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CN-121293768-B - Water-permeable and breathable sponge and preparation method thereof

CN121293768BCN 121293768 BCN121293768 BCN 121293768BCN-121293768-B

Abstract

The invention belongs to the field of high polymer materials, and provides a water-permeable and breathable sponge and a preparation method thereof. The invention adopts the collaborative design of the continuous phase of the crosslinked polydimethylsiloxane and the directional through hole network, forms the through hole network with the aperture ratio of 85-92% and the orientation index of not lower than 0.60 through the dissolution of the directional soluble particle template, introduces the cellulose nanocrystalline modified by silane coupling with the mass fraction of 0.50-2.00% to strengthen the network, and simultaneously realizes the surface hydrophilic modification by covalent fixation of hydrophilic functional silane of 0.10-1.00 wt%, thereby realizing the double-medium high-flux water permeability and air permeability with the air permeability of not lower than 400L m & lt-2 & s & lt-1 & gt and the aperture gradient of 150-250 mu m on the near skin side to 400-600 mu m on the far skin side, solving the coupling contradiction problems between the high aperture ratio and the mechanical bearing rebound attenuation, the directional through hole network circulation stability and the double-medium high flux and low VOC, and having wide application value in the fields of nursing and sports underwear, masks, underpants, eyemasks, shoes, mattresses and the like.

Inventors

  • WANG JIANWEI

Assignees

  • 汕头市至上科技有限公司

Dates

Publication Date
20260508
Application Date
20251211

Claims (9)

  1. 1. The permeable and breathable sponge is characterized by comprising a crosslinked polydimethylsiloxane continuous phase and a through hole network, and comprises the following characteristics: a. The through holes are formed by dissolving out directional soluble particle templates, the aperture ratio is 85-92%, the orientation index of the through holes is not lower than 0.60, the thickness is 2-8mm, and the aperture gradient is 150-250 mu m on the average pore diameter of the near skin side and 400-600 mu m on the average pore diameter of the far skin side; b. the continuous phase is a silicone rubber network formed by crosslinking vinyl-terminated polydimethylsiloxane and hydrogen-containing siloxane, wherein the hydrogen-containing siloxane is dimethyl methyl hydrogen siloxane or methyl hydrogen siloxane-dimethyl siloxane copolymer, and the crosslinking is a platinum-catalyzed hydrosilylation reaction; c. the sponge contains cellulose nanocrystalline modified by silane coupling, and the mass fraction is 0.50-2.00%; d. The surface or the bulk phase of the sponge contains a covalent anchoring layer of hydrophilic functional silane, wherein the hydrophilic functional silane is selected from 3-aminopropyl triethoxysilane and/or 3-glycidoxypropyl trimethoxysilane, and the total mass fraction of the hydrophilic functional silane in the finished sponge is 0.10-1.00%; e. The air permeability of the sponge is not lower than 400L m-2 s-1 according to GB/T5453-1997 and measured at a pressure difference of 100 Pa, the covalent fixation of the hydrophilic functional silane is carried out by mixing 0.10-1.00 and wt% of 3-aminopropyl triethoxysilane and/or 3-glycidoxypropyl trimethoxysilane into a composite prepolymerization system, and then the sponge is subjected to alkoxy hydrolysis-condensation and silanol condensation on the surface of a pore wall/cellulose nano-crystal in the curing process to form a covalent hydrophilic layer, wherein the process does not participate in hydrosilylation reaction.
  2. 2. The sponge according to claim 1, wherein the silane coupling modified cellulose nanocrystals are prepared as follows: A1. The raw materials comprise 100 parts by mass of microcrystalline cellulose, 60-65% by mass of sulfuric acid, sodium hydroxide and deionized water; A2. Acidolysis, namely treating the cellulose nanocrystalline dispersion liquid for 30-90 minutes according to the mass ratio of acid liquor to microcrystalline cellulose of 8:1-12:1 by using 60-65% sulfuric acid at the temperature of 40-50 ℃; A3. neutralizing and washing, namely neutralizing with sodium hydroxide solution to pH 6.0-8.0, and washing with deionized water for multiple times to obtain cellulose nanocrystalline dispersion liquid with solid content of 2-5%; A4. and (3) coupling, namely adding 3- (methacryloyloxy) propyl trimethoxy silane or 3-glycidoxy propyl trimethoxy silane into the dispersion liquid, wherein the mass ratio of the silane to the cellulose nanocrystalline is 2-10%, stirring and reacting for 1-3 hours, and then washing and drying to obtain the cellulose nanocrystalline powder modified by silane coupling.
  3. 3. The sponge of claim 1 wherein the directionally soluble particle template is prepared by the steps of: C1. raw materials are sodium chloride or sucrose; C2. grading, namely preparing two grades of particles, wherein the average particle size of one grade is 150-250 mu m, and the average particle size of the other grade is 400-600 mu m; C3. And (3) directional paving and prepressing, namely paving a small-grain-size layer and a large-grain-size layer in sequence from a near skin side to a far skin side, wherein the mass ratio of grains on the near skin side to grains on the far skin side is 1.0-2.0, the whole is subjected to unidirectional prepressing under 5-20MPa to form a directional soluble grain template with the thickness of 2-8mm, and the unidirectional prepressing direction of the template is parallel to the long axis orientation direction of the through hole.
  4. 4. The sponge according to claim 1, wherein the proximal layer has a thickness of 30-60% of the total thickness, an average pore size of 150-250 μm and the distal layer has an average pore size of 400-600 μm.
  5. 5. The sponge according to claim 1, wherein the mass ratio of hydrophilic functional silane to silane coupling modified cellulose nanocrystals is 0.20-1.00.
  6. 6. A method of preparing a water-permeable and air-permeable sponge according to any one of claims 1 to 5, comprising the steps of: S1, preparing a directional soluble particle template; S2, preparing a composite sizing material, wherein 100 parts by mass of vinyl-terminated polydimethylsiloxane, 0.80-1.20 parts by mass of hydrogen-containing siloxane crosslinking agent, 0.50-2.00 parts by mass of silane coupling modified cellulose nanocrystalline, 0.10-1.00 parts by mass of hydrophilic functional silane, 5-50 ppm parts by mass of platinum complex catalyst and 5-50 ppm parts by mass of platinum content of platinum (0) -1, 3-diethyl-1, 3-tetramethyl disiloxane are added according to the equivalent ratio of Si-H/C=C, and the mixture is defoamed under a low pressure condition; s3, impregnating the composite sizing material into the directional soluble particle template under a low-pressure environment of 10-50kPa until the composite sizing material is full; s4, curing for 0.50-2.00 hours at the temperature of 80-120 ℃ to obtain a composite template body; s5, dissolving out the directional soluble particle template by deionized water and drying to obtain the water-permeable and breathable sponge.
  7. 7. The method for producing a water-permeable and air-permeable sponge according to claim 6, wherein the impregnation time of S3 is 10 to 20 minutes.
  8. 8. The method for preparing a water-permeable and air-permeable sponge according to claim 6, wherein the directional soluble particle template is eluted by multistage countercurrent washing, and the volume of the washing liquid is 10-30 times of the volume of the template.
  9. 9. The use of a water-permeable and breathable sponge according to any one of claims 1 to 5 or a water-permeable and breathable sponge obtained according to the method of any one of claims 6 to 8 in nursing and athletic undergarments, masks, underpants, eye masks, apparel, shoes and mattresses for water-permeable and breathable and support rebound.

