A bio-based microporous membrane and method of making

Abstract

The application relates to the technical field of microporous membranes, and discloses a bio-based microporous membrane and a preparation method thereof. The bio-based microporous membrane comprises raw materials: 4,4-diisocyanate dicyclohexyl methane, polycaprolactone diol which is a bio-based raw material, a chain extender which is composed of hydrogen-containing eugenol functionalized siloxane and 1,4-butanediol, and hydrogen-containing eugenol functionalized siloxane which is prepared by the reaction of bio-based raw material eugenol, 1,3-divinyltetramethyldisiloxane and phenylsilane; and alkenyl functionalized antibacterial nanoparticles which are covalently bonded with the hydrogen-containing eugenol functionalized siloxane through a platinum-catalyzed hydrosilylation reaction, and are prepared into the bio-based microporous membrane through a wet film forming method and by taking bio-based polyurethane as the raw material. The prepared membrane product has a bacteriostatic rate of more than 99%, and the bio-based carbon content thereof is more than 60%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microporous membrane, in particular to a bio-based microporous membrane and a preparation method thereof. BACKGROUND

[0002] The microporous membrane is a kind of thin film material filled with micro-pores inside, and its working principle is that: the external liquid water is blocked because its size is much larger than the micro-pore, so as to realize waterproof; the moisture emitted by the human body can diffuse out through the micro-pore by virtue of the concentration difference, so as to realize moisture permeability; the high water vapor transmission capacity avoids the condensation and accumulation of moisture between the body surface and the fabric, and keeps the wearing dry. The microporous membrane and the fabric can be combined through lamination and other technologies to endow the fabric with excellent waterproof and moisture permeable functions, so as to have broad application prospects in the fields of outdoor sports clothing and professional protective equipment.

[0003] The key monomers (such as polyols and isocyanate) of traditional polyurethane are mainly derived from non-renewable petroleum-based materials. In the face of the increasingly exhausted oil resources and related environmental problems, the development of bio-based polyurethane has become a research hotspot. Bio-based refers to raw materials derived from renewable biomass resources (such as plants, microorganisms, etc.), which has the characteristics of low carbon and environmental protection. The development of bio-based polyurethane meets the needs of green consumption and sustainable development.

[0004] Based on this, the present application intends to first synthesize a new type of bio-based polyurethane, and then prepare a bio-based microporous membrane based on it, and finally apply it in the field of functional textiles. SUMMARY

[0005] The present application uses polycaprolactone diol, 1,4-butanediol, hydrogen-containing eugenol functionalized siloxane, 4,4-diisocyanate dicyclohexyl methane and alkenyl functionalized antibacterial nanoparticles as raw materials, and through urethane reaction and hydrosilylation reaction, a bio-based polyurethane is prepared, and a bio-based microporous membrane is prepared by wet film forming method. The antibacterial performance of the membrane product meets the technical requirements of GB / T20944.3-2008 "Evaluation of Textile Antimicrobial Performance Part 3: Oscillation Method" on the inhibition rate of Staphylococcus aureus and Escherichia coli, which is ≥70%.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A bio-based microporous membrane, the bio-based carbon content in the bio-based microporous membrane is >60%, and the bio-based microporous membrane comprises the following raw materials by weight:

[0008] 9.0-9.5 parts of 4,4-diisocyanate dicyclohexyl methane;

[0009] 18-22 parts of polycaprolactone diol, which is a bio-based raw material;

[0010] 5.5-10.5 parts of chain extender, which consists of hydrogen-containing eugenol-functionalized siloxane and 1,4-butanediol, the mass ratio of hydrogen-containing eugenol-functionalized siloxane to 1,4-butanediol is 0.3-1:1;

[0011] The hydrogen-containing eugenol-functionalized siloxane is prepared by reaction of bio-based raw material eugenol, 1,3-divinyltetramethyldisiloxane and phenylsilane;

[0012] 0.1-0.5 parts of alkenyl-functionalized antibacterial nanoparticles, which are covalently bonded to the hydrogen-containing eugenol-functionalized siloxane through platinum-catalyzed hydrosilylation reaction.

