Phase-change temperature-adjusting blended fabric and preparation method thereof

Abstract

The invention discloses a phase-change temperature-adjusting blended fabric and a preparation method thereof, and belongs to the technical field of functional fabrics. The fabric comprises a fabric layer, a temperature adjusting layer and a coating, the fabric layer comprises meta-aramid porous fibers and flame-retardant viscose, the interior of the fabric layer is of a honeycomb structure, and the porous fibers are prepared from meta-aramid and metal organic framework nanoparticles through wet spinning; the component of the temperature adjusting layer is phase change microcapsules which are embedded in the honeycomb structure; and the component of the coating is waterborne polyurethane. Based on the strong adsorption effect and chemical immobilization effect of the honeycomb porous structure in the aramid porous fiber on the phase change microcapsule, efficient loading of the phase change material in the fabric can be realized, and the problem of leakage caused by large volume change of the traditional phase change material in the fabric is solved; by means of the excellent serviceability of the flame-retardant viscose, the fabric can be endowed with good application potential; the fabric has outstanding flame retardance and thermal protection capability, and has important value in the aspect of personal thermal protection in extreme environments such as extremely cold environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional fabrics, and particularly relates to a phase change temperature-regulating blended fabric and a preparation method thereof. Background Art

[0002] Textiles with functions such as temperature regulation and heat storage have received extensive attention due to their obvious advantages in improving human comfort and energy conservation and consumption reduction. Such fabrics can freely adjust the temperature within a certain temperature range according to the changes in the external environmental temperature. When the external temperature rises, it can store energy and slow down the temperature rise, while when the external temperature drops, it can release energy and slow down the temperature drop, thereby forming a microclimate with a basically constant temperature between the clothing and the human body and improving the comfort of the fabric. The loading of phase change materials in the preparation of such textiles is the core problem to be solved. Phase change materials rely on their own properties to absorb or release heat within the phase change range, thereby realizing the storage and release of energy within a certain temperature range, which is the core of realizing the temperature-regulating function of textiles. Generally speaking, the preparation of such textiles includes the synthesis of phase change materials, the compounding with fibers, and encapsulation, etc.

[0003] Currently, the common binding methods of phase change materials with fibers or textiles mainly include the co-blending spinning method, the porous fiber filling method, and the fabric post-treatment method based on microcapsule technology, etc. The invention patent CN202110193486.5 discloses a method for preparing a phase change temperature-regulating functional intelligent fiber by blending phase change microcapsules with a cellulose spinning solution and then through spinning forming and cross-linking; the invention patent CN202211042277.1 discloses a new method for preparing a blended fabric with temperature-regulating and protective functions by physically adsorbing phase change materials on porous fibers. However, the currently commonly used preparation technologies for temperature-regulating fabrics all have certain limitations: how to effectively disperse and stably distribute microcapsules in the fiber matrix in the microcapsule co-blending spinning method, how to ensure that the phase change materials are not compressed and extruded during the large deformation of porous fibers in the porous fiber adsorption method, and problems such as the rough touch, poor abrasion resistance and washing resistance of the temperature-regulating textiles prepared by the fabric post-treatment method based on microcapsule technology all need to be solved. Summary of the Invention

[0004] Technical problems to be solved: Aiming at the above technical problems, the present invention provides a phase change temperature-regulating blended fabric and a preparation method thereof, which can realize the efficient loading of phase change materials inside the fabric and solve the leakage problem caused by the large volume change of traditional phase change materials inside the fabric; in addition, with the excellent wearing performance of flame-retardant viscose, good application potential can be given to such fabrics; at the same time, such blended fabrics have outstanding flame retardancy and heat protection capabilities and have important value in personal heat protection in extreme environments.

[0005] Technical solution: A phase change temperature-regulating blended fabric, comprising a fabric layer, a temperature-regulating layer and a coating. The components of the fabric layer include meta-aramid porous fibers and flame-retardant viscose, and the interior has a honeycomb structure. Among them, the meta-aramid porous fibers are prepared by wet spinning of meta-aramid and metal-organic framework nanoparticles; the components of the temperature-regulating layer are phase change microcapsules, which are embedded in the honeycomb structure inside the fabric layer; the components of the coating are waterborne polyurethane, which is provided on the outer surface of the fabric layer.

