Organic silicon modified rosin-based polyurethane material as well as preparation method and application thereof

Abstract

The invention discloses an organic silicon modified rosin-based polyurethane material which is prepared from the following raw materials in parts by weight: 39 to 88 parts of rosin-based polyol, 19 to 49 parts of isophorone diisocyanate, 0.1 to 1.9 parts of a catalyst, 49 to 79 parts of polyether polyol, 4.9 to 9.9 parts of a chain extender, 2.9 to 8.9 parts of an amino-terminated silane coupling agent and 55 to 159 parts of an organic solvent. According to the invention, a rosin rigid framework, a polyether polyol flexible chain segment and an amino-terminated siloxane network are combined, so that the rigid structure characteristic of rosin is retained, and the relatively good flexibility of polyether polyol is retained, and the obtained material realizes rigidity-flexibility-hydrophobicity multi-dimensional performance optimization; the coating has the advantages of high strength, high toughness, excellent thermal stability, excellent hydrophobicity and excellent corrosion resistance. The invention also discloses a preparation method and application of the organosilicon modified rosin-based polyurethane material.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and particularly relates to a silicone-modified rosin-based polyurethane material, a preparation method thereof and application thereof. BACKGROUND

[0002] Polyurethane materials have important positions in the fields of flexible electronics, biomedical and environmentally friendly coatings due to their adjustable molecular structure and excellent flexibility. In the field of polyurethane, polyols mainly come from petroleum-based materials. It is a promising alternative to obtain polyols from bio-based materials. Among them, the rigid tricyclic diterpene skeleton in the rosin-based polyol provides a unique advantage for constructing high-performance bio-based polyurethane. However, the polyurethane synthesized by isophorone diisocyanate and rosin-based polyol has the core defect of strong rigidity and insufficient toughness, and this performance imbalance seriously limits its practical application potential. Therefore, developing a multi-component synergistic modification strategy and green preparation technology has become an effective way for the development of rosin-based polyurethane. SUMMARY

[0003] The present application aims to provide a silicone-modified rosin-based polyurethane material, a preparation method thereof and application thereof, in order to solve the defect of strong rigidity and insufficient toughness of the polyurethane synthesized by rosin-based polyol and IPDI in the prior art.

[0004] According to a first aspect of the present application, a silicone-modified rosin-based polyurethane material is provided, and the raw materials thereof include, in parts by weight, 39-88 parts of rosin-based polyol, 19-49 parts of isophorone diisocyanate (IPDI), 0.1-1.9 parts of catalyst, 49-79 parts of polyether polyol, 4.9-9.9 parts of chain extender, 2.9-8.9 parts of amino-terminated silane coupling agent, and 55-159 parts of organic solvent.

[0005] In some embodiments, the catalyst can be selected from at least one of organic tin and organic bismuth. Preferably, the catalyst can be selected from at least one of dibutyltin dilaurate (DBTDL), stannous octoate, bismuth isooctoate, and bismuth laurate.

[0006] In some embodiments, the rosin-based polyol is a trifunctional rosin-based polyol.

[0007] In some embodiments, the rosin-based polyol (MEH) has the following structural formula: .

[0008] In some embodiments, the polyether polyol can be selected from at least one of polyoxypropylene glycol, polyoxypropylene triol, polytetrahydrofuran ether glycol (PTMG), polyoxyethylene glycol, and polyoxyethylene triol.

[0009] In some embodiments, the chain extender can be an alcohol chain extender, in particular, the chain extender is selected from at least one of 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, hydroquinone dihydroxyethyl ether, neopentyl glycol.

[0010] In some embodiments, the amino-terminated silane coupling agent can be selected from at least one of 3-aminopropyltriethoxysilane, aminopropyl silicone oil, secondary amine trimethoxysilane, amino-terminated polydimethylsiloxane, gamma- aminoethylaminopropyltrimethoxysilane.

[0011] In some embodiments, the polyether polyol has a number average molecular weight of 1000-2000.

[0012] In some embodiments, the polydimethylsiloxane has a polymerization degree of 10-24.

[0013] In some embodiments, the organic solvent can be selected from at least one of acetone, butanone, cyclohexanone, 1,4-dioxane, tetrahydrofuran.

[0014] In some embodiments, the mass ratio of the rosin-based polyol, isophorone diisocyanate, polyether polyol, and amino-terminated silane coupling agent is (50-70):(25-30):(50-55):(3-10). Preferably, the mass ratio of the rosin-based polyol, isophorone diisocyanate, polyether polyol, and amino-terminated silane coupling agent is 66:30:52:4.

