Environment-friendly multifunctional finishing agent as well as preparation method and application thereof

Abstract

The invention discloses an environment-friendly multifunctional finishing agent as well as a preparation method and application thereof, and belongs to the technical field of cotton fabrics. The PDMS elastomer is prepared through hydrosilylation reaction; then ethyl acetate is added into a PDMS elastomer for dispersing the amino active O-acyl isourea intermediate and the amino modified PDMS solution, so that the amino active O-acyl isourea intermediate and the amino modified PDMS solution quickly react to form amido bonds, and an isourea byproduct is released; finally, TiO2 powder and aluminum compound powder are added, the multifunctional finishing agent with the properties of heat insulation, water repellency, self-cleaning and the like is obtained in a physical mixing mode, and when the multifunctional finishing agent is applied to cotton fabrics, the cotton fabrics can have multiple functions of water repellency, heat insulation, self-cleaning and the like and have good durability.

Description

Technical Field

[0001] The invention relates to the technical field of cotton fabrics, and in particular to a green and environment-friendly multifunctional finishing agent and a preparation method and application thereof. Background Art

[0002] With the rapid development of science and technology, remarkable achievements have been made in the field of materials science, opening up broad prospects for the development and application of various functional materials. Among many fields, the development and application of multifunctional finishing agents in the clothing, building materials and environmental protection industries are particularly urgent. Such finishing agents not only need to have multiple functions such as water repellency, heat insulation, and self-cleaning, but also need to improve their durability and environmental protection while ensuring the original physical and chemical properties of the materials.

[0003] Nano-titanium dioxide (TiO 2 ) As a high-performance material, its unique photocatalytic performance, UV resistance and antibacterial properties make it popular in the field of functional materials. It can decompose pollutants under photocatalysis, realize self-cleaning function, and improve the durability of materials. On the other hand, aluminum compounds such as aluminum hydroxide, aluminum oxide, and aluminum phosphate play an important role in the field of flame retardants and adsorbents due to their excellent flame retardancy and adsorption properties. It can reduce the heat release during material combustion to a certain extent and improve the fire resistance of materials.

[0004] However, the research on combining nano-titanium dioxide and aluminum hydroxide for multifunctional finishing agents is still immature and needs further development. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a green and environmentally friendly multifunctional finishing agent and its preparation method and application, wherein a PDMS elastomer is prepared by a hydrosilation reaction, and then ethyl acetate is added to the PDMS elastomer, and finally TiO 2 Powder and Al(OH) 3 The powder is physically mixed to obtain a multifunctional finishing agent with properties such as heat insulation, water repellency and self-cleaning. Applying it on cotton fabric can make it have multiple functions such as water repellency, heat insulation and self-cleaning, and at the same time have good durability.

[0006] The technical solution of the present invention is:

[0007] In a first aspect, the present invention provides a method for preparing a green and environmentally friendly multifunctional finishing agent, comprising the following steps:

[0008] Preparation of S1PDMS: Mix PDMS base glue and cross-linking agent evenly to obtain PDMS;

[0009] Preparation of S2 composite precursor solution: Ethyl acetate was added to PDMS and mixed evenly to obtain the composite precursor solution;

[0010] Preparation of S3 multifunctional finishing agent: TiO 2 powder and aluminum compound powder were added to the composite precursor solution and stirred evenly to obtain the green and environmentally friendly multifunctional finishing agent.

[0011] Preferably, in step S1, the mass ratio of PDMS base gum to crosslinking agent is (5 - 20):1.

[0012] Preferably, in step S1, stirring was carried out during mixing, and the stirring time was 5 - 30 min.

[0013] Preferably, in step S2, the mass ratio of ethyl acetate to PDMS is (5 - 50):1.

[0014] Preferably, in step S2, stirring was carried out during mixing, and the stirring time was 15 - 60 min.

