Low-odor environment-friendly functional textile fiber and surface modification method thereof

Abstract

The invention discloses a low-odor environment-friendly functional textile fiber and a surface modification method thereof. The method comprises the following steps: by taking polyethylene glycol terephthalate fibers as a base material, sequentially carrying out washing and alkali treatment by using a nonionic surfactant, forming an intermediate layer by self-polymerization of dopamine, initiating group fixation, and initiating two-stage polymerization on the surface of a water phase to construct a gradient-distributed zwitterionic polymer brush layer; and carrying out poly (diallyldimethylammonium chloride) treatment and salt solution stabilization treatment to obtain the functional fiber with a stable surface structure. The modification method is completed under a water phase condition, the process is mild, release of peculiar smell substances in the fibers can be effectively reduced, and the fibers are endowed with good hydrophilicity, low adsorptivity and washing resistance. The obtained fiber shows a relatively low peculiar smell release level, a relatively stable surface state and good environmental adaptability under the conditions of use and repeated washing.

Description

Technical Field

[0001] This invention relates to the technical field of surface modification of textile materials, and in particular to a low-odor, environmentally friendly functional textile fiber and its surface modification method. Background Technology

[0002] Polyethylene terephthalate (PET) fiber is widely used in clothing and home textiles. During use and washing, it is prone to contact with and retention of sweat, sebum, and organic matter in the environment. With prolonged use, problems such as odor accumulation and stain residue may occur, affecting the performance of the fabric.

[0003] Existing technologies typically improve the hydrophilicity or stain resistance of fibers through surface finishing, coating, or grafting. However, some finishing layers have limited bonding strength with the fiber matrix, and their performance is prone to degradation under repeated washing or friction, resulting in inconsistent low-odor or easy-to-clean effects. Other modification methods involve harsh process conditions or complex structural control, making it difficult to balance treatment stability and repeatability in practical applications.

[0004] Furthermore, some surface-modified structures are prone to interfacial changes after repeated washing, causing fluctuations in hydrophilicity and low adsorption properties during service, thus affecting long-term performance. Therefore, there is still room for further optimization in achieving stable maintenance of the modification effect during washing while ensuring that the basic properties of the fiber are not affected. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned problems existing in the prior art and to provide a low-odor, environmentally friendly functional textile fiber and its surface modification method.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for surface modification of low-odor, environmentally friendly functional textile fibers, comprising the following steps: S1, polyethylene terephthalate fibers are washed with nonionic surfactants and then treated with alkali. S2, dopamine self-polymerization reaction is carried out on the fibers treated in step S1 in a weakly alkaline buffer system to form a polydopamine layer on the fiber surface; S3, through the reaction of haloacyl bromide compounds with polydopamine layers, fixes surface initiation groups on the fiber surface; S4, using an aqueous surface-initiated polymerization method, two-stage polymerization is carried out sequentially on the fiber surface to form a gradient-distributed zwitterionic polymer brush layer; S5, the fibers treated in step S4 are placed in an aqueous solution containing polydiallyldimethylammonium chloride and then fixed by heat treatment; S6, after being briefly treated with a salt solution and then dried, yields a low-odor, environmentally friendly functional textile fiber.

[0007] Furthermore, the nonionic surfactant mentioned in step S1 is a fatty alcohol polyoxyethylene ether with a mass concentration of 1–5 g / L, a washing temperature of 40–80°C, and a washing time of 5–30 min.

[0008] Furthermore, the alkali treatment in step S1 uses an aqueous sodium carbonate solution with a sodium carbonate concentration of 0.05–0.3 mol / L, a treatment temperature of 40–80 °C, and a treatment time of 5–30 min.

[0009] Furthermore, the dopamine self-polymerization reaction in step S2 is carried out in a buffer solution with a pH of 8.0 to 9.5, wherein the concentration of dopamine hydrochloride in the buffer solution is 0.5 to 5 g / L, the reaction temperature is 15 to 35°C, and the reaction time is 1 to 8 h.

[0010] Furthermore, the haloacyl bromide compound mentioned in step S3 is bromoisobutyryl bromide, the reaction solvent is an anhydrous alcohol solvent, an organic base is added to the system as an acid scavenger, and the reaction temperature includes a low temperature stage of 0-10℃ and a high temperature reaction stage of 20-30℃.

[0011] Furthermore, in the first stage of polymerization in step S4, the polymerization monomer is sulfobetaine methacrylate with a concentration of 0.8–1.5 mol / L, and polyethylene glycol methacrylate and glycidyl methacrylate are introduced as comonomers.

[0012] Furthermore, in the first polymerization stage, the amount of polyethylene glycol methacrylate is 0.5 to 3 mol relative to the molar amount of sulfobetaine methacrylate, and the amount of glycidyl methacrylate is 0.1 to 1.5 mol.

