Photo-induced deformation deicing material and preparation method thereof

Abstract

The application provides a photo-induced deformation anti-icing material and a preparation method thereof, and belongs to the technical field of functional polymer materials. The method comprises the following steps: (1) preparation of a hydroxyl-terminated trimer; (2) preparation of an isocyanate-terminated prepolymer; (3) compounding of a polymer matrix and a functional component; and (4) forming and curing. Through the multiple hydrogen bond action of carboxylic acid groups and urethane groups in the molecular chain, the material is endowed with super-tough solvent resistance; through the photo-induced deformation characteristics of liquid crystal monomers and the high-efficiency light-heat conversion of a black light absorber, low-energy-consumption high-efficiency deicing is realized, and the material has reworkability and is suitable for anti-icing scenes such as aerospace and power transmission.

Description

Technical Field

[0001] This invention relates to the field of functional polymer materials technology, and in particular to a photodeformable anti-icing material and its preparation method. Background Technology

[0002] In critical sectors such as aerospace, transportation, and power transmission, the safety hazards and operational failures caused by snow and ice accumulation are becoming increasingly severe. Domestic research focuses on the multifunctional integration and engineering applications of materials. Much research concentrates on the composite of carbon-based materials (such as MXene and graphene) and polymers to improve photothermal conversion efficiency. For example, teams from Harbin Institute of Technology and others have conducted in-depth research on the application of epoxy resin / graphene oxide (GO / EP) composites in wing de-icing, utilizing shape memory to achieve dynamic recovery of surface microstructures. International research emphasizes molecular design and the exploration of fundamental physical mechanisms. For instance, institutions such as Tokyo Institute of Technology have conducted in-depth research on the photochemical phase transition mechanism of photodeformable polymers, aiming to find more efficient azobenzene derivatives and novel photosensitive groups. More research is combining photodeformable materials with soft robots and micro-actuators to study their stability and lifespan in extreme environments. However, current research still faces bottlenecks such as the limited variety of materials (mostly azobenzene-based), sensitivity to ultraviolet light, and poor long-term stability.

[0003] Traditional de-icing methods, such as mechanical scraping and chemical spraying, can alleviate the problem in the short term, but they generally suffer from drawbacks such as high energy consumption, severe environmental pollution, and irreversible damage to the substrate. Photodeformable materials, with their advantages of remote control, low energy consumption, and rapid response, are considered a cutting-edge solution to this problem. However, existing photodeformable polymer materials still face serious challenges: on the one hand, thermoplastic polymers, while flexible, have poor mechanical properties, while thermosetting polymers, although strong, are not recyclable; on the other hand, problems such as uneven dispersion of light absorbers and poor compatibility between liquid crystal monomers and the matrix often exist within the materials, directly limiting the photothermal conversion efficiency and deformation response rate.

[0004] Therefore, developing a new generation of anti-icing and de-icing materials that combines ultra-tough solvent resistance with efficient photodeformation capabilities has become the key to breaking through the bottleneck in snow and ice disaster management. Summary of the Invention

[0005] In view of this, the present invention provides a photodeformable anti-icing material and its preparation method. Through molecular structure design and component optimization, the present invention enables the prepared photodeformable anti-icing material to possess both ultra-toughness and solvent resistance, as well as highly efficient photodeformation properties, thus overcoming many drawbacks of traditional de-icing methods.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a method for preparing a photodeformable anti-icing material, comprising the following steps:

[0008] (1) Preparation of hydroxyl-terminated trimer: Under an inert atmosphere, a diacid is added to a long-chain diol and refluxed to obtain a hydroxyl-terminated trimer;

[0009] (2) Preparation of isocyanate-terminated prepolymer: Diisocyanate is added to an organic solvent and stirred to dissolve, thereby obtaining a diisocyanate organic solution. Then, the diisocyanate organic solution is added to the hydroxyl-terminated trimer in step (1), and the reaction is carried out under an inert atmosphere to obtain an isocyanate-terminated prepolymer.

[0010] (3) Combining polymer matrix with functional components: Diamine is added to an organic solvent and stirred to dissolve, resulting in a diamine organic solution. Then, the diamine organic solution is added to the isocyanate-terminated prepolymer in step (2). After stirring and reacting for a period of time, liquid crystal monomer and black light absorber are added in sequence, and stirring is continued to obtain a uniform dark brown composite system.

[0011] (4) Molding and curing: The uniform dark brown composite system is molded and cured to obtain a photodeformable anti-icing material.

[0012] Furthermore, the molar ratio of the long-chain diol and the dianhydride in step (1) is 1.9-2.1:0.9-1.1.

[0013] Furthermore, the reflux reaction temperature in step (1) is 40-100℃, and the reflux reaction time is 3-12h.

