Biobased multifunctional denim yarn with specific environmental degradation profile

Abstract

The present application relates to the technical field of environmental degradation material and high polymer compound composition, and discloses a bio-based multifunctional jean yarn with specific environmental degradation time effect, comprising the following steps: preparing a latent sacrificial phase, embedding an osmotic pressure regulator in a bio-based polyester resin; constructing a transition coupling layer component, mixing an interface anchor agent with a specific grafting rate and an inorganic stress concentrator; and using a composite process to make the latent sacrificial phase distributed in the main base material in the form of island phase, and forming a transition coupling layer at the interface, wherein the inorganic stress concentrator is used to concentrate external mechanical stress on the chemical anchoring point, induce interface disentanglement to produce a detached crack, make moisture penetrate to trigger swelling, and use swelling stress to drive structure collapse, and the degradation mode is changed from spontaneous linear hydrolysis to controlled threshold triggering, mechanical stability during service period is maintained, and efficient degradation from the surface to the inside after abandonment is realized.

Description

Technical Field

[0001] This invention relates to a bio-based multifunctional denim yarn with specific environmental degradation time, belonging to the technical field of environmentally degradable materials and polymer compound compositions. Background Technology

[0002] Currently, bio-based polyesters possess ecological compatibility and degradation potential, and are often used to prepare fibers. They utilize the breaking of the main chain ester bonds under the action of moisture to achieve degradation. Denim fabrics endure repeated washing, high-temperature drying, and continuous mechanical friction during their service life, and have strict requirements for mechanical integrity. Bio-based polyester degradation kinetics exhibit linear characteristics, and the main chain ester bonds enter an irreversible hydrolytic decay process from the material forming stage, causing fiber embrittlement and strength damage in the early stages of fabric service.

[0003] Introducing hydrophobic components or increasing crosslinking density to enhance hydrolysis resistance makes it difficult for materials to initiate degradation in landfill environments after disposal. This creates a fundamental conflict between long service life and rapid decomposition after disposal. Sacrificing degradation efficiency for stability leads to failure as service intensity increases, and there is a lack of a mechanism to convert the accumulated mechanical stress of washing into energy for degradation initiation. For example, Chinese invention patent CN119661494B discloses a method for preparing a bio-based cyclic ester monomer and its corresponding bio-based polyester. By inhibiting the olefin isomerization side reaction through a specific synthetic pathway, the melting point and strength of the bio-based polyester are increased, providing matrix protection for long service life. Although the above solution solves the static performance bottleneck, it is difficult to cope with the complex dynamic service environment of denim fabrics and improve chemical stability to extend service life. This makes it difficult for materials to initiate degradation in landfill environments after disposal, creating a fundamental conflict between long service life and rapid decomposition after disposal. Developing bio-based multifunctional denim yarn with specific environmental degradation time, and constructing an interface activation scheme driven by the accumulation of washing frequency within the polymer matrix, to maintain service stability while rapidly decomposing in the disposal environment, has become a current research and development need.

[0004] Therefore, the core of preparing bio-based multifunctional denim yarn with specific environmental degradation aging lies in developing a controllable triggerable environmental degradation polymer compound composition, constructing a composition system for induction of interfacial fatigue failure induced by cyclic mechanical stress accumulation, and resolving the contradiction between service stability and rapid collapse after disposal technology. This is the technical problem to be solved by this invention. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: a bio-based multifunctional denim yarn with specific environmental degradation time, comprising the following steps:

[0006] Step S1: Prepare a latent sacrificial phase with a particle size of 0.5 mm. m to 2.0 The osmotic pressure regulator of m is embedded in bio-based polyester resin and granulated to form latent sacrificial phase particles.

[0007] Step S2: Construct the transition coupling layer component by mixing the interface anchoring agent, inorganic stress concentrate and dispersing agent, and performing blending modification through an extruder to obtain the transition coupling layer component; wherein, the interface anchoring agent is a maleic anhydride-grafted polymer, and the maleic anhydride grafting rate of the interface anchoring agent is in the range of 1.2% to 2.5%.

[0008] Step S3, composite spinning processing: using hydrophobic bio-based resin as the main substrate, latent sacrificial phase particles are distributed in the main substrate in the form of island phases through a multi-component composite spinning device. A transition coupling layer is formed at the interface between the main substrate and the latent sacrificial phase particles using a transition coupling layer component, resulting in a fibrous bio-based multifunctional polymer composition. When the fibrous bio-based multifunctional polymer composition is subjected to external cyclic mechanical stress, the local stress field generated by inorganic stress concentrates transfers mechanical deformation energy to the chemical anchoring points formed by the interface anchoring agent in the transition coupling layer. When the energy generated by the cumulative number of mechanical stress cycles exceeds the molecular chain entanglement energy of the chemical anchoring points, the chemical anchoring points disentangle, leading to physical desorption of the transition coupling layer and generation of phase interface cracks. The phase interface cracks constitute physical channels for the external polar fluid medium to penetrate into the latent sacrificial phase, triggering the swelling of the osmotic pressure regulator to generate expansion stress pointing towards the core of the main substrate, thereby achieving the structural disintegration of the fibrous bio-based multifunctional polymer composition.