[0015] Preferably, in step S3, the mass ratio of TiO 2 powder and aluminum compound powder is (1 - 3):(1 - 3), and the total mass of TiO 2 powder and aluminum compound powder to the mass of the composite precursor solution is (1 - 10):100.

[0016] Preferably, in step S3, the aluminum compound powder is one or more of aluminum hydroxide powder, aluminum oxide powder, and aluminum phosphate powder.

[0017] Second, the present invention provides a green and environmentally friendly multifunctional finishing agent prepared by the above - mentioned preparation method of the green and environmentally friendly multifunctional finishing agent.

[0018] Third, the present invention provides the application of the above - mentioned green and environmentally friendly multifunctional finishing agent on fabrics.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. First, the present invention prepares PDMS elastomer from PDMS base gum and crosslinking agent through hydrosilylation reaction; then ethyl acetate is added to the PDMS elastomer to disperse the amino - active O - acylisourea intermediate and the amino - modified PDMS solution, enabling them to react quickly to form amide bonds and release isourea by - products; finally, TiO 2 powder and Al(OH) 3 powder are added, and through physical mixing, a multifunctional finishing agent with heat insulation, water repellency, self - cleaning and other properties is obtained. When it is applied to cotton fabrics, the cotton fabrics can have multiple functions such as water repellency, heat insulation, and self - cleaning, and at the same time have good durability.

[0021] 2. The finishing agent of the present invention is not only environmentally friendly and non-toxic, but also can effectively ensure that a variety of finishing effects are imparted to the fabric in one-step finishing, meeting the market demand for multifunctional textiles, reducing energy consumption such as water and electricity, and reducing the total pollution emissions. The present invention also provides an application method of the finishing agent on cotton fabrics. Through processes such as padding and drying, the cotton fabrics are provided with multiple functions without affecting their original softness, air permeability and comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a dust removal test photo of the original cotton fabric without being treated with the finishing agent.

[0023] Figure 2 It is a dust removal test photo of the woven fabric treated with the finishing agent of Comparative Example 1.

[0024] Figure 3 It is a dust removal test photo of the woven fabric treated with the finishing agent of Comparative Example 2.

[0025] Figure 4 It is a dust removal test photo of the woven fabric treated with the finishing agent of Comparative Example 3.

[0026] Figure 5 It is a dust removal test photo of the woven fabric treated with the finishing agent of Example 1.

[0027] Figure 6 It is an SEM image of the original cotton fabric without being treated with the finishing agent.

[0028] Figure 7 It is an SEM image of the woven fabric treated with the finishing agent of Comparative Example 1.

[0029] Figure 8 It is an SEM image of the woven fabric treated with the finishing agent of Comparative Example 2.

[0030] Figure 9 It is an SEM image of the woven fabric treated with the finishing agent of Comparative Example 3.

[0031] Figure 10 It is an SEM image of the woven fabric treated with the finishing agent of Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention.

[0033] The PDMS base gum and cross-linking agent used in the following examples and comparative examples are components of Dow Corning 184.

[0034] Example 1

[0035] The preparation method of the green and environment-friendly multifunctional finishing agent in this embodiment includes the following steps:

[0036] S1 Preparation of PDMS: Mix 10 g of PDMS base glue and 1 g of crosslinking agent, stir with a glass rod for 10 min, and prepare uniform PDMS through hydrosilylation reaction;

[0037] S2 Preparation of composite precursor solution: Add 90 g of ethyl acetate to PDMS, stir and mix with a stirrer for 45 min to obtain a uniform composite precursor solution;

[0038] S3 Preparation of multifunctional finishing agent (PDMS / TiO 2 / Al(OH) 3 ) : Add 1.1 g of TiO 2 powder and 1.1 g of Al(OH) 3 powder to the composite precursor solution and stir evenly to obtain the green and environment-friendly multifunctional finishing agent.

