Method for modifying marine polyester fabric by using dynamic siloxy polyimine coating

Abstract

The invention discloses a preparation method for modifying a polyester fabric by utilizing siloxane-based dynamic polyimine. The method comprises the following steps: pretreating a polyester fabric with alkali, and impregnating and coating the polyester fabric with siloxane-based dynamic polyimide. Preferred raw materials comprise terephthalaldehyde, trimethylolpropane tripolypropylene glycol ether (amino-terminated), siloxane-containing diamine, a polyester fabric and the like. The preparation method comprises the following steps: pretreating the polyester fabric with sodium hydroxide alkali, removing surface oil, and drying for later use; the preparation method comprises the following steps: adding terephthalaldehyde into a certain amount of solvent, stirring until terephthalaldehyde is completely dissolved, then adding a diamine monomer into the mixed solution, and stirring for a certain time to form a linear polyimine prepolymer; then adding a triamine cross-linking agent, stirring and reacting for a certain time, dipping the polyester fabric subjected to alkali pretreatment in a solution for a certain time, taking out, and putting into a blast oven for fully drying, so as to obtain the polyester fabric modified by the siloxane-based polyimide coating. According to the invention, the application field of the dynamic polyimine polymer material can be broadened, and the polyester fabric can be more efficiently applied in the fields of offshore oil sewage treatment, maritime work cables and the like.

Description

Technical Field

[0001] The invention relates to the technical field of polyester fabric modification, in particular to a method of modifying polyester fabric by utilizing a dynamic silicone-based polyimide coating. Background Art

[0002] As an important type of synthetic fabric material, polyester fabric is widely used in marine engineering, clothing and home furnishing, biomedicine and other fields due to its advantages such as low price, light weight, high strength, corrosion fatigue resistance, and large-scale production. However, since the surface of polyester fabric generally contains polar groups such as ester, carboxyl, and hydroxyl groups, it has strong water affinity and biological adhesion, especially when used in marine environments where bacterial communities are prone to breed, which will seriously limit its application in marine engineering fields such as ship mooring cables, offshore aquaculture nets, sails, and underwater protective anti-fouling nets.

[0003] In response to the above problems, researchers have proposed some solutions to improve the application of polyester fabrics in marine engineering and other fields, including: introducing hydrophobic functional groups or chemical modifications on the surface; copolymerization modification of molecular structure, etc. Among them, siloxane compounds have low surface energy, and the molecular structure of siloxane compounds contains one or more long-chain siloxane bonds, which can form a dense, low-surface-energy hydrophobic layer on the surface. The hydrophobicity of siloxanes can be widely used in many fields, such as coatings, waterproof materials, lubricants, dyes, textiles, medical devices, etc. In addition, the dynamic polymer materials prepared by dynamic imine bonds are repairable, and the dynamic imine bonds can also enhance the membrane permeability of bacterial cells, leading to bacterial penetration and lysis. Its unique antibacterial activity has attracted much attention ( J. Am. Chem. Soc. 2019, 141 : 12064; Carbohydr. Polym. 2020, 230 : 115671), which is enriched with a large number of microorganisms and bacteria in the ocean, and has important application significance. At present, there is no report on the use of dynamic polyimine as a coating to impregnate modified polyester fabrics. The present invention helps to improve the application field of dynamic polyimine polymer materials and promote the large-scale application of polyester fabrics in the treatment of oily wastewater in seas, rivers, lakes, etc. Summary of the invention

[0004] The present invention aims to prepare super-hydrophobic polyester fabrics to expand the application of polyester fabrics in the ocean and other fields, and provides a polyester fabric modified by siloxane polyimide. The present invention first removes the oil agent on the surface of the polyester fabric by alkali treatment to increase its bonding, modification and other functions, and then immerses the treated polyester fabric in a dynamic siloxane polyimide solution to prepare a hydrophobic and antibacterial modified polyester fabric.

[0005] The purpose of the present invention is achieved through the following technical solutions: The composite material obtained by the preparation method is a polyester fabric modified by silicone polyimide.

