An ultralight material, its preparation method, and its application in footwear materials

Abstract

This invention discloses an ultralight material, its preparation method, and its application in footwear materials, belonging to the field of materials technology. The footwear material prepared by this invention includes: polyether diol, isophorone diisocyanate, functional chain extender, dibutyltin dilaurate, modified hollow glass microspheres, and trifluoromethanesulfonic acid. The functional chain extender is obtained by reacting 3-hexene-1,6-diol and phenylphosphonodichloro with heptamethylcyclotetrasiloxane. The modified hollow glass microspheres are obtained by polymerizing isoprene and 1-(4-vinyl-phenyl)-ethyl ketone on the surface of pretreated hollow glass microspheres, followed by reaction with diethyl oxalate and 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole. The ultralight material prepared by this invention has excellent anti-aging, flame-retardant, and antibacterial properties, and has broad application prospects in the field of footwear materials.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, specifically relating to an ultralight material, its preparation method, and its application in footwear materials. Background Technology

[0002] Shoe sole materials are typically made of rubber, EVA (ethylene-vinyl acetate copolymer), polyurethane (PU), thermoplastic polyurethane (TPU), and thermoplastic rubber (TPR), among others. Polyurethane, due to its unique properties, is widely used in athletic shoes, casual shoes, and protective footwear. Polyurethane soles are characterized by low density, soft texture, good elasticity, high abrasion resistance, and excellent chemical resistance. They provide good shock absorption, slip resistance, and cushioning, while their lightweight properties significantly reduce shoe weight and improve wearing comfort.

[0003] However, existing polyurethane materials still have many shortcomings. For example, they are prone to yellowing and deterioration of mechanical properties. After long-term use, they are susceptible to aging due to oxidation, ultraviolet radiation, or humid and hot environments, shortening their service life. In addition, polyurethane materials are prone to generating heat and posing a risk of combustion under high temperature or friction conditions, and their lack of flame retardant properties may affect their safety protection function. At the same time, the long-term contact between shoe soles and feet makes them prone to bacterial growth, leading to odor and foot health problems, while existing materials have insufficient antibacterial properties to meet hygiene requirements. Therefore, developing an ultralight material that combines anti-aging, flame retardant, and antibacterial properties has become a key direction in shoe sole material research. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing ultralight materials.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] A method for preparing an ultralight material includes the following preparation steps:

[0009] 1) 3-Hexen-1,6-diol and phenylphosphonic dichloride were reacted to obtain a functional chain extender precursor; the functional chain extender precursor and heptamethylcyclotetrasiloxane were reacted to obtain a functional chain extender.

[0010] 2) Pretreated hollow glass microspheres, isoprene, and 1-(4-vinyl-phenyl)-ethyl ketone were reacted to obtain pre-modified hollow glass microspheres;

[0011] 3) Modified hollow glass microspheres were obtained by reacting pre-modified hollow glass microspheres, diethyl oxalate, and 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole.

[0012] 4) Weigh the following components: polyether diol, isophorone diisocyanate, functional chain extender, dibutyltin dilaurate, modified hollow glass microspheres, trifluoromethanesulfonic acid, and acetone; mix and cure the above components to obtain an ultralight material.

[0013] As an optimization, the preparation method of the functional chain extender in step 1) is as follows: 3-hexen-1,6-diol, phenylphosphonodichloro, and N,N-dimethylaniline are mixed and heated to 120-130℃ for 8-10 hours. After the reaction, the product is dissolved in acetone and the pH is adjusted to 7 using 10wt% sodium bicarbonate solution. The crude product is precipitated by cold water at 0-4℃, and then redissolved in methanol at 60-80℃, cooled, crystallized, filtered, and dried to obtain the functional chain extender precursor. The functional chain extender precursor, heptamethylcyclotetrasiloxane, caster catalyst, and toluene are mixed and heated to 100-110℃ for 4-6 hours to obtain the functional chain extender.

[0014] As an optimization, the molar ratio of 3-hexene-1,6-diol, phenylphosphonodichloro, and N,N-dimethylaniline is (2.1-2.2):1:(3.1-3.2); the molar ratio of the functional chain extender precursor and heptamethylcyclotetrasiloxane is (1.1-1.2):1; and the mass ratio of the functional chain extender precursor, caster catalyst, and toluene is 1:(0.001-0.002):(10-12).