[0009] Preferably, the amount of inorganic stress concentrate added is 3% to 8% of the total mass of the transition coupling layer components; the inorganic stress concentrate is selected from at least one of nano-sized silica, nano-sized calcium carbonate, or layered silicates; in step S2, the inorganic stress concentrate is surface-activated using a dispersing agent, and the inorganic stress concentrate is distributed in a discontinuous nodal pattern in the transition coupling layer; when the fibrous bio-based multifunctional polymer composition is in a low-frequency mechanical stress alternation cycle, the chemical anchoring points dissipate energy through the viscoelastic deformation of the molecular chains.

[0010] Preferably, the bio-based polyester resin is selected from at least one of polylactic acid, polyhydroxyalkanoate, polybutylene succinate, or polybutylene adipate / terephthalate; the hydrophobic bio-based resin is selected from bio-based polyamide or bio-based polyester; the melting point of the main substrate is 15° higher than the melting point of the latent sacrificial phase. Up to 30 In step S3, the spinning temperature is controlled to allow the transition coupling layer to form a gradient molecular chain permeation structure on the island phase surface.

[0011] Preferably, the interface anchoring agent constructs an ion network locking structure through multivalent cation coordination bonds; when the fibrous bio-based multifunctional polymer composition is in a low ionic strength fluid environment, the ion network locking structure blocks the path of external polar fluid medium to penetrate into the latent sacrificial phase; when the fibrous bio-based multifunctional polymer composition is in a discarded environment, the ion network locking structure collapses due to the exchange between monovalent cations and multivalent cations in the external environment.

[0012] Preferably, the osmotic pressure regulator is selected from at least one of sodium polyacrylate, sodium carboxymethyl cellulose, or cassava starch modifier; in step S1, the osmotic pressure regulator is encapsulated inside the bio-based polyester resin by microencapsulation to limit the physical contact between the osmotic pressure regulator and moisture before the transition coupling layer is peeled off.

[0013] Preferably, the interfacial delamination criterion for fibrous bio-based multifunctional polymer compositions follows the following rules: ,in, To accumulate mechanical strain energy; This represents the number of mechanical stress cycles. The stress concentration factor is determined by the inorganic stress concentrate. For the first The objective stress amplitude generated by secondary stress alternation; The elastic modulus of the transition coupling layer; when When the molecular chain entanglement energy exceeds the chemical anchoring point, structural delamination occurs in the transition coupling layer.

[0014] Preferably, the molecular weight distribution index of the interface anchoring agent is between 1.8 and 2.5; in step S2, by controlling the dispersion shear rate of the interface anchoring agent in the main substrate, the interface anchoring agent is oriented and arranged on the surface of the latent sacrificial phase particles to form oriented chemical anchoring points.

[0015] Preferably, after step S3, the method further includes a heat-setting treatment of the obtained fibrous bio-based multifunctional polymer composition; the heat-setting treatment temperature is 80°C. Up to 120 The time is 30s to 120s; heat setting treatment is used to eliminate the residual internal stress generated in the spinning process of fibrous bio-based multifunctional polymer compositions.

[0016] Preferably, before step S3, the antibacterial agent and the UV-resistant agent are pre-blended with the hydrophobic bio-based resin; the antibacterial agent is selected from silver-loaded nano-zeolite or chitosan derivatives; the UV-resistant agent is selected from nano-zinc oxide or sodium lignosulfonate; the resulting fibrous bio-based multifunctional polymer composition retains a fracture strength of not less than 90% of the initial value during its service life.

[0017] Preferably, after the fibrous bio-based multifunctional polymer composition structure disintegrates, the core of the main substrate is exposed to the disposal environment; in the disposal landfill environment, the degradation rate of the fibrous bio-based multifunctional polymer composition is increased to more than 5 times the linear hydrolysis rate during service life by utilizing the local osmotic pressure gradient established by the osmotic pressure regulator.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. In multifunctional denim yarn, the composition constructs a chemical pin structure with specific peeling function between the main substrate and the latent sacrificial phase through an interface anchoring agent. Combined with inorganic stress concentrates distributed at the interface, the mechanical deformation energy of the washing cycle is converted into fatigue loss of the molecular chains of the interface transition layer. The degradation initiation mode changes from spontaneous linear hydrolysis to a controlled threshold triggering mode. Before the stress accumulation reaches the threshold, the interface layer remains sealed, blocking the water penetration path and avoiding the problem of excessively rapid strength decline during the service life of the material, thus ensuring the mechanical stability of the fabric under frequent washing.

[0020] 2. The latent sacrificial phase embeds an osmotic pressure regulator that couples with the interfacial fatigue cracks. Moisture penetration triggers a swelling process, establishing a local osmotic pressure gradient in the micro-nano space. This generates expansion stress pointing towards the core of the main substrate. The expansion stress acts as a physical wedge, driving the interfacial microcracks to spontaneously extend into the deeper layers of the composition. The degradation process overcomes the limitations of the external humidity diffusion rate, achieving disintegration from the surface to the interior, thus improving the degradation consistency of heavy fabrics in arid landfill environments. The interfacial anchoring agent constructs an ion network locking structure through multivalent cation coordination bonds, maintaining the chemical seal of the interface in low-ionic-strength washing environments. In disposal environments, it induces the instantaneous collapse of the ion network through external monovalent cation exchange. This dual verification mechanism enhances the composition's resistance to accidental degradation under complex service conditions.