[0013] Furthermore, in the second polymerization stage of step S4, the concentration of sulfobetaine methacrylate is 0.3–0.8 mol / L, and the amount of polyethylene glycol methacrylate is 2–8 mol%, to form a gradient distribution structure of the brush layer components along the fiber surface.

[0014] A second aspect of the present invention provides a low-odor, environmentally friendly functional textile fiber prepared according to the above-described modification method, comprising a polyethylene terephthalate fiber substrate, wherein the surface of the fiber substrate is sequentially provided with: Surface layer activated by alkali treatment; A polydopamine intermediate layer covering the surface layer; An initiation group layer anchored to the surface of the polydopamine intermediate layer; A gradient-distributed zwitterionic polymer brush layer formed by surface-initiated polymerization; And the outermost layer of polydiallyldimethylammonium chloride control layer.

[0015] Furthermore, the gradient-distributed zwitterionic polymer brush layer is formed by segmented surface-initiated polymerization of zwitterionic monomers with different concentrations and different copolymerization ratios, and the thickness of the brush layer is continuously varied along the radial direction of the fiber.

[0016] The present invention, by adopting the above technical solution, has the following beneficial effects: First, the polyethylene terephthalate (PET) fibers undergo surface pretreatment. A dual process combining nonionic surfactant washing and mild alkali treatment effectively removes spinning oils, low-molecular-weight organic residues, and weakly adsorbed impurities from the fiber surface. This treatment significantly improves the uniformity and stability of the fiber surface energy distribution while ensuring that the fiber's main structure and mechanical properties are not damaged. This method avoids the use of harmful chemicals, provides a clean reaction interface for subsequent modification, and reduces the risk of introducing odor substances at the source.

[0017] Secondly, based on the activated surface, a continuous and dense polydopamine (PDA) coating is formed on the fiber surface through a dopamine self-polymerization reaction in a weakly alkaline buffer system. This coating has the ability to adaptively cover the micro-rough structure of the fiber surface, providing a consistent reaction platform across different batches of fibers while retaining functional groups that can be further reacted. By optimizing the reaction conditions, the deposition amount of the PDA layer is controlled to avoid excessive accumulation that could affect subsequent modification.

[0018] Subsequently, a haloacyl bromide compound was reacted with the PDA layer, and a process combining low temperature and high temperature was used to introduce uniformly distributed initiating groups onto the fiber surface. This step achieved precise fixation of the initiation sites and effectively suppressed the occurrence of side reactions.

[0019] After the initiating groups are fixed, a gradient zwitterionic brush layer is constructed in stages using aqueous surface-initiated polymerization. The first stage involves polymerization at a high monomer concentration to rapidly form a continuous and dense bottom layer. By introducing a specific proportion of comonomers, structural units with moderate flexibility are formed within the brush layer, laying the foundation for subsequent gradient construction. The second stage reduces the concentration of the main monomer and increases the proportion of comonomers, resulting in a structural region on the outer side of the brush layer with stronger hydration capabilities and more flexible chain segments. These techniques avoid the performance degradation caused by swelling or collapse during service of traditional homogeneous brush layers.

[0020] After the gradient brush layer is formed, a conditioning layer is constructed on the outer side of the brush layer by introducing polydiallyl dimethyl ammonium chloride (PDADMAC) and performing moderate heat treatment. This conditioning layer does not increase surface residue, does not affect the fiber feel, and can adjust the ionic environment and hydration state of the brush layer surface.

[0021] Finally, a short-term salt solution treatment induces conformational rearrangement of the polymer chains. This step eliminates unstable bonding states that may exist in the early stages of modification, ensuring that the final multilayer structure maintains a stable interface after drying.

[0022] In summary, the five-layer structure design of this method enables the fiber surface to simultaneously possess a low adsorption hydration barrier and high structural stability, effectively inhibiting the retention and accumulation of organic pollutants and odor precursors even under repeated washing, friction, and changes in the salt ion environment. Detailed Implementation

[0023] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0024] Unless otherwise defined, all scientific and technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0027] The present invention will now be described in detail with reference to specific embodiments, which are intended to understand rather than limit the invention.

[0028] Unless otherwise specified, the raw materials in the following examples use the following specific components: PET fiber / fabric: Textile-grade PET filaments produced by Yizheng Chemical Fiber Co., Ltd.

[0029] Nonionic surfactant: AEO-9 fatty alcohol polyoxyethylene ether manufactured by BASF.

[0030] Tris buffer: Analytical grade Tris was used, provided by Sinopharm Chemical Reagent Co., Ltd.

[0031] Dopamine hydrochloride: Biochemical grade dopamine hydrochloride provided by Sigma-Aldrich.