[0015] According to a second aspect of the present application, a preparation method of a silicone-modified rosin-based polyurethane material is provided, comprising the following steps: S1, mixing a rosin-based polyol, isophorone diisocyanate, a catalyst, and an organic solvent to obtain a reaction system, and then reacting at 35-79°C for 1-4h; S2, adding a polyether polyol to the reaction system, and reacting at 45-65°C for 1-3h; S3, adjusting the temperature of the reaction system to 30-49°C, adding a chain extender to the reaction system and reacting for 3-5h, reducing to room temperature, adding an amino-terminated silane coupling agent to the reaction system, and reacting for 0.5-1.5h.

[0016] The preparation method of the present application first performs bulk polymerization of the rosin-based polyol and isophorone diisocyanate as a hard segment, then introduces a polyether polyol as a soft segment, thereby realizing the alternate connection of the soft and hard segments of the polyurethane; then adds a chain extender for chain extension, and finally adds an amino-terminated silane coupling agent to improve the flexibility, corrosion resistance, and hydrophobicity of the material.

[0017] In some embodiments, the reaction system can be reacted in a nitrogen atmosphere.

[0018] According to a second aspect of the present application, there is provided the use of the organosilicon-modified rosin-based polyurethane material in the preparation of a protective coating having at least one of the properties of corrosion resistance, hydrophobicity.

[0019] The present application has the following advantages: (1) Compared with the existing thermoplastic polyurethane, the present application uses a bio-based material, bio-based rosin trifunctional resin polyol (MEH), to replace traditional petroleum-based raw materials, which is green and environmentally friendly. (2) The present application combines the rigid backbone of rosin-based polyol, the flexible segment of polyether polyol, and the amino-terminated silane coupling agent, which not only retains the rigid structural characteristics of rosin, but also retains the good flexibility of polyether polyol. Moreover, the organosilicon-modified rosin-based polyurethane material prepared has excellent comprehensive performance in mechanical properties, thermal stability, chemical corrosion resistance, and corrosion resistance. (3) The present application uses a multi-component synergistic modification strategy. The organosilicon-modified rosin-based polyurethane material has high strength and toughness, thermal stability, hydrophobicity, and corrosion resistance, achieving multi-dimensional performance optimization of material rigidity-flexibility-hydrophobicity. Without the use of fluorine-containing compounds, the environmental risk can be significantly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The synthesis path of the organosilicon-modified rosin-based polyurethane material of the present application is as follows: Figure 2 The Fourier transform infrared spectrum of Example 1 of the present application is as follows: Figure 3 The water contact angle test results of the cured films obtained in Examples 1-4 and Comparative Examples 1-3 of the present application are as follows: Figure 4 The electrochemical test results of the coatings obtained in Comparative Examples 1-3 of the present application are as follows: Figure 5 The electrochemical test results of the coatings obtained in Examples 1-4 of the present application are as follows. DETAILED DESCRIPTION

[0021] The present application will be further described in detail below with reference to the accompanying drawings, but the embodiments of the present application are not limited thereto. The raw materials and reagents involved in the following examples can be obtained from commercial channels.

[0022] The synthesis path of the organosilicon-modified rosin-based polyurethane material of the present application is as follows: Figure 1As shown. Specifically, a trifunctional rosin-based polyol (MEH) and isophorone diisocyanate (IPDI) undergo bulk polymerization at 65°C under the action of a catalyst (DBTDL) to obtain rosin-based polyurethane (M-OPU); M-OPU and PTMG continue to react at 65°C, and then 1,4-butanediol is added for chain extension at 45°C to obtain polyether-modified rosin-based polyurethane (P / M-OPU); finally, the -NCO group of P / M-OPU reacts with the -NH2 group of amino-terminated polydimethylsiloxane (APT-PDMS) at 30°C to obtain organosilicon-modified rosin-based polyurethane (AP / P / M-OPU).

[0023] It should be noted that in the synthesis route of the present invention, the reaction temperature and some raw materials are not the only options. Among them, PTMG can be selected from other materials that are also polyether polyols, 1,4-butanediol can be selected from other materials that are also alcohols as chain extenders, and amino-terminated polydimethylsiloxane can be selected from amino-terminated silane coupling agents.