[0015] As an optimization, the preparation method of the pre-modified hollow glass microspheres in step 2) is as follows: the hollow glass microspheres are uniformly dispersed in an ethanol / water solution, 3-mercaptopropyltrimethoxysilane is added, the pH of the solution is adjusted to 3-4 with sulfuric acid, and the temperature is raised to 70-80℃ for 5-6 hours to obtain the pretreated hollow glass microspheres; the mass ratio of hollow glass microspheres, 3-mercaptopropyltrimethoxysilane, and ethanol / water solution is 1:(0.5-1.0):(20-30);

[0016] Pretreated hollow glass microspheres were uniformly dispersed in toluene at 25-35 times their mass to obtain a dispersion. Isoprene was dissolved in toluene at 5-6 times its mass. Under nitrogen protection, the dispersion and half of the azobisisobutyronitrile were added, and the mixture was stirred at 60-70℃ for 4-5 hours. The remaining azobisisobutyronitrile and 1-(4-vinyl-phenyl)-ethyl ketone were added, and the reaction was continued for 4-5 hours. Then, 0.2% (by mass of the pretreated hollow glass microspheres) of the photoinitiator dimethyl benzoate was added. After stirring in the dark for 1 hour, the mixture was poured into a petri dish to evaporate the solvent. Finally, the mixture was treated with a 365nm UV lamp (intensity 80mW / cm²). 2 Pre-modified hollow glass microspheres were prepared by irradiating them at a distance of 15 cm for 30-40 minutes. The mass ratio of the pre-treated hollow glass microspheres, isoprene, 1-(4-vinyl-phenyl)-ethyl ketone, and azobisisobutyronitrile was 1:(0.6-0.8):(0.2-0.4):(0.003-0.005).

[0017] As an optimization, the preparation method of the modified hollow glass microspheres in step 3) is as follows: pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, alkaline catalyst, and N-methylpyrrolidone are mixed and reacted under microwave radiation to obtain modified hollow glass microspheres.

[0018] As an optimization, the mass ratio of pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, alkaline catalyst, and N-methylpyrrolidone is 1:(0.2-0.3):(0.2-0.3):(0.3-0.5):(20-30).

[0019] As an optimization, the amounts of the components in step 4) are as follows: by mass parts, 100 parts of polyether diol, 17-23 parts of isophorone diisocyanate, 15-20 parts of functional chain extender, 0.1-0.3 parts of dibutyltin dilaurate, 20-30 parts of modified hollow glass microspheres, 0.5-1.0 parts of trifluoromethanesulfonic acid, and 100-150 parts of acetone.

[0020] As an optimization, the preparation method of the ultralight material in step 4) is as follows: isophorone diisocyanate, polyether diol, and dibutyltin dilaurate are mixed and stirred at 70-80°C for 3-4 hours under a nitrogen atmosphere. Acetone solvent is added and stirred evenly. Then, a functional chain extender is added and reacted for 1-2 hours. Trifluoromethanesulfonic acid and modified hollow glass microspheres are added at 2000 rpm and mixed evenly. The mixture is then poured into a mold and cured to obtain the ultralight material.

[0021] The present invention also provides an ultralight material prepared according to any one of the above-described preparation methods.

[0022] The present invention also provides an application of the above-mentioned ultralight material in footwear materials.

[0023] Beneficial effects of this invention:

[0024] In preparing ultralight materials, this invention first reacts 3-hexene-1,6-diol and phenylphosphonic dichloride to generate a functional chain extender precursor with hydroxyl groups at both ends by controlling the molar ratio. Heptamethylcyclotetrasiloxane undergoes a hydrosilylation reaction with the alkenyl group on 3-hexene-1,6-diol under the action of a catalyst, thereby introducing cyclosiloxane into the functional chain extender. This functional chain extender, through the reaction of its active hydroxyl groups with the isocyanate groups (-NCO) of the polyurethane prepolymer to form urethane bonds, achieves molecular chain extension and cross-linking network reinforcement. Simultaneously, the phosphorus element in the functional chain extender catalyzes dehydration to form char during combustion, creating a dense barrier layer and imparting good flame-retardant properties to the material. Furthermore, during the synthesis of polyurethane, the cyclosiloxane chain undergoes ring-opening in the presence of an acid catalyst, cross-linking within the polyurethane molecular chain to form flexible siloxane segments. The presence of these siloxane segments imparts good hydrophobic properties to the material, and the cross-linking network significantly improves the material's toughness.

[0025] Secondly, hollow glass microspheres, as a new type of inorganic functional material, are mainly composed of borosilicates. Hollow glass microspheres are regularly spherical in shape, exhibiting good flowability and a particle size in the micrometer range. They possess highly stable physicochemical properties, and their stable hollow structure makes them ideal lightweight fillers. Under treatment with a mercaptosilane coupling agent, the surface of the glass microspheres contains mercapto groups. In the initial stage of the reaction, the mercapto groups preferentially react with the double bonds of isoprene to undergo a mercapto-alkene click reaction, anchoring the monomers to the microsphere surface. Subsequently, the remaining isoprene monomers and 1-(4-vinyl-phenyl)-ethyl ketone grow through free radical polymerization, forming a cross-linked / linear ketone-containing elastomer network on the microsphere surface. The addition of a photoinitiator further polymerizes the remaining monomers on the microsphere surface, ensuring a complete reaction and guaranteeing that the elastomer can completely encapsulate the microspheres. The elastomer-encapsulated microspheres form a flexible transition interface between the microspheres and the polyurethane matrix. This elastomer layer effectively buffers external impacts and evenly disperses stress, transforming the microspheres from vulnerable points prone to stress concentration into energy dissipation units, thus enhancing the material's impact resistance.