[0006] Preferably, the mass ratio of the meta-aramid porous fibers to the flame-retardant viscose is (40-60):(60-40).

[0007] Preferably, the linear density of the meta-aramid porous fibers is 0.5-1.2 dtex, the length is 25-38 mm, the breaking strength is 200-300 MPa, the breaking elongation is 30-40%, the pore size is 800 nm-1 μm, and the porosity is 87%-92%; the linear density of the flame-retardant viscose is 1.0-3.33 dtex, the length is 25-38 mm, the dry breaking strength is 250-300 MPa, and the breaking elongation is 15%-20%.

[0008] Preferably, the phase change microcapsules have a nano-spherical core-shell structure with a size of 500-800 nm; among them, the core material is a phase change material, and the shell material is carboxylated SiO2.

[0009] Further, the mass ratio of the core material to the shell material is 1:(1-1.5).

[0010] Further, the phase change material is octadecane, eicosane, paraffin or stearic acid.

[0011] Preferably, the mass of the temperature-regulating layer is 10-20% of the mass of the fabric layer.

[0012] The preparation method of the above-mentioned phase change temperature-regulating blended fabric includes the following steps: Step 1: React tetraethyl orthosilicate in an ethanol solution to obtain an aqueous solution, disperse the phase change material into the aqueous solution for emulsification, add 1,3-bis(3-carboxypropyl)tetramethyldisiloxane and ammonia water solution during stirring, and obtain phase change microcapsules after reaction, precipitation, washing and drying; Step 2: Obtain meta-aramid porous fibers by wet spinning and heat treatment of a mixed solution of meta-aramid and metal-organic framework nanoparticles; Step 3: Prepare a blended fabric from the meta-aramid porous fibers and the flame-retardant viscose; Step 4: Place the blended fabric in an ethanol or aqueous dispersion of the phase change microcapsules and perform vacuum treatment; Step 5: Spray and coat the blended fabric treated in Step 4 with an aqueous polyurethane solution, and obtain the phase change temperature-regulating blended fabric after air drying.

[0013] Preferably, in the second step, the metal-organic framework nanoparticles are ZIF-6 or ZIF-8 nanoparticles, and their content in the mixed solution is 5-30 wt%.

[0014] Preferably, in the fourth step, the concentration of the ethanol or aqueous dispersion of the phase change microcapsules is 20-40 wt%.

[0015] Beneficial effects: The meta-aramid porous fibers used in the present invention are prepared by wet spinning from a mixed solution of meta-aramid and metal-organic framework ZIF materials. The coordination between -NHC=O in the meta-aramid and the metal ions of the ZIF materials can evenly disperse the ZIF in the fiber matrix and form a strong interfacial bond, ensuring good mechanical properties of the fibers and forming a honeycomb-like porous structure inside the composite fibers. The meta-aramid porous fibers are blended with flame-retardant viscose to form a fabric. On the one hand, the meta-aramid porous fibers provide excellent heat resistance and flame retardancy, while the flame-retardant viscose provides good comfort and wearability. The two can form a synergistic effect in extreme environments such as high temperature through a rich hydrogen bond network, enhancing the protective function of the fabric. The honeycomb-like porous structure inside the meta-aramid in the blended fabric and the rich N-H units on the fiber surface can form a hydrogen bond network with the carboxylated SiO2 microcapsules, realizing the effective dispersion and immobilization of the nano-microcapsules inside the fabric, inhibiting problems such as the overflow of the phase change material, and endowing the fabric with functions such as good temperature regulation. At the same time, it effectively inhibits the leakage of the phase change material during fabric torsion, bending, and stretching, and endows the fabric with good washability. Description of the Drawings

[0016] Figure 1 is the internal morphology of the meta-aramid porous fibers in Example 1. Detailed Embodiments

[0017] The present invention will be further described below with reference to the drawings and specific embodiments.