[0024] The trifunctional rosin-based polyol (MEH) of the present invention is prepared by the method described in prior art CN119431142A, comprising the following steps: (1) After heating and dissolving 27-79 parts of maleic anhydride and 165-225 parts of epichlorohydrin into a homogeneous phase, add 0.13-1.50 parts of tetrabutylammonium bromide and react at 80-130℃ until the acid value is less than 1mgKOH / g. Then, cool down to 50-90℃ and add 8-33 parts of sodium hydroxide. React until the pH value no longer decreases. Remove epichlorohydrin by vacuum distillation at a temperature of 60-70℃ and a pressure of 120-150Pa to obtain maleic epoxy resin. (2) Mix 33-77 parts of hydroxyethyl methacrylate, 19-59 parts of maleic anhydride and 0.05-0.25 parts of hydroquinone, and react in a nitrogen atmosphere at a temperature of 80-130℃ for 3.5-8.5 h to obtain hydroxy acrylate. (3) Mix 27-79 parts of pine resin, 15-77 parts of hydroxy acrylate, 0.05-0.75 parts of hydroquinone and 0.07-1.53 ​​parts of tetrabutylammonium bromide, heat to 80-130℃ in a nitrogen atmosphere, and then react until the acid value is less than 15mgKOH / g to obtain the product.

[0025] In the following examples and comparative examples, trifunctional rosin-based polyols (MEHs) were prepared by the following steps: (1) Add 50.00g of maleic anhydride and 185.00g of epichlorohydrin to a three-necked flask equipped with a stirrer, condenser and thermometer. Heat to dissolve into a homogeneous phase, then add 2.35g of tetrabutylammonium bromide. The reaction system is reacted at 110℃ until the acid value is lower than 1mgKOH / g. Then the temperature is lowered to 70℃, 15g of sodium hydroxide is added, and the reaction is continued for 3h until the pH value of the system no longer decreases. Filter, wash the filtrate with deionized water until neutral, and distill under reduced pressure at 65℃ and 120-150Pa to recover excess epichlorohydrin and obtain maleic anhydride epoxy resin. (2) 52.10g of hydroxyethyl methacrylate, 39.20g of maleic anhydride and 0.18g of hydroquinone were added to a three-necked flask with a stirrer, a condenser and a thermometer. In a nitrogen atmosphere, the reaction system was first heated to 70°C in an oil bath and stirred until the maleic anhydride solid melted. Then the temperature was raised to 100°C and the reaction was carried out for 5 hours to obtain hydroxy acrylate. (3) Add 58.60g of maleic pine epoxy resin, 36.28g of hydroxy acrylate, 0.95g of N,N-dimethylbenzylamine and 0.19g of hydroquinone to a three-necked flask equipped with a stirrer, condenser and thermometer. Stir and react at 105℃ for 5h under nitrogen atmosphere until the acid value is lower than 15mgKOH / g. Cool to room temperature to obtain the product.

[0026] In the following examples and comparative examples, the number average molecular weight of PTMG was 2000, and the degree of polymerization of amino-terminated polydimethylsiloxane was 10-15. All raw materials underwent appropriate dehydration treatment before the reaction. The purpose of dehydration treatment is to prevent water in the raw materials from reacting with IPDI, which can easily lead to phenomena such as gelation during the reaction.

[0027] Example 1 This embodiment provides a method for preparing an organosilicon-modified rosin-based polyurethane material (AP / P / M-OPU), comprising the following steps: 66.0 g MEH, 30.0 g IPDI, 1.0 g DBTDL and 100 mL tetrahydrofuran were added to a three-necked flask. After mechanical stirring at 65 °C under a nitrogen atmosphere for 2 h, rosin-based polyurethane (M-OPU) was obtained. 51.4 g PTMG was added to the three-necked flask, and the reaction was continued for 2 h. Then the temperature was lowered to 45 °C, and 7.0 g 1,4-butanediol was added to the three-necked flask for chain extension reaction for 3 h to obtain polyether-modified rosin-based polyurethane (P / M-OPU). The temperature was then lowered to room temperature, and 3.8 g APT-PDMS was added to the three-necked flask. The reaction was carried out for 1 h to obtain the final product.

[0028] Example 2 This embodiment provides a method for preparing an organosilicon-modified rosin-based polyurethane material, including the following steps: 62.0 g MEH, 30.0 g IPDI, 1.0 g DBTDL and 100 mL tetrahydrofuran were added to a three-necked flask. After mechanical stirring at 65 °C under a nitrogen atmosphere for 2 h, rosin-based polyurethane (M-OPU) was obtained. 51.4 g PTMG was added to the three-necked flask, and the reaction was continued for 2 h. Then the temperature was lowered to 45 °C, and 7.0 g 1,4-butanediol was added to the three-necked flask for chain extension reaction for 3 h to obtain polyether-modified rosin-based polyurethane (P / M-OPU). The temperature was then lowered to room temperature, and 5.8 g APT-PDMS was added to the three-necked flask. The reaction was carried out for 1 h to obtain the final product.