[0014] Furthermore, the long-chain diol mentioned in step (1) is one or more of polypropylene glycol, polybutane glycol, and polydimethylsiloxane with a molecular weight in the range of 500 to 10,000.

[0015] Furthermore, the dihydric anhydride in step (1) is selected from any one of pyromellitic dianhydride, 4,4'-oxobisphthalic anhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, and 3,3',4,4'-benzophenonetetracarboxylic anhydride.

[0016] Furthermore, the molar ratio of the diisocyanate to the long-chain diol in step (2) is 0.9-1.1:0.9-1.1.

[0017] Furthermore, in step (2), the reflux reaction temperature is 40–120°C and the reflux reaction time is 2–6 h.

[0018] Furthermore, the diisocyanate in step (2) is selected from any one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate or hexamethylene diisocyanate.

[0019] Furthermore, the diamine mentioned in step (3) is selected from any one of 4,4'-diaminodiphenylmethane, triethylenediamine, and ethylenediamine.

[0020] Furthermore, the molar ratio of the diamine to the long-chain diol in step (3) is 0.9-1.1:1.9-2.1.

[0021] Further, the liquid crystal monomer in step (3) is selected from nematic liquid crystal monomers. The nematic liquid crystal monomer is selected from one or more mixtures of RM257, 2-methyl-1,4-phenyl 4-(3-acryloyloxypropoxy)benzoic acid, 4-cyano-4'-pentylbiphenyl, 4-cyano-4'-octylbiphenyl, 1-ethoxy-2,3-difluoro-4-(trans-4-propylcyclohexyl)benzene, trans,trans-4'-(trans-4-propylcyclohexyl)-4-vinylbiscyclohexane, 4-(trans-4-vinylcyclohexyl)benzonitrile, 6-hydroxy-2-benzoic acid, and N,N'-diphenylmethylene benzidine.

[0022] Furthermore, the amount of liquid crystal monomer added in step (3) is 5 to 15% of the polymer matrix mass.

[0023] Furthermore, the black light absorber in step (3) is one or more of lignin, fulvic acid, and black phosphorus.

[0024] Furthermore, the amount of black light absorber added in step (3) is 0.1 to 1% of the total mass of the material.

[0025] The present invention also provides a photodeformable anti-icing material prepared according to the method.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. This invention uses diacids as reactants to introduce carboxylic acid groups into the polymer molecular chain. It utilizes the reaction of diisocyanate with hydroxyl groups to introduce urethane groups. Through multiple intermolecular hydrogen bonds between carboxylic acid groups and urethane groups, it effectively inhibits molecular chain slippage and solvent erosion, giving the material super toughness and solvent resistance. The elongation at break can reach more than 1500%. After being soaked in organic solvents such as toluene and tetrahydrofuran for 60 days, it can still maintain structural integrity and stable mechanical properties.

[0028] 2. Triethylenediamine is used as a crosslinking regulator. Its unique molecular structure can optimize the crosslinking density of the polymer matrix, taking into account both the flexibility and structural stability of the material. Combined with a specific ratio of liquid crystal monomers, the photo-induced deformation characteristics of liquid crystal elastomers are utilized to achieve rapid deformation of the material under light, forming microcracks at the ice-material interface and destroying the adhesion of the ice layer. Lignin, fulvic acid, black phosphorus and other black light absorbers have high photothermal conversion efficiency. Only 0.1% to 1% of the amount is needed to achieve a significant photothermal effect, reduce de-icing energy consumption and improve de-icing efficiency.

[0029] 3. The material preparation process adopts a thermoplastic polymer system, which has good reprocessing and recycling value and complies with the "dual carbon" policy requirements. The entire preparation process is mild and highly controllable, making it suitable for large-scale production. It has broad application prospects in anti-icing and de-icing fields such as aerospace, power transmission, and building curtain walls. Attached Figure Description

[0030] Figure 1 The diagram shows the change process of the linear thermoplastic polymer prepared in Example 5 of this invention after being exposed to light.

[0031] Figure 2 GPC curve of the linear thermoplastic polymer prepared in Example 5 of this invention.

[0032] Figure 3 Fourier transform infrared spectrum of the linear thermoplastic polymer prepared in Example 5 of this invention.

[0033] Figure 4 X-ray diffraction pattern of the linear thermoplastic polymer prepared in Example 5 of this invention.

[0034] Figure 5 Stress-strain curve of the linear thermoplastic polymer prepared in Example 5 of this invention.

[0035] Figure 6 The linear thermoplastic polymer prepared in Example 5 of this invention was immersed in toluene, water, tetrahydrofuran, hydrochloric acid, and sodium hydroxide solutions for 60 days, respectively, and the product status diagrams are shown.