[0018] The meta-aramid solution was provided by Donghua University; Flame-retardant viscose, 3 D × 60 mm, provided by Shanghai Zhuli Textile Technology Co., Ltd.; Waterborne polyurethane was provided by Anhui Dawei Huatai New Material Technology; The phase change material was purchased from the China National Pharmaceutical Group Corporation; The mechanical properties of the blended fabric were tested using an Instron 3300 at a tensile rate of 5 cm / min and a clamp distance of 2 cm; The content of the phase change material in the blended fabric was determined by TGA test. A Netzsh 209F3 thermogravimetric analyzer was used, with a heating rate of 5 °C / min, a temperature range of 30 - 500 °C, and a nitrogen atmosphere. The phase change enthalpy of the blended fabric was tested by DSC. A TA Q200 type DSC tester was used, with a heating rate of 5 °C / min, a temperature range of 0 - 100 °C, and a nitrogen atmosphere.

[0019] The limiting oxygen index was tested according to the method described in GB / T 5454 - 1997. Example 1

[0020] Tetraethyl orthosilicate (TEOS) was reacted in a water / ethanol mixture at 40 °C for 2 h to prepare a uniform aqueous solution; then eicosane was dispersed into the above solution and emulsified for 20 min. Finally, 1,3 - bis(3 - carboxypropyl)tetramethyldisiloxane and an ammonia aqueous solution were added under stirring and reacted at 40 °C for 24 h; the reaction solution was poured into ethanol for precipitation, washed 3 times with petroleum ether, and dried to prepare carboxylated phase change microcapsules with a size of 800 nm; an aramid - 1313 spinning solution with a solid content of 20 wt% containing ZIF - 6 nanoparticles was used to prepare as - spun fibers by wet spinning and hot - drawn 2.5 times at 200 °C to prepare aramid - 1313 porous fibers with a pore size of 800 ± 20 nm and a ZIF - 6 content of 20 wt%; according to a mass ratio of 40:60, the aramid - 1313 porous fibers and flame - retardant viscose fibers were made into a 32 S blended yarn through the processes of blowroom - drawing - roving - spinning - winding - doubling - twisting, and finally woven into a plain fabric with 220 warp ends per 10 cm and 220 weft ends per 10 cm by a digital sample rapier loom. The prepared plain fabric was placed in a 20 wt% eicosane phase change microcapsule dispersion liquid in a vacuum oven at a vacuum degree of 100 Pa for 2 h. After the fabric surface was dried, a water - borne polyurethane solution was spray - coated on the fabric surface to form a thin polyurethane coating. The eicosane content in the fabric was about 17 wt%, the warp and weft tensile strength was 70 ± 13 N / cm, and the phase change enthalpy was about 67 J g -1 After 10 times of washing, the phase change enthalpy retention rate was 92%, the limiting oxygen index LOI = 32%, and there was no melt - dripping. Example 2

[0021] Tetraethyl orthosilicate (TEOS) was reacted in a water / ethanol mixture at 40 °C for 2 h to prepare a homogeneous aqueous solution; then eicosane was dispersed into the above solution and emulsified for 20 min. Finally, 1,3-bis(3-carboxypropyl)tetramethyldisiloxane and an aqueous ammonia solution were added under stirring and reacted at 40 °C for 24 h; the reaction solution was poured into ethanol for precipitation and washed 3 times with petroleum ether and dried to prepare carboxylated phase change microcapsules with a size of 500 nm; an aramid meta - phenylene spinning solution containing 20 wt% ZIF-6 nanoparticles with a solid content was used to prepare green fibers by wet spinning and hot drawn 2.5 times at 200 °C to prepare aramid meta - phenylene porous fibers with a pore size of 800 ± 20 nm and a ZIF-6 content of 20 wt%; an aramid meta - phenylene porous fiber and a flame - retardant viscose fiber were made into a 32 S blended yarn according to a mass ratio of 60:40 through the processes of blow room - drawing - roving - spinning - winding - doubling - twisting, and finally woven into a plain fabric with 220 warp ends per 10 cm and 220 weft ends per 10 cm by a digital small - sample rapier loom. The prepared plain fabric was placed in a 40 wt% eicosane phase change microcapsule dispersion liquid in a vacuum oven at a vacuum degree of 100 Pa for 1 h. After the fabric surface was dried, an aqueous polyurethane solution was spray - coated on the fabric surface to form a thin polyurethane coating. The eicosane content in the fabric was about 20 wt%, the tensile strength in the warp and weft directions was 82 ± 15 N / cm, and the phase change enthalpy was about 93 J g -1 . After 10 times of washing, the phase change enthalpy retention rate was 94%, the limiting oxygen index LOI = 34%, and there was no melt dripping. Example 3