[0029] Example 3 This embodiment provides a method for preparing an organosilicon-modified rosin-based polyurethane material, including the following steps: 58.0 g MEH, 30.0 g IPDI, 1.0 g DBTDL and 100 mL tetrahydrofuran were added to a three-necked flask. After mechanical stirring at 65 °C under a nitrogen atmosphere for 2 h, rosin-based polyurethane (M-OPU) was obtained. 51.4 g PTMG was added to the three-necked flask, and the reaction was continued for 2 h. Then the temperature was lowered to 45 °C, and 7.0 g 1,4-butanediol was added to the three-necked flask for chain extension reaction for 3 h to obtain polyether-modified rosin-based polyurethane (P / M-OPU). The temperature was then lowered to room temperature, and 7.8 g APT-PDMS was added to the three-necked flask. The reaction was carried out for 1 h to obtain the final product.

[0030] Example 4 This embodiment provides a method for preparing an organosilicon-modified rosin-based polyurethane material, including the following steps: 54.0 g MEH, 30.0 g IPDI, 1.0 g DBTDL and 100 mL tetrahydrofuran were added to a three-necked flask. After mechanical stirring at 65 °C under a nitrogen atmosphere for 2 h, rosin-based polyurethane (M-OPU) was obtained. 51.4 g PTMG was added to the three-necked flask, and the reaction was continued for 2 h. Then the temperature was lowered to 45 °C, and 7.0 g 1,4-butanediol was added to the three-necked flask for chain extension reaction for 3 h to obtain polyether-modified rosin-based polyurethane (P / M-OPU). The temperature was then lowered to room temperature, and 9.8 g APT-PDMS was added to the three-necked flask. The reaction was carried out for 1 h to obtain the final product.

[0031] Comparative Example 1 This comparative example provides a method for preparing a rosin-based ultraviolet-curable material, including the following steps: Mix 5g MEH, 1.5g hydroxy acrylate and 0.2g photoinitiator 1173 evenly to obtain the final product.

[0032] Comparative Example 2 This comparative example provides a method for preparing a rosin-based polyurethane material, comprising the following steps: 102.0 g MEH, 30.0 g IPDI, 1.0 g DBTDL and 100 mL tetrahydrofuran were added to a three-necked flask. After mechanical stirring at 65 °C under a nitrogen atmosphere for 2 h, the temperature was lowered to 45 °C, and 7.0 g 1,4-butanediol was added to the three-necked flask to carry out a chain extension reaction for 3 h to obtain M-OPU.

[0033] Comparative Example 3 This comparative example provides a method for preparing a rosin-based polyurethane material, comprising the following steps: 68.0 g MEH, 30.0 g IPDI, 1.0 g DBTDL and 100 mL tetrahydrofuran were added to a three-necked flask. After mechanical stirring for 2 h under a nitrogen atmosphere at 65 °C, 51.4 g PTMG was added to the three-necked flask and the reaction was continued for 2 h. Then the temperature was lowered to 45 °C and 7.0 g 1,4-butanediol was added to the three-necked flask for chain extension reaction for 3 h to obtain P / M-OPU.

[0034] Infrared spectroscopy was performed on MEH, IPDI, PTMG, APT-PDMS, the product of Example 1, the product of Comparative Example 2, and the product of Comparative Example 3. The results are as follows: Figure 2 As shown. By Figure 2 (a) It can be seen that 2270 cm in the IPDI map -1 The peak is the absorption peak of -NCO, at 1107 cm⁻¹ in the PTMG spectrum. -1 The peak at 3332 cm⁻¹ represents the stretching vibration of the ether bond. (This is from the APT-PDMS spectrum.) -1 The peak at 1020 cm⁻¹ corresponds to the characteristic absorption peak of -NH₂. -1 The peak at 1633 cm⁻¹ is the stretching vibration peak of Si-O-Si. In the MEH spectrum, this peak is at 1633 cm⁻¹. -1 and 1725 cm -1 The peaks at 3500 cm⁻¹ represent the absorption peaks of the carbon-carbon double bond and the ester carbonyl group, respectively. -1 The corresponding absorption peak is a hydroxyl group. Figure 2 (b) It can be seen that the peak positions of M-OPU, P / M-OPU, and AP / P / M-OPU are mostly consistent, around 3500 cm⁻¹. -1 The hydroxyl absorption peak at 2270 cm⁻¹ -1 The -NCO absorption peaks at this point disappear, and all peaks are located at 1537 cm⁻¹. -1 and 3350 cm -1The appearance of a stretching vibration peak of -NH in urethane at 1107 cm⁻¹ confirms the complete reaction of the hydroxyl group in MEH and the -NCO group in IPDI. In contrast, due to the addition of PTMG to P / M-OPU and AP / P / M-OPU, a peak is observed at 1107 cm⁻¹. -1 Stretching vibration peaks of ether bonds appeared at all locations. In AP / P / M-OPU, the amino group of APT-PDMS participates in the reaction, and its peak appears at 3332 cm⁻¹. -1 The characteristic absorption peak of -NH2 disappears at 1020 cm⁻¹ -1 The presence of a stretching vibration peak in Si-O-Si from APT-PDMS at this location proves the successful synthesis of an organosilicon-modified rosin-based polyurethane material.

