Antibacterial degradable bio-based polyurethane waterproof moisture-permeable film and preparation method thereof

Abstract

The invention discloses an antibacterial and degradable bio-based polyurethane waterproof and moisture-permeable film and a preparation method thereof, and belongs to the technical field of waterproof and moisture-permeable films. The antibacterial degradable bio-based polyurethane waterproof moisture-permeable film is prepared from the following raw materials in parts by weight: 12 to 15 parts of bio-based waterborne polyurethane, 2 to 5 parts of silane coupling agent modified inorganic filler, 5 to 8 parts of antibacterial agent, 3 to 5 parts of silane coupling agent modified 2D mesoporous porous adsorbent and 2 to 5 parts of polyurethane plasticizer. According to the antibacterial and degradable bio-based polyurethane waterproof and moisture-permeable film disclosed by the invention, the water absorption of the bio-based polyurethane waterproof and moisture-permeable film can be reduced, and the moisture permeability of the bio-based polyurethane waterproof and moisture-permeable film is improved.

Description

Technical Field

[0001] The invention relates to the technical field of waterproof and breathable membranes, in particular to an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane and a preparation method thereof. Background Art

[0002] Nowadays, with the continuous development of social living standards and economic conditions, people have put forward higher requirements for the comfort and functionality of clothing. Waterproof and breathable fabrics have the advantages of small pore size and high porosity. The pore size can effectively block the intrusion of liquid water while allowing water vapor to pass freely. It has attracted much attention because it can effectively maintain the humidity balance of the microenvironment between the human body and clothing and significantly improve the comfort of human wearing.

[0003] Waterproof and breathable membrane is a functional membrane material with excellent water permeability and moisture permeability. It is usually compounded with natural fiber fabrics or synthetic fiber fabrics to manufacture functional clothing with unique protection and comfort, such as mountaineering suits, ski suits, assault suits, field military uniforms, chemical protection suits, shoes, socks and gloves, etc. Clothing made with waterproof and breathable membrane as the core material can block rain and snow from penetrating into the interior and prevent damage from harsh external conditions, while transmitting the sweat produced by the human body in the form of moisture, thereby ensuring the safety and comfort of the human body. Therefore, it is becoming more and more important in people's production activities and daily life.

[0004] Petroleum-based polyurethane waterproof and breathable membrane materials are usually synthesized from petroleum-derived polyols and isocyanates. They consume a lot of energy in processing, pose a threat to the human body and the environment, are prone to produce volatile organic compounds during use, and are difficult to recycle and degrade after use. Moisture permeability is one of the important indicators of waterproof and breathable membranes. It determines whether sweat can pass through the membrane material smoothly, thereby maintaining the comfort of the human body. If the moisture permeability is insufficient, it may cause the wearer to feel stuffy and uncomfortable during exercise. Bio-based polyurethane waterproof and breathable membranes can replace traditional petroleum-based raw materials, which has attracted widespread attention in the industry, but the moisture permeability of bio-based polyurethane may not be as good as that of petroleum-based polyurethane. Bio-based polyurethane is usually synthesized from natural polyols (such as polytrimethylene ether glycol) and isocyanates (such as isophorone diisocyanate). Although the molecular structure of these raw materials contains more hydrophilic groups, such as hydroxyl groups and ether bonds, these groups can absorb and transmit water molecules to achieve moisture permeability. However, too many hydrophilic groups may also increase the water absorption rate of the material, thereby affecting its water resistance and moisture permeability. The moisture permeability is due to the presence of a certain amount of hydrophilic groups in the polyurethane material. These groups first "capture" the water vapor molecules emitted by the human body in the form of hydrogen bonds. Due to the thermal motion of the polyurethane macromolecular chain, a momentary gap is formed between the molecular chains. Coupled with the promotion of the water vapor pressure difference between the inside and outside of the film, the water vapor molecules are "transferred" from the side with high vapor pressure to the other side along the dense gaps between the molecular chains, that is, from the side in contact with the skin to the surrounding environment, achieving the purpose of moisture permeability. This kind of moisture permeability relies on the action of hydrophilic segments or hydrophilic groups, so it is also called "hydrophilic moisture permeability". There are fewer hydrophilic groups in the molecular structure of petroleum-based polyurethane waterproof and breathable membrane materials, but the moisture permeability can be improved by adding specific hydrophilic additives (such as polyethylene glycol PEG), although the moisture permeability of petroleum-based polyurethane waterproof and breathable membrane materials is usually more stable and has a lower water absorption rate. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, one of the objects of the present invention is to provide an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, which can reduce the water absorption of the bio-based polyurethane waterproof and breathable membrane and improve the moisture permeability of the bio-based polyurethane waterproof and breathable membrane.