[0022] Tetraethyl orthosilicate (TEOS) was reacted in a water / ethanol mixture at 40 °C for 2 h to prepare a homogeneous aqueous solution; octadecane was then dispersed into the above solution and emulsified for 20 min. Finally, 1,3-bis(3-carboxypropyl)tetramethyldisiloxane and an ammonia water solution were added under stirring and reacted at 40 °C for 24 h; the reaction solution was poured into ethanol for precipitation, washed 3 times with petroleum ether, and dried to prepare carboxylated phase change microcapsules with a size of 650 nm; a meta-aramid spinning solution containing ZIF-8 nanoparticles with a solid content of 20 wt% was used to prepare nascent fibers by wet spinning and hot drawn 2.5 times at 200 °C to prepare meta-aramid porous fibers with a pore size of 800 ± 20 nm and a ZIF-8 content of 30 wt%; a 32 S blended yarn was made from the meta-aramid porous fibers and flame-retardant viscose fibers according to a mass ratio of 50:50 through the processes of blow room - drawing - roving - spinning - winding - doubling - twisting, and finally woven into a plain fabric with 220 warp ends per 10 cm and 220 weft ends per 10 cm by a digital sample rapier loom. The prepared plain fabric was placed in a dispersion liquid of octadecane phase change microcapsules with a concentration of 40 wt% in a vacuum oven at a vacuum degree of 100 Pa for 2 h. After the fabric surface was dried, an aqueous polyurethane solution was spray-coated on the fabric surface to form a thin polyurethane coating. The octadecane content in the fabric was about 20 wt%, the tensile strength in the warp and weft directions was 85 ± 10 N / cm, and the phase change enthalpy was about 110 J g -1 . After 10 washes, the phase change enthalpy retention rate was 94%, the limiting oxygen index LOI = 33%, and there was no melt dripping. Example 4

[0023] Tetraethyl orthosilicate (TEOS) was reacted in a water / ethanol mixture at 40 °C for 2 h to prepare a homogeneous aqueous solution; then stearic acid was dispersed into the above solution and emulsified for 20 min. Finally, 1,3-bis(3-carboxypropyl)tetramethyldisiloxane and an ammonia aqueous solution were added under stirring and reacted at 40 °C for 24 h; the reaction solution was poured into ethanol for precipitation, washed 3 times with petroleum ether, and dried to prepare carboxylated phase change microcapsules with a size of 700 nm; a meta-aramid spinning solution containing 20 wt% ZIF-8 nanoparticles was used to prepare as-spun fibers by wet spinning and hot drawn 2.5 times at 200 °C to prepare meta-aramid porous fibers with a pore size of 800 ± 20 nm and a ZIF-6 content of 20 wt%; according to a mass ratio of 50:50, the meta-aramid porous fibers and flame-retardant viscose fibers were made into a 32 S blended yarn through the processes of blow room - drawing - roving - spinning - winding - doubling - twisting, and finally woven into a plain fabric with 220 warp ends per 10 cm and 220 weft picks per 10 cm by a digital sample rapier loom. The prepared plain fabric was placed in a dispersion liquid of stearic acid phase change microcapsules with a concentration of 40 wt% in a vacuum oven, with a vacuum degree of 100 Pa, and maintained for 2 h. After the fabric surface was dried, an aqueous polyurethane solution was spray-coated on the fabric surface to form a thin polyurethane coating. The stearic acid content in the fabric was about 20 wt%, the tensile strength in the warp and weft directions was 85 ± 10 N / cm, and the phase change enthalpy was about 78 J g -1 . After 10 washes, the phase change enthalpy retention rate was 94%, the limiting oxygen index LOI = 33%, and there was no melt dripping.