[0036] Figure 7 The stress-strain curve of the linear thermoplastic polymer prepared in Example 5 of this invention after immersion in tetrahydrofuran solution for 60 days. Detailed Implementation

[0037] This invention provides a method for preparing a photodeformable anti-icing material, comprising the following steps:

[0038] (1) Preparation of hydroxyl-terminated trimer: Under an inert atmosphere, a diacid is added to a long-chain diol and refluxed to obtain a hydroxyl-terminated trimer;

[0039] (2) Preparation of isocyanate-terminated prepolymer: Diisocyanate is added to an organic solvent and stirred to dissolve, thereby obtaining a diisocyanate organic solution. Then, the diisocyanate organic solution is added to the hydroxyl-terminated trimer in step (1), and the reaction is carried out under an inert atmosphere to obtain an isocyanate-terminated prepolymer.

[0040] (3) Combining polymer matrix with functional components: Diamine is added to an organic solvent and stirred to dissolve, resulting in a diamine organic solution. Then, the diamine organic solution is added to the isocyanate-terminated prepolymer in step (2). After stirring and reacting for a period of time, liquid crystal monomer and black light absorber are added in sequence, and stirring is continued to obtain a uniform dark brown composite system.

[0041] (4) Molding and curing: The uniform dark brown composite system is molded and cured to obtain a photodeformable anti-icing material.

[0042] In some embodiments of the present invention, the molar ratio of the long-chain diol and the dianhydride in step (1) is 1.9-2.1:0.9-1.1. Preferably, the molar ratio of the long-chain diol and the dianhydride in step (1) is 2:1.

[0043] In some embodiments of the present invention, the reflux reaction temperature in step (1) is 40-100°C and the reflux reaction time is 3-12h.

[0044] In some embodiments of the present invention, the long-chain diol in step (1) is one or a mixture of polypropylene glycol, polybutane, and polydimethylsiloxane with a molecular weight in the range of 500 to 10,000; the dihydric anhydride in step (1) is selected from any one of pyromellitic dianhydride, 4,4'-oxobisphthalic anhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, and 3,3',4,4'-benzophenonetetracarboxylic anhydride.

[0045] In some embodiments of the present invention, the inert atmosphere includes either nitrogen or argon.

[0046] In some embodiments of the present invention, the long-chain diol in step (1) is subjected to vacuum drying treatment before reaction. The vacuum drying treatment is carried out at a temperature of 100-120°C for 2-12 hours to ensure the removal of moisture and impurities. Preferably, the vacuum drying treatment temperature is 110°C, and the drying time is adjusted according to the molecular weight: 2-4 hours for molecular weight of 500-2000, 4-8 hours for molecular weight of 2000-6000, and 8-12 hours for molecular weight of 6000-10000.

[0047] In some embodiments of the present invention, the molar ratio of the diisocyanate to the long-chain diol in step (2) is 0.9-1.1:0.9-1.1. Preferably, the molar ratio of the diisocyanate to the long-chain diol in step (2) is 1:1.

[0048] In some embodiments of the present invention, the reflux reaction temperature in step (2) is 40-120°C and the reflux reaction time is 2-6 hours.

[0049] In some embodiments of the present invention, the diisocyanate in step (2) is selected from any one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate or hexamethylene diisocyanate.

[0050] In some embodiments of the present invention, the diamine in step (3) can be replaced by any one of 4,4'-diaminodiphenylmethane, triethylenediamine, and ethylenediamine. The molar ratio of the diamine to the long-chain diol is 0.9-1.1:1.9-2.1. Preferably, the molar ratio of the diamine to the long-chain diol in step (3) is 1:2.

[0051] In some embodiments of the present invention, the liquid crystal monomer in step (3) is selected from nematic liquid crystal monomers.

[0052] In some embodiments of the present invention, the nematic liquid crystal monomer is selected from one or more mixtures of RM257, 2-methyl-1,4-phenyl 4-(3-acryloyloxypropoxy)benzoic acid, 4-cyano-4'-pentylbiphenyl, 4-cyano-4'-octylbiphenyl, 1-ethoxy-2,3-difluoro-4-(trans-4-propylcyclohexyl)benzene, trans,trans-4'-(trans-4-propylcyclohexyl)-4-vinylbiscyclohexane, 4-(trans-4-vinylcyclohexyl)benzonitrile, 6-hydroxy-2-benzoic acid, and N,N'-diphenylmethylene benzidine.

[0053] Preferably, the mixing ratio of each liquid crystal monomer in the mixture is arbitrary. Most preferably, the liquid crystal monomer is a mixture of RM257 and 5CB in a mass ratio of 1:1. In this case, the photodeformation rate of the material is optimal.

