Preparation method of marine regenerated PET (Polyethylene Terephthalate) environment-friendly clothing fastener

Abstract

The invention provides a preparation method of a marine regenerated PET environment-friendly clothing fastener, and relates to the technical field of manufacturing of environment-friendly clothing accessories. By using the marine regenerated PET material, the demand on raw plastic is reduced, and the consumption of non-renewable resources such as petroleum is reduced; plastic pollution in the ocean is effectively reduced, and the ocean ecological environment is protected; compared with the original PET material, the energy can be saved, and the carbon footprint is reduced; the marine regenerated PET fastener and the polyester garment fabric are homologous, so that the'material homogenization recovery 'of the garment can be realized; in addition, the cellulose nanocrystals (CNC) in the reinforced phase complex are derived from renewable resources and are biodegradable, so that the green sustainability of the environment-friendly fastener is further enhanced; the graphene-cellulose nanocrystal (CNC) complex is compounded and combined in a silane coupling agent ethanol solution to form an interpenetrating network structure, so that the strength, rigidity, toughness and heat resistance of the marine regenerated PET are synergistically improved by a reinforcing phase, and the tensile strength is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing environmentally friendly clothing accessories, and in particular to a method for preparing environmentally friendly clothing fasteners made of marine recycled PET. Background Art

[0002] Traditional fasteners are mostly made of urea-formaldehyde resin, polyester resin, and plastics such as ABS, PA, POM, and PMMA. With the implementation of environmental protection goals and measures, traditional fasteners that rely on petroleum-based raw materials have shown environmental disadvantages. Therefore, the use of recycled plastic fasteners in clothing accessories has gradually become popular, especially marine recycled PET fasteners. PET (polyethylene terephthalate) is derived from marine resources and contributes to marine environmental governance. Compared to virgin PET, it can save 52% of energy and reduce its carbon footprint by 80%. More significantly, marine recycled PET can be made into fasteners, which are derived from the same source as polyester fabric, enabling "material homogeneity recycling" for clothing. However, long-term exposure to ultraviolet light, saltwater, and microbial environments in the ocean can easily lead to molecular chain breakage in marine recycled PET, resulting in reduced mechanical and heat resistance properties after recycling. Therefore, marine recycled PET cannot meet the performance requirements of clothing fasteners. Therefore, we have addressed this issue and proposed a method for preparing environmentally friendly clothing fasteners made from marine recycled PET. Summary of the Invention

[0003] The present invention provides a method for preparing environmentally friendly clothing fasteners made of marine recycled PET, comprising the following steps: S1, marine recycled PET composite modification; S2, segmented temperature controlled injection molding.

[0004] As the preferred technical solution of this application, the composite modification of marine recycled PET includes: mixing marine recycled PET particles, graphene-cellulose nanocrystal (CNC) composite, plasticizer, antioxidant and lubricant according to mass percentage, and then melt-blending and granulating them through a twin-screw extruder to obtain a marine recycled PET composite modified material.

[0005] As the preferred technical solution of the present application, the temperature segmentation of the twin-screw extruder is set as follows: zone 1 220°C, zone 2 235°C, zone 3 240°C, and the screw speed is controlled at 200rpm.

[0006] As a preferred technical solution of this application, the marine recycled PET composite modified material contains: 80-95% marine recycled PET, 3-15% graphene-cellulose nanocrystal (CNC) composite, 1-8% plasticizer, 0.5-1.5% antioxidant and 0.5-1.5% lubricant.

[0007] As a preferred technical solution of the present application, the intrinsic viscosity of marine recycled PET is 0.75-0.85 dL / g; the graphene-cellulose nanocrystal (CNC) composite is ultrasonically treated in an ethanol solution of silane coupling agent KH560 for 30 minutes.

[0008] As a preferred technical solution of the present application, the graphene-cellulose nanocrystal (CNC) complex is ultrasonically treated in an ethanol solution of a silane coupling agent KH560 for 30 minutes, dried to evaporate the ethanol liquid, and the silane coupling agent KH560 is coated on the surface of the graphene-cellulose nanocrystal (CNC) complex.