[0026] In a one-pot reaction, 1-(4-vinyl-phenyl)-ethyl ketone, diethyl oxalate, and 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole are reacted. The amino group of 2-aminothiadiazole nucleophilically attacks the carbonyl carbon of diethyl oxalate to form an intermediate. In the presence of a strong base, the α-hydrogen of 1-(4-vinyl-phenyl)-ethyl ketone is deprotonated to form a carbanion, which attacks the carbonyl carbon of the intermediate, resulting in Claisen condensation. Under microwave conditions, dehydration is carried out to form a conjugated enone (chalcone) structure and generate an imidazothiadiazole ring. The conjugated enone system in the chalcone molecule efficiently absorbs ultraviolet light through π→π* transitions and intramolecular charge transfer, converting light energy into heat energy and giving the material good resistance to ultraviolet aging.

[0027] Aminothiadiazole condenses with a carbonyl group to form an imidazothiadiazole ring containing an o-chlorinated substituent. The o-chlorinated substituent reduces the molecular electron density through an inductive effect, enhancing the ability to penetrate bacterial cell membranes. The imidazothiadiazole ring contains multiple electronegative nitrogen atoms, which can further reduce the electron density and improve antibacterial activity. This ring, as an active unit, can endow the material with good antibacterial properties.

[0028] The experimental principle of the one-pot method is as follows:

[0029] Detailed Implementation

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0033] The hollow glass microspheres used in this invention are of model HN60 and were purchased from Shanxi Hainuo Technology Co., Ltd.; the polyether diol has a molecular weight of 1000; and the alkaline catalyst DBU is 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0034] Example 1: This example provides a method for preparing an ultralight material, specifically:

[0035] 1) Mix 3-hexen-1,6-diol, phenylphosphonic dichloride, and N,N-dimethylaniline, and heat to 130℃ for 10 h. After the reaction, dissolve the product in acetone and adjust the pH to 7 with 10 wt% sodium bicarbonate solution. Precipitate the crude product by precipitating it in cold water at 4℃, then redissolve it in methanol at 80℃, cool, crystallize, filter, and dry to obtain the functional chain extender precursor. The molar ratio of 3-hexen-1,6-diol, phenylphosphonic dichloride, and N,N-dimethylaniline is 2.1:1:3.1.

[0036] The functional chain extender precursor, heptamethylcyclotetrasiloxane, castor catalyst platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex, and toluene were mixed and reacted at 110℃ for 6 h. The crude product was obtained by rotary evaporation under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 1:1 (v / v)) and dried to obtain the functional chain extender. The molar ratio of the functional chain extender precursor to heptamethylcyclotetrasiloxane was 1.1:1. The mass ratio of the functional chain extender precursor to castor catalyst and toluene was 1:0.001:10.

[0037] 2) Hollow glass microspheres were uniformly dispersed in an ethanol / water solution (ethanol / water = 4:1 (v / v)), 3-mercaptopropyltrimethoxysilane was added, and the pH of the solution was adjusted to 4 using 20% ​​dilute sulfuric acid. After reacting at 80℃ for 6 hours, the solution was filtered, washed, and dried to obtain pretreated hollow glass microspheres. The mass ratio of hollow glass microspheres, 3-mercaptopropyltrimethoxysilane, and ethanol / water solution was 1:0.5:20.

[0038] Pretreated hollow glass microspheres were uniformly dispersed in toluene at 25 times their mass to obtain a dispersion. Isoprene was dissolved in toluene at 5 times its mass. Under nitrogen protection, the dispersion and half of the azobisisobutyronitrile were added, and the mixture was stirred at 70°C for 5 hours. Then, the remaining azobisisobutyronitrile and 1-(4-vinyl-phenyl)-ethyl ketone were added, and the reaction was continued for another 5 hours. Finally, 0.2% (by mass of the pretreated hollow glass microspheres) of the photoinitiator dimethyl benzoate was added, and the mixture was stirred in the dark for 1 hour. The mixture was then poured into a petri dish to evaporate the solvent. After the reaction was completed, the mixture was treated with a 365 nm UV lamp (intensity 80 mW / cm²). 2 Pre-modified hollow glass microspheres were obtained by irradiating them at a distance of 15 cm for 40 min, followed by washing and drying. The mass ratio of the pre-treated hollow glass microspheres, isoprene, 1-(4-vinyl-phenyl)-ethyl ketone, and azobisisobutyronitrile was 1:0.6:0.2:0.003.