[0021] 3. The composition utilizes inorganic stress concentrates to modify the surface of bio-based organic acid salts to generate a water-attracting effect. After the interface cracks open, they preferentially ionize, releasing carboxyl ions to form a dynamic autocatalytic system with the hydrolysis products of the sacrificial phase at the crack tip. This reduces the activation energy of the hydrolysis reaction of the main substrate, transforming passive water diffusion into active recruitment of the degradation reaction, eliminating the induction delay of the degradation initiation stage, and enabling the material to exhibit instantaneous response characteristics from steady state to collapse state under environmental stress. By adjusting the distribution of grafted monomers in the interface anchoring agent and the entanglement density of molecular chains in the main substrate, a damping energy dissipation layer is formed at the phase interface. The composition absorbs the strain energy in the early stage of service by utilizing molecular viscoelastic deformation. The composition has the ability to logically identify the frequency of mechanical loads, materializing the washing frequency into measurable fatigue damage, and achieving life cycle management of bio-based materials. Attached Figure Description

[0022] Figure 1This is a flowchart illustrating the preparation and degradation mechanism of the bio-based multifunctional denim yarn with specific environmental degradation time according to the present invention.

[0023] Figure 2 This is a graph showing the relationship between the grafting rate of the interface anchoring agent of the present invention and the strength retention rate and degradation rate multiple after washing.

[0024] Figure 3 This is a logic diagram showing the environmental response and structural evolution of the present invention at different deployment nodes throughout its entire lifecycle. Detailed Implementation

[0025] The following disclosure is intended to provide a more detailed description of the present invention. The following embodiments are only for explaining the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0026] This invention provides a bio-based multifunctional denim yarn with specific environmental degradation aging, comprising a continuous phase composed of a bio-based polyester substrate, a latent sacrificial phase polymer distributed in an island structure within the continuous phase, and a transition coupling layer component distributed at the interface between the two phases. Essentially, it is a biodegradable polymer composition. The transition coupling layer component consists of an interface anchoring agent and inorganic stress concentrates positioned at the interface. This composition senses the accumulation of external cyclic mechanical stress and generates fatigue microcracks, thereby opening physical channels for moisture to penetrate into the latent sacrificial phase and triggering the establishment of an internal osmotic pressure gradient, ultimately resulting in structural collapse from the surface inwards. In the preparation of the latent sacrificial phase, a bio-based polyester with a number-average molecular weight of 3000 to 5000 is selected as the shell layer, and a bio-based polyether with a number-average molecular weight of 15000 to 25000 is selected as the core layer. Particles with a particle size of 0.5 mm are embedded within the shell layer. Up to 2.0 The osmotic pressure regulator is selected from at least one of sodium polyacrylate, sodium carboxymethyl cellulose, or cassava starch modifier. The low molecular weight of the shell ensures its preferential enrichment on the surface of the island structure during subsequent melt spinning, forming a dense hydrophobic coating layer to block external fluids from penetrating into the highly hydrophilic core layer. The osmotic pressure regulator is encapsulated within the resin using microencapsulation technology, thereby limiting its contact with moisture before interfacial delamination occurs. To construct the transition coupling layer, an interfacial anchoring agent is mixed with inorganic stress concentrates and blended. The interfacial anchoring agent is maleic anhydride-grafted polylactic acid with a maleic anhydride grafting rate in the range of 1.2% to 2.5%. The number-average molecular weight of the interfacial anchoring agent is... Number average molecular weight of the main substrate Satisfying the relation The critical stripping work of the interface is established by the physical entanglement between molecular chain segments. The inorganic stress concentrate is selected from nano-sized calcium carbonate that has undergone surface activation treatment, and its addition amount is 1 to 3 parts. The inorganic stress concentrate is distributed at the interface between the main substrate and the sacrificial phase. It is used to sense external mechanical deformation and generate a stress field locally at the interface, thereby inducing the generation of micro-nano-scale fatigue cracks at the interface.

[0027] Needle-shaped nano-calcium carbonate with an average length-to-diameter ratio of 1.5 to 3.0 and an interfacial anchoring agent were placed in a co-rotating twin-screw extruder with an length-to-diameter ratio of 40:1, and the screw speed was set to 450 to 550 rpm. Control the residence time of the material in the extruder to 60 to 120 seconds. High shear fields are used to deagglomerate nanoparticles, allowing the surface to be wetted by an interfacial anchoring agent. Dispersing agents are used to reduce interparticle van der Waals forces, resulting in a discontinuous, nodal distribution of inorganic stress concentrates within the transition coupling layer matrix. Scanning electron microscopy is used to observe the cross-sectional morphology of the components, revealing the average dispersion spacing of the inorganic stress concentrates. Mean free path of the main substrate molecular chain satisfy The proportional relationship, when subjected to external cyclic mechanical loads, generates local stress field deformation, which directionally transmits the mechanical deformation energy to the molecular chain entanglement points formed by the interface anchoring agent, thus establishing the cumulative mechanical strain energy. This is transformed into the transmission path of the interface deentanglement energy, here. The distance between the centroids of adjacent inorganic stress condensers. Mean free path of the molecular chain of the main substrate, in units of To establish the expansion stress generated by the osmotic pressure regulator To quantify the correlation between compositional structural collapse and the system, a swelling stress calibration procedure based on osmotic pressure gradient was performed, selecting the swelling pressure constant of the osmotic pressure regulator in a polar medium. Combined with the volume fraction of the latent sacrificial phase in the host substrate The expansion stress driving the microcracks to propagate into the main substrate was determined using mathematical expressions. The mathematical expression is as follows: ,in, The resulting expansion stress is expressed in units of . ; This is a characteristic constant, the value of which is determined by the selection of the osmotic pressure regulator; in this embodiment, it is taken as 4.5. ; The value of this parameter is the volume fraction of the latent sacrificial phase in the composition, and is set between 0.15 and 0.35.