[0009] As a preferred technical solution of the present application, the weight ratio of the graphene-cellulose nanocrystal (CNC) composite to the silane coupling agent KH560 ethanol solution is 1:4, the weight ratio of graphene to cellulose nanocrystals is 1:30, and the KH560 content in the silane coupling agent ethanol solution is 5% of the weight of the graphene-cellulose nanocrystal (CNC) composite.

[0010] As the preferred technical solution of the present application, the segmented temperature-controlled injection molding includes: matching the color of the marine recycled PET composite modified material, placing it in an injection molding machine, and using segmented temperature control to obtain environmentally friendly clothing fasteners.

[0011] As the preferred technical solution of this application, the injection molding barrel temperature of the injection molding machine is: 210°C in zone I, 225°C in zone II, and 230°C in zone III, the injection mold temperature is 70-100°C, the injection pressure is 80-100MPa, and the holding time is 10-15 seconds.

[0012] As the preferred technical solution of this application, environmentally friendly fasteners are used in clothing and bags, and are made from the same source as polyester fabrics.

[0013] Compared with the prior art, the present invention has the following beneficial effects: In the scheme of this application: 1. Environmental friendliness: The use of marine recycled PET reduces the demand for virgin plastics and the consumption of non-renewable resources such as petroleum. It effectively reduces plastic pollution in the ocean and protects the marine ecosystem. Compared with virgin PET materials, it saves energy and reduces the carbon footprint. Marine recycled PET fasteners are derived from the same source as polyester clothing fabrics, enabling "material homogeneity recycling" of clothing. In addition, the cellulose nanocrystals (CNC) in the reinforcement phase composite are derived from renewable resources and are biodegradable, further enhancing the green sustainability of the environmentally friendly fasteners. 2. Performance improvement: Graphene-cellulose nanocrystal (CNC) composites are compounded and combined in silane coupling agent ethanol solution to form an interpenetrating network structure, which enhances the synergistic effect of marine recycled PET on strength, rigidity, toughness and heat resistance. The tensile strength is improved and the heat deformation temperature (HDT) is high. 3. Interface optimization: The compounding of graphene and cellulose nanocrystals has a synergistic effect. The two-dimensional structure of graphene can provide anchoring points for CNC, forming an interpenetrating network structure. Combined with the surface modification treatment of silane coupling agent, it can enhance the interface bonding between the composite and the marine recycled PET matrix, promote the chemical bonding between the marine recycled PET and the composite, and avoid phase separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A flow chart of the method for preparing environmentally friendly clothing fasteners made of marine recycled PET provided in this application; Figure 2 A scale diagram of the marine recycled PET composite modified material provided for this application. DETAILED DESCRIPTION

[0015] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0016] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions therein may be combined with each other.

[0017] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0018] Example 1, please refer to Figure 1-Figure 2 A method for preparing environmentally friendly clothing fasteners made of marine recycled PET comprises the following steps: S1. Marine recycled PET composite modification: used to improve the mechanical properties and thermal stability of marine recycled PET to meet the high strength and high temperature resistance requirements of clothing fasteners; S2, segmented temperature controlled injection molding.

[0019] Furthermore, the composite modification of marine recycled PET includes: mixing marine recycled PET particles, graphene-cellulose nanocrystal (CNC) composites, plasticizers, antioxidants and lubricants according to mass percentages, and then melt-blending and granulating them through a twin-screw extruder to obtain a marine recycled PET composite modified material.

[0020] Furthermore, the temperature of the twin-screw extruder was set to 220° C. in zone 1, 235° C. in zone 2, and 240° C. in zone 3, and the screw speed was controlled at 200 rpm.

[0021] Furthermore, the marine recycled PET composite modified material comprises: 80% marine recycled PET, 15% graphene-cellulose nanocrystal (CNC) composite, 3.5% plasticizer, 1% antioxidant and 0.5% lubricant; The tensile strength of the injection molded fastener is 68MPa and the heat deformation temperature HDT reaches 110℃.