[0039] 3) The pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, DBU alkaline catalyst, and N-methylpyrrolidone were ultrasonically mixed and reacted under microwave radiation (stage one: 80℃, 100W, 10min; stage two: 130℃, 250W, 15min). After cooling to 50℃, the mixture was filtered and washed and dried successively with N,N-dimethylformamide, tetrahydrofuran, and diethyl ether to obtain the modified hollow glass microspheres. The mass ratio of the pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, DBU alkaline catalyst, and N-methylpyrrolidone was 1:0.2:0.2:0.3:20.

[0040] 4) Weigh the following components: by mass parts, 100 parts polyether diol, 17 parts isophorone diisocyanate, 15 parts functional chain extender, 0.1 parts dibutyltin dilaurate, 20 parts modified hollow glass microspheres, 0.5 parts trifluoromethanesulfonic acid, and 100 parts acetone.

[0041] Isophorone diisocyanate, polyether diol, and dibutyltin dilaurate were mixed and stirred at 80°C for 4 hours under a nitrogen atmosphere. Acetone was added as a solvent and stirred until homogeneous. A functional chain extender was added and reacted for 2 hours. Trifluoromethanesulfonic acid and modified hollow glass microspheres were added at 2000 rpm and mixed. The mixture was poured into a preheated mold at 60°C and cured by step heating to obtain the material. The material was then heated at 60°C for 1 hour, 80°C for 3 hours, and 100°C for 1 hour. After demolding, the material was heat-treated at 100°C for 2 hours to obtain an ultralight material.

[0042] Example 2: This example provides a method for preparing an ultralight material, specifically:

[0043] 1) Mix 3-hexen-1,6-diol, phenylphosphonic dichloride, and N,N-dimethylaniline, and heat to 125℃ for 9 hours. After the reaction, dissolve the product in acetone and adjust the pH to 7 with 10wt% sodium bicarbonate solution. Precipitate the crude product by precipitating it in cold water at 3℃, then redissolve it in methanol at 70℃, cool, crystallize, filter, and dry to obtain the functional chain extender precursor. The molar ratio of 3-hexen-1,6-diol, phenylphosphonic dichloride, and N,N-dimethylaniline is 2.15:1:3.15.

[0044] The functional chain extender precursor, heptamethylcyclotetrasiloxane, castor catalyst platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex, and toluene were mixed and reacted at 105℃ for 5 h. The crude product was obtained by rotary evaporation under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 1:1 (v / v)) and dried to obtain the functional chain extender. The molar ratio of the functional chain extender precursor to heptamethylcyclotetrasiloxane was 1.15:1. The mass ratio of the functional chain extender precursor to castor catalyst and toluene was 1:0.001:11.

[0045] 2) Hollow glass microspheres were uniformly dispersed in an ethanol / water solution (ethanol / water = 4:1 (v / v)). 3-Mercaptopropyltrimethoxysilane was added, and the pH of the solution was adjusted to 3.5 using 20% ​​dilute sulfuric acid. The mixture was heated to 75℃ and reacted for 5.5 hours. After filtration, washing, and drying, pretreated hollow glass microspheres were obtained. The mass ratio of hollow glass microspheres, 3-mercaptopropyltrimethoxysilane, and ethanol / water solution was 1:0.7:25.

[0046] Pretreated hollow glass microspheres were uniformly dispersed in toluene at 30 times their weight to obtain a dispersion. Isoprene was dissolved in toluene at 5.5 times its weight. Under nitrogen protection, the dispersion and half of the azobisisobutyronitrile were added, and the mixture was stirred at 65°C for 4.5 h. Then, the remaining azobisisobutyronitrile and 1-(4-vinyl-phenyl)-ethyl ketone were added, and the reaction was continued for another 4.5 h. Finally, 0.2% (by weight of the pretreated hollow glass microspheres) of the photoinitiator benzoin dimethyl ether was added, and the mixture was stirred in the dark for 1 h. The mixture was then poured into a petri dish to evaporate the solvent. After the reaction was completed, the mixture was treated with a 365 nm UV lamp (intensity 80 mW / cm²). 2 Pre-modified hollow glass microspheres were obtained by irradiating them at a distance of 15 cm for 35 min, followed by washing and drying. The mass ratio of the pre-treated hollow glass microspheres, isoprene, 1-(4-vinyl-phenyl)-ethyl ketone, and azobisisobutyronitrile was 1:0.7:0.3:0.004.

[0047] 3) The pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, DBU alkaline catalyst, and N-methylpyrrolidone were ultrasonically mixed and reacted under microwave radiation (stage one: 80℃, 100W, 10min; stage two: 130℃, 250W, 15min). After cooling to 50℃, the mixture was filtered and washed and dried successively with N,N-dimethylformamide, tetrahydrofuran, and diethyl ether to obtain the modified hollow glass microspheres. The mass ratio of the pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, DBU alkaline catalyst, and N-methylpyrrolidone was 1:0.25:0.25:0.4:25.