[0006] The second object of the present invention is to provide a method for preparing an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, which is simple to prepare and convenient for on-site construction.

[0007] The third object of the present invention is to provide a waterproof and breathable fabric, which has waterproof and breathable properties.

[0008] One of the purposes of the present invention is achieved by the following technical solution:

[0009] An antibacterial and degradable bio-based polyurethane waterproof and breathable membrane comprises raw materials in parts by weight: 12 to 15 parts of bio-based waterborne polyurethane, 2 to 5 parts of inorganic filler modified by silane coupling agent, 5 to 8 parts of antibacterial agent, 3 to 5 parts of 2D mesoporous porous adsorbent modified by silane coupling agent, and 2 to 5 parts of polyurethane plasticizer.

[0010] Furthermore, the raw materials in parts by weight include 15 parts of bio-based waterborne polyurethane, 5 parts of inorganic filler modified by silane coupling agent, 5 parts of antibacterial agent, 3 parts of 2D mesoporous porous adsorbent modified by silane coupling agent, and 5 parts of polyurethane plasticizer.

[0011] Furthermore, the inorganic filler is one of diatomaceous earth and nano-silicon dioxide.

[0012] Furthermore, the antibacterial agent is one or both of nanosilver and organic antibacterial agent.

[0013] Furthermore, the preparation method of the bio-based waterborne polyurethane BWPU comprises the following steps:

[0014] S1. Preparation of oleic primary diol with long fatty chain: The oleic primary diol OPG with long fatty chain was prepared by mercaptoethanol and extended chain oleic acid methyl ester (CEMO) under ultraviolet light initiation thiol-ene click reaction, the optimal reaction conditions were 2% by mass of photoinitiator 1173, -SH and -C=C- molar ratio of 2:1, and reaction time of 1 hour;

[0015] S2, mixed diol: the oleic acid-based primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0016] S3, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0017] S4, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0018] S5, emulsification: finally, triethylamine TEA is added dropwise to perform deprotonation, and then added into water for emulsification to obtain the bio-based waterborne polyurethane.

[0019] Furthermore, the 2D mesoporous porous adsorbent is a mixture of one or more of 2D mesoporous zeolite powder, 2D mesoporous hydrotalcite powder, 2D mesoporous magnesium oxide powder, and 2D mesoporous aluminum oxide powder.

[0020] The second object of the present invention is achieved by adopting the following technical solution:

[0021] A method for preparing an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane comprises the following steps:

[0022] S1. Preparing the bio-based waterborne polyurethane, the preparation method of the bio-based waterborne polyurethane BWPU comprises the following steps:

[0023] S11. Preparation of oleic primary diol with long fatty chain: The oleic primary diol OPG with long fatty chain was prepared by mercaptoethanol and extended chain oleic acid methyl ester (CEMO) in a thiol-ene click reaction under ultraviolet light initiation. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0024] S12, mixed diol: the oleic acid-based primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0025] S13, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0026] S14, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0027] S15, emulsification: finally, triethylamine TEA is added dropwise for deprotonation, and then added into water for emulsification to obtain the bio-based waterborne polyurethane;

[0028] S2. According to the formula amount, the inorganic filler modified by the silane coupling agent, the antibacterial agent, the 2D mesoporous porous adsorbent modified by the silane coupling agent, and the polyurethane plasticizer are added to the bio-based waterborne polyurethane, and stirred to mix evenly to obtain a mixed solution;

[0029] S3, applying the mixed solution on a flat, clean and water-free substrate;

[0030] S4. Washing and drying the substrate coated with the liquid film in sequence, and then biaxially stretching the dried film to produce micropores, thereby obtaining the antibacterial and degradable bio-based polyurethane waterproof and moisture-permeable film.