[0054] In some embodiments of the present invention, the organic solvent is selected from any one of N,N-dimethylformamide, tetrahydrofuran, N,N-dimethylacetamide, or dimethyl sulfoxide.

[0055] In some embodiments of the present invention, the stirring reaction in step (3) lasts for 4 to 8 hours.

[0056] In some embodiments of the present invention, the amount of liquid crystal monomer added in step (3) is 5 to 15% of the polymer matrix mass. The liquid crystal monomer needs to be degassed under vacuum before being added to remove the influence of air bubbles on photodeformation performance.

[0057] In some embodiments of the present invention, the black light absorber in step (3) is one or more of lignin, fulvic acid, and black phosphorus. Preferably, the black light absorber is a mixture of lignin and black phosphorus in a mass ratio of 5:1, in which case the photothermal conversion efficiency is increased by 15-20% compared with a single light absorber.

[0058] In some embodiments of the present invention, the amount of black light absorber added in step (3) is 0.1 to 1% of the total mass of the material.

[0059] In some embodiments of the present invention, the black light absorber described in step (3) needs to be ultrasonically dispersed for 30 to 60 minutes before use, and the dispersion time is 30 to 60 minutes to ensure that it is evenly distributed in the composite system.

[0060] In some embodiments of the present invention, step (3) involves continuing stirring for 2 to 4 hours.

[0061] In some embodiments of the present invention, the molding and curing process in step (4) includes: pouring the uniform dark brown composite system obtained in step (3) into a polytetrafluoroethylene mold, heating it at 30-50°C for 12-48 hours, and then raising the temperature to 60-120°C for curing treatment for 2-8 hours to obtain a photodeformation anti-icing material.

[0062] The present invention also provides a photodeformable anti-icing material prepared according to the method.

[0063] The photodeformable de-icing material prepared by this invention contains carboxylic acid groups and urethane groups in its molecular structure, with a weight-average molecular weight of 43,200 to 155,600 and a molecular weight distribution of 1.15 to 6.38.

[0064] The photodeformable anti-icing material prepared by this invention has a surface temperature of 65-75°C within 5 minutes under 808nm near-infrared light irradiation, and a photodeformation rate of 35-45%. Under an environment of -10 to -20°C, the ice layer can be completely removed after 6-10 minutes of light irradiation.

[0065] The photodeformation anti-icing material prepared by this invention has an elongation at break of ≥1500% and a maximum tensile strength of ≥14MPa; after being soaked in toluene, tetrahydrofuran or acidic or alkaline solutions with pH=1~13 for 60 days, the elongation at break retains ≥95% and the tensile strength retains ≥85%.

[0066] This invention endows the material with super-tough solvent resistance through the multiple hydrogen bonding between carboxylic acid groups and urethane groups in the molecular chain; by utilizing the photo-deformation properties of liquid crystal monomers and the efficient photothermal conversion of black light absorbers, it achieves low-energy and high-efficiency de-icing, and the material is also reprocessable, making it suitable for de-icing scenarios such as aerospace and power transmission.

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0068] Unless otherwise specified, the test methods or experimental methods described in the following examples are all conventional methods; unless otherwise specified, the raw materials and additives are obtained from conventional commercial sources or prepared by conventional methods.

[0069] Example 1

[0070] A method for preparing a photodeformable anti-icing material, the specific steps of which are as follows:

[0071] (1) Preparation of hydroxyl-terminated trimer: Under the protection of high-purity nitrogen, 10.0 g of polybutanediol (PTMG1000, 0.01 mol) with a molecular weight of 1000 was dried in a vacuum oven at 110 °C for 2 h. 1.09 g of pyromellitic dianhydride (0.005 mol) was added and dissolved in ultra-dry tetrahydrofuran solvent. The molar ratio was controlled at 2:1. The mixture was stirred and refluxed at 50 °C for 3 h to obtain hydroxyl-terminated trimer.

[0072] (2) Preparation of isocyanate-terminated prepolymer: 2.62 g of dicyclohexylmethane diisocyanate was added to 20 ml of tetrahydrofuran and stirred to dissolve, thus obtaining an organic solution of diisocyanate; the solution was slowly added dropwise to the above trimer reaction system, and the molar ratio of polybutane glycol to diisocyanate was controlled to be 1:1. The reaction was carried out under high-purity nitrogen protection at 40 °C for 6 h to obtain the isocyanate-terminated prepolymer.

[0073] (3) Combining polymer matrix with functional components: 0.58g of triethylenediamine was added to 20ml of tetrahydrofuran and stirred to dissolve, resulting in a triethylenediamine organic solution; this solution was added to the prepolymer reaction system and stirred for 6h. Then, 1.2g of nematic liquid crystal monomer RM257 was added and stirred for 3h. Finally, 0.1g of lignin (dispersed by ultrasonication for 30min) was added and stirred for 1h to obtain a uniform dark brown composite system.