[0039] Example 2

[0040] The preparation method of the green and environment-friendly multifunctional finishing agent in this embodiment includes the following steps:

[0041] S1 Preparation of PDMS: Mix 15 g of PDMS base glue and 1.2 g of crosslinking agent, stir with a glass rod for 30 min, and prepare uniform PDMS through hydrosilylation reaction;

[0042] S2 Preparation of composite precursor solution: Add 90 g of ethyl acetate to PDMS, stir and mix with a stirrer for 60 min to obtain a uniform composite precursor solution;

[0043] S3 Preparation of multifunctional finishing agent (PDMS / TiO 2 / Al(OH) 3 ) : Add 1.5 g of TiO 2 powder and 0.75 g of Al(OH) 3 powder to the composite precursor solution and stir evenly to obtain the green and environment-friendly multifunctional finishing agent.

[0044] Example 3

[0045] The preparation method of the green and environment-friendly multifunctional finishing agent in this embodiment includes the following steps:

[0046] S1 Preparation of PDMS: Mix 8 g of PDMS base glue and 0.6 g of crosslinking agent, stir with a glass rod for 5 min, and prepare uniform PDMS through hydrosilylation reaction;

[0047] Preparation of S2 composite precursor solution: Add 90 g of ethyl acetate to PDMS and stir and mix for 15 min with a stirrer to obtain a uniform composite precursor solution;

[0048] S3 Preparation of multifunctional finishing agent (PDMS / TiO 2 / Al(OH) 3 ) : Add 0.8 g of TiO 2 powder and 1.2 g of Al(OH) 3 powder to the composite precursor solution and stir evenly to obtain a green and environmentally friendly multifunctional finishing agent.

[0049] Comparative Example 1

[0050] The difference from Example 1 is that in step S3, Al(OH) 3 powder is not added.

[0051] Comparative Example 2

[0052] The difference from Example 1 is that in step S3, TiO 2 powder is not added.

[0053] Comparative Example 3

[0054] The difference from Example 1 is that step S3 is not carried out.

[0055] Comparative Example 4

[0056] The difference from Example 1 is that in step S2, ethyl acetate is not added.

[0057] Comparative Example 5

[0058] The difference from Example 1 is that in step S3, the addition amount of TiO 2 powder is 4.4 g.

[0059] Comparative Example 6

[0060] The difference from Example 1 is that in step S3, the addition amount of Al(OH) 3 powder is 4.4 g.

[0061] Preparation of multifunctional performance fabric: Put the raw cotton cloth into the multifunctional finishing agents of Examples 1-3 and Comparative Examples 1-6 respectively by the two-dip and two-roll method, soak it thoroughly and then dip-roll and press it on a rolling machine; then dry it and wash it with water, and after 5 min, pre-bake it at 80 °C for 10 min, and then bake it at 140 °C for 5 min after pre-baking; repeat the above process to obtain the multifunctional performance fabric.

[0062] The following tests are carried out on the multifunctional performance fabrics treated in Examples 1-3 and Comparative Examples 1-6:

[0063] (1) Water contact angle measurement

[0064] The water contact angle was measured at ambient temperature using an OCA40 optical contact angle measuring instrument (Germany): After dropping distilled water onto the surface of the original cotton cloth, the multifunctional performance woven fabrics of Examples 1-3 and Comparative Examples 1-6 for 60 s, the contact angle was measured; the same sample was measured 5 times at different positions and the average value was taken.

[0065] (2) Thermal imaging test

[0066] The heat insulation temperature refers to the stable temperature value that the woven fabric can maintain on its surface under a specific heat source (such as infrared radiation, high-temperature environment) after being treated with a finishing agent. The lower this value, the stronger the heat insulation performance (the ability to block heat transfer) of the woven fabric. During the test, a thermal imaging camera was used to clamp the original cotton cloth, the multifunctional performance woven fabrics of Examples 1-3 and Comparative Examples 1-6 respectively, place a burning alcohol lamp at one end 10 cm away from it, and place an infrared imaging at the other end, and measure the surface temperature of the woven fabric at different times.