Description

Water-permeable and breathable sponge and preparation method thereof Technical Field The invention relates to the field of high polymer materials, in particular to a permeable and breathable sponge and a preparation method thereof. Background With the deep application of ergonomic design concepts in textile and personal protection products, close-fitting products such as nursing undergarments, masks, underpants, eye shields and the like have set forth severe comprehensive performance requirements on support materials. The product needs to be in contact with skin for a long time, the use scene relates to complex working conditions such as sports sweat, secretion of breast milk, high-temperature and high-humidity environments and the like, and the support material is required to have excellent mechanical bearing and rebound resilience performance so as to provide effective support and comfortable experience, and high-efficiency water permeability and air permeability are required to be realized at the same time, so that sweat and liquid are rapidly led out, air is freely circulated, and stuffy discomfort and microorganism breeding are avoided. Although the traditional silicone rubber sponge material has good elasticity and biocompatibility, the inherent hydrophobicity of the traditional silicone rubber sponge material leads to liquid retention, and low air permeability leads to heat and moisture accumulation, so that the comfort requirement of long-time wearing is difficult to meet. The development of the novel silicone rubber sponge material with high water permeability and air permeability, excellent mechanical properties and low VOC release has important significance for improving the wearing experience of close-fitting textiles and expanding the application range of the silicone rubber material in the personal protection and health field. The performance optimization of the material is related to the market competitiveness of the product and directly affects the health and comfort feeling of a user, so that the material becomes a research hotspot in the fields of material science and textile engineering. At present, the research and development of the water-permeable and breathable silicone rubber sponge face multiple technical bottlenecks and intrinsic contradictions. On the one hand, although the air permeability can be obviously improved by improving the aperture ratio, the continuity of the silicone rubber network is weakened due to the high aperture ratio, and the collapse, the permanent deformation increase and the bearing capacity attenuation of the pore wall easily occur in the repeated compression-rebound cycle, so that the coupling contradiction between the mechanical property and the air permeability is outstanding. On the other hand, the inherent hydrophobicity of the silicone rubber makes the high-open-pore structure difficult to realize rapid water permeability, and the traditional surface hydrophilic modification method such as plasma treatment and surface coating has the problems of poor durability of a modified layer and weak bonding force with a matrix, is easy to fall off and lose efficacy under the action of water washing and mechanical friction, and cannot meet the long-term use requirement. For example, chinese patent publication No. CN112940335A discloses a preparation method of a porous silicone rubber material, but the random foaming method adopted by the method leads to disordered pore orientation, wide pore size distribution, high tortuosity of ventilation path, failure to realize directional high-flux transmission, and no problem of hydrophilic modification durability is solved. In addition, in order to enhance the mechanical properties of the high-aperture ratio silicone rubber network, researchers try to introduce nano reinforcing fillers, but the addition of rigid nano particles obviously improves the viscosity of the sizing material, and the rigid nano particles are difficult to fully permeate into the inside of a preformed pore template in a low-pressure infiltration process, so that uneven filling and increased defects of a pore structure are caused, and the material performance is deteriorated. Meanwhile, the interface compatibility of the nano filler and the silicon rubber matrix is insufficient, so that stress concentration points are easily formed at the interface, and the fatigue resistance of the material is reduced. More critical is how to realize the synergistic optimization of hydrophilic modification, nano enhancement and low-viscosity processing window while guaranteeing the high aperture ratio and aperture gradient structure, construct a directional through-hole network to ensure the high flux transmission of double media and meet the low VOC release and biosafety requirements in the class A standard of textiles, and still the core difficult problem to be broken through in the field is urgent. Disclosure of Invention The invention aims to provide a permeable a