[0074] (4) Molding and curing: The composite system is poured into a polytetrafluoroethylene mold, heated in a vacuum oven at 30°C for 24 hours, and then heated to 60°C for 8 hours to obtain a photodeformation anti-icing material, named B1.

[0075] Performance tests were conducted on sample B1: the weight-average molecular weight was 118,600, and the molecular weight distribution was 5.82; the elongation at break was 1620%, and the maximum tensile strength was 15.8 MPa; under irradiation with 808 nm near-infrared light, the surface temperature rose to 65 °C within 5 minutes, and the photodeformation rate reached 35%; after being covered with ice at -10 °C and then exposed to light for 10 minutes, the ice layer completely detached; after being immersed in tetrahydrofuran for 60 days, the elongation at break remained at 1510%, and the tensile strength was 13.2 MPa.

[0076] Example 2

[0077] A method for preparing a photodeformable anti-icing material, the specific steps of which are as follows:

[0078] (1) Preparation of hydroxyl-terminated trimer: Under the protection of high-purity nitrogen, 10.0 g of polypropylene glycol (PPG1000, 0.01 mol) with a molecular weight of 1000 was dried in a vacuum oven at 110 °C for 4 h. 1.55 g of 4,4'-oxydiphthalic anhydride (0.005 mol) was added and dissolved in ultra-dry tetrahydrofuran solvent. The molar ratio was controlled at 2:1. The mixture was stirred and refluxed at 50 °C for 3 h to obtain hydroxyl-terminated trimer.

[0079] (2) Preparation of isocyanate-terminated prepolymer: 2.62 g of dicyclohexylmethane diisocyanate was added to 20 ml of tetrahydrofuran and stirred to dissolve, thus obtaining an organic solution of diisocyanate; the solution was slowly added dropwise to the above trimer reaction system, and the molar ratio of polypropylene glycol to diisocyanate was controlled to be 1:1. The reaction was carried out under the protection of high-purity nitrogen at 40 °C for 6 h to obtain the isocyanate-terminated prepolymer.

[0080] (3) Combining polymer matrix with functional components: 0.58g of triethylenediamine was added to 20ml of tetrahydrofuran and stirred to dissolve, resulting in a triethylenediamine organic solution; this solution was added to the prepolymer reaction system and stirred for 6h. Then, a mixture of 0.8g of 5CB and 0.4g of 8CB liquid crystal monomers (after vacuum degassing) was added and stirred for 3h. Finally, a mixture of 0.08g of fulvic acid and 0.02g of black phosphorus (after ultrasonic dispersion for 45min) was added and stirred for 1h to obtain a uniform dark brown composite system.

[0081] (4) Molding and curing: The composite system is poured into a polytetrafluoroethylene mold, placed in a vacuum oven at 40°C and heated for 24 hours, and then heated to 60°C for 6 hours to obtain a photodeformation anti-icing material, named B2.

[0082] Performance tests were conducted on sample B2: the weight-average molecular weight was 109,500, and the molecular weight distribution was 5.36; the elongation at break was 1580%, and the maximum tensile strength was 14.5 MPa; under irradiation with 808 nm near-infrared light, the surface temperature rose to 68 °C within 5 minutes, and the photodeformation rate reached 38%; after being covered with ice at -15 °C and irradiated with light for 8 minutes, the ice layer completely detached; after being immersed in toluene for 60 days, the elongation at break remained at 1490%, and the tensile strength was 12.8 MPa.

[0083] Example 3

[0084] A method for preparing a photodeformable anti-icing material, the specific steps of which are as follows:

[0085] (1) Preparation of hydroxyl-terminated trimer: Under the protection of high-purity nitrogen, 20.0 g of polypropylene glycol (PPG2000, 0.01 mol) with a molecular weight of 2000 was dried in a vacuum oven at 110 °C for 4 h. 1.09 g of pyromellitic dianhydride (0.005 mol) was added and dissolved in ultra-dry tetrahydrofuran solvent. The molar ratio was controlled at 2:1. The mixture was stirred and refluxed at 50 °C for 3 h to obtain hydroxyl-terminated trimer.

[0086] (2) Preparation of isocyanate-terminated prepolymer: 1.8 g of isophorone diisocyanate was added to 20 ml of N,N-dimethylformamide and stirred to dissolve, thus obtaining an organic solution of diisocyanate; the solution was slowly added dropwise to the above trimer reaction system, and the molar ratio of polypropylene glycol to diisocyanate was controlled to be 1:1. The reaction was carried out under the protection of high-purity nitrogen at 60 °C for 4 h to obtain the isocyanate-terminated prepolymer.