[0032] 2-Bromoisobutyryl bromide: Chemically pure reagents provided by Tokyo Chemical Industry Co., Ltd. (TCI) were used.

[0033] Triethylamine: Anhydrous triethylamine provided by Sinopharm Chemical Reagent Co., Ltd. was used.

[0034] Sulfobetaine methacrylate: The sulfobetaine methacrylate monomer provided by Sigma-Aldrich is an inhibitor-stabilized methacrylate monomer.

[0035] Polyethylene glycol methacrylate: Polyethylene glycol methacrylate monomers with methacrylate end groups provided by Sigma-Aldrich are used, with a number average molecular weight Mn of approximately 475.

[0036] Glycidyl methacrylate: The monomer used is glycidyl methacrylate supplied by Sigma-Aldrich, with a purity of not less than 97%.

[0037] Polydiallyl dimethyl ammonium chloride: The aqueous cationic polymer of polydiallyl dimethyl ammonium chloride provided by Sigma-Aldrich is used with water as solvent and has a mass fraction of 20 wt%.

[0038] Example 1 This embodiment discloses a low-odor, environmentally friendly functional textile fiber and its surface modification method. The modification method specifically includes the following steps: S1: Take PET fiber as the substrate and wash it in an aqueous solution containing a nonionic surfactant. The nonionic surfactant is fatty alcohol polyoxyethylene ether (AEO-9) at a concentration of 2 g / L. The washing temperature is 60℃ and the washing time is 15 min. After washing, rinse with deionized water until there is no obvious foam.

[0039] Subsequently, the washed PET fibers were placed in a 0.1 mol / L sodium carbonate aqueous solution and treated at 60°C for 10 min. After treatment, they were thoroughly washed with deionized water until neutral and then dried at 60°C for later use.

[0040] S2: The PET fibers treated in step S1 were placed in a dopamine self-polymerization reaction system. The dopamine self-polymerization reaction system was a Tris buffer solution with a pH of 8.5 and a Tris concentration of 10 mmol / L. Dopamine hydrochloride was added to this buffer solution to make its concentration 2 g / L. The PET fibers were immersed in the above solution and reacted at 25°C for 4 h. After the reaction was completed, the fibers were removed, washed repeatedly with deionized water, and then dried at 50°C to obtain PET fibers with a polydopamine layer on the surface.

[0041] S3: Using anhydrous ethanol as the reaction solvent, add triethylamine at a rate of 10 mL per liter of ethanol, and cool the system to 4°C. Under this temperature condition, slowly add 2-bromoisobutyryl bromide dropwise over a period of 15 min.

[0042] The polydopamine-coated PET fibers obtained in step S2 were then immersed in the above reaction system and reacted at 4°C for 30 min, followed by a further reaction at 25°C for 2 h. After the reaction was completed, the fibers were washed sequentially with ethanol and deionized water, and then dried at 50°C to obtain PET fibers with initiating groups fixed on their surface.

[0043] S4: Place the PET fibers obtained in step S3 into an aqueous surface-initiated polymerization system for two-stage polymerization.

[0044] (1) Deionized water and ethanol were mixed at a volume ratio of 90:10 to obtain a mixed solvent. Sulfobetaine methacrylate was added to this mixed solvent to form a solution with a concentration of 1.2 mol / L. Polyethylene glycol methacrylate was added at a rate of 1 mol% relative to the molar amount of sulfobetaine methacrylate, and glycidyl methacrylate was added at a rate of 0.5 mol% relative to the molar amount of sulfobetaine methacrylate to obtain the first polymerization solution. PET fibers were then immersed in the above solution and reacted at 30°C for 10 min.

[0045] (2) After the first stage of reaction, the fiber was removed and quickly rinsed once with deionized water, and then placed in the second stage polymerization solution. A mixed solvent was prepared by mixing deionized water and ethanol at a volume ratio of 95:5. Sulfobetaine methacrylate was added to this mixed solvent to form a solution with a concentration of 0.6 mol / L. Polyethylene glycol methacrylate was added simultaneously, with the amount of polyethylene glycol methacrylate being 4 mol% relative to the molar amount of sulfobetaine methacrylate, and the amount of glycidyl methacrylate being 0.5 mol% relative to the molar amount of sulfobetaine methacrylate. The reaction was continued at 30°C for 45 min. After the reaction, the fiber was thoroughly washed with deionized water and dried at 50°C to obtain PET fibers with a gradient zwitterionic brush layer on the surface.

[0046] S5: The PET fibers obtained in step S4 are treated in an aqueous solution containing polydiallyldimethylammonium chloride (0.15 wt%), and the solution is adjusted to a weakly alkaline state by adding sodium bicarbonate. The treatment temperature is 25°C, and the treatment time is 15 min. After treatment, the fibers are washed with deionized water and then heat-treated at 60°C for 10 min.