[0028] In the composite spinning process, hydrophobic bio-based resin is used as the main substrate. Through multi-component composite spinning equipment, latent sacrificial phase particles are distributed in the main substrate in the form of island phases. The melting point of the main substrate is 15°C higher than that of the latent sacrificial phase. Up to 30 By controlling the spinning temperature, a gradient molecular chain permeation structure is formed on the island phase surface of the transition coupling layer. After spinning, at 80°C... Up to 120 Heat setting is performed at a temperature of 30s to 120s to eliminate residual stress inside the fiber, ensuring that the composition has stable mechanical properties during service, with a breaking strength retention rate of not less than 90% of the initial value; the geometric diameter and aspect ratio of the spinneret flow channel are adjusted to control the shear rate generated by the melt fluid at the spinneret wall. At 1500 Up to 3500 Within the interval, the maleic anhydride functional groups in the interfacial anchoring agent are driven to displace in situ toward the host substrate by the shear force of the flow field, forming a 50mm thick layer at the interface between the latent sacrificial phase and the host substrate. Up to 150 The gradient molecular chain permeation structure; the thickness data was obtained by measuring ruthenium tetroxide-stained ultrathin sections of the fiber under a transmission electron microscope, and combined with spinning temperature control to maintain it 15°C above the melting point of the latent sacrificial phase. Up to 30 The range drives the thermal diffusion motion of molecular chain segments at the interface and establishes the initial molecular chain entanglement energy. Initial molecular chain entanglement energy Determined through dynamic mechanical-thermal analysis of the transition coupling layer, the energy integral value at the intersection of the loss modulus and the storage modulus is defined as the energy integral value at the point where the loss modulus and storage modulus intersect, with units of [unit missing]. To eliminate interface response aging deviations caused by processing flow field fluctuations; the interface delamination criterion of the composition under external cyclic mechanical stress follows the following relationship: ,in, To accumulate mechanical strain energy; This represents the number of mechanical stress cycles. The stress concentration factor is determined by the inorganic stress concentrate. For the first The objective stress amplitude generated by secondary stress alternation; The elastic modulus of the transition coupling layer; when the accumulated mechanical strain energy When the molecular chain entanglement energy exceeds the chemical anchoring point, the transition coupling layer undergoes structural delamination and generates phase interface cracks. These phase interface cracks form a path for external fluids to penetrate into the sacrificial phase, triggering the osmotic pressure regulator to absorb water and swell, generating expansion stress pointing towards the interior of the main substrate. This expansion stress drives the microcracks to extend deeper into the main substrate, increasing the degradation rate to more than 5 times the service life.

[0029] The interface anchoring agent constructs an ion network locking structure through multivalent cation coordination bonds. In low-ionic-strength washing or storage environments, the ion network blocks moisture penetration pathways through chemical locking, preventing premature degradation. When the composition is placed in a disposal soil environment containing monovalent cations, ion exchange occurs between the monovalent and multivalent cations, causing the ion network locking structure to collapse instantaneously. The chemical energy released in this process, combined with the physical effects of interfacial fatigue cracks, causes the latent sacrificial phase to fully desorb from the host substrate and be exposed, thereby triggering a threshold-based degradation response. This ensures that denim yarn can be rapidly degraded and disposed of after disposal, demonstrating the excellent environmental degradability of this polymer composition. The degradation response is based on the critical ion strength at which the collapse occurs. The chemical potential energy is pre-set, and the fibrous composition obtained by composite spinning is immersed in a solution with a concentration of 0.05 to 0.15. A multivalent cation precursor solution was used, and the immersion time was adjusted to allow the carboxyl groups on the side chains of the interfacial anchoring agent to form chelate nodes with calcium ions. The mass fraction of calcium in the fiber cross-section was determined using inductively coupled plasma mass spectrometry, and the precursor solution concentration was adjusted accordingly to optimize the ion coordination saturation index. Maintaining the ion network interlocking structure within the range of 0.85 to 0.95 establishes its physical blocking capability under low ionic strength environments, providing a pre-set chemical potential energy gradient for the ion exchange process after entering abandoned soil environments containing monovalent cations, driving the degradation triggering command to execute under chemical environmental excitation. It is the ratio of the number of carboxyl groups that have participated in coordination to the total number of carboxyl groups.

[0030] Example 1: In the application scenario of bio-based denim yarn where there is a high conflict between service stability and disposal degradation efficiency, the bio-based multifunctional denim yarn composition consisting of polyester main substrate, latent sacrificial phase and transition coupling layer exhibits nonlinear retention of mechanical integrity after undergoing no less than 50 cycles of mechanical washing. Conventional bio-based polymer materials exhibit linear performance decay that begins from the material forming stage due to the erosion of the main chain ester bonds by polar media, resulting in the inability to balance the strength loss in the early stage of service through conventional chemical stabilization methods. However, the composition prepared by the present invention embeds a latent sacrificial phase in the continuous phase consisting of polyester main substrate and utilizes the entanglement locking effect of the transition coupling layer to physically isolate external moisture from sensitive degradation sites, so that the fiber breaking strength retention rate is above 90% after 50 washing cycles.

