Bio-based modifier for PVC
By using core-shell composite particle modifiers, combined with dynamically cross-linked bio-based ABS and ternary composite shells, the problems of rigidity-toughness balance, processing thermal stability, and environmental protection of PVC products are solved, achieving multi-performance integration and improving the overall performance and sustainability of PVC products.
Patent Information
- Application Number
- CN202511920345.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-03-06
AI Technical Summary
Existing PVC modifiers suffer from contradictions in balancing rigidity and toughness, difficulty in balancing processing performance and thermal stability, dependence on fossil resources and poor environmental performance, limitations in single function, and pain points in derivative technologies, which restrict the application and sustainable development of PVC products.
The core-shell composite particle modifier is used. The core layer is dynamically cross-linked bio-based ABS, and the shell layer is a ternary composite nanosheet of graphene-bio-based UV absorber-calcium terephthalate. The interface bonding is strengthened through covalent and coordination bonds to achieve multifunctional integration and improve the impact strength, rigidity, processability and heat resistance of PVC.
It achieves simultaneous improvement in toughness and rigidity of PVC products, meets the needs of large-scale production, reduces carbon footprint, enhances environmental friendliness and sustainability, extends service life, simplifies formulation and avoids the risk of additive migration.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer material modification technology, specifically to a bio-based modifier for PVC. Background Technology
[0002] Thermoplastic polymer products, especially semi-rigid and rigid PVC products, require the addition of processing aids (such as acrylates) or small-molecule organic compounds (such as oils, waxes, and plasticizers) to their formulations to meet processing requirements. While these aids improve processing fluidity, they significantly reduce the rigidity and heat resistance of the products, limiting the application scenarios of PVC products. Furthermore, the core raw materials of existing PVC modifiers (such as petroleum-based ABS) rely on fossil resources, resulting in a high carbon footprint during production. They also suffer from insufficient anti-aging properties, difficulty in recycling discarded products, and easy peeling of the core-shell interface. Specifically, existing technologies have the following problems: 1. The contradiction between rigidity and toughness is prominent: Traditional PVC modification often involves direct blending with petroleum-based ABS, which can improve impact toughness but leads to a significant decrease in the rigidity (flexural modulus) of the product. For example, in the field of building formwork, PVC materials cannot meet the load-bearing requirements due to insufficient rigidity, and metal formwork can only be used, resulting in a waste of metal resources and violating the national strategy of "replacing steel with plastics". Plastic flooring products, on the other hand, are prone to deformation and warping in high-temperature environments due to insufficient rigidity and heat resistance, affecting the user experience.
[0003] 2. Difficulty in balancing processing performance and thermal stability: Existing processing aids, while reducing the viscosity of PVC melt, increase the risk of PVC molecular chain degradation, leading to a shorter thermal stability time. The Congo red thermal stability time for pure PVC is only 40 minutes, which cannot meet the needs of large-scale production such as continuous extrusion and injection molding, thus limiting the improvement of production efficiency.
[0004] 3. Dependence on fossil resources and poor environmental performance: Current core components of modifiers (such as petroleum-based ABS and traditional plasticizers) are derived from non-renewable fossil resources. The production process results in high carbon emissions, and the modifiers are difficult to degrade after disposal, easily causing environmental pollution. With tightening environmental policies and the depletion of fossil resources, the development of bio-based, low-carbon modifiers has become an urgent need for the industry.
[0005] 4. Limitations of single function: Existing PVC modifiers mostly focus on improving a single property (such as only toughening or only strengthening), which cannot simultaneously meet the comprehensive requirements of structural products for impact strength, rigidity, processing fluidity and heat resistance. Multiple additives need to be compounded, resulting in complex formulations, increased costs, and problems such as additive migration and poor compatibility.