[0047] S6: The PET fibers treated in step S5 are immersed in a 0.5 wt% sodium chloride aqueous solution for 2 minutes, then rinsed once with deionized water, and dried at 50°C to constant weight to obtain low-odor environmentally friendly PET fibers.

[0048] Example 2 This embodiment discloses a low-odor, environmentally friendly functional textile fiber and its surface modification method. The overall process flow is the same as that in Embodiment 1, except for the selection of some process parameters in each step.

[0049] S1: Take PET fiber as the substrate and wash it in an aqueous solution containing a nonionic surfactant, namely fatty alcohol polyoxyethylene ether, at a concentration of 1 g / L. The washing temperature is 45℃ and the washing time is 10 min. After washing, rinse with deionized water until there is no obvious foam.

[0050] Subsequently, the washed PET fibers were placed in a 0.05 mol / L sodium carbonate aqueous solution and treated at 45°C for 8 min. After treatment, they were thoroughly washed with deionized water until neutral and then dried at 55°C for later use.

[0051] S2: The PET fibers treated in step S1 are placed in a dopamine self-polymerization reaction system. The dopamine self-polymerization reaction system is a Tris buffer solution with a pH of 8.0 and a Tris concentration of 10 mmol / L. Dopamine hydrochloride is added to this buffer solution to achieve a concentration of 0.5 g / L. The PET fibers are immersed in the above solution and reacted at 20°C for 2 h. After the reaction is complete, the fibers are removed, repeatedly washed with deionized water, and then dried at 45°C to obtain PET fibers with a polydopamine layer on the surface.

[0052] S3: Using anhydrous ethanol as the reaction solvent, add triethylamine at a rate of 8 mL per liter of ethanol, and cool the system to 5°C. Under this temperature condition, slowly add 2-bromoisobutyryl bromide dropwise over a period of 12 min.

[0053] The polydopamine-coated PET fibers obtained in step S2 were then immersed in the above reaction system and reacted at 5°C for 20 min, followed by a further reaction at 22°C for 1.5 h. After the reaction was completed, the fibers were washed sequentially with ethanol and deionized water, and then dried at 45°C to obtain PET fibers with initiating groups fixed on their surface.

[0054] S4: Place the PET fibers obtained in step S3 into an aqueous surface-initiated polymerization system for two-stage polymerization.

[0055] In the first polymerization stage, deionized water and ethanol were mixed at a volume ratio of 92:8 to obtain a mixed solvent. Sulfobetaine methacrylate was added to this mixed solvent to form a solution with a concentration of 0.8 mol / L. Simultaneously, polyethylene glycol methacrylate was added at a concentration of 0.5 mol% relative to the molar amount of sulfobetaine methacrylate, and glycidyl methacrylate was added at a concentration of 0.1 mol% relative to the molar amount of sulfobetaine methacrylate. PET fibers were then immersed in the above solution and reacted at 25°C for 8 min.

[0056] In the second polymerization stage, deionized water and ethanol were mixed at a volume ratio of 96:4 to obtain a mixed solvent. Sulfobetaine methacrylate was added to this mixed solvent to form a 0.3 mol / L solution. Simultaneously, polyethylene glycol methacrylate was added at a rate of 2 mol% relative to the molar amount of sulfobetaine methacrylate, and glycidyl methacrylate was added at a rate of 0.1 mol%. The reaction was continued at 25°C for 30 min. After the reaction, the fibers were thoroughly washed with deionized water and dried at 45°C to obtain PET fibers with a gradient zwitterionic brush layer on the surface.

[0057] S5: The PET fibers obtained in step S4 are treated in an aqueous solution containing polydiallyldimethylammonium chloride (0.10 wt%), and the solution is adjusted to a weakly alkaline state by adding sodium bicarbonate. The treatment temperature is 22°C, and the treatment time is 10 min. After treatment, the fibers are washed with deionized water and then heat-treated at 55°C for 8 min.

[0058] S6: The PET fibers treated in step S5 are immersed in a sodium chloride aqueous solution with a mass fraction of 0.3 wt% for 1 min, then rinsed once with deionized water, and dried at 45°C to constant weight to obtain low-odor environmentally friendly PET fibers.

[0059] Example 3 This embodiment discloses a low-odor, environmentally friendly functional textile fiber and its surface modification method. The overall process flow is the same as that in Embodiment 1, except that some process parameters are different.

[0060] S1: Using PET fiber as the substrate, wash it in an aqueous solution containing fatty alcohol polyoxyethylene ether (FAE). The concentration of FAE is 3 g / L, the washing temperature is 55℃, and the washing time is 20 min. After washing, rinse with deionized water until no obvious foam remains.