[0031] When alternating mechanical loads generated during external washing are applied to the fiber body, inorganic stress concentrators distributed at the phase interface perform a transduction operation to concentrate the strain energy of the system towards local chemical anchoring points. The transition coupling layer, through its elastic modulus... Number-average molecular weight of the main substrate The mechanical adaptation mechanism, in the accumulation of mechanical strain energy Below the fatigue threshold, energy is dissipated by the viscoelastic deformation of the molecular chains, where the cumulative mechanical strain energy is calculated according to the following formula: ,in, To accumulate mechanical strain energy, The number of mechanical stress cycles, The stress concentration factor is determined by the inorganic stress concentrate. For the first The objective stress amplitude generated by secondary stress alternation The elastic modulus of the transition coupling layer is used to achieve coordinated control of service life stability and efficient collapse after disposal by changing the criterion for degradation initiation from a single time dimension to a mechanical work accumulation dimension, thus resolving the technical contradiction that materials cannot degrade due to excessive stability; with the number of washing cycles... As the chemical anchoring points disentangle, phase interface cracks are generated in the transition coupling layer. After entering the disposal stage, moisture reaches the osmotic pressure regulator embedded in the latent sacrificial phase along the crack channels. The osmotic pressure gradient generated by dissolution produces expansion stress pointing towards the core of the main substrate inside the fiber, which in turn drives the crack to propagate and triggers the global collapse of the composition structure. This process changes the boundary conditions for degradation initiation, increasing the mass loss rate in the disposal environment by more than 5 times compared to the service life, thus completing the threshold degradation initiation driven by environmental response.

[0032] Example 2: To verify the mechanical stability and degradation triggering mechanism of bio-based multifunctional denim yarn with specific environmental degradation aging under varying working conditions, an experimental environment was constructed using a circulating washing platform with dynamic stress monitoring function and a constant temperature hydrolysis device. The raw data used in the experiment were collected by a precision strain sensor with a resolution of not less than 0.01N and a sampling frequency of 100Hz. The sampling frequency was set based on the trade-off between capturing transient impact pulses during the washing process and reducing the computational load. When the rotation speed of the simulated washing machine was between 30rpm and 60rpm, signal aliasing was avoided and the stress concentration factor was ensured. To ensure completeness of the extraction, the sampling frequency was set to its lower limit of 100Hz. To mitigate electromagnetic noise and fluid pulsation interference in the test environment, a low-pass filter with a cutoff frequency of 20Hz was connected at the signal processing end to ensure the accumulation of mechanical strain energy. Calculate the purity of the basis; in the sample preparation stage, select the number-average molecular weight. Using polylactic acid (PLA) with a molecular weight of 80,000 as the main substrate, five test sample groups were prepared according to the aforementioned procedure. The grafting rate of the maleic anhydride in the interfacial anchoring agent and the content of inorganic stress concentrates exhibited a gradient distribution. The number of washing cycles was set. For 50 cycles, the environmental stress amplitude The simulated real washing conditions were set to 2.5N to 5.0N. During the test, the fiber breaking strength retention rate and the mass loss rate after disposal were monitored in real time, as shown in Table 1.

[0033] Table 1: Performance Characterization Data under Different Component Gradients

[0034]

[0035] Table 1 shows the inflection point characteristics of performance changes with parameters. When the grafting rate of the interface anchoring agent is less than 1.2%, control group 1, due to insufficient chemical anchoring point density, accumulates mechanical strain energy. Premature disentanglement occurs under the influence of the grafting agent, resulting in a service life strength retention rate of less than 70%. When the grafting rate exceeds 2.5%, although control group 2 is stable, the excessive molecular chain entanglement creates a physical shielding effect, hindering the penetration of water into the latent sacrificial phase, causing the degradation rate to decrease to 1.8, which is lower than the 5-fold threshold required by this invention. The preparation procedure of bio-based multifunctional denim yarn with specific environmental degradation time includes blending and granulating bio-based polyester, bio-based polyether, and micronized anhydrous sodium citrate at 170°C using a twin-screw extruder to obtain latent sacrificial phase particles, and then grafting maleic anhydride-grafted polylactic acid and nano-calcium carbonate at 190°C. The transition coupling layer components were prepared by mixing and then spun using a multi-component composite spinning device at 220°C. At a certain temperature, the latent sacrificial phase is distributed in an island structure within the polylactic acid substrate, forming a gradient molecular chain penetration structure at the interface. The spun product is then processed at 100°C. A 60-second heat setting treatment is performed to eliminate processing stress and solidify the phase structure, ensuring the mechanical integrity of the final product after 50 washing cycles; when the accumulated mechanical strain energy... Satisfying the criteria At that time, inorganic stress condensers induced the generation of micro- and nano-cracks in the transition coupling layer. To accumulate mechanical strain energy, The number of mechanical stress cycles, Stress concentration factor The objective stress amplitude, The elastic modulus of the transition coupling layer; after entering the abandoned soil, the external monovalent cations touch the interface cracks and perform ion exchange, causing the coordination structure to collapse instantaneously. Water infiltration triggers the osmotic pressure regulator to generate expansion stress. This stress, together with the interface fatigue effect, drives the rapid disintegration of the fiber structure from the surface to the inside, increasing the degradation rate by more than 5 times compared to the linear hydrolysis rate during service life, thus achieving a controlled conversion from the service state to the degradation state.