[0022] Furthermore, the intrinsic viscosity of marine recycled PET is 0.75-0.85 dL / g; the graphene-cellulose nanocrystal (CNC) composite is ultrasonically treated in an ethanol solution of silane coupling agent KH560 for 30 minutes; Marine recycled PET comes from the ocean and undergoes collection, classification, cleaning, crushing and reprocessing. Considering the performance requirements of environmentally friendly fasteners, the tackified marine recycled PET is preferred. Specifically, the raw materials of marine recycled PET come from marine plastic waste (such as discarded fishing nets, beverage bottles, etc.) and are produced through the following recycling processes: Collection and classification: screening of marine plastic waste made of PET; Cleaning and impurity removal: Soak and clean with 5% sodium hydroxide solution (60℃) for 2 hours to remove salt stains, microorganisms and oil stains; Crushing and granulation: crush to particle size 2-5mm, melt extrusion granulation; Viscosity enhancement: Use solid-phase viscosity enhancement technology or add 0.5% chain extender (such as ADR-4370S) through a twin-screw reactive extruder to increase the intrinsic viscosity to 0.75-0.85dL / g (GB / T 14190-2017 test).

[0023] Furthermore, graphene-cellulose nanocrystal composites are used as the reinforcement phase of marine recycled PET; Plasticizers can weaken the intermolecular forces in PET and increase the mobility of chain segments, thereby improving the flexibility and processability of marine recycled PET materials. Based on thermodynamic compatibility and intermolecular interactions, as well as the environmental and safety considerations of the plasticizer, acetyl tributyl citrate (ATBC) is the preferred choice. Specifically, the solubility parameter (SP value) of PET is 10.7 (cal / cm³)^0.5, while that of ATBC is 9.5-10.5 (cal / cm³)^0.5. The similar SP values ​​of the two ensure good compatibility and reduce the risk of plasticizer migration and precipitation. Furthermore, ATBC molecules contain polar ester groups (-COO-) and acetyl groups (-OAc), which can form dipole interactions or weak hydrogen bonds with the ester bonds (-COO-) of PET, reducing the cohesive energy between PET chain segments and increasing their freedom of movement. Furthermore, ATBC is a non-toxic and biodegradable citrate ester plasticizer that complies with food contact materials and environmental regulations. Antioxidants can inhibit the thermal oxidative degradation of marine recycled PET materials, delaying their aging, increasing their service life, and maintaining stable performance. Based on considerations of synergistic enhancement and dual protection, antioxidants 1010 and 168 are preferably compounded in a 1:1 ratio. Specifically, antioxidant 1010 is a hindered phenol antioxidant. During long-term use, the hydroxyl groups in its hindered phenol structure terminate free radical chain reactions, thereby delaying molecular chain breakage and mechanical property degradation caused by oxidation in marine recycled PET. Antioxidant 168 is a phosphite antioxidant. During the high-temperature processing stage of PET, trivalent phosphorus (P³⁺) decomposes hydroperoxides, preventing further decomposition to produce new free radicals and maintaining thermal stability during processing. The complementary combination of antioxidants 1010 and 168 forms a dual defense mechanism that covers the oxidation risks of marine recycled PET throughout its life cycle, from processing to use. Lubricants reduce friction, increase fluidity, and improve demoulding properties during the processing of marine recycled PET materials. Taking into account the high-temperature stability, low addition efficiency, and versatility of lubricants, PETS (pentaerythritol stearate) is the preferred lubricant. Specifically, the stearate groups in the PETS molecule form a polar-nonpolar interface in the marine recycled PET melt, with the polar end bonding to the PET molecular chain and the nonpolar end oriented outward, thereby reducing intermolecular friction and achieving synergistic internal and external lubrication. A relatively small addition amount can achieve a lubricating effect. Furthermore, the thermal decomposition temperature of PETS is as high as 400°C, and within the processing temperature range of marine recycled PET, there is almost no volatilization or degradation, and the lubrication effect can be stably maintained. In addition, PETS can also promote the uniform dispersion of graphene-cellulose nanocrystal complexes and has good compatibility with antioxidants.