[0061] Subsequently, the washed PET fibers were placed in a 0.15 mol / L sodium carbonate aqueous solution and treated at 55°C for 15 min. After treatment, they were thoroughly washed with deionized water until neutral and then dried at 60°C for later use.

[0062] S2: The PET fibers treated in step S1 were placed in a Tris buffer solution with a pH of 8.8 and a Tris concentration of 10 mmol / L. Dopamine hydrochloride was added to the buffer solution to bring its concentration to 2.5 g / L, and the reaction was carried out at 28°C for 5 h. After the reaction was completed, the fibers were removed, washed repeatedly with deionized water, and then dried at 50°C.

[0063] S3: Using anhydrous ethanol as the reaction solvent, triethylamine was added at a rate of 10 mL per liter of ethanol, and the system was cooled to 6°C. 2-Bromoisobutyryl bromide was then added dropwise at this temperature over a period of 15 min. The resulting fibers were then reacted at 6°C for 30 min, followed by a further reaction at 25°C for 2 h. After the reaction was complete, the fibers were washed and dried.

[0064] S4: In the first stage of polymerization, the concentration of sulfobetaine methacrylate is 1.0 mol / L, the amount of polyethylene glycol methacrylate is 1.5 mol%, and the amount of glycidyl methacrylate is 0.8 mol%. The reaction is carried out at 30℃ for 12 min.

[0065] In the second stage of polymerization, the concentration of sulfobetaine methacrylate was 0.5 mol / L, the amount of polyethylene glycol methacrylate was 4 mol%, and the reaction was carried out at 30℃ for 40 min. After the reaction was completed, the mixture was washed and dried.

[0066] S5: Polydiallyl dimethylammonium chloride with a mass fraction of 0.15 wt%, a treatment temperature of 25℃, a treatment time of 15 min, followed by heat treatment at 60℃ for 10 min.

[0067] S6: Sodium chloride aqueous solution with a mass fraction of 0.5 wt%, soaking time of 2 min, and drying to constant weight.

[0068] Example 4 This embodiment discloses a low-odor, environmentally friendly functional textile fiber and its surface modification method. The overall process flow is the same as that in Embodiment 1, except that some process parameters are different.

[0069] S1: Fatty alcohol polyoxyethylene ether concentration is 5 g / L, washing temperature is 80℃, and washing time is 30 min. Sodium carbonate concentration is 0.3 mol / L, treatment temperature is 80℃, and treatment time is 30 min.

[0070] S2: Dopamine hydrochloride concentration is 5 g / L, pH value is 9.5, reaction temperature is 35℃, and reaction time is 8 h.

[0071] S3: The low-temperature reaction temperature is 10℃, the high-temperature reaction temperature is 30℃, and the total reaction time is 3 h.

[0072] S4: In the first stage of polymerization, the concentration of sulfobetaine methacrylate is 1.5 mol / L, the amount of polyethylene glycol methacrylate is 3 mol%, the amount of glycidyl methacrylate is 1.5 mol%, and the reaction time is 20 min. In the second stage of polymerization, the concentration of sulfobetaine methacrylate is 0.8 mol / L, the amount of polyethylene glycol methacrylate is 8 mol%, and the reaction time is 60 min.

[0073] S5: Polydiallyl dimethylammonium chloride with a mass fraction of 0.30 wt%, a treatment temperature of 30℃, a treatment time of 20 min, and a heat treatment temperature of 65℃ for 15 min.

[0074] S6: Soak in a sodium chloride aqueous solution with a mass fraction of 0.8 wt% for 5 min, and dry to constant weight to obtain low-odor environmentally friendly PET fiber.

[0075] Comparative Example 1 This comparative example discloses a method for surface modification of textile fibers. Its overall process flow is basically the same as that of Example 1, except that the dopamine self-polymerization reaction step is omitted.

[0076] The specific steps are as follows: S1: Take PET fiber as the substrate and perform nonionic surfactant washing and sodium carbonate alkali treatment according to step S1 in Example 1. The washing, treatment and drying conditions are the same as in Example 1.

[0077] S2: The PET fibers treated in step S1 are placed directly into the initiator group fixed reaction system. Anhydrous ethanol is used as the reaction solvent. Triethylamine is added and 2-bromoisobutyryl bromide is added dropwise under low temperature conditions. Then the temperature is raised to react. The reaction conditions are the same as those in step S3 in Example 1.

[0078] S3: Place the PET fibers treated above into an aqueous surface-initiated polymerization system and carry out a two-stage polymerization reaction according to step S4 in Example 1.

[0079] S4: Perform polydiallyl dimethylammonium chloride treatment and heat treatment according to step S5 in Example 1.

[0080] S5: Perform sodium chloride aqueous solution treatment and drying according to step S6 in Example 1.