[0031] The third object of the present invention is to provide a waterproof and breathable fabric. The antibacterial and degradable bio-based polyurethane waterproof and breathable membrane is pasted on a textile fabric to obtain the waterproof and breathable fabric.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, which is a composite of bio-based water-based polyurethane and inorganic fillers (such as diatomaceous earth, nano-silicon dioxide, etc.) with good breathability. The inorganic filler particles are separated from the bio-based water-based polyurethane matrix during the stretching process to form micropores. These micropores allow water vapor molecules to pass through, but prevent the penetration of liquid water, thereby improving the hygroscopicity of the bio-based water-based polyurethane material and thus improving the breathability. The bio-based polyurethane is blended with other polymer materials (such as polyvinyl alcohol and polyacrylic acid) with excellent breathability. Through the synergistic effect between the materials, the shortcomings of the bio-based polyurethane in breathability can be compensated. 2D mesoporous porous adsorbents such as zeolite, hydrotalcite, magnesium oxide or aluminum oxide have good hygroscopic properties and improve the moisture permeability efficiency of bio-based waterborne polyurethane materials. After the inorganic filler and the 2D mesoporous porous adsorbent are modified by a silane coupling agent, the compatibility of the inorganic filler, the 2D mesoporous porous adsorbent and the bio-based waterborne polyurethane matrix is ​​improved. By adding inorganic fillers, they can act with the hydrophilic groups in the molecular chain of bio-based waterborne polyurethane to hinder the contact between the bio-based waterborne polyurethane material and water molecules, thereby significantly reducing the water absorption of the bio-based waterborne polyurethane and improving the moisture permeability of the bio-based polyurethane waterproof and breathable membrane. The polyurethane plasticizer molecules are inserted between the bio-based waterborne polyurethane molecular chains, weakening the hydrogen bonds and van der Waals forces between the bio-based waterborne polyurethane molecular chains. The polyurethane plasticizer molecules play a lubricating role between the bio-based waterborne polyurethane molecular chains and increase the degree of freedom of the molecular chains, which enables the bio-based waterborne polyurethane molecular chains to move and slide more freely, thereby forming a microporous structure between the bio-based waterborne polyurethane molecular chains. These micropores provide channels for the transmission of water molecules, thereby improving the moisture permeability of the antibacterial and degradable bio-based polyurethane waterproof and breathable membrane. The 2D mesoporous porous adsorbent modified by the silane coupling agent has a more uniform pore structure, which means that the size and shape of the pores are more consistent, and the resistance encountered by water molecules during the transmission process is smaller. These pores provide a more effective channel for the transmission of water molecules, thereby improving the moisture permeability efficiency of the film. The modified pores are not only uniform, but also have better connectivity. Water molecules can be transmitted from one side of the antibacterial and degradable bio-based polyurethane waterproof and breathable membrane to the other side through these connected pores, forming an effective transmission channel.

[0034] (2) Bio-based waterborne polyurethanes can be degraded in the natural environment and will not cause long-term pollution to the environment. Bio-based polyurethanes prepared using plant oil-based polyols, such as methyl oleate, introduce long aliphatic chains into the polymer network, which can improve their excellent hydrophobicity and durability. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with specific embodiments. It should be noted that, under the premise of no conflict, the embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0036] Methyl oleate (MO, 99%), polytetrahydrofuran diol (PTMG, molecular weight 2000 g / mol, named PTMG2000), triethylamine (TEA, AR grade purity, ≥99.0%), and 1,4-cyclohexanedimethanol (CHDM, ≥99.0%) were purchased from Aladdin Reagent Co., Ltd. (Shanghai, China).

[0037] Water resistance refers to the fact that the performance of a material remains basically unchanged under the action of water and after being soaked in water, and it has the ability to resist the action of water. Specifically, materials with good water resistance will not significantly absorb water, swell, dissolve or degrade in performance in a water environment. For waterproof and breathable membranes, water resistance means that the material can effectively prevent the penetration of liquid water while maintaining its breathable performance, thereby maintaining its function and performance in a humid or flooded environment.

[0038] Example 1

[0039] The present embodiment provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane. The raw materials include, in parts by weight, 15 parts of bio-based water-based polyurethane, 5 parts of diatomaceous earth modified by a silane coupling agent, 5 parts of antibacterial agent nanosilver, 3 parts of 2D mesoporous zeolite powder modified by a silane coupling agent, and 5 parts of a polyurethane plasticizer.

[0040] In this embodiment, the preparation method of bio-based waterborne polyurethane (BWPU) includes the following steps:

[0041] S1. Preparation of oleic primary diol with long fatty chain: oleic primary diol (OPG) with long fatty chain was prepared by thiol-ene click reaction of mercaptoethanol and extended chain oleic acid methyl ester (CEMO) under ultraviolet light initiation. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0042] S2, mixed diol: oleic acid primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0043] S3, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0044] S4, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0045] S5. Emulsification: Finally, triethylamine (TEA) is added dropwise for deprotonation, and then added into water for emulsification to obtain bio-based waterborne polyurethane.