[0006] A method for modifying marine polyester fabric using a dynamic siloxane polyimide coating, characterized in that the specific preparation comprises the following steps: (1) Under a certain temperature water bath condition, dissolve sodium hydroxide (NaOH) in deionized water according to a certain proportion. Then add polyester fabric cut into a certain size, stir mechanically for 1-4 hours, and then take out the polyester fabric. Then, wash it with 30-90 ℃ deionized water and room temperature ethanol for 3-6 times respectively, and finally put it into a blast oven to dry to constant weight.

[0007] (2) A certain amount of terephthalaldehyde is added to an organic solvent and stirred until it is completely dissolved. Then, a siloxane-containing diamine monomer is added to the mixed and dispersed solution and stirred for a certain period of time to form an aldehyde-terminated linear siloxane-based polyimine prepolymer. Then, commercial monomer trimethylolpropane tripropylene glycol ether (amino-terminated) (T-403) is added and stirred for a period of time. After the polyester fabric treated and dried in step (1) is immersed in the organic solvent, the fabric is taken out after being immersed for a period of time, placed in a blast oven and dried at a certain temperature for a certain period of time.

[0008] Preferably, the mass ratio of NaOH to deionized water in step (1) is 1:100-1:50.

[0009] Preferably, the organic solvent described in step (2) is one or a mixture of tetrahydrofuran, chloroform, ethanol, N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0010] Preferably, the time for stirring until dissolution after adding terephthalaldehyde in step (2) is 1-30 min, and the siloxane-containing diamine monomer is 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane ( M n =248.5), aminopropyl di-terminated polydimethylsiloxy M n =27000) or two thereof. The stirring time after the diamine is added is 0.5-3h. The stirring time after the triamine cross-linking agent is added is 0.5-600 min.

[0011] Preferably, the molar ratio of the aldehyde functional group (-CHO) to the amino functional group (-NH2) in the system described in step (2) is 0.8:1-1:0.8, and the solid content of the dynamic silicone-based polyimine coating in the organic solvent is 0.01-10 wt%. Preferably, in step (2), the soaking time of the polyester fabric is 0.5-24 h, the drying temperature is 40-120° C., and the drying time is 0.5-10 h.

[0012] The beneficial effects of the present invention are that the raw materials of the dynamic siloxane-based polyimine modified coating used in the present invention are all commercial monomers, low in cost, catalyst-free, simple in preparation process and mild in reaction conditions, and the surface of the modified polyester fabric obtained is smooth and uniform; based on the reversible Schiff base reaction, it is a self-repairing coating; the hydrophobicity and antibacterial properties of the polyester fabric modified by siloxane polyimine obtained in the present invention are greatly improved compared with the polyester fabric before modification; the polyester fabric modified by siloxane polyimine used in the present invention also has a good oil absorption effect, which greatly broadens the robustness of the polyester fabric in the application of marine environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a physical picture of the polyester fabric after alkali treatment prepared in Example 1.

[0014] Figure 2 This is a real picture of the polyester fabric modified with silicone polyimine prepared in Example 1.

[0015] Figure 3 This is the infrared characteristic peak spectrum of the polyester fabric modified by silicone polyimine prepared in Example 1-3. 1050 cm -1 The characteristic peak of the silanol group at 1640 cm -1 The characteristic peaks of the dynamic imine group at 1713 cm -1 The peak at the center is the stretching vibration peak of C=O in the ester group, which proves the successful modification of polyester fabric by siloxane polyimine.

[0016] Figure 4 This is a differential scanning calorimetry (DSC) diagram of the polyester fabric modified with siloxane polyimine prepared in Example 1. It can be seen that an obvious melting endothermic peak can be observed in the range of 225-275°C, indicating that the polyester fabric has a relatively high melting point of about 250°C.

[0017] Figure 5 The water contact angle test diagram of the polyester fabric modified with siloxane polyimine prepared in Examples 1 to 3. Compared with the contact angle of almost 0 for the polyester fabric not modified with dynamic siloxane polyimine coating, the polyester fabrics impregnated with polyimine of different solid contents all have a high hydrophobic effect, and the contact angle after modification is greater than 125°.