[0013] Preferably, the preparation method of the hydrogen-containing eugenol-functionalized siloxane is as follows:

[0014] Based on the hydrosilylation reaction mechanism, under the action of platinum catalyst, 1 mole equivalent of alkenyl functional group of 1,3-divinyltetramethyldisiloxane reacts with 2 mole equivalents of silicon-hydrogen bond functional group of phenylsilane to prepare a silicon-hydrogen bond-terminated siloxane, and then 1 mole equivalent of silicon-hydrogen bond functional group of the silicon-hydrogen bond-terminated siloxane reacts with 2 mole equivalents of alkenyl functional group of eugenol to prepare the hydrogen-containing eugenol-functionalized siloxane.

[0015] Preferably, the platinum catalyst is chloroplatinic acid isopropanol solution with a platinum mass fraction of 0.5-2.5%.

[0016] Preferably, the preparation method of the alkenyl-functionalized antibacterial nanoparticles is as follows: the surface of the antibacterial nanoparticles is modified by an alkenyl-functionalized silane coupling agent to prepare the alkenyl-functionalized antibacterial nanoparticles.

[0017] Preferably, the alkenyl-functionalized silane coupling agent is one of vinyltrimethoxysilane, allyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane and 3-(methacryloyloxy)propyltriethoxysilane.

[0018] Preferably, the antibacterial nanoparticles are one of nano-zinc oxide, nano-copper oxide and nano-magnesium oxide.

[0019] Preferably, the particle size of the antibacterial nanoparticles is 20-80 nm.

[0020] Preferably, the mass ratio of the antibacterial nanoparticles to the alkenyl-functionalized silane coupling agent is 1:0.01-0.10.

[0021] Preferably, the thickness of the bio-based microporous film is 50-100 μm.

[0022] A preparation method of a bio-based microporous film, comprising the following steps:

[0023] Preparation of polycaprolactone diol with ε-caprolactone and 1,4-butanediol as raw materials;

[0024] Preparation of isocyanate prepolymer by urethane reaction of polycaprolactone diol and 4,4-diisocyanate dicyclohexyl methane;

[0025] Preparation of silicon-hydrogen functional polyurethane by chain extension reaction of isocyanate prepolymer with 1,4-butanediol and hydrogen-containing eugenol functional siloxane as chain extender;

[0026] Preparation of bio-based polyurethane by silicon-hydrogen addition reaction of silicon-hydrogen functional polyurethane and alkenyl functional antibacterial nanoparticles;

[0027] Preparation of bio-based microporous membrane by wet film forming method with bio-based polyurethane as raw material, N,N-dimethylformamide as solvent and anhydrous ethanol as coagulation bath.

[0028] The beneficial effects of the present application are as follows:

[0029] Preparation of hydrogen-containing eugenol functional siloxane by silicon-hydrogen addition reaction of bio-based raw material eugenol, phenylsilane and 1,3-divinyl tetramethyl disiloxane;

[0030] Preparation of alkenyl functional antibacterial nanoparticles with alkenyl functional silane coupling agent and antibacterial nanoparticles as raw materials;

[0031] Preparation of bio-based polycaprolactone diol with bio-based ε-caprolactone and 1,4-butanediol as raw materials;

[0032] Preparation of bio-based polyurethane by urethane reaction and silicon-hydrogen addition reaction of bio-based polycaprolactone diol, 4,4-diisocyanate dicyclohexyl methane and alkenyl functional antibacterial nanoparticles with hydrogen-containing eugenol functional siloxane and 1,4-butanediol as chain extender, preparation of bio-based microporous membrane by wet film forming method with bio-based polyurethane as raw material, N,N-dimethylformamide as solvent and anhydrous ethanol as coagulation bath according to the principle of non-solvent induced phase separation;

[0033] The experimental results prove that the bio-based carbon content of the bio-based microporous membrane prepared by the present application reaches more than 60%, and the antibacterial rate of the membrane product reaches more than 99%, and the antibacterial performance meets the technical requirements of GB / T 20944.3-2008 "Evaluation of Textiles for Antibacterial Performance Part 3: Oscillation Method" for the antibacterial rate of Staphylococcus aureus and Escherichia coli ≥70%. DETAILED DESCRIPTION

[0034] Example 1:

[0035] The reaction mechanism for preparing hydrogen-containing eugenol functional siloxane is:

[0036] Based on the mechanism of hydrosilylation reaction, 1 mole equivalent of alkenyl functional group of 1, 3-divinyltetramethyldisiloxane reacts with 2 mole equivalents of silicon-hydrogen bond functional group of phenylsilane in the presence of platinum catalyst to produce silicon-hydrogen bond terminated siloxane, and then 1 mole equivalent of silicon-hydrogen bond functional group of silicon-hydrogen bond terminated siloxane reacts with 2 mole equivalents of alkenyl functional group of eugenol to produce hydrogen-containing eugenol functionalized siloxane;

[0037] The chemical structural formula of hydrogen-containing eugenol functionalized siloxane is:

[0038] ;

[0039] The specific preparation steps of hydrogen-containing eugenol functionalized siloxane are as follows:

[0040] Adsorb and remove trace amount of water in isopropanol solution, add 0.53 g of chloroplatinic acid hexahydrate and 12 mL of isopropanol solution to prepare chloroplatinic acid isopropanol solution with platinum mass fraction of 2%;

[0041] Add 20 mL of toluene, 2.3 mL of 1, 3-divinyltetramethyldisiloxane and 2 drops of chloroplatinic acid isopropanol solution with platinum mass fraction of 2% into a three-necked flask, mix well, add 2.5 mL of phenylsilane and 20 mL of toluene into a constant pressure dropping funnel, mix well, heat to 60℃ under nitrogen protection, slowly drop the solution in the funnel into the three-necked flask, drop for 1 h, heat to 75℃ again, react for 5 h, then cool to 60℃, add 3.1 mL of eugenol and 20 mL of toluene into a constant pressure dropping funnel, mix well, slowly drop into the three-necked flask, drop for 1 h, heat to 80℃, react for 6 h to obtain a crude product, remove toluene by rotary evaporation, wash with deionized water and ethanol in sequence, dry at 60℃ for 12 h to obtain hydrogen-containing eugenol functionalized siloxane;

[0042] The hydrogen spectrum characterization result of hydrogen-containing eugenol functionalized siloxane is as follows:

[0043] 1 H NMR (400MHz, DMSO-D6, δ, ppm): 0.05 (s, 12H), 0.87-0.91 (t, 4H), 1.07-1.15 (m, 8H), 1.63-1.69 (m, 4H), 2.54-2.67 (m, 4H), 3.82 (s, 6H), 4.18-4.23 (m, 2H), 6.04 (s, 2H), 6.63-6.65 (d, 4H), 6.75-6.77 (d, 2H), 7.28-7.34 (m, 6H), 7.49-7.54 (m, 4H);

[0044] The reaction mechanism for preparing the alkenyl functionalized antibacterial nanoparticles is as follows:

[0045] The alkenyl functionalized silane coupling agent is hydrolyzed to generate Si-OH, which condenses with the hydroxyl groups on the surface of the antibacterial nanoparticles to prepare the alkenyl functionalized antibacterial nanoparticles;

[0046] The alkenyl functionalized silane coupling agent is one of vinyltrimethoxysilane, allyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, and 3-(methacryloyloxy)propyltriethoxysilane, and 3-(methacryloyloxy)propyltriethoxysilane is selected in this embodiment;

[0047] The antibacterial nanoparticles are one of nano-zinc oxide, nano-copper oxide, and nano-magnesium oxide, and nano-zinc oxide is selected in this embodiment;

[0048] The specific preparation steps of the alkenyl functionalized antibacterial nanoparticles are as follows:

[0049] 30 mL of an ethanol solution is mixed with 10 mL of deionized water, then 0.12 mL of 3-(methacryloyloxy)propyltriethoxysilane is added, and magnetic stirring is performed for 30 min, 2 g of nano-zinc oxide (with a particle size of 50 nm) is added, magnetic stirring is performed for 30 min, ultrasonic dispersion is performed for 25 min to form a uniform dispersion liquid, the dispersion liquid is immediately transferred to a magnetic stirring oil bath, the temperature is set to 85°C, and after 1 h of reaction, the temperature is cooled to room temperature, filtration, washing, and vacuum drying at 65°C for 10 h are performed to prepare the alkenyl functionalized antibacterial nanoparticles.