[0006] 5. Pain points of derivative technologies: Traditional core-shell modifiers have problems such as easy peeling of the physical coating at the interface, decline in the anti-aging performance of products after long-term use, and the inability to recycle and reuse cross-linking modifiers, which further limit the service life and application value of PVC modified products. Summary of the Invention
[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A bio-based modifier for PVC, wherein the modifier is a core-shell composite particle comprising a core layer and a shell layer, wherein the core layer is dynamically cross-linked bio-based ABS and the surface of the core layer is pretreated with a bio-based coupling agent (BCA) to enhance the core-shell interface bonding through a dual action of "covalent bond + coordination bond"; and the shell layer is a graphene-bio-based UV absorber (BA-UV)-calcium terephthalate (CaTP) ternary composite nanosheet.
[0008] In a preferred embodiment of the bio-based modifier for PVC described in this invention, the mass ratio of the core layer to the shell layer is set to 1:0.3-1:0.5.
[0009] As a preferred embodiment of the bio-based modifier for PVC described in this invention, the shell thickness is set to 10-30 nm.
[0010] As a preferred embodiment of the bio-based modifier for PVC described in this invention, it further includes a preparation method, the specific steps of which are as follows: S1, Preparation of bio-based ABS with dynamic cross-linking of the core layer: S11 is a basic bio-based ABS prepared by emulsion graft polymerization using starch-derived bio-based styrene-acrylonitrile copolymer (SAN) as the hard segment and bio-based butadiene rubber as the soft segment. S12, introduce a bio-based dynamic crosslinking agent (BDC) to graft maleic anhydride-boronic acid ester (bio-based content ≥85%) onto starch, with an amount of 3%-5% of the total mass of bio-based ABS; at the same time, during the emulsion grafting polymerization stage, when the monomer conversion rate reaches 70%-80%, add the bio-based dynamic crosslinking agent, control the reaction temperature and reaction time, and utilize the maleic anhydride group to undergo an esterification reaction with the hydroxyl groups of the SAN segment in the bio-based ABS to form a dynamic crosslinking network that can dissociate and recombine; S2, Preparation of shell ternary composite modified calcium terephthalate: S21, Preparation of bio-based UV absorber (BA-UV): Prepared by esterification reaction of ferulic acid and starch-derived polyol; S22, Synthesis of Ternary Composite Shell: Graphene dispersion, bio-based UV absorber dispersion, and calcium terephthalate precursor solution are mixed in a specific mass ratio and ultrasonically dispersed. The pH is adjusted to 6.5-7.5 to allow calcium terephthalate to precipitate in nanosheet form. Simultaneously, the carboxyl groups in ferulic acid molecules react with... Coordination bonds are formed to achieve in-situ composite of graphene, bio-based UV absorber and calcium terephthalate, resulting in a ternary composite shell material. S3, Core-shell interface pretreatment and composite particle synthesis: S31, Core layer pretreatment: After the bio-based ABS emulsion polymerization is completed, a bio-based coupling agent (BCA) is added to graft γ-aminopropyltriethoxysilane (bio-based content ≥75%) onto cellulose. The concentration is controlled at 0.8-1.0 mg / mL, and the pH is adjusted to 8.0-8.5. The coupling agent is hydrolyzed to generate silanol groups, which form covalent bonds with the carboxyl groups on the surface of the bio-based ABS. The mixture is then kept at a certain temperature to complete the functional modification of the core layer surface. S32, Synthesis of Core-Shell Composite Particles: An in-situ coating method was used to introduce a ternary composite shell dispersion into a pretreated bio-based ABS system, utilizing the silanol groups on the core surface to... The secondary coordination bond, combined with the original carboxyl group - Coordination occurs, creating a dual-interface bond of covalent and coordination bonds, ultimately forming a core-shell composite particle.
[0011] As a preferred embodiment of the bio-based modifier for PVC described in this invention, in S11, the bio-based raw material accounts for 60%-80% of the total mass of ABS, and the starch-derived SAN is obtained by copolymerizing styrene monomer and acrylonitrile monomer prepared by starch fermentation, which reduces the carbon footprint by 30%-40% compared with petroleum-based SAN.
[0012] As a preferred embodiment of the bio-based modifier for PVC described in this invention, in step S12, the reaction temperature is set to 65-70°C, the reaction time is set to 1-1.5 hours, and the degree of crosslinking is controlled at 15%-20%.
[0013] As a preferred embodiment of the bio-based modifier for PVC described in this invention, wherein: in S21, the bio-based content is ≥90%, and it has both ultraviolet shielding and interface compatibility functions.