[0035] Comparative Example 4 This comparative example provides a method for preparing an organosilicon-modified rosin-based polyurethane material, comprising the following steps: 66.0 g MEH, 30.0 g IPDI, 1.0 g DBTDL and 100 mL tetrahydrofuran were added to a three-necked flask. After mechanical stirring at 65 °C under a nitrogen atmosphere for 2 h, rosin-based polyurethane (M-OPU) was obtained. The temperature was lowered to 45 °C, and 3.8 g APT-PDMS was added to the three-necked flask. The reaction was carried out for 1 h, and then 7.0 g 1,4-butanediol was added to the three-necked flask for chain extension reaction for 3 h. Finally, 51.4 g PTMG was added to the three-necked flask, and the reaction was continued for 2 h to obtain the final product.

[0036] The results showed that PTMG could not participate in the reaction effectively. Most of it was physically encapsulated in the already cross-linked PDMS network as an inert filler or unreacted material, and could not achieve chemical bonding at the molecular level. This resulted in easy gelation and extremely poor performance.

[0037] Comparative Example 5 This comparative example provides a method for preparing an organosilicon-modified rosin-based polyurethane material, comprising the following steps: Add 66.0 g MEH, 30.0 g IPDI, 1.0 g DBTDL, 3.8 g APT-PDMS, 7.0 g 1,4-butanediol and 100 mL tetrahydrofuran to a three-necked flask and stir mechanically under a nitrogen atmosphere at 65 °C.

[0038] The results showed that the reactants in the three-necked flask exhibited gelation, which may be because: 1. The raw materials have relatively large molecular weights, making them prone to cross-linking and gel formation; 2. Functionality Imbalance: MEH is a trifunctional polyol, and the addition of APT-PDMS instantly and significantly increased the effective average functionality of the entire system to well above 2; 3. The presence of highly active amino groups: The amino groups of APT-PDMS react with the NCO groups of IPDI at an extremely fast rate, and the resulting urea bonds can react further, easily forming cross-linking points; 4. The two NCO groups of IPDI have different reactivity, which may lead to heterogeneous reaction and branching.

[0039] The silicone-modified rosin-based polyurethane materials of Examples 1-4 and the rosin-based polyurethane materials of Comparative Examples 2-3 were cured into films. The preparation method of the rosin-based polyurethane cured film is as follows: the rosin-based polyurethane material is injected into a polytetrafluoroethylene mold, the mold is placed at 25°C for 12 h to evaporate most of the solvent, and then the mold is dried at 50°C for 12 h to obtain the cured film.

[0040] The rosin-based UV-curable material of Comparative Example 1 was UV-cured for 3 min under UV light at a wavelength of 365 nm to obtain a rosin-based UV-curable film.

[0041] The cured films of the organosilicon-modified rosin-based polyurethane materials of Examples 1-4, the cured films of the rosin-based polyurethane materials of Comparative Examples 2-3, and the rosin-based ultraviolet-cured film of Comparative Example 1 were subjected to the following tests.

[0042] I. Tensile Properties Testing of Plastics The tensile properties of the samples (cured film) were tested using a Shimadzu AGS-X 1kN universal testing instrument. The dumbbell-shaped samples conformed to GB / T 1040.2-2006, and the crosshead speed was 1 mm·min. -1 To ensure the accuracy of the test results, each sample was tested three times, and the average of the results was taken.

[0043] II. Thermogravimetric Test Thermogravimetric analysis (TGA) of the cured film was performed using a Netzsch STA 449C thermal analyzer. The required temperature range for the TGA test was set to 35-800℃, and the heating rate was 10℃·min. -1 A nitrogen atmosphere was maintained during the experiment, with a nitrogen introduction rate of 20 mL / min. -1 To ensure the accuracy of the test results, each sample was measured three times and the average value was taken.