[0036] Example 3: This example combines Figures 1 to 3 This describes a bio-based multifunctional denim yarn with specific environmental degradation time, such as... Figure 1 As shown, using hydrophobic bio-based resin as the main substrate, steps S1 and S2 are performed in parallel. Step S1 involves preparing a latent sacrificial phase by embedding an osmotic pressure regulator in the bio-based polyester resin and granulating it to form particles. Step S2 involves constructing a transition coupling layer component by mixing an interface anchoring agent and inorganic stress concentrates, controlling the grafting rate of the interface anchoring agent to be between 1.2% and 2.5%. Step S3, composite spinning, distributes the latent sacrificial phase as islands within the main substrate and utilizes the transition coupling layer component to form an interface layer, thereby forming a fibrous bio-based multifunctional polymer composition at the interface. A transition coupling layer and chemical anchoring points are formed, and the service-life material generates a cumulative mechanical stress response under the action of external cyclic mechanical stress. The inorganic stress condenser generates a local stress field and transfers energy to the chemical anchoring points. At this time, the system executes judgment logic. If the accumulated energy is greater than the molecular chain entanglement energy, it leads to interface failure and crack generation. Specifically, the chemical anchoring points are de-entangled and the transition coupling layer is physically desorbed, which in turn generates phase interface crack channels and allows water to penetrate. Finally, in the stage of structural disintegration and abandonment of the environment, the external fluid penetration contact triggers the swelling of the regulator and uses the expansion stress to drive the structure to collapse from the surface to the inside.

[0037] like Figure 2 As shown in the figure, this graph illustrates the effect of different interfacial anchoring agent grafting rates on material properties. The horizontal axis represents the interfacial anchoring agent grafting rate, with values ​​of 0.8%, 1.2%, 1.8%, 2.5%, and 3.2%. The left vertical axis represents the strength retention rate after 50 washes (in percentage), and the right vertical axis represents the ratio of the degradation rate after disposal to the service life multiple. The solid line in the graph represents the trend of the strength retention rate after 50 washes, which increases with the grafting rate, reaching 68% at 0.8% and peaking at 3.2%. The dashed line represents the trend of the degradation rate multiple after disposal, which increases with the grafting rate from 0.8% to 2.5%, peaking at 2.5% and decreasing at 3.2%. Figure 3As shown, in the deployment node, i.e., the manufacturing environment, latent sacrificial phase containing osmotic pressure regulators and bio-based polyester resin, and transition coupling layer components containing interface anchoring agents and inorganic stress concentraters are processed through high-temperature melting and physical blending. Gradient molecular chain permeation structure control and composite processing are then performed using multi-component composite spinning equipment to obtain bio-based multifunctional denim yarn with eliminated residual internal stress. This yarn then enters the distribution and service stages. In the deployment node, i.e., the service application environment, during cyclic washing or in low ionic strength conditions, ion network locking is used to achieve sealing and block moisture permeation paths, while mechanical stress accumulation occurs through the use of inorganic... The mechanical stress concentrate generates local stress field deformation, and when the accumulation does not exceed the threshold, it dissipates energy through viscoelastic deformation of molecular chains to maintain a high fracture strength retention rate. When the accumulation exceeds the threshold, it enters the critical point, i.e., fatigue threshold triggering. The chemical anchoring point undergoes disentanglement and generates phase interface cracks. Finally, after being abandoned or landfilled, it enters the deployment node, i.e., disposal and environmental soil landfill or monovalent cations. Monovalent cations in the environment exchange with polyvalent cations, triggering ion network collapse and failure of chemical locking structure, opening the channel and causing the osmotic pressure regulator to swell and generate expansion stress pointing towards the core.

[0038] Example 4: In the calibration procedure for the mechanical fatigue life of high-count combed bio-based denim yarn, the geometric parameters and interface distribution of inorganic stress concentrators are obtained through an optical lens system. Needle-shaped nano-calcium carbonate with an average aspect ratio in the range of 1.5 to 3.0 is selected as the inorganic stress concentrator. The average dispersion spacing of the concentrators in the transition coupling layer is measured. Combined with the mean free path of the main substrate The stress concentration factor is determined using mathematical expressions. The mathematical expression is as follows: ,in, Stress concentration factor; Mean free path of the main substrate, in units of ; The average dispersion spacing of inorganic stress concentrates, in units of Stress concentration factor The transfer coefficient is used to quantify the conversion of external mechanical loads to the entanglement points of the interface anchoring agent molecular chains, ensuring the directional guidance of washing strain energy.