[0014] As a preferred embodiment of the bio-based modifier for PVC described in this invention, in step S22, the mass ratio of graphene dispersion, bio-based UV absorber dispersion, and calcium terephthalate precursor solution is set to 1:0.2-0.3:5-8.
[0015] As a preferred embodiment of the bio-based modifier for PVC described in this invention, in step S22, the concentration of the graphene dispersion is set to 0.5-1.0 mg / mL, and the concentration of the bio-based UV absorber dispersion is set to 0.3-0.5 mg / mL; simultaneously, the power of ultrasonic dispersion is set to 400-500 W, and the time is set to 25-35 minutes.
[0016] As a preferred embodiment of the bio-based modifier for PVC described in this invention, in step S31, the heat preservation time is set to 30-35 minutes.
[0017] Compared with existing technologies: 1. Through the synergistic design of "dynamic cross-linked bio-based ABS flexible core - graphene - bio-based UV absorber - calcium terephthalate ternary composite rigid shell", combined with the complementary effects of core layer impact energy absorption and shell layer crystal refinement and three-dimensional reinforcement network, it has the advantages of achieving simultaneous improvement of toughness and rigidity of PVC products and solving the contradiction of rigidity and toughness balance. 2. Through the coordination reaction of calcium terephthalate in the shell with unstable chlorine atoms in PVC, the lubrication effect of the nanosheets, and the dissociation characteristics of the dynamic cross-linked bonds in the core layer at the processing temperature, it has the advantages of achieving both optimized processing fluidity and thermal stability, and meeting the needs of large-scale production. 3. By replacing petroleum-based raw materials with fully bio-based components derived from starch and cellulose, and combining them with an integrated core-shell structure to avoid the need for multiple additives, it has the advantages of achieving low-carbon modification of modifiers, reducing carbon footprint, and improving environmental protection and sustainability. 4. Through the multi-functional integrated design of core-shell composite particles, PVC is simultaneously endowed with comprehensive properties such as impact strength, rigidity, processability, and heat resistance. There is no need to add single-function additives. It has the advantages of meeting the multi-performance requirements of structural products in one integrated way, simplifying the formulation and avoiding the risk of additive migration. 5. Through the synergistic effect of ultraviolet shielding and thermal conduction of the ternary composite shell, the "dissociation-recombination" characteristics of the dynamic cross-linked network of the core layer, and the dual interface combination design of "covalent bond + coordination bond", it has the advantages of improving the anti-aging performance of PVC products, making them recyclable and reusable, ensuring a firm and stable core-shell interface, solving the pain points of traditional modifiers in one integrated way, and extending the service life of products. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below. Example 1:
[0019] This invention provides a bio-based modifier for PVC, wherein the modifier is a core-shell composite particle comprising a core layer and a shell layer. The core layer is dynamically cross-linked bio-based ABS, and the surface of the core layer is pretreated with a bio-based coupling agent (BCA) to enhance the core-shell interface bonding through a dual action of "covalent bond + coordination bond". The shell layer is a ternary composite nanosheet of graphene-bio-based UV absorber (BA-UV)-calcium terephthalate (CaTP).
[0020] The mass ratio of the core layer to the shell layer is set to 1:0.3, and the shell layer thickness is set to 10 nm.