[0044] Thermogravimetric analysis was performed on the samples, and the thermal degradation temperature (T0) at which the cured films of Examples 1-4 and Comparative Examples 1-3 experienced a 10% weight loss was recorded. 10% ), 50% thermal degradation temperature (T) 50% ), and the carbon residue at 800℃.

[0045] III. Water Contact Angle Test The water contact angle (WCA) of the cured film was measured using a DATAPHYSICS DCA20 contact angle meter. For each WCA test, the measurement was repeated three times at randomly distributed locations on the coating.

[0046] IV. Electrochemical Testing Preparation of coating samples: The surface of Q235 carbon steel (120 mm × 50 mm × 0.3 mm) was polished sequentially with 300-grit and 1500-grit sandpaper, and then wiped clean with ethanol. The reacted polyurethane coating liquid (organosilicon-modified rosin-based polyurethane materials of Examples 1-4 and rosin-based polyurethane materials of Comparative Examples 2-3) was vacuumed at room temperature for 10 min to remove organic solvents, and then uniformly coated onto the surface of Q235 carbon steel using a 250 μm four-sided coater. After coating, all samples were placed at 25℃ for 12 h, and then cured at 50℃ for 12 h. The cured coating thickness was (100±5) μm.

[0047] It should be noted that the coating sample of Comparative Example 1 was prepared by the following steps: the rosin-based UV-curable coating of Comparative Example 1 was uniformly coated onto the surface of Q235 carbon steel after polishing and wiping by the above method using a 250 μm four-sided coater, and then UV-cured for 3 min under UV light with a wavelength of 365 nm. The thickness of the cured coating was (100±5) μm.

[0048] Electrochemical measurements were performed on a CHI-660E electrochemical station manufactured by Shanghai Chenhua, equipped with a three-electrode battery system, at room temperature on a coating sample immersed in a 3.5 wt% NaCl solution to evaluate the corrosion resistance of the composite coating. The area was 2.5 cm². 2 A platinum sheet was used as the counter electrode (CE), a saturated Ag / AgCl electrode as the reference electrode (RE), and a coated carbon steel sheet as the working electrode. Electrochemical impedance spectroscopy (EIS) data were recorded in the frequency range of 100 kHz to 0.01 Hz and with a sinusoidal amplitude of 10 mV. Potentials were measured at 0.01 V·s⁻¹ relative to the open-circuit voltage from -500 to 500 mV. -1 Polarization measurements were performed using the scan rate. Each sample was tested three times.

[0049] The comprehensive mechanical properties of the cured film are shown in Table 1. As can be seen from Table 1, compared to the unmodified Comparative Example 1, Comparative Example 2 (which underwent IPDI crosslinking and added a chain extender), and Comparative Example 3 (modified with IPDI and polytetrahydrofuran ether diol), the rosin-based polyurethane cured films prepared by the synergistic modification of rosin trifunctional resin polyols with flexible polyether polyol segments and amino-terminated polysiloxanes in Examples 1-4 of this invention exhibit significantly improved elongation at break. Furthermore, the elongation at break of the cured film of the silicone-modified rosin-based polyurethane material increases with the increase of the amino-terminated polydimethylsiloxane content, indicating that the silicone-modified rosin-based polyurethane material maintains a certain rigidity while significantly improving toughness, and its glass transition temperature (T0) is also improved. g All temperatures remained above 68℃, exhibiting good mechanical properties. This is likely because polytetrahydrofuran ether diol, as a long-chain polyether soft segment, provides high flexibility and molecular chain slippage capability. The ether bonds (—O—) form hydrogen bonds with the hard segments, maintaining material coherence. The rigidity of the siloxane chains (Si—O—Si) and the amino crosslinking points form a physical / chemical crosslinking network, limiting excessive chain slippage. The elongation at break is affected by the length and content of the soft segments, thus showing a gradually increasing trend.