[0024] Furthermore, the graphene-cellulose nanocrystal (CNC) composite was ultrasonically treated in an ethanol solution of the silane coupling agent KH560 for 30 minutes, and the ethanol liquid was dried to evaporate, and the silane coupling agent KH560 was coated on the surface of the graphene-cellulose nanocrystal (CNC) composite. Because graphene and cellulose nanocrystals are prone to agglomeration, it is difficult to evenly disperse and mix them in the ethanol solution of the silane coupling agent KH560, which affects the uniformity of the composite of graphene and cellulose nanocrystals and the surface treatment effect of the silane coupling agent. Therefore, ultrasonic treatment was adopted. The high-frequency vibration generated by the ultrasonic wave can generate strong eddy currents and shear forces in the ethanol solution of the silane coupling agent KH560, destroying the agglomeration force and achieving uniform dispersion and mixing of the graphene and cellulose nanocrystals. The ethanol liquid was dried to evaporate, and the silane coupling agent was coated on the surface of the composite.

[0025] Furthermore, the weight ratio of the graphene-cellulose nanocrystal (CNC) composite to the silane coupling agent KH560 ethanol solution is 1:4, the weight ratio of graphene to cellulose nanocrystals is 1:30, and the KH560 content in the silane coupling agent ethanol solution is 5% of the weight of the graphene-cellulose nanocrystal (CNC) composite; the graphene and cellulose nanocrystals are compounded to produce a synergistic effect. The two-dimensional structure of graphene can provide anchoring points for the rod-like structure of the cellulose nanocrystal CNC, forming an interpenetrating network structure, and combined with the surface modification treatment of the silane coupling agent to enhance the interface bonding with the marine recycled PET material.

[0026] Cellulose nanocrystals (CNCs) have high specific strength and a dense structure, with a modulus of up to 150 GPa, which can significantly improve the mechanical properties of marine-recycled PET. Graphene is a two-dimensional network of carbon nanomaterials with an extremely large specific surface area, ultra-high strength, and superb thermal and electrical conductivity, with a tensile strength of up to 130 GPa. Graphene can also improve the crystallization behavior and crystallization rate of PET, thereby increasing the thermal stability and mechanical strength of marine-recycled PET. Therefore, the synergistic combination of graphene and cellulose nanocrystals can achieve a simultaneous improvement in the strength, rigidity, toughness, and heat resistance of marine-recycled PET. In addition, the cellulose nanocrystals (CNC) in the composite are derived from renewable resources such as wood and cotton. Compared with traditional reinforcement materials such as carbon fiber, glass fiber or mineral fillers, CNC is lighter and more environmentally friendly, which also enhances the green sustainability of environmentally friendly fasteners. Furthermore, the segmented temperature-controlled injection molding includes: matching the color of the marine recycled PET composite modified material, placing it in an injection molding machine, and using segmented temperature control to obtain environmentally friendly clothing fasteners.

[0027] Furthermore, the injection barrel temperature of the injection molding machine is: 210°C in zone I, 225°C in zone II, and 230°C in zone III; the injection mold temperature is 70-100°C; the injection pressure is 80-100 MPa; and the holding time is 10-15 seconds.

[0028] Furthermore, environmentally friendly fasteners are used in clothing and bags, and are made from the same source as polyester fabrics.

[0029] Example 2. The difference between Example 2 and Example 1 is that the marine recycled PET composite modified material contains: 85% marine recycled PET, 10% graphene-cellulose nanocrystal (CNC) composite, 3.5% plasticizer, 1% antioxidant and 0.5% lubricant; the tensile strength of the injection-molded fastener is 65 MPa, and the heat deformation temperature HDT reaches 105°C. The rest are the same and will not be repeated.

[0030] Example 3. The difference between Example 3 and Example 1 is that the marine recycled PET composite modified material contains: 90% marine recycled PET, 5% graphene-cellulose nanocrystal (CNC) composite, 3.5% plasticizer, 1% antioxidant and 0.5% lubricant; the tensile strength of the injection-molded fastener is 62 MPa, and the heat deformation temperature HDT reaches 100°C. The rest are the same and will not be repeated.