[0087] (3) Combining polymer matrix with functional components: 0.58g of triethylenediamine was added to 20ml of N,N-dimethylformamide and stirred to dissolve, resulting in a triethylenediamine organic solution; this solution was added to the prepolymer reaction system and stirred for 5h. Then, 2.0g of a mixed liquid crystal monomer of RM257 and 5CB (mass ratio 1:1, after vacuum degassing) was added and stirred for 3h. Then, a mixture of 0.5g of lignin and 0.3g of black phosphorus (dispersed by ultrasound for 60min) was added and stirred for 1h to obtain a uniform dark brown composite system.

[0088] (4) Molding and curing: The composite system is poured into a polytetrafluoroethylene mold, placed in a vacuum oven at 50°C and heated for 24 hours, and then heated to 80°C for curing for 4 hours to obtain a photodeformation anti-icing material, named B3.

[0089] Performance tests were conducted on sample B3: the weight-average molecular weight was 125,300, and the molecular weight distribution was 6.12; the elongation at break was 1550%, and the maximum tensile strength was 16.2 MPa; under irradiation with 808 nm near-infrared light, the surface temperature rose to 72 °C within 5 minutes, and the photodeformation rate reached 42%; after being covered with ice at -20 °C and irradiated with light for 6 minutes, the ice layer completely fell off; after being soaked in hydrochloric acid solution (pH=1) for 60 days, the elongation at break remained at 1480%, and the tensile strength was 13.5 MPa.

[0090] Example 4

[0091] A method for preparing a photodeformable anti-icing material, the specific steps of which are as follows:

[0092] (1) Preparation of hydroxyl-terminated trimer: Under the protection of high-purity nitrogen, 10.0 g of polybutanediol (PTMG1000, 0.01 mol) with a molecular weight of 1000 was dried in a vacuum oven at 110 °C for 2 h. 1.09 g of pyromellitic dianhydride (0.005 mol) was added and dissolved in ultra-dry tetrahydrofuran solvent. The molar ratio was controlled at 2:1. The mixture was stirred and refluxed at 50 °C for 3 h to obtain hydroxyl-terminated trimer.

[0093] (2) Preparation of isocyanate-terminated prepolymer: 2.62 g of dicyclohexylmethane diisocyanate was added to 20 ml of tetrahydrofuran and stirred to dissolve, thus obtaining an organic solution of diisocyanate; the solution was slowly added dropwise to the above trimer reaction system, and the molar ratio of polybutane glycol to diisocyanate was controlled to be 1:1. The reaction was carried out under high-purity nitrogen protection at 40 °C for 6 h to obtain the isocyanate-terminated prepolymer.

[0094] (3) Combining polymer matrix with functional components: 0.58g of triethylenediamine was added to 20ml of tetrahydrofuran and stirred to dissolve, resulting in a triethylenediamine organic solution; this solution was added to the prepolymer reaction system and stirred for 6h. Then, 1.2g of 4-(3-acryloyloxypropoxy)benzoic acid 2-methyl-1,4-phenyl ester liquid crystal monomer (after vacuum degassing for 30min) was added and stirred for 3h. Then, 0.1g of lignin (after ultrasonic dispersion for 30min) was added and stirred for 1h to obtain a uniform dark brown composite system.

[0095] (4) Molding and curing: The composite system is poured into a polytetrafluoroethylene mold, placed in a vacuum oven at 30°C and heated for 24 hours, and then heated to 60°C for 8 hours to obtain a photodeformation anti-icing material, named B4.

[0096] Performance tests were conducted on sample B4: the weight-average molecular weight was 115,200, and the molecular weight distribution was 5.68; the elongation at break was 1590%, and the maximum tensile strength was 15.5 MPa; under irradiation with 808 nm near-infrared light, the surface temperature rose to 66 °C within 5 minutes, and the photodeformation rate reached 36%; after being covered with ice at -10 °C and then exposed to light for 9 minutes, the ice layer completely detached; after being immersed in tetrahydrofuran for 60 days, the elongation at break remained at 1505%, and the tensile strength was 13.0 MPa.

[0097] Comparative Example 1

[0098] The difference from Example 1 is that no liquid crystal monomer was added, but the remaining steps are the same as in Example 1, and the resulting material is named D1.

[0099] Performance tests were conducted on sample D1: the weight-average molecular weight was 114,500, and the molecular weight distribution was 5.65; the elongation at break was 1420%, and the maximum tensile strength was 14.8 MPa; under irradiation with 808 nm near-infrared light, the surface temperature rose to 64 °C within 5 minutes, with no obvious photo-induced deformation (deformation rate <1%); at -10 °C, after being covered with ice and irradiated with light for 30 minutes, only the edges melted slightly and could not be completely removed; after being immersed in tetrahydrofuran for 60 days, the elongation at break remained at 1310%, and the tensile strength was 12.5 MPa.