[0081] Comparative Example 2 This comparative example discloses a method for surface modification of textile fibers. Its overall process flow is basically the same as that of Example 1, except that a two-stage polymerization method is not used, but a single-stage surface-initiated polymerization method is used instead.

[0082] The specific steps are as follows: S1: The PET fibers are washed with nonionic surfactants and treated with alkali according to step S1 in Example 1.

[0083] S2: Form a polydopamine layer on the surface of PET fibers according to step S2 in Example 1.

[0084] S3: Immobilize initiation groups on the surface of the polydopamine layer according to step S3 in Example 1.

[0085] S4: The PET fibers obtained in step S3 are placed in a single aqueous polymerization solution for surface-initiated polymerization. The concentration of sulfobetaine methacrylate in the polymerization solution is 0.9 mol / L. Polyethylene glycol methacrylate is added at an amount of 2 mol% relative to the molar amount of sulfobetaine methacrylate, and glycidyl methacrylate is added at an amount of 0.5 mol%. The reaction is carried out at 30°C for 60 min.

[0086] S5: Perform polydiallyl dimethylammonium chloride treatment and heat treatment according to step S5 in Example 1.

[0087] S6: Perform sodium chloride aqueous solution treatment and drying according to step S6 in Example 1.

[0088] Comparative Example 3 This comparative example discloses a surface modification method for textile fibers. Its overall process flow is basically the same as that of Example 1, except that the outer layer control step of polydiallyldimethylammonium chloride is omitted.

[0089] The specific steps are as follows: S1: Perform washing and alkali treatment of PET fibers according to step S1 in Example 1.

[0090] S2: Form a polydopamine layer according to step S2 in Example 1.

[0091] S3: Fix the initiating group according to step S3 in Example 1.

[0092] S4: Perform two-stage aqueous surface-initiated polymerization according to step S4 in Example 1 to form a gradient zwitterionic brush layer.

[0093] S5: The PET fibers treated in step S4 are directly immersed in a 0.5 wt% sodium chloride aqueous solution for 2 min, then rinsed with deionized water and dried.

[0094] Comparative Example 4 This comparative example discloses a surface modification method for textile fibers. The overall process flow is basically the same as that of Example 1, except that salt solution stabilization treatment is not performed.

[0095] The specific steps are as follows: S1: Perform washing and alkali treatment of PET fibers according to step S1 in Example 1.

[0096] S2: Form a polydopamine layer according to step S2 in Example 1.

[0097] S3: Fix the initiating group according to step S3 in Example 1.

[0098] S4: Perform two-stage aqueous surface-initiated polymerization according to step S4 in Example 1 to form a gradient zwitterionic brush layer.

[0099] S5: Perform polydiallyl dimethylammonium chloride treatment and heat treatment according to step S5 in Example 1.

[0100] S6: The PET fibers treated in step S5 are dried directly at 50°C to constant weight without being soaked in sodium chloride aqueous solution.

[0101] Performance testing Examples 1 to 4 and Comparative Examples 1 to 4 were selected as test samples, and unmodified PET fiber was set as a blank sample. The following detection methods were then used for testing.

[0102] Sample pretreatment: Each sample was equilibrated at 20℃ and 65% relative humidity for 24 hours before testing. Durability testing employed a standard washing procedure. After washing, samples were air-dried at room temperature and equilibrated again for 12 hours before retesting. The specific washing steps were as follows: Samples were cut into approximately 10 g pieces and placed in a laboratory thermostatic stirring washing apparatus. Deionized water was added at a liquor ratio of 1:50, along with a neutral detergent at a concentration of 1 g / L. The washing temperature was controlled at 40℃, and the washing time was 15 min, with moderate mechanical stirring intensity (100 r / min) during the washing process. After washing, two rinsing cycles were performed, each lasting 5 min, using deionized water without adding additional detergent. After rinsing, the samples were dehydrated and air-dried at room temperature. This process was recorded as one washing cycle, and repeated 20 times as needed for durability evaluation.

[0103] 1. Odor rating was assessed using a simple closed-container olfactory method. Samples were cut into 5 g pieces and placed in a 1 L covered glass container. The container was sealed at 50°C for 1 hour, then removed and cooled to room temperature for 5 minutes. Five participants then rated the odor on a scale of 0 to 5, where 0 indicates no odor, 1 indicates a slight odor, 2 indicates a identifiable but not pungent odor, 3 indicates a distinct odor, 4 indicates a strong odor, and 5 indicates a pungent or unpleasant strong odor. The average odor rating was taken. To eliminate randomness, the same sample was tested three times, and the average was used.