[0048] 4) Weigh the following components: by mass parts, 100 parts polyether diol, 20 parts isophorone diisocyanate, 17 parts functional chain extender, 0.2 parts dibutyltin dilaurate, 25 parts modified hollow glass microspheres, 0.7 parts trifluoromethanesulfonic acid, and 120 parts acetone.

[0049] Isophorone diisocyanate, polyether diol, and dibutyltin dilaurate were mixed and stirred at 75°C for 3.5 hours under a nitrogen atmosphere. Acetone was added as a solvent and stirred until homogeneous. A functional chain extender was added and reacted for 1.5 hours. Trifluoromethanesulfonic acid and modified hollow glass microspheres were added at 2000 rpm and mixed. The mixture was poured into a preheated mold at 60°C and cured by step heating to obtain the material. The material was then heated at 60°C for 1 hour, 80°C for 3 hours, and 100°C for 1 hour. After demolding, the material was heat-treated at 100°C for 2 hours to obtain the ultralight material.

[0050] Example 3: This example provides a method for preparing an ultralight material, specifically:

[0051] 1) Mix 3-hexen-1,6-diol, phenylphosphonodichloro, and N,N-dimethylaniline, and heat to 120℃ for 8 hours. After the reaction, dissolve the product in acetone and adjust the pH to 7 with 10wt% sodium bicarbonate solution. Precipitate the crude product by precipitating it in cold water at 0℃, then redissolve it in methanol at 60℃, cool, crystallize, filter, and dry to obtain the functional chain extender precursor. The molar ratio of 3-hexen-1,6-diol, phenylphosphonodichloro, and N,N-dimethylaniline is 2.2:1:3.2.

[0052] The functional chain extender precursor, heptamethylcyclotetrasiloxane, castor catalyst platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex, and toluene were mixed and reacted at 100℃ for 4 h. The crude product was obtained by rotary evaporation under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 1:1 (v / v)) and dried to obtain the functional chain extender. The molar ratio of the functional chain extender precursor to heptamethylcyclotetrasiloxane was 1.2:1. The mass ratio of the functional chain extender precursor to castor catalyst and toluene was 1:0.002:12.

[0053] 2) Hollow glass microspheres were uniformly dispersed in an ethanol / water solution (ethanol / water = 4:1 (v / v)), 3-mercaptopropyltrimethoxysilane was added, and the pH of the solution was adjusted to 3 using 20% ​​dilute sulfuric acid. After reacting at 70°C for 5 hours, the solution was filtered, washed, and dried to obtain pretreated hollow glass microspheres. The mass ratio of hollow glass microspheres, 3-mercaptopropyltrimethoxysilane, and ethanol / water solution was 1:1.0:30.

[0054] Pretreated hollow glass microspheres were uniformly dispersed in toluene at 35 times their mass to obtain a dispersion. Isoprene was dissolved in toluene at 6 times its mass. Under nitrogen protection, the dispersion and half of the azobisisobutyronitrile were added, and the mixture was stirred at 60°C for 4 hours. The remaining azobisisobutyronitrile and 1-(4-vinyl-phenyl)-ethyl ketone were added, and the reaction was continued for 4 hours. Then, 0.2% (by mass of the pretreated hollow glass microspheres) of the photoinitiator dimethyl benzoate was added, and the mixture was stirred in the dark for 1 hour. The mixture was then poured into a petri dish to evaporate the solvent. After the reaction was completed, the mixture was treated with a 365 nm UV lamp (intensity 80 mW / cm²). 2 Pre-modified hollow glass microspheres were obtained by irradiating them at a distance of 15cm for 30 minutes, followed by washing and drying.

[0055] The mass ratio of pretreated hollow glass microspheres, isoprene, 1-(4-vinyl-phenyl)-ethyl ketone, and azobisisobutyronitrile was 1:0.8:0.4:0.005.

[0056] 3) The pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, DBU alkaline catalyst, and N-methylpyrrolidone were ultrasonically mixed and reacted under microwave radiation (stage one: 80℃, 100W, 10min; stage two: 130℃, 250W, 15min). After cooling to 50℃, the mixture was filtered and washed and dried successively with N,N-dimethylformamide, tetrahydrofuran, and diethyl ether to obtain the modified hollow glass microspheres. The mass ratio of the pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, DBU alkaline catalyst, and N-methylpyrrolidone was 1:0.3:0.3:0.5:30.

[0057] 4) Weigh the following components: by mass parts, 100 parts polyether diol, 23 parts isophorone diisocyanate, 20 parts functional chain extender, 0.3 parts dibutyltin dilaurate, 30 parts modified hollow glass microspheres, 1.0 part trifluoromethanesulfonic acid, and 150 parts acetone.

[0058] Isophorone diisocyanate, polyether diol, and dibutyltin dilaurate were mixed and stirred at 70°C for 3 hours under a nitrogen atmosphere. Acetone was added as a solvent and stirred until homogeneous. A functional chain extender was added and reacted for 1 hour. Trifluoromethanesulfonic acid and modified hollow glass microspheres were added at 2000 rpm and mixed. The mixture was poured into a preheated mold at 60°C and cured by step heating to obtain the material. The material was then heated at 60°C for 1 hour, 80°C for 3 hours, and 100°C for 1 hour. After demolding, the material was heat-treated at 100°C for 2 hours to obtain an ultralight material.