[0039] When performing composite spinning, the flow channel geometry of the composite spinning assembly is adjusted to adjust the shear rate of the melt fluid at the spinneret wall. Maintain at 1500 Up to 3500 Within this range, the shear stress generated by this shear rate exceeds the elastic restoring force of the interface anchoring agent molecular chains, driving the maleic anhydride functional groups in the interface anchoring agent to undergo directional displacement towards the host substrate. This physical migration process generates a gradient molecular chain infiltration structure in situ on the island phase surface, with an average thickness of 50 mm. Up to 150 In between, a critical peeling work benchmark for the interface layer is established, locking the energy dissipation path of the fiber under mechanical load within the transition coupling layer; and to address random impact interference during the washing monitoring process, the system operates an energy accumulation procedure based on a sliding time window, setting the sliding time window. 3600 In this sliding time window The objective stress amplitude of the internally collected fiber The system sets the pulse extraction threshold. Pulse extraction threshold The value is taken as 3 times the variance of the environmental background noise, when the objective stress amplitude is collected. satisfy Under certain conditions, the objective stress amplitude Including cumulative mechanical strain energy The summation term; this logic judgment procedure is used to shield the interference generated by ineffective cyclic mechanical loads, ensure that the degradation trigger command is issued after effective washing cycle accumulation, so that the fracture strength retention rate of the material during its service life is not less than 90% of the initial value, while in the disposal environment, external monovalent cations touch the interface cracks and perform ion exchange, triggering the coordinated collapse of the ion network locking structure, so as to achieve controlled control of degradation time.

[0040] Example 5: In the offline calibration procedure for physical criteria executed for different raw material batches, the system establishes the molecular chain entanglement energy benchmark value by performing dynamic mechanical-thermal analysis on the transition coupling layer, and prepares a layer with a thickness of 1.0. The composition standard test piece, at a frequency of 10 Furthermore, the intersection of the loss modulus and the storage modulus was measured in a controlled oscillating flow field with a strain amplitude of 0.1%, and the energy integral corresponding to this intersection was defined as the initial molecular chain entanglement energy. Initial molecular chain entanglement energy maleic anhydride grafting rate with interface anchoring agent Satisfying linear mapping relationship ,in, The initial molecular chain entanglement energy, in units of ; The entanglement enhancement factor is determined by the molecular weight distribution index of the main substrate, and is set to 16.5 in this embodiment. The matrix background energy is expressed in units of 1. ; The grafting rate of maleic anhydride is determined by performing a pre-energy scan on each batch of raw materials to establish the cumulative mechanical strain energy. The physical threshold that triggers the stripping of the transition coupling layer.

[0041] In the pre-deployment debugging stage of the composition, the system performs a chemical potential energy pre-setting operation for the ion network locking structure. The prepared composition is immersed in a multivalent cation precursor solution to perform coordination equilibrium treatment. By adjusting the immersion time, the carboxyl groups of the interfacial anchoring agent side chain form chelate nodes with calcium ions. The system sets the ion coordination saturation index. The calcium content in the fiber cross-section was measured using an inductively coupled plasma mass spectrometer, ranging from 0.85 to 0.95. The concentration of the precursor solution was adjusted based on the measurement results. The difference between the loading concentration of polyvalent cations and the background conductivity of the environment determined the chemical potential energy gradient of ion exchange during the disposal stage. This adjustment process provides chemical energy reserves for instantaneous collapse after entering the disposal soil, while maintaining the daily stability of the ion network.

[0042] Example 6: In the system state calibration procedure deployed in a climate zone with high humidity differences, the system obtains the dynamic elastic modulus of the transition coupling layer through an environmental simulation device. With real-time relative humidity The quantitative correlation mapping was used to adjust the equilibrium moisture regain of bio-based multifunctional denim yarn under controlled conditions, and the relative humidity was set. With humidity gradients of 30%, 60%, and 90%, the energy storage modulus of the transition coupling layer was collected using a dynamic mechanical analyzer at each humidity equilibrium point to establish the humidity sensitivity coefficient. The cumulative mechanical strain energy is corrected through mathematical expressions. The calculation benchmark is expressed mathematically as follows: ,in, This is the corrected dynamic elastic modulus, in units of... ; The elastic modulus under standard conditions, in units of . ; The humidity sensitivity coefficient is 0.12. This represents the real-time relative humidity percentage; the procedure eliminates the degradation trigger threshold shift caused by environmental humidity fluctuations by establishing a functional relationship between physical properties and the service environment.

[0043] In the ion triggering threshold calibration process performed on heterogeneous abandoned soil environments, the system establishes the critical ion intensity for the collapse of the ion network locking structure through impedance spectroscopy analysis. Fiber samples with different polyvalent cation loading concentrations were prepared, and the chemical characteristics of soil pore water were simulated in a controlled electrolyte solution. The monovalent cation strength was set. The gradient is 0.05 0.15 and 0.50 The interfacial charge transfer resistance of the transition coupling layer is monitored in real time using a precision impedance meter. When the interface charge transfer resistance When a magnitude-splitting decrease occurs, the corresponding monovalent cation strength is defined as the collapse critical ionic strength. Collapse critical ionic strength With the loading concentration of multivalent cations Satisfying linear mapping relationship ,in, The critical ionic strength for collapse, in units of ; This is the ion exchange efficiency factor, which is set to 0.45 under the current operating conditions. The loading concentration of polyvalent cations, in units of This process establishes a mapping model between the physical response of the interface and the chemical excitation of the external environment, ensuring that the instantaneous desorption rate of the material after entering a high-salinity disposal environment remains more than 5 times that of its service life, thus achieving a physical and chemical closed loop of degradation response.