[0050] Embodiment two:

[0051] A bio-based microporous membrane includes the following raw materials by weight:

[0052] The amount-of-substance ratio of isocyanate to hydroxyl is set to 1.03:1, and accordingly the raw material formula of the bio-based microporous membrane is obtained as follows:

[0053] 9.4 g of 4,4-diisocyanate dicyclohexyl methane;

[0054] 20 g of polycaprolactone diol;

[0055] 1.7 g of bio-based 1,4-butanediol;

[0056] 4.4 g of hydrogen-containing eugenol functionalized siloxane;

[0057] 0.3 g of alkenyl functionalized antibacterial nanoparticles;

[0058] A preparation method of a bio-based microporous membrane includes the following steps:

[0059] 4.25 parts by weight of ε-caprolactone was placed in a three-necked flask, 0.2 parts by weight of 1,4-butanediol was mixed uniformly, then 0.01 g of stannous octoate was added, nitrogen was introduced, and reaction was carried out at 150°C for 24 h. After cooling to 60°C, the precipitate was washed with methanol, cooled, suction filtered, and dried in a vacuum at 50°C for 24 h to obtain poly-caprolactone diol. According to the formula m2 = m1M2 / (M n n M2 is the relative molecular weight of 1,4-butanediol, M n is the relative molecular weight of poly-caprolactone diol, and it was calculated that the relative molecular weight was about 2000.

[0060] According to the formula amount, nitrogen was introduced for protection, poly-caprolactone diol was mixed with 4,4-diisocyanate dicyclohexyl methane, and the temperature was raised to 50°C. After mechanical stirring for 1 h, the temperature was raised to 80°C, and stirring was continued for 2 h to form an isocyanate prepolymer. Then 1,4-butanediol and hydrogen-containing eugenol-functionalized siloxane were added to 30 mL of anhydrous N,N-dimethylformamide, mixed uniformly, slowly added to the isocyanate prepolymer, and reacted at 70°C for 1 h. Then 0.1 g of dibutyltin dilaurate was added, the temperature was raised to 80°C, and reaction was carried out for 4 h to obtain a silicon-hydrogen functionalized polyurethane. Alkenyl-functionalized antibacterial nanoparticles and 4 drops of a 2% platinum mass fraction isopropanol solution of chloroplatinic acid were added to the silicon-hydrogen functionalized polyurethane, the temperature was raised to 85°C, and reaction was carried out for 5 h. After cooling to room temperature, the product was placed in a vacuum drying oven at 80°C to obtain a bio-based polyurethane.

[0061] The bio-based polyurethane was added to N,N-dimethylformamide, stirred thoroughly, and then placed in a 60°C constant-temperature water bath for stirring for 2 h to prepare a 20% polyurethane casting solution. The solution was vacuum degassed at room temperature, a dry and clean glass plate was used as a template, a wire bar coater was used to uniformly scrape and coat the polyurethane casting solution into a film, then the film was immersed in anhydrous ethanol to solidify, and the shaped film was transferred from the glass plate to deionized water for immersion for 2 h. The film was taken out, naturally dried, and a bio-based microporous membrane a with a thickness of 65 μm was obtained.

[0062] Example Three:

[0063] A bio-based microporous membrane b was prepared, and the difference between the preparation method thereof and that of the bio-based microporous membrane a was that 1.5 g of 1,4-butanediol and 6 g of hydrogen-containing eugenol-functionalized siloxane were used.

[0064] Example Four:

[0065] A bio-based microporous membrane c was prepared, and the difference between the preparation method thereof and that of the bio-based microporous membrane a was that 1.2 g of 1,4-butanediol and 8.4 g of hydrogen-containing eugenol-functionalized siloxane were used.