[0046] This embodiment also provides a method for preparing an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, comprising the following steps:

[0047] S1. Preparing bio-based waterborne polyurethane. The preparation method of bio-based waterborne polyurethane comprises the following steps:

[0048] S11. Preparation of oleic primary diol with long fatty chain: oleic primary diol (OPG) with long fatty chain was prepared by thiol-ene click reaction of mercaptoethanol and extended chain oleic acid methyl ester (CEMO) under ultraviolet light initiation. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0049] S12, mixed diol: oleic acid-based primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0050] S13, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0051] S14, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0052] S15, emulsification: finally, triethylamine (TEA) is added dropwise for deprotonation, and then added into water for emulsification to obtain a bio-based waterborne polyurethane;

[0053] S2. According to the formula amount, silane coupling agent-modified diatomaceous earth, antibacterial agent nanosilver, silane coupling agent-modified 2D mesoporous zeolite powder, and polyurethane plasticizer are added to the bio-based waterborne polyurethane, and stirred to mix evenly to obtain a mixed solution;

[0054] S3, applying the mixed solution on a flat, clean and water-free substrate;

[0055] S4. Wash and dry the substrate coated with the liquid film in sequence, and then biaxially stretch the dried film to produce micropores, so as to obtain an antibacterial and degradable bio-based polyurethane waterproof and breathable film.

[0056] This embodiment also provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane pasted on a textile fabric to obtain a waterproof and breathable fabric.

[0057] The role of the inorganic filler in this embodiment is as follows:

[0058] The inorganic filler is treated with a silane coupling agent. By forming a layer of organic silicon bonding layer on the surface of the inorganic filler, the silane coupling agent can transform the hydrophilic surface of the inorganic filler into a hydrophobic surface, which can make the inorganic filler more compatible with the polyurethane matrix, reduce stress concentration points, and improve the overall strength and toughness of the polyurethane material. At the same time, it helps the inorganic filler to form a more uniform microporous structure in the polyurethane material, thereby improving the moisture permeability of the polyurethane material. The inorganic filler modified by the silane coupling agent is added to the polyurethane material, the polyurethane material is the continuous phase, and the inorganic filler modified by the silane coupling agent is the dispersed phase. The interface between the two is strongly bonded, which can effectively hinder the contact between the polyurethane material and water molecules, thereby significantly reducing the water absorption rate.

[0059] By adding inorganic fillers, they can react with polar groups (such as amide groups, terminal amino groups and carboxyl groups) in the polyurethane molecular chain that are easy to absorb water, shielding them, thereby significantly reducing the water absorption rate. For example, in PA6 modification, adding inorganic fillers such as calcium carbonate and talcum powder can effectively reduce the water absorption rate.

[0060] Polyurethane is a semi-crystalline material. Water molecules can easily enter the amorphous area with larger polar groups. Adding inorganic fillers can improve the crystallinity of polyurethane materials. The increase in crystallinity means that the structure of the material is more compact, reducing the free volume of the amorphous area, thereby reducing the penetration path of water molecules. Not only the mechanical properties are improved, but also the water absorption rate will be greatly reduced. The addition of inorganic fillers can improve the crystallinity of polyurethane.

[0061] The functions of the 2D mesoporous porous adsorbent in this embodiment are as follows:

[0062] Zeolite: Zeolite is a hydrous porous alkali or alkaline earth metal aluminosilicate mineral with good hygroscopic properties. Its three-dimensional skeleton structure gives it good physical and chemical properties in adsorption, ion exchange, catalysis, etc. Zeolite has high hygroscopicity, but its moisture permeability depends on its pore structure and surface properties.

[0063] Hydrotalcite: Hydrotalcite is a layered double hydroxide with good hygroscopic properties. Its adsorption properties can be further improved by modification. For example, the adsorption properties of modified hydrotalcite for phosphate are affected by many factors.

[0064] Magnesium oxide: Magnesium oxide has good hygroscopic properties and can effectively absorb moisture from the air. Its hygroscopicity is high, but its moisture permeability depends on its surface properties and pore structure.

[0065] Alumina: Alumina has good hygroscopic properties and can effectively absorb moisture from the air. Its hygroscopicity is high, but its moisture permeability depends on its surface properties and pore structure.

[0066] Organic antimicrobial agents can provide a long-lasting antimicrobial effect and are environmentally friendly. By coating the organic antimicrobial agent on the surface of the membrane, the antimicrobial function can be achieved.

[0067] The pore size distribution is wide, including micropores, mesopores and macropores. Micropores provide the main adsorption sites, while mesopores and macropores provide channels for the transport of adsorbates. The pore structure is not uniform, which may lead to low transport efficiency of adsorbates in the pores. 2D mesoporous porous adsorbents are a special type of porous material with a two-dimensional (2D) structure and mesopore (2-50 nm) pore size. These materials usually have a highly ordered pore structure, uniform pore size distribution, and adjustable surface properties.