[0024] Comparative Example 1 The preparation of eicosane phase change microcapsules was the same as in Example 1; directly, a meta-aramid spinning solution with a solid content of 20 wt% and without ZIF-6 nanoparticles was used to prepare as-spun fibers by wet spinning and hot drawn 2.5 times at 200 °C to prepare meta-aramid porous fibers with a pore size of only 300 ± 20 nm; according to a mass ratio of 40:60, the meta-aramid porous fibers and flame-retardant viscose fibers were made into a 32 S blended yarn through the processes of blow room - drawing - roving - spinning - winding - doubling - twisting, and finally woven into a plain fabric with 220 warp ends per 10 cm and 220 weft picks per 10 cm by a digital sample rapier loom. The prepared plain fabric was placed in a dispersion liquid of eicosane phase change microcapsules with a concentration of 20 wt% in a vacuum oven, with a vacuum degree of 100 Pa, and maintained for 2 h. After the fabric surface was dried, an aqueous polyurethane solution was spray-coated on the fabric surface to form a thin polyurethane coating. The eicosane content in the fabric was about 6 wt%, the tensile strength in the warp and weft directions was 97 ± 15 N / cm, and the phase change enthalpy was about 24 Jg -1After 10 washes, the phase change enthalpy retention rate was 43%, the limiting oxygen index LOI = 33%, and there was no dripping.

[0025] Comparative Example 2 The preparation of the eicosane phase change microcapsules was the same as in Example 1; directly using flame-retardant viscose fibers, through the processes of blowroom - drawing - roving - spinning - winding - doubling - twisting, a 32 S viscose fiber yarn was made, and finally a plain fabric with 220 warp ends per 10 cm and 220 weft density per 10 cm was woven by a digital sample rapier loom. The prepared plain fabric was placed in a 20 wt% eicosane phase change microcapsule dispersion in a vacuum oven with a vacuum degree of 100 Pa and kept for 2 h. After the fabric surface was dried, a waterborne polyurethane solution was spray-coated on the fabric surface to form a thin polyurethane coating. The eicosane content in the fabric was about 3 wt%, the warp and weft tensile strength was 83 ± 15 N / cm, and the phase change enthalpy was about 12 J g -1 After 10 washes, the phase change enthalpy retention rate was 45%, the limiting oxygen index LOI = 28%, and there was no dripping.

[0026] Comparative Example 3 The preparation of the eicosane phase change microcapsules was the same as in Example 1; directly using the prepared meta-aramid porous fibers, through the processes of blowroom - drawing - roving - spinning - winding - doubling - twisting, a 32 S viscose fiber yarn was made, and finally a plain fabric with 220 warp ends per 10 cm and 220 weft density per 10 cm was woven by a digital sample rapier loom. The prepared plain fabric was placed in a 20 wt% eicosane phase change microcapsule dispersion in a vacuum oven with a vacuum degree of 100 Pa and kept for 2 h. After the fabric surface was dried, a waterborne polyurethane solution was spray-coated on the fabric surface to form a thin polyurethane coating. The eicosane content in the fabric was about 35 wt%, the warp and weft tensile strength was 41 ± 7 N / cm, and the phase change enthalpy was about 127 J g -1 After 10 washes, the phase change enthalpy retention rate was 91%, the limiting oxygen index LOI = 33%, and there was no dripping.