[0066] Comparative Example:

[0067] A bio-based microporous membrane, comprising the following raw materials by weight:

[0068] The amount ratio of isocyanate to hydroxyl is set to 1.03:1, according to which the raw material formula of the bio-based microporous membrane is obtained as follows:

[0069] 5.8 g of 4,4-diisocyanate dicyclohexyl methane;

[0070] 20 g of polycaprolactone diol;

[0071] 1 g of 1,4-butanediol;

[0072] The preparation method of the polycaprolactone diol with a relative molecular mass of about 2000 is consistent with that in Example Two;

[0073] According to the formula amount, nitrogen protection is carried out, the polycaprolactone diol and the 4,4-diisocyanate dicyclohexyl methane are mixed, the temperature is raised to 50°C, mechanical stirring is carried out for 1 h, then the temperature is raised to 80°C, and stirring is continued for 2 h to form an isocyanate prepolymer, then 1,4-butanediol is added to 30 mL of anhydrous N,N-dimethylformamide, mixed uniformly, slowly added to the isocyanate prepolymer, reacted at 70°C for 1 h, then 0.1 g of dibutyltin dilaurate is added, the temperature is raised to 80°C, and reacted for 4 h, then cooled to room temperature, and placed in a vacuum drying box at 80°C to obtain a bio-based polyurethane after drying;

[0074] The bio-based polyurethane is added to N,N-dimethylformamide, stirred thoroughly, and then placed in a 60°C constant temperature water bath for stirring for 2 h to prepare a 20% polyurethane casting solution, vacuum degassed at room temperature, and a dry and clean glass plate is used as a template, a wire bar coater is used to uniformly scrape and coat the polyurethane casting solution into a film, then immersed in anhydrous ethanol coagulation bath to form a film, the formed film is transferred from the glass plate to deionized water for immersion for 2 h, the film is taken out and naturally dried to obtain a bio-based microporous membrane with a thickness of 65 μm.

[0075] Performance test:

[0076] I. Mechanical property test of bio-based microporous membrane

[0077] The electronic fabric strength tester is used to test the tensile property and elongation at break of the bio-based microporous membrane, the bio-based microporous membrane is prepared into a strip-shaped sample with a size of 25 mm x 150 mm, the clamping length of the sample is 100 mm, the tensile speed is 10 mm / min, the sample is tested for 3 times, and the average value is taken;

[0078] Table 1 Mechanical property test results of bio-based microporous membrane

[0079] Product No. Tensile strength (MPa) Elongation at break (%) Bio-based microporous membrane a 18.7 334.2 Bio-based microporous membrane b 20.5 354.3 Bio-based microporous membrane c 19.8 342.4 Comparative Example 11.4 237.9

[0080] II. Test of moisture permeability of bio-based microporous membrane

[0081] According to the method in GB / T 12704.1-2009 Textiles - Test methods for water vapour permeability - Part 1: Moisture method, a moisture permeability tester is used to test the moisture permeability of the bio-based microporous membrane, and the moisture permeability rate is calculated;

[0082] Table 2 Experimental results of moisture permeability of bio-based microporous membrane

[0083] Product No. moisture permeability [g / (m 2 ·24h) Bio-based microporous membrane a 4132 Bio-based microporous membrane b 4495 Bio-based microporous membrane c 4258

[0084] III. Test of antibacterial property of bio-based microporous membrane

[0085] The sample is sterilized, and then E. coli (ATCC8739) and S. aureus (ATCC6538) are used as test bacteria, the bacteria are cultured at 37℃ for 24h, and then diluted to 106 colony forming units (CFU) per milliliter;

[0086] 0.1g of the sample is added to 10mL of the bacterial dilution, and irradiated at room temperature for 2h under the condition of a 40W ultraviolet lamp, and then 0.1mL of the solution is dropped into an AGAR plate and uniformly coated, and placed at 37℃ for 12h;

[0087] The antibacterial rate is calculated as (P-M) / P*100%, wherein P and M are the average number of bacteria in the control group and the experimental group sample, respectively;

[0088] Table 3 Experimental results of antibacterial property of bio-based microporous membrane

[0089] Product No. Bacteriostatic rate against E. coli (%) Bacteriostatic rate against S. aureus (%) Bio-based microporous membrane a ≥99.9 ≥99.9 Bio-based microporous membrane b ≥99.9 ≥99.9 Bio-based microporous membrane c ≥99.9 ≥99.9

[0090] The antibacterial rate of the bio-based microporous membrane prepared in the application meets the technical requirement of GB / T 20944.3-2008 Textiles - Evaluation of antibacterial properties - Part 3: Shake flask method that the antibacterial rate of S. aureus and E. coli is ≥70%, and the sample has antibacterial effect;