[0059] Comparative Example 1 differs from Example 2 in that it does not contain a functional chain extender, specifically step (1). Step (4) is modified as follows: isophorone diisocyanate, polyether diol, and dibutyltin dilaurate are mixed and stirred at 75°C for 3.5 hours under a nitrogen atmosphere. Acetone solvent is added and stirred evenly. Modified hollow glass microspheres are added at 2000 rpm and mixed evenly. The mixture is poured into a preheated mold at 60°C and cured by step heating to obtain the material. The material is then heated at 60°C for 1 hour, at 80°C for 3 hours, and at 100°C for 1 hour. After demolding, it is heat-treated at 100°C for 2 hours to obtain the ultralight material. The remaining steps are the same as in Example 2.

[0060] Comparative Example 2 differs from Example 2 in that the functional chain extender precursor is used as the functional chain extender. Specifically, step (1) is modified as follows: 3-hexene-1,6-diol, phenylphosphonodichloride, and N,N-dimethylaniline are mixed and heated to 125°C for 9 hours. After the reaction, the product is dissolved in acetone and the pH is adjusted to 7 using 10wt% sodium bicarbonate solution. The crude product is precipitated by cold water at 3°C, and then redissolved in methanol at 70°C, cooled, crystallized, filtered, and dried to obtain the functional chain extender. The molar ratio of 3-hexene-1,6-diol, phenylphosphonodichloride, and N,N-dimethylaniline is 2.15:1:3.15.

[0061] Step (4) is modified as follows: Isophorone diisocyanate, polyether diol, and dibutyltin dilaurate are mixed and stirred at 75°C for 3.5 hours under a nitrogen atmosphere. Acetone solvent is added and stirred evenly. Then, a functional chain extender is added and reacted for 1.5 hours. Modified hollow glass microspheres are added and mixed evenly at 2000 rpm. The mixture is poured into a preheated mold at 60°C and cured by step heating to obtain the material. The material is then heated at 60°C for 1 hour, at 80°C for 3 hours, and at 100°C for 1 hour. After demolding, the material is heat-treated at 100°C for 2 hours to obtain the ultralight material.

[0062] Comparative Example 3 differs from Example 2 in that the pre-modified hollow glass microspheres are not modified: specifically, step (3) is omitted, and step (4) is modified as follows: isophorone diisocyanate, polyether diol, and dibutyltin dilaurate are mixed and stirred at 75°C for 3.5 hours under a nitrogen atmosphere. Acetone solvent is added and stirred evenly. Then, a functional chain extender is added and reacted for 1.5 hours. Trifluoromethanesulfonic acid and pre-modified hollow glass microspheres are added and mixed evenly at 2000 rpm. The mixture is poured into a preheated mold at 60°C and cured by step heating to obtain the material. The material is then heated at 60°C for 1 hour, at 80°C for 3 hours, and at 100°C for 1 hour. After demolding, the material is heat-treated at 100°C for 2 hours to obtain the ultralight material.

[0063] Test Example 1: Flame retardant performance was tested according to GB / T 2406.1—2008, with the limiting oxygen index measured. The sample size was 120mm × 6mm × 4mm. The results are shown in Table 1.

[0064] Table 1

[0065] LOI (%) LOI (%) Example 1 31.5 Comparative Example 1 24.0 Example 2 31.8 Comparative Example 2 27.8 Example 3 32.2 Comparative Example 3 28.5

[0066] As can be seen from Table 1, the material prepared by this invention has good flame retardant properties. This is because, in the preparation of the ultralight material, 3-hexene-1,6-diol and phenylphosphonic dichloride are reacted to generate a functional chain extender precursor with hydroxyl groups at both ends by controlling the molar ratio. Heptamethylcyclotetrasiloxane undergoes a hydrosilylation reaction with the alkenyl group on 3-hexene-1,6-diol under the action of a catalyst to obtain the functional chain extender. The phosphorus element in the functional chain extender catalyzes dehydration to form carbon during combustion, creating a dense barrier layer that imparts good flame retardant properties to the material. This characteristic is crucial for footwear materials, especially work safety shoes, fire boots, children's shoes, and sports shoes or outdoor shoes that emphasize fire safety. It can significantly improve the flame retardant rating of footwear, slow down the spread of flames, and provide wearers with valuable escape time in the event of accidental contact with a fire source, meeting strict footwear safety standards.

[0067] Test Example 2: Antibacterial performance test. The antibacterial performance of the material was tested using the shaking method according to GB / T 20944—2008. The bacterial species used in the test was Gram-negative Escherichia coli (ATCC 8099). The results are shown in Table 2.