[0100] Comparative Example 2

[0101] The difference from Example 1 is that no black light absorber was added, but the rest of the steps are the same as in Example 1, and the resulting material is named D2.

[0102] Performance tests were conducted on sample D2: the weight-average molecular weight was 115,800, and the molecular weight distribution was 5.72; the elongation at break was 1580%, and the maximum tensile strength was 15.3 MPa; under 808 nm near-infrared light irradiation, the surface temperature only rose to 28 °C within 5 minutes, and the photodeformation rate was only 5%; at -10 °C, after being covered with ice and irradiated for 30 minutes, there was no melting or peeling, and only slight shape changes were observed; after being immersed in tetrahydrofuran for 60 days, the elongation at break remained at 1460%, and the tensile strength was 13.0 MPa.

[0103] Comparative Example 3

[0104] The difference from Example 1 is that no liquid crystal monomer and black light absorber were added, while the remaining steps were the same as in Example 1, and the resulting material was named D3.

[0105] Performance tests were conducted on sample D3: the weight-average molecular weight was 113,800, and the molecular weight distribution was 5.60; the elongation at break was 1380%, and the maximum tensile strength was 14.5 MPa; under 808 nm near-infrared light irradiation, the surface temperature only rose to 25 °C within 5 minutes, with no deformation or ice-melting effect; at -10 °C, after being covered with ice and irradiated with light for 30 minutes, the ice layer showed no change and could not be de-iced at all; after being soaked in tetrahydrofuran for 60 days, the elongation at break remained at 1270%, and the tensile strength was 12.2 MPa.

[0106] Comparative Example 4

[0107] The difference from Example 1 is that the amount of liquid crystal monomer added is adjusted to 20% of the polymer matrix mass, and the remaining steps are the same as in Example 1. The resulting material is named D4.

[0108] Performance tests were conducted on sample D4: the weight-average molecular weight was 119,200, and the molecular weight distribution was 5.85; the elongation at break was 1450%, and the maximum tensile strength was 13.2 MPa; under 808 nm near-infrared irradiation, the surface temperature rose to 63℃ within 5 minutes, and the photodeformation rate was 30%; at -10℃, after being covered with ice, the ice layer completely detached after 12 minutes of light irradiation; after immersion in tetrahydrofuran for 60 days, the elongation at break remained at 1320%, and the tensile strength was 11.0 MPa. Excessive addition of liquid crystal monomers led to decreased compatibility with the polymer matrix, reduced material mechanical properties, and negatively impacted photodeformation and de-icing effects.

[0109] Example 5

[0110] Under high-purity nitrogen protection, 10.0 g of polybutanediol (PTMG1000, 0.01 mol) with a molecular weight of 1000 was dried in a vacuum oven at 110°C for 2 hours. Then, 1.09 g of pyromellitic dianhydride (0.005 mol) was dissolved in a three-necked flask containing ultra-dry tetrahydrofuran solvent, controlling the molar ratio of PTMG1000 to pyromellitic dianhydride to be 2:1. After reflux reaction at 50°C for 3 hours under uniform stirring, hydroxyl-terminated trimers were obtained.

[0111] 2.62 g of dicyclohexylmethane diisocyanate was added to 20 ml of tetrahydrofuran solvent and stirred to dissolve, yielding an organic solution of diisocyanate. This solution was then added dropwise to the trimer, maintaining a molar ratio of PTMG1000 to dicyclohexylmethane diisocyanate of 1:1. The mixture was then heated and refluxed at 40°C for 6 hours under high-purity nitrogen protection to obtain an isocyanate-terminated prepolymer.

[0112] 0.8 g of ethylenediamine was dissolved in 20 ml of tetrahydrofuran solvent by stirring to obtain an ethylenediamine tetrahydrofuran solvent solution. This solution was then added to the prepolymer, maintaining a molar ratio of PTMG1000 to ethylenediamine of 2:1. After stirring for 6 hours, 1.2 g of nematic liquid crystal monomer RM257 (after vacuum degassing for 30 min) was added, and stirring continued for 3 hours. Then, 0.1 g of lignin (after ultrasonic dispersion for 30 min) was added, and stirring was continued for 1 hour to obtain a uniform dark brown composite system. The resulting liquid was then poured into a polytetrafluoroethylene mold and heated in a 30°C vacuum oven for 24 hours. The temperature was then increased to 60°C for curing for 8 hours to obtain a linear thermoplastic polymer.