[0050] Table 1. Test results of comprehensive mechanical properties of the cured film

[0051] The thermal stability test results of the cured film are shown in Table 2. As can be seen from Table 2, compared to the unmodified Comparative Example 1, Comparative Example 2 with crosslinking reaction using IPDI and the addition of a chain extender, and Comparative Example 3 modified with IPDI and polytetrahydrofuran ether diol, the rosin-based polyurethane cured films prepared by the synergistic modification of rosin trifunctional resin polyols with flexible polyether polyol segments and amino-terminated siloxanes in Examples 1-4 of this invention exhibit improved thermal stability. 10% All above 300℃, T 50% All films cured at temperatures above 400℃ showed significantly higher char residue rates than the cured films of Comparative Examples 1-3. This change is attributed to the introduction of APT-PDMS. The amino groups in APT-PDMS react with the isocyanate groups in the polyurethane to form a cross-linked network structure, enhancing the intermolecular forces and thus improving the thermal stability of the polyurethane. With increasing APT-PDMS content, T... 10% T 50% The carbon residue initially increases and then decreases. This may be because the Si-O bond in APT-PDMS has a higher bond energy than the C-C and CO bonds. When APT-PDMS is added in an appropriate amount, the thermal stability of polyurethane is improved. However, when the amount added is too large, the aggregation of APT-PDMS causes defects, leading to a decrease in thermal stability.

[0052] Table 2. Thermal stability test results of the cured film

[0053] The water contact angle test results of each cured film are as follows: Figure 3 As shown. From Figure 3 It can be seen that when polyurethane was not modified with APT-PDMS and PTMG, the static water contact angle of the cured films in Comparative Examples 1-3 was less than 80°. The static water contact angle of the cured films of the modified silicone-modified rosin-based polyurethane materials in Examples 1-4 changed significantly. The static water contact angle of the cured film in Example 1 was 83.00°, while the static water contact angle of the cured films in Examples 2-4 was greater than 90°, indicating that their surfaces possess hydrophobic properties. This is because PTMG, as a polyether glycol, has flexible segments that can adjust the ratio of soft to hard segments in polyurethane, reducing the overall polarity of the material and thus reducing the exposure of hydrophilic groups. Furthermore, with the increase of APT-PDMS content, the coating changes from hydrophilic to hydrophobic. This change is attributed to the migration of silicone segments with significant hydrophobic properties from APT-PDMS to the coating surface, which reduces the surface energy of the coating, thereby achieving a hydrophobic effect. However, the water contact angle did not increase with the increase of APT-PDMS content because the siloxane segments reached their maximum value on the coating surface, and the structure of the coating surface would not become rougher. Therefore, further increasing the APT-PDMS content would not increase the water contact angle of the coating.

[0054] Electrochemical test results as follows Figures 4-5 As shown. From Figures 4-5 It can be seen that, in the initial stage of immersion, the Bode impedance curves of the coatings in Comparative Examples 1-3 and Examples 1-4 show diagonal lines over a wide frequency range. Among them, the Bode impedance curves of the coatings in Comparative Examples 1-3 exhibit a lower |Z| during the middle stage of immersion. 0.01 Hz The value, as the immersion time increases, shows that the comparative resin coating, after 56 days of immersion, |Z |0.01 Hz The value dropped to 10 6 ~10 8 Ω·cm 2 The values ​​were 2-4 orders of magnitude lower than the initial immersion values, meaning that the corrosion resistance of the coatings in comparison samples 1-3 continued to decline. From... Figure 5 The Bode impedance curves show that the coatings of Examples 1-4, which are co-modified with PTMG and APT-PDMS, exhibit |Z | 0.01 Hz The value decreases slowly, |Z| 0.01 Hz Value from 10 10 Ω·cm 2 dropped to 10 8 ~10 9 Ω·cm 2It only reduces by 1 to 2 orders of magnitude, and its |Z| 0.01 Hz The values ​​were all higher than the control group, with |Z| values ​​after soaking for 56 days being higher. 0.01 Hz The value compared to |Z| after soaking for 0 days 0.01 Hz The rate of decrease in the value was also lower than that of the comparative example, indicating that the coatings prepared from the organosilicon-modified rosin-based polyurethane materials in Examples 1-4 exhibited superior anti-corrosion performance in electrochemical tests. Moreover, the anti-corrosion ability of the coating in Example 4, which had an excessive amount of amino-terminated silane coupling agent added, was lower than that of the coatings in Examples 1-3. Among them, the coating in Example 2 showed the best anti-corrosion performance.

[0055] This application found that when trifunctional rosin-based polyols are reacted with IPDI, the resulting polyurethane exhibits significantly insufficient flexibility. To achieve multidimensional performance optimization of polyurethane materials, encompassing rigidity, flexibility, and hydrophobicity, this invention uses polyether polyols, amino-terminated silane coupling agents, IPDI, and rosin-based polyols as raw materials. It combines the rigid rosin backbone, the flexible segments of the polyether polyol, and the amino-terminated siloxane network, resulting in a polyurethane material that retains both the rigid structural characteristics of rosin and the good flexibility of the polyether polyol. When an appropriate amount of amino-terminated silane coupling agent is added, the resulting coating exhibits excellent overall performance, combining strength and high toughness, excellent thermal stability, hydrophobicity, and corrosion resistance.