[0068] Table 2

[0069] Antibacterial rate (%) Antibacterial rate (%) Example 1 96.5 Comparative Example 1 87.3 Example 2 97.1 Comparative Example 2 91.7 Example 3 97.7 Comparative Example 3 35.6

[0070] As shown in Table 2, the material prepared by this invention exhibits excellent antibacterial properties. This is because, during the preparation of the ultralight material, this invention utilizes a one-pot method to react 1-(4-vinyl-phenyl)-ethyl ketone, diethyl oxalate, and 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole. The amino group of 2-aminothiadiazole nucleophilically attacks the carbonyl carbon of diethyl oxalate, forming an intermediate. In the presence of a strong base, the α-hydrogen of 1-(4-vinyl-phenyl)-ethyl ketone is deprotonated to form a carbanion, which attacks the carbonyl carbon of the intermediate, undergoing Claisen condensation. Under microwave conditions, the intermediate is dehydrated to form... It forms a conjugated enone (chalcone) structure, generating an imidazothiadiazole ring. This ring contains an o-chlorine substituent, which reduces the molecular electron density through an inductive effect, enhancing the ability to penetrate bacterial cell membranes. The imidazothiadiazole ring contains multiple electronegative nitrogen atoms, which can further reduce the electron density and improve antibacterial activity. This ring, as the active unit, can endow the material with excellent antibacterial properties. When the material is used in shoe linings, insoles, and uppers, this property can effectively inhibit the growth and reproduction of common bacteria (such as Staphylococcus aureus and bacilli that cause odor) and fungi (such as fungi that cause athlete's foot) in the shoe environment. This not only significantly reduces shoe odor and keeps the shoe environment fresh and hygienic, but also reduces the risk of foot health problems caused by bacterial infections (such as athlete's foot and dermatitis), greatly improving the comfort and health properties of footwear.

[0071] Test Example 3: Mechanical property testing. The tensile strength of the material was tested according to standard GB / T 1040.2-2006. The materials prepared in the examples and comparative examples were cut into dumbbell strips. The dumbbell strips were of type I size. Tensile tests were conducted using a universal testing machine at a speed of 50 mm / min. The results are shown in Table 3.

[0072] For the anti-aging performance test, the materials prepared in the examples and comparative examples were cut into dumbbell strips, which were type I specimens. These were placed in an accelerated UV aging chamber and irradiated with a 200W mercury light source for 360 hours. The aged samples were then tested according to the mechanical property testing methods. The tensile strength retention rate before and after aging was calculated; the results are shown in Table 3.

[0073] Table 3

[0074]

[0075]

[0076] As shown in Table 3, the material prepared by this invention exhibits excellent mechanical and anti-aging properties. This is because, in preparing the ultralight material, the present invention first reacts 3-hexene-1,6-diol and phenylphosphonic dichloride to generate a functional chain extender precursor with hydroxyl groups at both ends by controlling the molar ratio. Heptamethylcyclotetrasiloxane then undergoes a hydrosilylation reaction with the alkenyl group on 3-hexene-1,6-diol under the action of a catalyst, thereby introducing cyclosiloxane into the functional chain extender. This functional chain extender, through the reaction of its active hydroxyl groups with the isocyanate group (-NCO) of the polyurethane prepolymer, forms an urethane. The cyclosiloxane chain, through the formation of bonds, enables molecular chain extension and cross-linking network reinforcement. During the synthesis of polyurethane, the cyclosiloxane chain undergoes ring-opening in the presence of an acid catalyst, cross-linking within the polyurethane molecular chain to form flexible siloxane segments. The presence of these siloxane segments imparts excellent hydrophobic properties to the material, and the cross-linking network significantly enhances the material's toughness. As a sole material (midsole, outsole) or upper material that needs to withstand repeated bending (such as athletic shoes and casual shoes), this property endows footwear with excellent tear resistance, impact resistance, and flexural strength, effectively resisting wear and deformation during daily wear and exercise, and significantly extending the lifespan of the footwear.

[0077] A one-pot reaction is used to react 1-(4-vinyl-phenyl)-ethyl ketone, diethyl oxalate, and 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole. The amino group of 2-aminothiadiazole nucleophilically attacks the carbonyl carbon of diethyl oxalate, forming an intermediate. In the presence of a strong base, the α-hydrogen of 1-(4-vinyl-phenyl)-ethyl ketone is deprotonated to form a carbanion, which attacks the carbonyl carbon of the intermediate, undergoing Claisen condensation. Under microwave conditions, dehydration forms a conjugated enone (chalcone) structure, generating an imidazothiadiazole ring. The conjugated enone system in the chalcone molecule efficiently absorbs ultraviolet light through π→π* transitions and intramolecular charge transfer, converting light energy into heat energy, thus endowing the material with excellent anti-UV aging properties. This characteristic gives shoe materials (especially shoe uppers and insoles exposed to sunlight) excellent anti-UV aging capabilities. It can effectively prevent color fading, yellowing, surface powdering, embrittlement, and strength reduction caused by long-term sun exposure. Maintain the vibrant and lasting appearance of footwear while ensuring the long-term stability of its mechanical and protective properties (such as water resistance and toughness), ensuring that footwear maintains good functionality and aesthetics throughout its entire lifespan;