[0104] 2. Total volatile organic compounds (VOCs) were measured using a portable PID total VOCs analyzer. 2g samples were placed in sealed 500mL bags and equilibrated at 50℃ for 30 min. The PID probe was then used to measure the volume fraction of VOCs within the bag and convert it to the total VOCs release per sample mass, expressed in mg / kg. This method was repeated three times and the average was taken. While this method does not distinguish between specific components, it is suitable for comparing low-odor trends between different samples.

[0105] 3. Hydrophilicity and hydration layer stability were determined using the static water contact angle method. The fiber sample was spread and fixed on a glass slide, 2 μL of deionized water was added, and the static contact angle was recorded at 5 s. The average of the measurements at 5 different locations was taken.

[0106] 4. Low adsorption and antifouling ability are evaluated using two indicators. One is the methylene blue adsorption capacity test. Weigh 0.20 g of the sample and place it in 100 mL of methylene blue aqueous solution with an initial concentration of 20 mg / L. Shake at 25℃ and 150 rpm for 30 min, then take the supernatant and measure the concentration change at 664 nm using a UV-Vis spectrophotometer. Calculate the adsorption capacity per unit mass of sample, in mg / g. The second test was the stain removal level test. A simulated sebum stain system was used. An equal amount of artificial sebum standard solution (the formula of which is oleic acid, stearic acid, squalene and liquid paraffin mixed in a mass ratio of 3:3:2:2. Before use, the mixture was heated to a uniform liquid state at 40℃) was dropped onto the sample surface and allowed to stand for 1 hour. Then, it was washed with a standard detergent solution at 40℃ for 10 minutes. After drying, it was compared with a standard color card and scored from 1 to 5. A grade of 5 indicates that the stain is basically removed and a grade of 1 indicates that there is obvious residue. The test was repeated 3 times and the average value was taken.

[0107] 5. Durability evaluation was conducted using the performance retention rate before and after a washing cycle. The washing program used equivalent conditions for household machine washing: 40°C, 1 g / L neutral detergent, washing for 15 min, rinsing twice, spin-drying, and air-drying. The number of washing cycles was set to 10 and 20, and the changes in contact angle, methylene blue adsorption amount, and odor level were measured to characterize the stability of the brush layer and outer layer control structure under service conditions.

[0108] The test results are shown in Tables 1 and 2 below.

[0109] Table 1. Odor level, total volatile organic compound release, static water contact angle, and low adsorption antifouling index of different samples.

[0110] Table 2 Comparison of Washing Durability Data

[0111] As shown in Table 1, Examples 1 to 4 all exhibited significantly lower odor levels and total volatile organic compound (VOC) emissions than the blank PET, and were generally superior to the comparative examples. In Comparative Example 1, omitting the polydopamine layer formed by dopamine self-polymerization increased the odor level and VOC emissions, indicating that the lack of a polydopamine reaction platform leads to uneven initiation and polymerization layers, easily resulting in residues and migration, thus weakening the low-odor effect. In Comparative Example 2, changing the two-stage polymerization to a single-stage polymerization increased odor and VOC emissions, indicating that the gradient brush layer structure promotes reduced adsorption and residue. In Comparative Examples 3 and 4, omitting outer layer regulation and salt stabilization respectively, the odor index rebounded compared to the examples, indicating that subsequent regulation and stabilization steps contribute to suppressing odor accumulation caused by structural fluctuations during service.

[0112] Secondly, the contact angles of Examples 1 to 4 decreased significantly, indicating the formation of a stable hydrophilic hydration layer on the fiber surface. Simultaneously, the methylene blue adsorption amount decreased significantly, and the stain removal efficiency improved significantly, demonstrating a simultaneous improvement in low surface adsorption and antifouling performance. Comparative Example 1, due to the lack of a polydopamine interlayer, resulted in fixed initiation sites and unstable brush layer formation, manifesting as a rebound in contact angle, increased adsorption amount, and decreased stain removal efficiency. Although Comparative Example 2 had a lower contact angle, its adsorption amount and stain removal efficiency were inferior to the examples, indicating that forming only a homogeneous brush layer is insufficient to simultaneously achieve a hydration barrier and structural stability; a gradient brush layer structure enhances low adsorption and antifouling performance. Comparative Examples 3 and 4 initially showed contact angles and adsorption amounts close to the examples, but still exhibited some differences, suggesting that outer layer regulation and salt stabilization have a reinforcing effect on optimizing the outer conformation and interface state of the brush layer.