[0067] The test results of the water contact angle and heat insulation temperature of the original cotton cloth, the multifunctional performance woven fabrics of Examples 1-3 and Comparative Examples 1-6 are shown in Table 1:

[0068] Table 1 Test results of water contact angle and heat insulation temperature of the original cotton cloth, the woven fabrics of Examples 1-3 and Comparative Examples 1-6

[0069]

[0070] As can be seen from Table 1, the water contact angle of the woven fabric treated with the finishing agent of Comparative Example 1 is 124.2°, lower than 156.4° of Example 1, and the heat insulation temperature is 27.1 °C, higher than 28.3 °C of Example 1. This is because the finishing agent of Comparative Example 1 does not contain Al(OH) 3 powder, resulting in a decrease in its water repellency. Although Al(OH) 3 is a hydrophilic particle, when it is compounded with TiO 2 , it can be wrapped by the hydrophobic network of the PDMS elastomer to form a "core-shell" structure; without adding Al(OH) 3 , the individual dispersion of TiO 2 will result in insufficient surface roughness of the coating and weakened hydrophobic effect. At the same time, the endothermic thermal decomposition of Al(OH) 3 (absorbing heat during decomposition at 200-300 °C) is the key heat insulation mechanism. Without adding Al(OH) 3 and only relying on the light reflection of TiO 2 , the ability to block infrared heat decreases, resulting in an increase in the surface temperature of the woven fabric.

[0071] The water contact angle of the woven fabric treated with the finishing agent of Comparative Example 2 was 112.6°, lower than 156.4° of Example 1, and the heat insulation temperature was 30.3 °C (close to the heat insulation temperature of the original cotton fabric), higher than 28.3 °C of Example 1. This is because the roughness of TiO 2 nanoparticles and the low surface energy of PDMS act synergistically as the key to water repellency. Without adding TiO 2 and relying only on the formation of a PDMS film, the surface is smooth, the contact angle decreases (the contact angle of PDMS itself is about 110°, not reaching the superhydrophobic effect), and the water repellency performance drops significantly. At the same time, without TiO 2 light reflection and photocatalytic functions, heat insulation only depends on the heat absorption of Al(OH) 3 , but the latter accounts for a small proportion (due to the reduction of the total addition amount), resulting in an increase in the heat insulation temperature.

[0072] The water contact angle of the woven fabric treated with the finishing agent of Comparative Example 3 was 105°, lower than 156.4° of Example 1, and the heat insulation temperature was 34.5 °C (close to the heat insulation temperature of the original cotton fabric), higher than 28.3 °C of Example 1. This is because Comparative Example 3 only contains a PDMS elastomer, without the synergism of Al(OH) 3 powder and TiO 2 powder particles, so that the finishing agent only retains the basic properties of PDMS. The PDMS film is thin and smooth, and the contact angle is only slightly higher than that of the original cotton fabric (the original cotton fabric is hydrophilic, PDMS is hydrophobic but without roughness support). At the same time, Comparative Example 3 has no Al(OH) 3 heat absorption and TiO 2 reflection, resulting in direct heat transfer, making the heat insulation temperature of the woven fabric close to that of the untreated original cotton fabric.

[0073] The water contact angle of the woven fabric treated with the finishing agent of Comparative Example 4 was 98.5°, lower than 156.4° of Example 1, and the heat insulation temperature was 33.2 °C, higher than 28.3 °C of Example 1. This is because ethyl acetate is used as a solvent to dissolve PDMS and form a uniform precursor solution. Therefore, when ethyl acetate is not added in Comparative Example 4, it will cause the PDMS matrix and the cross-linking agent to not be fully mixed due to high viscosity, uneven cross-linking, forming a porous or broken elastomer film, resulting in a decrease in the coating density, easy penetration of water molecules (contact angle < 100°), and interruption of the heat conduction path and discontinuous film layer, and the heat insulation effect of the woven fabric is close to that of the original cotton fabric.