[0027] Comparative Example 4 The meta-aramid spinning solution with a solid content of 20 wt% containing ZIF-6 nanoparticles was used to prepare the as-spun fibers by wet spinning, and then hot drawn 2.5 times at 200 °C to prepare the meta-aramid porous fibers with a pore size of 800 ± 20 nm and a ZIF-6 content of 20 wt%. The meta-aramid porous fibers and flame-retardant viscose fibers were made into a 32 S blended yarn through the processes of blow room - drawing - roving - spinning - winding - doubling - twisting according to a mass ratio of 40:60, and finally woven into a plain fabric with 220 warp ends per 10 cm and 220 weft picks per 10 cm by a digital small-sample rapier loom. The prepared plain fabric was placed in a 20 wt% eicosane dispersion liquid in a vacuum oven at a vacuum degree of 100 Pa for 2 h. After the fabric surface was dried, a waterborne polyurethane solution was spray-coated on the fabric surface to form a thin polyurethane coating. The eicosane content in the fabric was about 33 wt%, the tensile strength in the warp and weft directions was 66 ± 8 N / cm, and the phase change enthalpy was about 109 J g -1 . After 10 washes, the phase change enthalpy retention rate was 32%, the limiting oxygen index LOI = 28%, and there was no melt dripping.

Claims

1. A phase change temperature-regulating blended fabric, characterized in that, It includes a fabric layer, a temperature-regulating layer and a coating. The components of the fabric layer include meta-aramid porous fibers and flame-retardant viscose, and the interior has a honeycomb structure. Among them, the meta-aramid porous fibers are prepared by wet spinning of meta-aramid and metal-organic framework nanoparticles; the components of the temperature-regulating layer are phase change microcapsules, which are embedded in the honeycomb structure inside the fabric layer; the components of the coating are waterborne polyurethane, which is provided on the outer surface of the fabric layer.

2. The phase change temperature-regulating blended fabric according to claim 1, wherein The mass ratio of the meta-aramid porous fibers to the flame-retardant viscose is (40-60):(60-40).

3. The phase change temperature-regulating blended fabric according to claim 1, wherein, The linear density of the meta-aramid porous fibers is 0.5-1.2 dtex, the length is 25-38 mm, the breaking strength is 200-300 MPa, the breaking elongation is 30-40%, the pore size is 800 nm-1 μm, and the porosity is 87%-92%; the linear density of the flame-retardant viscose is 1.0-3.33 dtex, the length is 25-38 mm, the dry breaking strength is 250-300 MPa, and the breaking elongation is 15%-20%.

4. A phase change temperature-regulating blended fabric according to claim 1, wherein, The phase change microcapsules are of a nano-spherical core-shell structure with a size of 500-800 nm; among them, the core material is a phase change material, and the shell material is carboxylated SiO2.

5. The phase change temperature-regulating blended fabric according to claim 4, wherein The mass ratio of the core material to the shell material is 1:(1-1.5).

6. The phase change temperature-regulating blended fabric according to claim 4, wherein The phase change material is octadecane, eicosane, paraffin or stearic acid.

7. The phase change temperature-regulating blended fabric according to claim 1, wherein The mass of the temperature-regulating layer is 10-20% of the mass of the fabric layer.

8. The preparation method of the phase change temperature-regulating blended fabric according to claim 1, characterized in that, It includes the following steps: Step 1: React tetraethyl orthosilicate in an ethanol solution to obtain an aqueous solution, disperse the phase change material into the aqueous solution for emulsification, add 1,3-bis(3-carboxypropyl)tetramethyldisiloxane and an ammonia water solution during stirring, and after reaction, obtain phase change microcapsules through precipitation, washing and drying; Step 2: Obtain meta-aramid porous fibers by wet spinning and heat treatment of a mixed solution of meta-aramid and metal-organic framework nanoparticles; Step 3: Prepare a blended fabric from the meta-aramid porous fibers and the flame-retardant viscose; Step 4: Place the blended fabric in an ethanol or aqueous dispersion of the phase change microcapsules and perform a vacuum treatment; Step 5: Spray-coat an aqueous polyurethane solution on the blended fabric treated in Step 4, and dry it to obtain the phase change temperature-regulating blended fabric.

9. The preparation method of the phase change temperature-regulating blended fabric according to claim 8, wherein In the said Step 2, the metal-organic framework nanoparticles are ZIF-6 or ZIF-8 nanoparticles, and their content in the mixed solution is 5-30 wt%.

10. The preparation method of the phase change temperature-regulating blended fabric according to claim 8, characterized in that, In the said Step 4, the concentration of the ethanol or aqueous dispersion of the phase change microcapsules is 20-40 wt%.

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