[0068] Example 2

[0069] The present embodiment provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, and the raw materials include, by weight: 12 parts of bio-based waterborne polyurethane, 3 parts of nano-silicon dioxide modified by a silane coupling agent, 7 parts of an organic antibacterial agent SCJ, 4 parts of 2D mesoporous hydrotalcite modified by a silane coupling agent, and 2 parts of a polyurethane plasticizer.

[0070] In this embodiment, the preparation method of bio-based waterborne polyurethane comprises the following steps:

[0071] S1. Preparation of oleic acid primary diol with long fatty chain: oleic acid primary diol with long fatty chain was prepared by mercapto-ene click reaction between mercaptoethanol and extended chain oleic acid methyl ester under ultraviolet light initiation. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0072] S2, mixed diol: oleic acid primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0073] S3, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0074] S4, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0075] S5. Emulsification: Finally, triethylamine is added dropwise for deprotonation, and then added into water for emulsification to obtain bio-based waterborne polyurethane.

[0076] This embodiment also provides a method for preparing an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, comprising the following steps:

[0077] S1. Prepare bio-based waterborne polyurethane. The preparation method of bio-based waterborne polyurethane BWPU comprises the following steps:

[0078] S11. Preparation of oleic primary diol with long fatty chain: oleic primary diol OPG with long fatty chain was prepared by mercaptoethanol and extended chain methyl oleate (CEMO) in a thiol-ene click reaction under ultraviolet light initiation. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0079] S12, mixed diol: oleic acid-based primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0080] S13, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0081] S14, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0082] S15, emulsification: finally, triethylamine is added dropwise for deprotonation, and then added into water for emulsification to obtain a bio-based waterborne polyurethane;

[0083] S2. According to the formula amount, add inorganic filler modified by silane coupling agent, nano-silica modified by silane coupling agent, organic antibacterial agent SCJ, 2D mesoporous hydrotalcite modified by silane coupling agent, and polyurethane plasticizer to bio-based waterborne polyurethane, stir and mix evenly to obtain a mixed solution;

[0084] S3, applying the mixed solution on a flat, clean and water-free substrate;

[0085] S4. Wash and dry the substrate coated with the liquid film in sequence, and then biaxially stretch the dried film to produce micropores, so as to obtain an antibacterial and degradable bio-based polyurethane waterproof and breathable film.

[0086] This embodiment also provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane pasted on a textile fabric to obtain a waterproof and breathable fabric.

[0087] Example 3

[0088] The present embodiment provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, and the raw materials include, by weight: 13 parts of bio-based waterborne polyurethane, 2 parts of nano-silicon dioxide modified by silane coupling agent, 8 parts of organic antibacterial agent SCJ, 5 parts of 2D mesoporous magnesium oxide powder modified by silane coupling agent, and 3 parts of polyurethane plasticizer.

[0089] In this embodiment, the preparation method of bio-based waterborne polyurethane comprises the following steps:

[0090] S1. Preparation of oleic primary diol with long fatty chain: The oleic primary diol with long fatty chain was prepared by mercaptoethanol and extended chain methyl oleate (CEMO) under ultraviolet light initiation thiol-ene click reaction. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0091] S2, mixed diol: oleic acid primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0092] S3, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0093] S4, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0094] S5. Emulsification: Finally, triethylamine is added dropwise for deprotonation, and then added into water for emulsification to obtain bio-based waterborne polyurethane.

[0095] This embodiment also provides a method for preparing an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, comprising the following steps:

[0096] S1. Prepare bio-based waterborne polyurethane. The preparation method of bio-based waterborne polyurethane BWPU comprises the following steps:

[0097] S11. Preparation of oleic primary diol with long fatty chain: oleic primary diol with long fatty chain was prepared by thiol-ene click reaction of mercaptoethanol and extended chain oleic acid methyl ester (CEMO) under ultraviolet light initiation. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0098] S12, mixed diol: oleic acid-based primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0099] S13, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0100] S14, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0101] S15, emulsification: finally, triethylamine is added dropwise for deprotonation, and then added into water for emulsification to obtain a bio-based waterborne polyurethane;

[0102] S2. According to the formula amount, add nano-silica modified by silane coupling agent, organic antibacterial agent SCJ, 2D mesoporous magnesium oxide powder modified by silane coupling agent, and polyurethane plasticizer to bio-based waterborne polyurethane, stir and mix evenly to obtain a mixed solution;

[0103] S3, applying the mixed solution on a flat, clean and water-free substrate;

[0104] S4. Wash and dry the substrate coated with the liquid film in sequence, and then biaxially stretch the dried film to produce micropores, so as to obtain an antibacterial and degradable bio-based polyurethane waterproof and breathable film.