[0091] IV. Test of bio-based carbon content

[0092] Biomass contains 100% C14 content, while fossil raw materials do not contain C14 (0%), and the bio-based carbon content in the bio-based microporous membrane, i.e., the percentage of bio-based carbon in total organic carbon, is measured by the method of ASTM D68866 and using accelerator mass spectrometry (AMS) technology;

[0093] Table 4 Experimental results of bio-based carbon content of bio-based microporous membrane

[0094] Product No. Bio-based carbon content (%) Bio-based microporous membrane a 61.2 Bio-based microporous membrane b 61.7 Bio-based microporous membrane c 62.3

[0095] From the above experimental results, it can be seen that the film product prepared by the application has very excellent antibacterial performance, the biological-based carbon content reaches 60%, and belongs to a biological-based microporous film.

Claims

1. A bio-based microporous membrane, characterized in that, The bio-based microporous membrane has a bio-based carbon content of >60%, and is made of a bio-based polyurethane, which comprises the following raw materials by weight: 9.0-9.5 parts of 4,4-diisocyanate dicyclohexyl methane; 18-22 parts of polycaprolactone diol, which is a bio-based raw material; 5.5-10.5 parts of a chain extender consisting of hydrogen-containing eugenol functionalized siloxane and 1,4-butanediol, the mass ratio of hydrogen-containing eugenol functionalized siloxane to 1,4-butanediol being 0.3-1:1; Based on the mechanism of hydrosilylation reaction, 1 mole equivalent of alkenyl functional group of 1,3-divinyltetramethyldisiloxane reacts with 2 mole equivalents of silicon-hydrogen bond functional group of phenylsilane under the action of platinum catalyst to prepare a silicon-hydrogen bond terminated siloxane, and then 1 mole equivalent of silicon-hydrogen bond functional group of the silicon-hydrogen bond terminated siloxane reacts with 2 mole equivalents of alkenyl functional group of eugenol to prepare hydrogen-containing eugenol functionalized siloxane; The chemical structural formula of the hydrogen-containing eugenol functionalized siloxane is: ； 0.1-0.5 parts of alkenyl functionalized antibacterial nanoparticles, which are covalently bonded to the hydrogen-containing eugenol functionalized siloxane through platinum-catalyzed hydrosilylation reaction; The alkenyl functionalized antibacterial nanoparticles are prepared by surface modification of antibacterial nanoparticles with an alkenyl functionalized silane coupling agent, and the mass ratio of the antibacterial nanoparticles to the alkenyl functionalized silane coupling agent is 1:0.01-0.

10.

2. The bio-based microporous membrane according to claim 1, wherein, The platinum catalyst is chloroplatinic acid isopropanol solution with a platinum mass fraction of 0.5-2.5%.

3. The bio-based microporous membrane of claim 1, wherein, The alkenyl functionalized silane coupling agent is one of vinyltrimethoxysilane, allyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane and 3-(methacryloyloxy)propyltriethoxysilane.

4. The bio-based microporous membrane of claim 1, wherein, The antibacterial nanoparticles are one of nano-zinc oxide, nano-copper oxide and nano-magnesium oxide.

5. The bio-based microporous membrane of claim 1, wherein, The particle size of the antibacterial nanoparticles is 20-80 nm.

6. The bio-based microporous membrane of claim 1, wherein, The thickness of the bio-based microporous membrane is 50-100 μm.

7. A method of producing a bio-based microporous membrane according to any one of claims 1-6, characterized in that, The steps include: Preparation of polycaprolactone diol from ε-caprolactone and 1,4-butanediol as raw materials; Preparation of isocyanate prepolymer by urethane reaction of polycaprolactone diol and 4,4-diisocyanate dicyclohexyl methane; Preparation of silicon-hydrogen functionalized polyurethane by chain extension reaction of isocyanate prepolymer with 1,4-butanediol and hydrogen-containing eugenol functionalized siloxane as chain extenders; Preparation of bio-based polyurethane by hydrosilylation reaction of alkenyl functionalized antibacterial nanoparticles and silicon-hydrogen functionalized polyurethane; Preparation of bio-based microporous membrane by wet film forming method from bio-based polyurethane as raw material, N,N-dimethylformamide as solvent and anhydrous ethanol as coagulation bath.

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