[0113] The obtained linear thermoplastic polymer was named Y1. The changes that occurred in Y1 after exposure to light are as follows: Figure 1 As shown. Figure 2 The GPC curve for sample Y1 shows its weight-average molecular weight of 117,863 and molecular weight distribution of 5.945.

[0114] The chemical structural characteristic peaks of sample Y1 were determined by Fourier transform infrared spectroscopy, and the curve is shown below. Figure 3 ,pass Figure 3 It can be seen that Y1 was successfully synthesized. The crystallinity of Y1 was tested using X-ray diffraction, as shown... Figure 4 It can be seen that Y1 has good crystallization ability.

[0115] like Figure 5 It can be seen that the elongation at break of sample Y1 reaches about 1600%, and the maximum pressure it can withstand is about 16MPa.

[0116] To measure its solvent resistance, sample Y1 was immersed in toluene, water, tetrahydrofuran, hydrochloric acid, and sodium hydroxide solutions for 60 days respectively. Figure 6 The Y1 samples all retained their original shapes. Figure 7 After being immersed in tetrahydrofuran solution for 60 days, sample Y1 achieved an elongation at break of approximately 1500%, and its maximum withstand pressure was approximately 13 MPa. This demonstrates that the sample exhibits excellent solvent resistance.

[0117] Under irradiation with 808nm near-infrared light, the surface temperature rises to 72℃ within 5 minutes, and the photodeformation rate reaches 42%; in an environment of -20℃, after being covered with ice and irradiated with light for 6 minutes, the ice layer completely falls off.

[0118] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a photodeformable anti-icing material, characterized in that, Includes the following steps: (1) Preparation of hydroxyl-terminated trimer: Under an inert atmosphere, a diacid is added to a long-chain diol and refluxed to obtain a hydroxyl-terminated trimer; (2) Preparation of isocyanate-terminated prepolymer: Diisocyanate is added to an organic solvent and stirred to dissolve, thereby obtaining a diisocyanate organic solution. Then, the diisocyanate organic solution is added to the hydroxyl-terminated trimer in step (1), and the reaction is carried out under an inert atmosphere to obtain an isocyanate-terminated prepolymer. (3) Combining polymer matrix with functional components: Diamine is added to an organic solvent and stirred to dissolve, resulting in a diamine organic solution. Then, the diamine organic solution is added to the isocyanate-terminated prepolymer in step (2). After stirring and reacting for a period of time, liquid crystal monomer and black light absorber are added in sequence, and stirring is continued to obtain a uniform dark brown composite system. (4) Molding and curing: The uniform dark brown composite system is molded and cured to obtain a photodeformable anti-icing material.

2. The method for preparing the photodeformation anti-icing material according to claim 1, characterized in that, The molar ratio of the long-chain diol and the dianhydride in step (1) is 1.9-2.1:0.9-1.1; the reflux reaction temperature in step (1) is 40-100℃ and the reflux reaction time is 3-12h.

3. The method for preparing the photodeformation anti-icing material according to claim 1, characterized in that, The long-chain diol in step (1) is one or a mixture of polypropylene glycol, polybutane, and polydimethylsiloxane with a molecular weight in the range of 500 to 10,000; the dianhydride in step (1) is selected from any one of pyromellitic dianhydride, 4,4'-oxobisphthalic anhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, and 3,3',4,4'-benzophenonetetracarboxylic anhydride.

4. The method for preparing the photodeformation anti-icing material according to claim 1, characterized in that, The molar ratio of the diisocyanate to the long-chain diol in step (2) is 0.9-1.1:0.9-1.1; the reflux reaction temperature in step (2) is 40-120℃, and the reflux reaction time is 2-6h; the diisocyanate in step (2) is selected from any one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate or hexamethylene diisocyanate.

5. The method for preparing the photodeformation anti-icing material according to claim 1, characterized in that, The diamine in step (3) is selected from any one of 4,4'-diaminodiphenylmethane, triethylenediamine, and ethylenediamine; the molar ratio of the diamine to the long-chain diol in step (3) is 0.9-1.1:1.9-2.

1.

6. The method for preparing the photodeformation anti-icing material according to claim 1, characterized in that, The liquid crystal monomer in step (3) is selected from nematic liquid crystal monomers.

7. The method for preparing the photodeformation anti-icing material according to claim 1, characterized in that, The amount of liquid crystal monomer added in step (3) is 5 to 15% of the polymer matrix mass.

8. The method for preparing the photodeformation anti-icing material according to claim 1, characterized in that, The black light absorber in step (3) is one or more of lignin, fulvic acid, and black phosphorus.

9. The method for preparing the photodeformation anti-icing material according to claim 1, characterized in that, The amount of black light absorber added in step (3) is 0.1% to 1% of the total mass of the material.

10. The photodeformable anti-icing material prepared by the method according to any one of claims 1-9.

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