[0113] As shown in Table 2, Examples 1 to 4 maintained low contact angles, low adsorption amounts, and low odor levels after 20 washes, indicating that the formed multilayer structure has good stability under repeated washing conditions. Comparative Example 1 showed the most significant performance degradation after washing, indicating that the lack of a polydopamine intermediate layer significantly weakens the durability of the brush layer structure, leading to hydration barrier instability and a rebound in adsorption and odor. Comparative Example 2 showed a more significant increase in adsorption and odor rebound after washing, indicating that the gradient brush layer structure formed by two-stage polymerization plays a crucial role in resisting swelling and conformational collapse caused by washing. Although Comparative Examples 3 and 4 had good initial performance, their odor levels and adsorption amounts rebounded more significantly after washing, indicating that the outer layer polydiallyldimethylammonium chloride regulation and salt solution stabilization steps significantly contribute to improving the interfacial stability and service consistency of the outer brush layer.

[0114] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for surface modification of low-odor, environmentally friendly functional textile fibers, characterized in that, Includes the following steps: S1, polyethylene terephthalate fibers are washed with nonionic surfactants and then treated with alkali. S2, dopamine self-polymerization reaction is carried out on the fibers treated in step S1 in a weakly alkaline buffer system to form a polydopamine layer on the fiber surface; S3, through the reaction of haloacyl bromide compounds with polydopamine layers, fixes surface initiation groups on the fiber surface; S4, using an aqueous surface-initiated polymerization method, two-stage polymerization is carried out sequentially on the fiber surface to form a gradient-distributed zwitterionic polymer brush layer; S5, the fibers treated in step S4 are placed in an aqueous solution containing polydiallyldimethylammonium chloride and then fixed by heat treatment; S6, after being briefly treated with a salt solution and then dried, yields a low-odor, environmentally friendly functional textile fiber.

2. The surface modification method for low-odor, environmentally friendly functional textile fibers according to claim 1, characterized in that, The nonionic surfactant mentioned in step S1 is fatty alcohol polyoxyethylene ether, with a mass concentration of 1-5 g / L, a washing temperature of 40-80℃, and a washing time of 5-30 min.

3. The surface modification method for low-odor, environmentally friendly functional textile fibers according to claim 1, characterized in that, The alkali treatment in step S1 uses an aqueous sodium carbonate solution with a sodium carbonate concentration of 0.05–0.3 mol / L, a treatment temperature of 40–80℃, and a treatment time of 5–30 min.

4. The surface modification method for low-odor, environmentally friendly functional textile fibers according to claim 1, characterized in that, The dopamine self-polymerization reaction in step S2 is carried out in a buffer solution with a pH of 8.0 to 9.5, wherein the concentration of dopamine hydrochloride in the buffer solution is 0.5 to 5 g / L, the reaction temperature is 15 to 35°C, and the reaction time is 1 to 8 h.

5. The surface modification method for low-odor, environmentally friendly functional textile fibers according to claim 1, characterized in that, The haloacyl bromide compound mentioned in step S3 is bromoisobutyryl bromide, the reaction solvent is anhydrous alcohol solvent, an organic base is added to the system as an acid scavenger, and the reaction temperature includes a low temperature stage of 0-10℃ and a high temperature reaction stage of 20-30℃.

6. The surface modification method for low-odor, environmentally friendly functional textile fibers according to claim 1, characterized in that, In the first stage of polymerization in step S4, the monomer is sulfobetaine methacrylate with a concentration of 0.8–1.5 mol / L, and polyethylene glycol methacrylate and glycidyl methacrylate are introduced as comonomers.

7. The surface modification method for low-odor, environmentally friendly functional textile fibers according to claim 6, characterized in that, In the first polymerization stage, the amount of polyethylene glycol methacrylate is 0.5 to 3 mol relative to the molar amount of sulfobetaine methacrylate, and the amount of glycidyl methacrylate is 0.1 to 1.5 mol.

8. The surface modification method for low-odor, environmentally friendly functional textile fibers according to claim 1, characterized in that, In the second polymerization stage of step S4, the concentration of sulfobetaine methacrylate is 0.3–0.8 mol / L, and the amount of polyethylene glycol methacrylate is 2–8 mol%, in order to form a gradient distribution structure of the brush layer components along the fiber surface.

9. A low-odor, environmentally friendly functional textile fiber prepared by the modification method according to any one of claims 1 to 8, characterized in that, The fiber substrate includes polyethylene terephthalate fiber substrate, the surface of which is sequentially provided with: Surface layer activated by alkali treatment; A polydopamine intermediate layer covering the surface layer; An initiation group layer anchored to the surface of the polydopamine intermediate layer; A gradient-distributed zwitterionic polymer brush layer formed by surface-initiated polymerization; And the outermost layer of polydiallyldimethylammonium chloride control layer.

10. The low-odor, environmentally friendly functional textile fiber according to claim 9, characterized in that, The gradient-distributed zwitterionic polymer brush layer is formed by segmented surface-initiated polymerization of zwitterionic monomers with different concentrations and copolymerization ratios, and the thickness of the brush layer is continuously varied along the radial direction of the fiber.

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