[0105] This embodiment also provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane pasted on a textile fabric to obtain a waterproof and breathable fabric.

[0106] Example 4

[0107] The present embodiment provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane. The raw materials include, by weight, 14 parts of bio-based water-based polyurethane, 4 parts of diatomaceous earth modified by a silane coupling agent, 4 parts of antibacterial agent nanosilver, 3 parts of 2D mesoporous alumina powder modified by a silane coupling agent, and 4 parts of a polyurethane plasticizer.

[0108] In this embodiment, the preparation method of bio-based waterborne polyurethane comprises the following steps:

[0109] S1. Preparation of oleic primary diol with long fatty chain: oleic primary diol with long fatty chain was prepared by thiol-ene click reaction of mercaptoethanol and extended chain oleic acid methyl ester (CEMO) under ultraviolet light initiation. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0110] S2, mixed diol: oleic acid primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0111] S3, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0112] S4, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0113] S5. Emulsification: Finally, triethylamine is added dropwise for deprotonation, and then added into water for emulsification to obtain bio-based waterborne polyurethane.

[0114] This embodiment also provides a method for preparing an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, comprising the following steps:

[0115] S1. Prepare bio-based waterborne polyurethane. The preparation method of bio-based waterborne polyurethane BWPU comprises the following steps:

[0116] S11. Preparation of oleic primary diol with long fatty chain: oleic primary diol OPG with long fatty chain was prepared by mercaptoethanol and extended chain methyl oleate (CEMO) in a thiol-ene click reaction under ultraviolet light initiation. The optimal reaction conditions were 2% by mass of photoinitiator 1173, a molar ratio of -SH to -C=C- of 2:1, and a reaction time of 1 hour.

[0117] S12, mixed diol: oleic acid-based primary diol with a long fatty chain and polytetramethylene glycol (PTMG) are mixed in a ratio of 30% to prepare a mixed diol;

[0118] S13, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine (IPDA) to generate a prepolymer;

[0119] S14, chain extension reaction: adding 1,4-cyclohexanedimethanol (CHDM) and dimethacrylate glycerol (DMPA) as chain extenders to carry out chain extension reaction to generate polyurethane;

[0120] S15, emulsification: finally, triethylamine is added dropwise for deprotonation, and then added into water for emulsification to obtain a bio-based waterborne polyurethane;

[0121] S2. Adding inorganic filler modified by silane coupling agent, antibacterial agent, 2D mesoporous alumina powder modified by silane coupling agent, and polyurethane plasticizer to bio-based waterborne polyurethane according to the formula amount, stirring and mixing evenly to obtain a mixed solution;

[0122] S3, applying the mixed solution on a flat, clean and water-free substrate;

[0123] S4. Wash and dry the substrate coated with the liquid film in sequence, and then biaxially stretch the dried film to produce micropores, so as to obtain an antibacterial and degradable bio-based polyurethane waterproof and breathable film.

[0124] This embodiment also provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane pasted on a textile fabric to obtain a waterproof and breathable fabric.

[0125] Comparative Example 1

[0126] Different from Example 1, this comparative example provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane. The raw materials, in parts by weight, include 15 parts of bio-based water-based polyurethane, 5 parts of diatomaceous earth modified by silane coupling agent, 5 parts of antibacterial agent nanosilver, 3 parts of zeolite powder modified by silane coupling agent, and 5 parts of polyurethane plasticizer.

[0127] Comparative Example 2

[0128] Different from Example 1, this comparative example provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, and the raw materials include 15 parts of bio-based water-based polyurethane, 5 parts of silane coupling agent modified diatomaceous earth, and 5 parts of antibacterial agent nanosilver in parts by weight.

[0129] Comparative Example 3

[0130] Different from Example 1, this comparative example provides an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, and the raw materials include 15 parts of bio-based water-based polyurethane and 5 parts of antibacterial agent nano silver in parts by weight.

[0131] Experimental example

[0132] Water Vapor Transmission Rate (WVTR) Test Procedure

[0133] 1. Cup method (weight gain method)

[0134] The cup method is a common method for measuring water vapor transmission rate (WVTR). The specific steps are as follows:

[0135] Prepare equipment and materials:

[0136] Constant temperature and humidity chamber: temperature accuracy is ±0.6℃, relative humidity accuracy is ±2%, wind speed is 0.5-2.5m / s. The constant temperature and humidity chamber should have good sealing performance to ensure the stability of temperature and humidity in the chamber.