[0074] The water contact angle of the woven fabric treated with the finishing agent of Comparative Example 5 was 140.2°, lower than 156.4° of Example 1, and the heat insulation temperature was 29.8 °C, higher than 28.3 °C of Example 1. This is because TiO 2Excessive addition will cause aggregation in the PDMS solution to form large particles, destroying the uniformity of the coating, exposing the hydrophilic groups on the surface of the aggregates, reducing the contact angle, and blocking the Al(OH) 3 The endothermic site of TiO 2 The self-reflection efficiency decreases due to agglomeration, and the thermal insulation temperature of the fabric increases. 2 Too high a proportion dilutes Al(OH) 3 The concentration of TiO2 is insufficient to absorb heat and cannot offset the excess 2 The negative impact of agglomeration will also cause the insulation temperature of the fabric to increase.

[0075] The water contact angle of the fabric treated with the finishing agent of Comparative Example 6 is 132.7°, which is lower than 156.4° of Example 1, and the heat insulation temperature is 31.2°C, which is higher than 28.3°C of Example 1. This is because Al(OH) 3 Al(OH) is a hydrophilic particle. Excessive addition results in the inability of the PDMS hydrophobic network to completely wrap the particle surface, exposing the hydroxyl group (-OH) on the particle surface, increasing the hydrophilicity of the fabric surface and significantly reducing the contact angle. 3 Although it can absorb heat, excessive addition will cause the gaps between particles to increase, and the PDMS matrix cannot be filled, forming a "thermal bridge", which will promote heat transfer and increase the insulation temperature of the fabric. 3 The particles are hard and brittle. Adding too much will cause the coating to lose flexibility and become prone to cracking and falling off (performance decays faster after washing).

[0076] (3) Self-cleaning test

[0077] The dust removal test was conducted on the original cotton cloth, the multifunctional fabrics of Example 1 and Comparative Examples 1-3 respectively: the samples were cut to the size of a glass slide and glued on, the glass slide was at the same angle, the dust of uniform thickness was sprinkled on the surface of the fabric, 5 drops of water were dripped on the top with a rubber dropper, and the fabric after dripping was photographed. The test results are shown in the figure below. Figures 1-5 As shown in the figure, by comparison, due to the low surface energy of PDMS and TiO 2 The roughness of the powder and the aluminum compound powder enables the fabric of Example 1 to have both low surface energy and a rough surface with a micro / nano structure, thereby achieving the self-cleaning performance of the "lotus effect".

[0078] (4) Surface morphology measurement

[0079] The surface morphology of the raw cotton cloth, the multifunctional fabrics of Example 1 and Comparative Examples 1-3 was measured by scanning electron microscopy and atomic force microscopy; wherein the scanning electron microscope was JSM-5600LV from Jeol Company of Japan.

[0080] like Figure 6As shown, the fiber surface of the original cotton fabric without the finishing agent treatment is smooth, with natural grooves, and the pores between the fibers are irregular, resulting in the fibers being completely hydrophilic. After stains are directly adsorbed on the fiber surface, they are difficult to remove; moreover, the air layer between the fibers is thin, and the heat conduction path is direct.

[0081] The SEM image of the woven fabric treated with the finishing agent of Comparative Example 1 is as Figure 7 shown. It can be seen that TiO 2 nanoparticles are dispersed in the PDMS film, and some particles are exposed on the surface, forming nanoscale protrusions. However, due to the absence of Al(OH) 3 , the gaps between the particles are large, and the hydrophobic network is incomplete. The TiO 2 photocatalytic activity exists, but the exposed particles are prone to agglomeration (local accumulation can be seen in the SEM), the active sites are reduced, and the stain decomposition efficiency decreases. Only relying on the reflection of TiO 2 to ultraviolet / infrared, without Al(OH) 3 absorbing heat, the heat insulation performance is limited.