[0078] The ultralight material prepared in this invention integrates multiple core functions such as flame retardancy, antibacterial properties, and strong resistance to ultraviolet aging through ingenious molecular design. These characteristics perfectly meet the core requirements of modern footwear materials for safety, hygiene, durability, aesthetic longevity, and lightweight comfort. This material provides an ideal material solution for developing a new generation of high-performance, multifunctional, and high-value-added safety shoes, sports shoes, outdoor shoes, casual shoes, and everyday footwear that emphasizes health and hygiene, and has broad market application prospects.

[0079] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing an ultralight material, characterized in that: The preparation steps include the following: 1) 3-Hexen-1,6-diol and phenylphosphonic dichloride were reacted to obtain a functional chain extender precursor; the functional chain extender precursor and heptamethylcyclotetrasiloxane were reacted to obtain a functional chain extender. 2) Hollow glass microspheres were treated with 3-mercaptopropyltrimethoxysilane to obtain pretreated hollow glass microspheres; Pre-modified hollow glass microspheres were obtained by reacting pretreated hollow glass microspheres, isoprene, and 1-(4-vinyl-phenyl)-ethyl ketone. 3) Modified hollow glass microspheres were obtained by reacting pre-modified hollow glass microspheres, diethyl oxalate, and 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole. 4) Weigh the following components: polyether diol, isophorone diisocyanate, functional chain extender, dibutyltin dilaurate, modified hollow glass microspheres, trifluoromethanesulfonic acid, and acetone; mix and cure the above components to obtain an ultralight material.

2. The method for preparing the ultralight material as described in claim 1, characterized in that: Step 1) The preparation method of the functional chain extender is as follows: 3-hexen-1,6-diol, phenylphosphonodichloro, and N,N-dimethylaniline are mixed and heated to 120-130℃ for 8-10 hours to obtain the functional chain extender precursor; the functional chain extender precursor, heptamethylcyclotetrasiloxane, caster catalyst, and toluene are mixed and heated to 100-110℃ for 4-6 hours to obtain the functional chain extender.

3. The method for preparing the ultralight material as described in claim 2, characterized in that: The molar ratio of 3-hexene-1,6-diol, phenylphosphonodichloro, and N,N-dimethylaniline is (2.1-2.2):1:(3.1-3.2); the molar ratio of the functional chain extender precursor and heptamethylcyclotetrasiloxane is (1.1-1.2):1; and the mass ratio of the functional chain extender precursor, caster catalyst, and toluene is 1:(0.001-0.002):(10-12).

4. The method for preparing the ultralight material as described in claim 1, characterized in that: Step 2) The preparation method of the pre-modified hollow glass microspheres is as follows: isoprene is reacted with 1-(4-vinyl-phenyl)-ethyl ketone and pretreated hollow glass microspheres under nitrogen protection, at 60-70℃ and in the presence of azobisisobutyronitrile, a photoinitiator is added, and the mixture is irradiated under ultraviolet light to obtain the pre-modified hollow glass microspheres.

5. The method for preparing the ultralight material as described in claim 4, characterized in that: The mass ratio of the pretreated hollow glass microspheres, isoprene, 1-(4-vinyl-phenyl)-ethyl ketone, and azobisisobutyronitrile is 1:(0.6-0.8):(0.2-0.4):(0.003-0.005).

6. The method for preparing the ultralight material as described in claim 1, characterized in that: Step 3) The method for preparing the modified hollow glass microspheres is as follows: pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, alkaline catalyst, and N-methylpyrrolidone are mixed and reacted under microwave irradiation to obtain modified hollow glass microspheres.

7. The method for preparing the ultralight material as described in claim 6, characterized in that: The mass ratio of the pre-modified hollow glass microspheres, diethyl oxalate, 2-amino-5-(2-chlorophenyl)-1,3,4-thiadiazole, alkaline catalyst, and N-methylpyrrolidone is 1:(0.2-0.3):(0.2-0.3):(0.3-0.5):(20-30).

8. The method for preparing the ultralight material as described in claim 1, characterized in that: Step 4) The amounts of the components are as follows: by mass parts, 100 parts of polyether diol, 17-23 parts of isophorone diisocyanate, 15-20 parts of functional chain extender, 0.1-0.3 parts of dibutyltin dilaurate, 20-30 parts of modified hollow glass microspheres, 0.5-1.0 parts of trifluoromethanesulfonic acid, and 100-150 parts of acetone.

9. The ultralight material prepared by the preparation method according to any one of claims 1-8.

10. The application of the ultralight material as described in claim 9 in footwear materials.

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