[0137] Moisture permeable cup: used to hold desiccant.

[0138] Desiccant: Anhydrous calcium chloride is usually used, with a particle size of 0.60-2.36 mm. It should be dried in an oven at 200℃±2℃ for 2 hours before use.

[0139] Sealing wax: used to seal the moisture-permeable cup mouth. The sealing wax should not soften or deform under the conditions of 38°C and 90% relative humidity.

[0140] Sample preparation:

[0141] Cut the sample to be tested into a specified size, usually a circle with a diameter matching the mouth of the moisture permeable cup. The area of ​​the sample in this experiment is 0.01m 2 , the sample is mounted on a moisture permeable cup, and the surrounding of the sample is sealed with sealing wax to expose a circular test surface with a certain area. In this experiment, an antibacterial and degradable bio-based polyurethane waterproof and moisture permeable membrane prepared in Example 1-4 and Comparative Example 1-3 is used for the experiment.

[0142] Initial weighing: Place the sealed moisture permeable cup in an environment of 23℃±2℃ for 30 minutes, weigh and record the initial weight.

[0143] Test process: Place the moisture permeable cup in a constant temperature and humidity chamber with adjusted temperature and humidity. Take it out of the chamber after 16 hours and place it in a desiccator at 23℃±2℃. After balancing for 30 minutes, weigh it. After weighing, place the moisture permeable cup back into the constant temperature and humidity chamber. The interval between weighings is 24, 48 or 96 hours. Before weighing, place it in a desiccator at 23℃±2℃ for 30 minutes.

[0144] End of the experiment:

[0145] The test can be terminated only when the difference between the two mass increments is no more than 5%. At the same time, take a test sample for a blank test.

[0146] Calculate WVTR:

[0147] Calculate water vapor transmission (WVT) using the following formula:

[0148]

[0149] in:

[0150] WVT is the water vapor transmission rate of the test sample, in g / (m 2 24h);

[0151] t is the time interval between two times after the mass increment is stable, in hours;

[0152] m1 is the test mass increment of the test sample within time t, in grams;

[0153] m2 is the mass increment of the blank test within time t, in grams;

[0154] A is the water vapor permeability area of ​​the test sample, in square meters;

[0155] Meaning of 24: The "24" in the formula is to convert the water vapor permeation per unit time into the permeation per 24 hours, so as to standardize and compare the moisture permeability of different materials.

[0156] The water vapor transmission rate (WVTR) measurement results of an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane prepared in Examples 1-4 and Comparative Examples 1-3 are shown in Table 1.

[0157] Table 1

[0158]

[0159] As can be seen from Table 1, compared with Comparative Examples 1-3, the WVTR of an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane prepared in Examples 1-3 is significantly increased, indicating that the moisture permeability is significantly improved. Specifically, compared with Comparative Example 1, it is explained that the porous adsorbent performs poorly in moisture permeability, the water molecule transmission speed is slow, and it is easy to accumulate in the pores, resulting in low moisture permeability efficiency. The 2D mesoporous porous adsorbent has a more uniform pore structure, and water molecules can be more effectively transmitted through these pores, thereby improving the moisture permeability efficiency of the film; compared with Comparative Examples 1 and 2, the WVTR is further significantly reduced, indicating that the polyurethane plasticizer molecules are inserted between the bio-based waterborne polyurethane molecular chains, weakening the hydrogen bonds and Van der Waals force, polyurethane plasticizer molecules play a lubricating role between the molecular chains of bio-based waterborne polyurethane, increasing the freedom of the molecular chains, which enables the bio-based waterborne polyurethane molecular chains to move and slide more freely, thereby forming a microporous structure between the bio-based waterborne polyurethane molecular chains. These micropores provide channels for the transmission of water molecules, thereby improving the moisture permeability of the film; compared with Comparative Examples 1, 2 and 3, WVTR is further significantly reduced, indicating that by adding inorganic fillers, it can interact with the hydrophilic groups in the bio-based waterborne polyurethane molecular chains to hinder the contact between the bio-based waterborne polyurethane material and water molecules, thereby significantly reducing the water absorption of the bio-based waterborne polyurethane and improving the moisture permeability of the bio-based polyurethane waterproof and breathable membrane.