[0056] When APT-PDMS and PTMG are used simultaneously as raw materials for rosin-based polyurethanes, the addition of APT-PDMS promotes and strengthens the microphase separation structure of the polyurethane. The soft segment phase region formed by PTMG provides the bulk mechanical properties, while APT-PDMS tends to form a thin layer rich in siloxanes on the surface. This structure allows the material to retain the good mechanical properties imparted by PTMG inside, while acquiring the unique properties (hydrophobicity, lubrication, and biocompatibility) imparted by APT-PDMS on the surface. The presence of PTMG provides the "driving force" and "substrate" for the surface enrichment of APT-PDMS, making the surface modification effect of siloxanes more significant and stable.

[0057] This application found that when PTMG, 1,4-butanediol, rosin-based polyol, and IDPI are reacted together, the product tends to gel. If PDMS is added before PTMG, PTMG cannot effectively participate in the reaction; most of it acts as an inert filler or unreacted material, physically encapsulated within the already cross-linked PDMS network, failing to achieve molecular-level chemical bonding, resulting in easy gelation or extremely poor performance. This invention, however, chooses to add polytetrahydrofuran first, followed by PDMS, achieving "chain extension before cross-linking," making the reaction process less prone to gelation. Through the order of addition in this invention's preparation method, the reaction network can achieve alternating connections of soft and hard segments, resulting in an organosilicon-modified rosin-based polyurethane material that combines flexibility, hydrophobicity, rigidity, and corrosion resistance.

[0058] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. Silicone-modified rosin-based polyurethane material, characterized in that, The raw materials include, by weight: 39-88 parts of rosin-based polyol, 19-49 parts of isophorone diisocyanate, 0.1-1.9 parts of catalyst, 49-79 parts of polyether polyol, 4.9-9.9 parts of chain extender, 2.9-8.9 parts of amino-terminated silane coupling agent, and 55-159 parts of organic solvent.

2. The silicone-modified rosin-based polyurethane material of claim 1, wherein, The polyether polyol is selected from at least one of polyoxypropylene diol, polyoxypropylene triol, polytetrahydrofuran ether diol, and polyoxyethylene polyol.

3. The silicone-modified rosin-based polyurethane material according to claim 1 or 2, characterized in that, The number average molecular weight of the polyether polyol is 1000-2000.

4. The silicone-modified rosin-based polyurethane material of claim 1, wherein, The amino-terminated silane coupling agent is selected from at least one of 3-aminopropyl triethoxysilane, aminopropyl silicone oil, secondary amine-based trimethoxysilane, amino-terminated polydimethylsiloxane, and γ-aminoethyl aminopropyl trimethoxysilane.

5. The silicone-modified rosin-based polyurethane material of claim 4, wherein, The degree of polymerization of the amino-terminated polydimethylsiloxane is 10-24.

6. The silicone-modified rosin-based polyurethane material of claim 1, wherein, The rosin-based polyol has the following structural formula: 。 7. The silicone-modified rosin-based polyurethane material of claim 1, wherein, The organic solvent is selected from at least one of acetone, butanone, cyclohexanone, 1,4-dioxane, and tetrahydrofuran; the chain extender is selected from at least one of 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, hydroquinone dihydroxyethyl ether, and neopentyl glycol; and the catalyst is selected from at least one of organic tin and organic bismuth.

8. The silicone-modified rosin-based polyurethane material of claim 1, wherein, The mass ratio of the rosin-based polyol, isophorone diisocyanate, polyether polyol, and amino-terminated silane coupling agent is (50-70):(25-30):(50-55):(3-10).

9. A process for the preparation of the silicone-modified rosin-based polyurethane material according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: S1, mixing the rosin-based polyol, isophorone diisocyanate, catalyst, and organic solvent to obtain a reaction system, and then reacting at 35-79°C for 1-4h; S2, adding the polyether polyol to the reaction system, and reacting at 45-65°C for 1-3h; S3, adjusting the temperature of the reaction system to 30-49°C, adding the chain extender to the reaction system, and reacting for 3-5h, then reducing to room temperature, adding the amino-terminated silane coupling agent to the reaction system, and reacting for 0.5-1.5h to obtain the product.

10. Use of the silicone-modified rosin-based polyurethane material according to any one of claims 1-8 in the preparation of a protective coating having at least one of corrosion resistance and hydrophobicity.

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