[0018] Figure 6The figures show the comparison of the hydrophobic effects of the polyester fabric not modified with siloxane polyimine (left side) and the polyester fabric modified with siloxane polyimine in Example 1 (right side). It can be seen that the polyester fabric modified with the dynamic siloxane polyimine coating almost completely absorbs the water droplets dyed with methylene blue, while the polyester fabric modified with siloxane polyimine in Example 1 can maintain a relatively high hydrophobic effect. DETAILED DESCRIPTION

[0019] In order to better understand the present invention, the technical solution of the present invention is further described below in conjunction with embodiments and drawings, but the implementation mode of the present invention is not limited thereto. Example 1

[0020] At 75 °C in a water bath, add 10 g of sodium hydroxide (NaOH) to 800 mL of deionized water and stir until the NaOH is completely dissolved; then 6 pieces of cut polyester fabric (5 cm × 5 cm) are immersed in the NaOH solution and stirred continuously for 2 h at 75 °C in a water bath. Then take out the polyester fabric, wash it three times with 60 °C deionized water and room temperature deionized water respectively, and then put it into a 100 °C forced air oven to dry for 2 h. After drying, take it out to obtain the polyester fabric after alkali pretreatment.

[0021] Figure 1 This is a physical picture of the polyester fabric after alkali treatment prepared in Example 1.

[0022] At room temperature, weigh 0.27 g of terephthalaldehyde and add 70.6 g of chloroform solvent and stir for 10 min until dissolved. After all the terephthalaldehyde is dissolved, add 0.31 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, rinse the residue in the beaker with 1 g of chloroform, and stir for 2 h. Then add 0.22 g of triamine crosslinker trimethylolpropane tripropylene glycol ether (amino terminated) and rinse the residue in the beaker with 1 g of chloroform, and continue to stir for 1 min to form a network dynamic polyimine structure. Finally, stop stirring, immerse the polyester fabric cloth after alkali pretreatment in the polyimine solution for 2 h, and let the polyimine coating adhere to the surface of the polyester fabric. After the attachment is completed, take out the polyester fabric cloth and dry it in a 60 ℃ forced air oven for 2 h, and finally obtain a polyester fabric modified with siloxane polyimine.

[0023] Figure 2 This is a physical picture of the polyester fabric modified by dynamic siloxane polyimine prepared in Example 1.

[0024] Figure 3 This is the infrared characteristic peak spectrum of the polyester fabric modified by dynamic siloxane polyimine prepared in Example 1 (see 1%).

[0025] Figure 4 This is a differential scanning calorimetry (DSC) graph of the polyester fabric modified with dynamic silicone polyimine prepared in Example 1.

[0026] Figure 5 This is a water contact angle test diagram of the polyester fabric modified with dynamic siloxane polyimine prepared in Example 1. Example 2

[0027] The method for alkali pretreatment of polyester fabric is the same as that in Example 1.

[0028] At room temperature, weigh 0.14 g of terephthalaldehyde and add 70.6 g of chloroform solvent and stir for 10 min until dissolved. After all the terephthalaldehyde is dissolved, add 0.16 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, rinse the residue in the beaker with 1 g of chloroform, and stir for 2 h. Then add 0.11 g of triamine crosslinker trimethylolpropane tripropylene glycol ether (amino terminated) and rinse the residue in the beaker with 1 g of chloroform, and continue to stir for 1 min to form a network dynamic polyimine structure. Finally, stop stirring, immerse the polyester fabric cloth after alkali pretreatment in the polyimine solution for 2 h, and allow the polyimine network to adhere to the surface of the polyester fabric. After the attachment is completed, take out the polyester fabric cloth and dry it in a 60 ℃ forced air oven for 2 h, and finally obtain a polyester fabric modified with siloxane polyimine.

[0029] Figure 3 This is the infrared characteristic peak spectrum of the polyester fabric modified with silicone polyimine prepared in Example 2 (see 0.5%).

[0030] Figure 5 This is a water contact angle test diagram of the polyester fabric modified with silicone polyimine prepared in Example 2 (see 0.5%). Example 3

[0031] The method for alkali pretreatment of polyester fabric is the same as that in Example 1.

