and reacted for 3 h to obtain poly(3-hydroxybutyric acid) polybutylene terephthalate.

[0092] The properties of the bio-based polyester material in this embodiment are shown in Table 2.

[0093] Comparative Example 1 In this comparative example, the polyurethane material is polyethylene glycol-based polyurethane, and its preparation method includes: After purging nitrogen into the reaction vessel for 10 min, 0.05 mol of polyethylene glycol and 0.105 mol of hexamethylene diisocyanate (molar ratio 1:2.1) were added, along with 50 ml of toluene and 0.25 mmol of stannous octoate catalyst. The mixture was slowly heated to 90 °C at a rate of 20 °C / min under normal pressure and reacted for 3 h. Then, 0.05 mol of chain extender 1,4-butanediol was added, and the reaction was continued for another 6 h to obtain polyethylene glycol-based polyurethane.

[0094] The properties of the polyethylene glycol-based polyurethane in this comparative example are shown in Table 2.

[0095] Comparative Example 2 In this comparative example, the polyurethane material is polytetrahydrofuran-based polyurethane, and its preparation method includes: After purging nitrogen into the reaction vessel for 10 min, 0.06 mol of polytetrahydrofuran glycol and 0.126 mol of diphenylmethane diisocyanate (molar ratio 1:2.1) were added, followed by 60 ml of toluene and 0.5 mmol of stannous octoate catalyst. The mixture was then slowly heated to 90 °C at a rate of 20 °C / min under normal pressure and reacted for 3 h. 0.06 mol of chain extender ethylene glycol was then added, and the reaction was continued for another 6 h to obtain polytetrahydrofuran-based polyurethane.

[0096] The properties of the polytetrahydrofuran-based polyurethane in this comparative example are shown in Table 2.

[0097] Comparative Example 3 In this comparative example, the polyester material is polybutylene terephthalate, and its preparation method includes: After nitrogen gas was introduced into the reaction vessel for 10 min, 0.2 mol of dimethyl terephthalate and 0.22 mol of 1,4-butanediol (molar ratio 1:1.1) were added, followed by 0.15 mmol of tetrabutyl titanate catalyst. The mixture was slowly heated to 180 °C at a rate of 20 °C / min under normal pressure and reacted for 4 h. Then, 0.15 mmol of antimony trioxide condensation catalyst and 0.15 mmol of triphenyl phosphate stabilizer were added, and the mixture was heated to 240 °C. The vacuum was then evacuated to a vacuum degree of 10 Pa and reacted for 3 h to obtain polybutylene terephthalate.

[0098] The properties of polybutylene terephthalate in this comparative example are shown in Table 2.

[0099]

[0100]

[0101] As shown in Table 1, the molecular weight of the bio-based polyester polyol based on hydroxy fatty acids / esters of the present invention is controllable and has a narrow distribution. As shown in Table 2, the mechanical property data indicate that, compared with the comparative example without the addition of the bio-based polyester polyol based on hydroxy fatty acids / esters of the present invention, the performance of each embodiment is significantly improved.

[0102] In summary, this invention uses hydroxy fatty acids / esters as raw materials and employs a simple, controllable, and mild process to successfully prepare bio-based polyester polyols with precisely tunable molecular weight, low acid value, and flexible structure. These polyols can be used alone or combined with other polyols to effectively regulate and improve the mechanical properties of polymer materials, demonstrating broad application prospects.

[0103] All aspects, embodiments, and features of this invention should be considered illustrative in all respects and not limiting of the invention; the scope of the invention is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0104] In the preparation method of this invention, the order of the steps is not limited to the listed order. For those skilled in the art, variations in the order of the steps without creative effort are also within the scope of protection of this invention. Furthermore, two or more steps or actions can be performed simultaneously.

[0105] Finally, it should be noted that the specific embodiments described herein are merely illustrative examples of the invention and are not intended to limit the implementation of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them; it is neither necessary nor possible to exemplify all embodiments here. However, these obvious variations or modifications derived from the essential spirit of the invention still fall within the scope of protection of the invention, and interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A method for preparing bio-based polyester polyols based on hydroxy fatty acids / esters, characterized in that, The preparation method includes: In an inert gas atmosphere, hydroxy fatty acid / ester, polyol and catalyst are mixed and heated to the first reaction temperature of 90~120℃ for 0.1~3h, then heated to the second reaction temperature of 110~180℃ for 6~24h, and then evacuated to a vacuum of 0~400 Pa for 1~5h to obtain bio-based polyester polyol based on hydroxy fatty acid ester. The molar ratio of the hydroxy fatty acid / ester and the polyol is (1~50):1; The amount of catalyst added is 0.001~1% of the molar amount of hydroxy fatty acid / ester; The hydroxy fatty acid / ester includes at least one of 3-hydroxybutyric acid, methyl 3-hydroxybutyrate, and ethyl 3-hydroxybutyrate; The polyols include chain polyols and / or cyclic polyols; The catalyst includes at least one of stannous octoate, dibutyltin dilaurate, tetrabutyl titanate, and tin dioxylate.

2. The method for preparing bio-based polyester polyols based on hydroxy fatty acids / esters according to claim 1, characterized in that, The chain polyols include at least one of ethylene glycol, polyethylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerol, pentaerythritol, and 3-hydroxymethylpropane. The cyclic polyols include at least one of 1,4-cyclohexanediol, isosorbide, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 4,4'-bicyclohexanol.

3. The method for preparing bio-based polyester polyols based on hydroxy fatty acids / esters according to claim 1, characterized in that, The hydroxy fatty acid / ester includes at least one of 3-hydroxybutyric acid, methyl 3-hydroxybutyrate, and ethyl 3-hydroxybutyrate.

4. The method for preparing bio-based polyester polyols based on hydroxy fatty acids / esters according to claim 1, characterized in that, The bio-based polyester polyol based on hydroxy fatty acids / esters is poly(3-hydroxybutyrate) polyol, and the end group of this polyol is a secondary hydroxyl group.

5. The method for preparing bio-based polyester polyols based on hydroxy fatty acids / esters according to claim 1, characterized in that, The molecular weight of the bio-based polyester polyol based on hydroxy fatty acids / esters is 300~5000; the molecular weight distribution of the bio-based polyester polyol based on hydroxy fatty acids / esters is ≤1.

5.

6. A bio-based polyester polyol based on hydroxy fatty acid esters, characterized in that, It is prepared by the method for preparing bio-based polyester polyols based on hydroxy fatty acid esters as described in any one of claims 1 to 5.

7. A bio-based polyester material, characterized in that, Its raw materials include the bio-based polyester polyol based on hydroxy fatty acids / esters as described in claim 6.

8. A method for preparing the bio-based polyester material as described in claim 7, characterized in that, The preparation method includes: mixing a bio-based polyester polyol based on hydroxy fatty acids / esters with dimethyl terephthalate, polyol, and catalyst, and then carrying out a first reaction at 130~210℃ for 1~12h, followed by adding a polycondensation catalyst and stabilizer, and continuing to raise the temperature to 220~260℃ for a second reaction for 1~6h to obtain a bio-based polyester material.

9. A bio-based polyurethane material, characterized in that, Its raw materials include the bio-based polyester polyol based on hydroxy fatty acids / esters as described in claim 6.

10. A method for preparing the bio-based polyurethane material as described in claim 9, characterized in that, The preparation method includes: adding a bio-based polyester polyol based on hydroxy fatty acid / ester, a polyol, an isocyanate, and a catalyst into a solvent, heating to 70~120℃ and reacting for 1~6h, adding a chain extender, and continuing the reaction for 1~12h to obtain a bio-based polyurethane material.

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