[0082] The SEM image of the woven fabric treated with the finishing agent of Comparative Example 2 is as Figure 8 shown. It can be seen that the Al(OH) 3 particles are partially wrapped by PDMS and partially exposed, and local particle agglomeration occurs. The hydrophilic Al(OH) 3 exposed leads to an increase in surface energy, which is lower than that of the composite system. Without TiO 2 photocatalysis, only relying on physical adsorption to block stains, the cleaning effect is poor. Al(OH) 3 plays a role in heat decomposition and heat absorption, but particle agglomeration causes the PDMS film to be discontinuous, the heat conduction path is interrupted, and the heat insulation temperature is high.

[0083] The SEM image of the woven fabric treated with the finishing agent of Comparative Example 3 is as Figure 9 shown. It can be seen that the surface of the cotton fiber is covered with a uniform PDMS film, the film layer is continuous but smooth, and there are no particle protrusions. However, due to the lack of the support of nanoparticle roughness, the superhydrophobic state is not achieved, and there are no TiO 2 photocatalytic particles. Only relying on the physically smooth surface to reduce stain adhesion, the cleaning efficiency is low; the PDMS film blocks part of the heat conduction.

[0084] The SEM image of the woven fabric treated with the finishing agent of Example 1 is as Figure 10 shown. It can be seen that TiO 2 , Al(OH) 3It is uniformly dispersed in PDMS to form a "nano - sub - micron" multi - level structure. The particle surface is completely wrapped by the PDMS film, and there are no exposed hydroxyl groups. The multi - level roughness and the low surface energy of PDMS work together, with the water contact angle > 150°, water droplets being spherical on the surface, and the rolling angle < 10°, achieving the "lotus - leaf effect". The super - hydrophobic surface reduces stain adhesion, and combined with photocatalysis, it realizes "dual - mechanism self - cleaning". The continuous PDMS film blocks the heat conduction between fibers, forming a triple heat - insulation mechanism of "reflection - heat absorption - barrier", with good heat - insulation performance.

Claims

1. A method for preparing a green and environmentally friendly multifunctional finishing agent, characterized in that: The following steps are involved: Preparation of S1PDMS: Mix PDMS base glue and cross-linking agent evenly to obtain PDMS; Preparation of S2 composite precursor solution: adding ethyl acetate to PDMS and mixing well to obtain a composite precursor solution; Preparation of S3 multifunctional finishing agent: Add TiO2 powder and aluminum compound powder into the composite precursor solution and stir evenly to obtain a green and environmentally friendly multifunctional finishing agent.

2. The method for preparing the green and environmentally friendly multifunctional finishing agent according to claim 1, characterized in that: In step S1, the mass ratio of PDMS base glue to cross-linking agent is (5-20):

1.

3. The method for preparing the green and environmentally friendly multifunctional finishing agent according to claim 1, characterized in that: In step S1, stirring is performed during mixing, and the stirring time is 5-30 minutes.

4. The method for preparing the green and environmentally friendly multifunctional finishing agent according to claim 1, characterized in that: In step S2, the mass ratio of ethyl acetate to PDMS is (5-50):

1.

5. The method for preparing the green and environmentally friendly multifunctional finishing agent according to claim 1, characterized in that: In step S2, stirring is performed during mixing, and the stirring time is 15-60 minutes.

6. The method for preparing the green and environmentally friendly multifunctional finishing agent according to claim 1, characterized in that: In step S3, the mass ratio of TiO2 powder and aluminum compound powder is (1-3):(1-3), and the mass ratio of the total mass of TiO2 powder and aluminum compound powder to the composite precursor solution is (1-10):

100.

7. The method for preparing the green and environmentally friendly multifunctional finishing agent according to claim 1, characterized in that: In step S3, the aluminum compound powder is one or more of aluminum hydroxide powder, aluminum oxide powder and aluminum phosphate powder.

8. Green and environmentally friendly multifunctional finishing agent, characterized in that: The green and environment-friendly multifunctional finishing agent is prepared by the preparation method of any one of claims 1 to 7.

9. Use of the green, environmentally friendly, multifunctional finishing agent as claimed in claim 8 on fabrics.

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