[0044] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bio-based multifunctional denim yarn with specific environmental degradation time, characterized in that, Includes the following steps: Step S1: Prepare a latent sacrificial phase with a particle size of 0.5 mm. m to 2.0 The osmotic pressure regulator of m is embedded in bio-based polyester resin and granulated to form latent sacrificial phase particles. Step S2: Construct the transition coupling layer component by mixing the interface anchoring agent, inorganic stress concentrate and dispersing agent, and performing blending modification through an extruder to obtain the transition coupling layer component; wherein, the interface anchoring agent is a maleic anhydride-grafted polymer, and the maleic anhydride grafting rate of the interface anchoring agent is in the range of 1.2% to 2.5%. Step S3, composite spinning processing: using hydrophobic bio-based resin as the main substrate, latent sacrificial phase particles are distributed in the main substrate in the form of island phases through a multi-component composite spinning device. A transition coupling layer component is used to form a transition coupling layer at the interface between the main substrate and the latent sacrificial phase particles to obtain a fibrous bio-based multifunctional polymer composition. When the fibrous bio-based multifunctional polymer composition is subjected to external cyclic mechanical stress, the local stress field generated by the inorganic stress concentrates is used to transfer the mechanical deformation energy to the chemical anchoring points formed by the interface anchoring agent in the transition coupling layer. When the energy generated by the cumulative number of mechanical stress cycles exceeds the molecular chain entanglement energy of the chemical anchoring points, the chemical anchoring points are deentangled, resulting in physical desorption of the transition coupling layer and generation of phase interface cracks. The phase interface cracks form a physical channel for the external polar fluid medium to penetrate into the latent sacrificial phase, and generate expansion stress pointing towards the core of the main substrate by triggering the swelling of the osmotic pressure regulator.

2. The bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, The amount of inorganic stress concentrate added is 3% to 8% of the total mass of the transition coupling layer components; the inorganic stress concentrate is selected from at least one of nano-sized silica, nano-sized calcium carbonate, or layered silicates; in step S2, the inorganic stress concentrate is surface-activated using a dispersing agent, and the inorganic stress concentrate is distributed in a discontinuous nodal pattern in the transition coupling layer; when the fibrous bio-based multifunctional polymer composition is in a low-frequency mechanical stress alternation cycle, the chemical anchoring points dissipate energy through the viscoelastic deformation of the molecular chains.

3. The bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, The bio-based polyester resin is selected from at least one of polylactic acid, polyhydroxyalkanoate, polybutylene succinate, or polybutylene adipate / terephthalate; the hydrophobic bio-based resin is selected from bio-based polyamide or bio-based polyester; the melting point of the main substrate is 15° higher than the melting point of the latent sacrificial phase. Up to 30 In step S3, the spinning temperature is controlled to allow the transition coupling layer to form a gradient molecular chain permeation structure on the island phase surface.

4. The bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, The interface anchoring agent constructs an ion network locking structure through the coordination bonds of multivalent cations. When the fibrous bio-based multifunctional polymer composition is in a low-ionic-strength fluid environment, the ion network locking structure blocks the path of external polar fluid medium to the latent sacrificial phase. When the fibrous bio-based multifunctional polymer composition is in a discarded environment, the ion network locking structure collapses due to the exchange between monovalent cations and multivalent cations in the external environment.

5. The bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, The osmotic pressure regulator is selected from at least one of sodium polyacrylate, sodium carboxymethyl cellulose, or cassava starch modifier; in step S1, the osmotic pressure regulator is encapsulated inside the bio-based polyester resin by microencapsulation to limit the physical contact between the osmotic pressure regulator and water before the transition coupling layer is peeled off.

6. The bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, The interfacial delamination criterion for fibrous bio-based multifunctional polymer compositions follows these rules: ,in, To accumulate mechanical strain energy; This represents the number of mechanical stress cycles. The stress concentration factor is determined by the inorganic stress concentrate. For the first The objective stress amplitude generated by secondary stress alternation; The elastic modulus of the transition coupling layer; when When the molecular chain entanglement energy exceeds the chemical anchoring point, structural delamination occurs in the transition coupling layer.

7. The bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, The molecular weight distribution index of the interface anchoring agent is between 1.8 and 2.5; in step S2, by controlling the dispersion shear rate of the interface anchoring agent in the main substrate, the interface anchoring agent is oriented and arranged on the surface of the latent sacrificial phase particles to form oriented chemical anchoring points.

8. The bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, Following step S3, the process further includes a heat-setting treatment of the obtained fibrous bio-based multifunctional polymer composition; the heat-setting temperature is 80°C. Up to 120 The time is 30s to 120s; heat setting treatment is used to eliminate the residual internal stress generated in the spinning process of fibrous bio-based multifunctional polymer compositions.

9. A bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, Before step S3, the antibacterial agent and the UV-resistant agent are pre-blended with the hydrophobic bio-based resin; the antibacterial agent is selected from silver-loaded nano-zeolite or chitosan derivatives; the UV-resistant agent is selected from nano-zinc oxide or sodium lignosulfonate; the resulting fibrous bio-based multifunctional polymer composition retains a fracture strength of not less than 90% of the initial value during its service life.

10. A bio-based multifunctional denim yarn with specific environmental degradation aging according to claim 1, characterized in that, After the structure of the fibrous bio-based multifunctional polymer composition disintegrates, the core of the main substrate is exposed to the disposal environment. In the disposal landfill environment, the degradation rate of the fibrous bio-based multifunctional polymer composition is increased to more than 5 times the linear hydrolysis rate during its service life by utilizing the local osmotic pressure gradient established by the osmotic pressure regulator.

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