[0031] Example 4 is a comparative example. Graphene-cellulose nanocrystal (CNC) composite is not used. The example comprises: 95% marine recycled PET, 3.5% plasticizer, 1% antioxidant, and 0.5% lubricant. The injection molded fastener has a tensile strength of 46 MPa and a heat deformation temperature (HDT) of 80°C.

[0032] Example 5, test method: Tensile Strength: ASTM D638; ASTM D638 is an international standard developed by the American Society for Testing and Materials (ASTM). It is primarily used to determine the tensile properties of plastics (including reinforced and unreinforced plastics), providing a scientific basis for the design, production, and quality control of plastic products. This standard specifies the measurement of the mechanical properties of plastic materials under stress through tensile testing, including key indicators such as tensile strength (yield and fracture), tensile modulus (elastic modulus), elongation, and Poisson's ratio. These are used to evaluate the durability, damage resistance, and processing performance of the materials. HDT: ASTM D648 (0.45 MPa load); ASTM D648 is a standard test method developed by the American Society for Testing and Materials (ASTM). It is mainly used to determine the heat deflection temperature (HDT) of plastics and elastic materials, that is, the temperature when the material deforms by 0.25 mm under a specific bending load. It is an important indicator for evaluating the heat resistance of plastics.

[0033] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0034] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned specific embodiments, or to make equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the present invention specification and drawings, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A method for preparing environmentally friendly clothing fasteners made of marine recycled PET, characterized in that: The following steps are involved: S1, marine recycled PET composite modification; S2, segmented temperature controlled injection molding.

2. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to claim 1, characterized in that: The composite modification of marine recycled PET includes: mixing marine recycled PET particles, graphene-cellulose nanocrystal (CNC) composites, plasticizers, antioxidants and lubricants according to mass percentages, and then melt-blending and granulating them through a twin-screw extruder to obtain a marine recycled PET composite modified material.

3. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to claim 2, characterized in that: The temperature sections of the twin-screw extruder were set as follows: zone 1 220°C, zone 2 235°C, zone 3 240°C, and the screw speed was controlled at 200 rpm.

4. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to claim 2, characterized in that: The marine recycled PET composite modified material comprises: 80-95% marine recycled PET, 3-15% graphene-cellulose nanocrystal (CNC) composite, 1-8% plasticizer, 0.5-1.5% antioxidant and 0.5-1.5% lubricant.

5. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to claim 4, characterized in that: The intrinsic viscosity of marine recycled PET is 0.75-0.85 dL / g; the graphene-cellulose nanocrystal (CNC) composite is ultrasonically treated in an ethanol solution of silane coupling agent KH560 for 30 minutes.

6. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to claim 5, characterized in that: The graphene-cellulose nanocrystal (CNC) composite is ultrasonically treated in an ethanol solution of a silane coupling agent KH560 for 30 minutes, and then dried to volatilize the ethanol liquid. The silane coupling agent KH560 is coated on the surface of the graphene-cellulose nanocrystal (CNC) composite.

7. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to claim 6, characterized in that: The weight ratio of the graphene-cellulose nanocrystal (CNC) composite to the silane coupling agent KH560 ethanol solution is 1:4, the weight ratio of graphene to cellulose nanocrystal is 1:30, and the content of KH560 in the silane coupling agent ethanol solution is 5% of the weight of the graphene-cellulose nanocrystal (CNC) composite.

8. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to any one of claims 1 to 7, characterized in that: The segmented temperature-controlled injection molding comprises: matching the color of the marine recycled PET composite modified material, placing it in an injection molding machine, and adopting segmented temperature control to obtain the environmentally friendly clothing fastener.

9. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to claim 8, characterized in that: The injection molding machine has an injection barrel temperature of 210°C in zone I, 225°C in zone II, and 230°C in zone III; an injection mold temperature of 70-100°C; an injection pressure of 80-100 MPa; and a holding time of 10-15 seconds.

10. The method for preparing environmentally friendly clothing fasteners made of marine recycled PET according to claim 8, characterized in that: Environmentally friendly fasteners are used in clothing and bags and are made from the same source as polyester fabrics.

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