[0160] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. An antibacterial and degradable bio-based polyurethane waterproof and breathable membrane, characterized in that: The raw materials include, by weight: 12 to 15 parts of bio-based waterborne polyurethane, 2 to 5 parts of inorganic filler modified by silane coupling agent, 5 to 8 parts of antibacterial agent, 3 to 5 parts of 2D mesoporous porous adsorbent modified by silane coupling agent, and 2 to 5 parts of polyurethane plasticizer.

2. The antibacterial and degradable bio-based polyurethane waterproof and breathable membrane according to claim 1, characterized in that: The raw materials in parts by weight include 15 parts of bio-based waterborne polyurethane, 5 parts of inorganic filler modified by silane coupling agent, 5 parts of antibacterial agent, 3 parts of 2D mesoporous porous adsorbent modified by silane coupling agent, and 5 parts of polyurethane plasticizer.

3. The antibacterial and degradable bio-based polyurethane waterproof and breathable membrane according to claim 1, characterized in that: The inorganic filler is one of diatomaceous earth and nano silicon dioxide.

4. The antibacterial and degradable bio-based polyurethane waterproof and breathable membrane according to claim 1, characterized in that: The antibacterial agent is one or two of nano silver and organic antibacterial agent.

5. The antibacterial and degradable bio-based polyurethane waterproof and breathable membrane according to claim 1, characterized in that: The preparation method of the bio-based waterborne polyurethane comprises the following steps: S1. Preparation of oleic primary diol with long fatty chain: preparing the oleic primary diol with long fatty chain by mercaptoethanol and extended chain oleic acid methyl ester through thiol-ene click reaction under ultraviolet light initiation, the optimal reaction conditions are 2% by mass of photoinitiator 1173, the molar ratio of -SH of the mercaptoethanol to -C=C- of the oleic acid methyl ester is 2:1, and the reaction time is 1 hour; S2, mixed diol: the oleic acid-based primary diol with a long fatty chain and polytetrahydrofuran diol are mixed in a ratio of 30% to prepare a mixed diol; S3, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine to generate a prepolymer; S4, chain extension reaction: adding 1,4-cyclohexanedimethanol and glycerol dimethacrylate as chain extenders to carry out chain extension reaction to generate polyurethane; S5, emulsification: finally, triethylamine is added dropwise for deprotonation, and then added into water for emulsification to obtain the bio-based waterborne polyurethane.

6. The antibacterial and degradable bio-based polyurethane waterproof and breathable membrane according to claim 1, characterized in that: The 2D mesoporous porous adsorbent is a mixture of one or more of 2D mesoporous zeolite powder, 2D mesoporous hydrotalcite powder, 2D mesoporous magnesium oxide powder and 2D mesoporous aluminum oxide powder.

7. A method for preparing an antibacterial and degradable bio-based polyurethane waterproof and breathable membrane according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Preparation of the bio-based waterborne polyurethane: The preparation method of the bio-based waterborne polyurethane comprises the following steps: S11. Preparation of oleic primary diol with long fatty chain: preparing the oleic primary diol with long fatty chain by mercaptoethanol and extended chain methyl oleate through a thiol-ene click reaction initiated by ultraviolet light. The optimal reaction conditions are 2% by mass of photoinitiator 1173, a molar ratio of -SH of the mercaptoethanol to -C=C- of the methyl oleate of 2:1, and a reaction time of 1 hour. S12, mixed diol: the oleic acid-based primary diol with a long fatty chain and polytetrahydrofuran diol are mixed in a ratio of 30% to prepare a mixed diol; S13, pre-reaction: pre-reacting the mixed diol with isophorone diisocyanate diamine to generate a prepolymer; S14, chain extension reaction: adding 1,4-cyclohexanedimethanol and glycerol dimethacrylate as chain extenders to carry out chain extension reaction to generate polyurethane; S15, emulsification: finally, triethylamine is added dropwise for deprotonation, and then added into water for emulsification to obtain the bio-based waterborne polyurethane; S2. According to the formula amount, the inorganic filler modified by the silane coupling agent, the antibacterial agent, the 2D mesoporous porous adsorbent modified by the silane coupling agent, and the polyurethane plasticizer are added to the bio-based waterborne polyurethane, and stirred to mix evenly to obtain a mixed solution; S3, applying the mixed solution on a flat, clean and water-free substrate; S4. Washing and drying the substrate coated with the liquid film in sequence, and then biaxially stretching the dried film to produce micropores, thereby obtaining the antibacterial and degradable bio-based polyurethane waterproof and moisture-permeable film.

8. A waterproof and breathable fabric, characterized in that: The antibacterial and degradable bio-based polyurethane waterproof and breathable membrane described in any one of claims 1 to 6 is pasted on a textile fabric to obtain the waterproof and breathable fabric.

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