[0032] At room temperature, 0.03 g of terephthalaldehyde was weighed and added to 70.6 g of chloroform solvent and stirred for 10 min until dissolved. After all the terephthalaldehyde was dissolved, 0.03 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane was added, and the residue in the beaker was rinsed with 1 g of chloroform, and the reaction was stirred for 2 h. Subsequently, 0.11 g of triamine crosslinker trimethylolpropane tripropylene glycol ether (amino terminated) was added and the residue in the beaker was rinsed with 1 g of chloroform, and the reaction was continued for 1 min to form a network dynamic polyimine structure. Finally, the stirring was stopped, and the polyester fabric cloth pretreated with alkali was immersed in the polyimine solution for 2 h to allow the polyimine network to adhere to the surface of the polyester fabric. After the attachment was completed, the polyester fabric cloth was taken out and dried in a 60 ℃ forced air oven for 2 h, and finally a polyester fabric modified with siloxane polyimine was obtained.

[0033] Figure 3 This is the infrared characteristic peak spectrum of the polyester fabric modified with silicone polyimine prepared in Example 3 (see 0.1%).

[0034] Figure 5 This is a water contact angle test diagram of the polyester fabric modified with silicone polyimine prepared in Example 3 (see 0.1%).

Claims

1. A method for modifying marine polyester fabric using a dynamic siloxane polyimide coating, characterized in that: The specific preparation includes the following steps: (1) Under a certain temperature water bath condition, dissolve sodium hydroxide NaOH in deionized water according to a certain proportion. Then add polyester fabric cut into a certain size, stir mechanically for 1-4 hours, take out the polyester fabric; then, wash it with 30-90 ℃ deionized water and room temperature ethanol for 3-6 times respectively, and finally put it into a blast oven to dry to constant weight; (2) adding a certain amount of terephthalaldehyde to an organic solvent and stirring thoroughly until it is completely dissolved, then adding a siloxane-containing diamine monomer to the mixed and dispersed solution, stirring and reacting for a certain period of time, first forming an aldehyde-terminated linear siloxane-based polyimine prepolymer; then adding a commercial monomer trimethylolpropane tripropylene glycol ether (amino-terminated), stirring and reacting for a period of time, immersing the polyester fabric treated and dried in step (1) therein, taking it out after being fully immersed for a period of time, placing it in a blast oven and drying it at a certain temperature for a certain period of time.

2. A method for modifying marine polyester fabric using dynamic siloxane polyimide coating according to claim 1, characterized in that: The mass ratio of NaOH to deionized water in step (1) is 1:100-1:

50.

3. A method for modifying marine polyester fabric using dynamic siloxane polyimide coating according to claim 1, characterized in that: The organic solvent described in step (2) is one or a mixture of tetrahydrofuran, chloroform, ethanol, N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, and N-methylpyrrolidone.

4. A method for modifying marine polyester fabric using dynamic siloxane polyimide coating according to claim 1, characterized in that: The stirring time after adding terephthalaldehyde to dissolve in step (2) is 1-30 min, and the siloxane-containing diamine monomer is 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane ( M n =248.5), aminopropyl di-terminated polydimethylsiloxy M n =27000) or two thereof; the stirring time after the diamine is added is 0.5-3h; the stirring time after the triamine cross-linking agent is added is 0.5-600 min.

5. The method for modifying marine polyester fabric using dynamic siloxane polyimide coating according to claim 1, characterized in that: The molar ratio of the aldehyde functional group (-CHO) to the amino functional group (-NH2) in step (2) is 0.8:1-1:0.8, and the solid content of the dynamic silicone-based polyimine coating in the organic solvent is 0.01-10 wt%.

6. A method for modifying marine polyester fabric using dynamic siloxane polyimide coating according to claim 1, characterized in that: In step (2), the polyester fabric is soaked for 0.5-24 h, the drying temperature is 40-120° C., and the drying time is 0.5-10 h.

7. A polyester fabric modified with silicone polyimide obtained by the preparation method according to any one of claims 1 to 6.

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