[0021] It also includes a preparation method, the specific steps of which are as follows: S1, Preparation of bio-based ABS with dynamic cross-linking of the core layer: S11 is a basic bio-based ABS prepared by emulsion graft polymerization using starch-derived bio-based styrene-acrylonitrile copolymer (SAN) as the hard segment and bio-based butadiene rubber as the soft segment. Bio-based raw materials account for 60% of the total mass of ABS. Starch-derived SAN is obtained by copolymerizing styrene monomer and acrylonitrile monomer prepared by starch fermentation, and its carbon footprint is reduced by 30% compared with petroleum-based SAN. S12, a bio-based dynamic crosslinking agent (BDC) is introduced to graft maleic anhydride-boron ester (bio-based content ≥85%) onto starch, with an amount of 3% of the total mass of bio-based ABS. Simultaneously, during the emulsion grafting polymerization stage, the bio-based dynamic crosslinking agent is added when the monomer conversion rate reaches 70%, and the reaction temperature and time are controlled. The maleic anhydride groups react with the hydroxyl groups of the SAN segments in the bio-based ABS through esterification, forming a dissociable-recombinable dynamic crosslinked network. The reaction temperature is set at 65℃, the reaction time at 1 hour, and the degree of crosslinking is controlled at 15%. S2, Preparation of shell ternary composite modified calcium terephthalate: S21, Preparation of bio-based UV absorber (BA-UV): Prepared by esterification reaction of ferulic acid and starch-derived polyol; wherein, the bio-based content is ≥90%, and it has both ultraviolet shielding and interface compatibility functions; S22, Synthesis of Ternary Composite Shell: Graphene dispersion (concentration set at 0.5 mg / mL), bio-based UV absorber dispersion (concentration set at 0.3 mg / mL), and calcium terephthalate precursor solution were mixed at a mass ratio and ultrasonically dispersed (power set at 400 W, time set at 25 minutes). The pH was adjusted to 6.5 to allow calcium terephthalate to precipitate in the form of nanosheets. Simultaneously, the carboxyl groups in the ferulic acid molecules react with… Coordination bonds are formed to achieve in-situ composite of graphene, bio-based UV absorber and calcium terephthalate, resulting in a ternary composite shell material; wherein the mass ratio of graphene dispersion, bio-based UV absorber dispersion and calcium terephthalate precursor solution is set to 1:0.2:5. S3, Core-shell interface pretreatment and composite particle synthesis: S31, Core layer pretreatment: After the bio-based ABS emulsion polymerization is completed, a bio-based coupling agent (BCA) is added to graft γ-aminopropyltriethoxysilane (bio-based content ≥75%) onto cellulose. The concentration is controlled at 0.8 mg / mL, and the pH is adjusted to 8.0. The coupling agent is hydrolyzed to generate silanol groups, which form covalent bonds with the carboxyl groups on the surface of the bio-based ABS. The mixture is then kept at a temperature of 30 minutes to complete the functional modification of the core layer surface. S32, Synthesis of Core-Shell Composite Particles: An in-situ coating method was used to introduce a ternary composite shell dispersion into a pretreated bio-based ABS system, utilizing the silanol groups on the core surface to... The secondary coordination bond, combined with the original carboxyl group - Coordination acts to construct a dual-interface bond of covalent and coordination bonds, ultimately forming a core-shell composite particle. S4, PVC blend modification: Mix 80 parts of PVC resin with 20 parts of this modifier, add heat stabilizer and lubricant, and extrude and granulate through a twin-screw extruder at an extrusion temperature of 160℃ and a screw speed of 300rpm to obtain modified PVC granules. Example 2:
[0022] This invention provides a bio-based modifier for PVC, wherein the modifier is a core-shell composite particle comprising a core layer and a shell layer. The core layer is dynamically cross-linked bio-based ABS, and the surface of the core layer is pretreated with a bio-based coupling agent (BCA) to enhance the core-shell interface bonding through a dual action of "covalent bond + coordination bond". The shell layer is a ternary composite nanosheet of graphene-bio-based UV absorber (BA-UV)-calcium terephthalate (CaTP).
[0023] The mass ratio of the core layer to the shell layer is set to 1:0.4, and the shell layer thickness is set to 20 nm.
[0024] It also includes a preparation method, the specific steps of which are as follows: S1, Preparation of bio-based ABS with dynamic cross-linking of the core layer: S11 is a basic bio-based ABS prepared by emulsion graft polymerization using starch-derived bio-based styrene-acrylonitrile copolymer (SAN) as the hard segment and bio-based butadiene rubber as the soft segment. Bio-based raw materials account for 70% of the total mass of ABS. Starch-derived SAN is obtained by copolymerizing styrene monomers with acrylonitrile monomers prepared by starch fermentation. The carbon footprint is reduced by 35% compared to petroleum-based SAN. S12, a bio-based dynamic crosslinking agent (BDC) is introduced to graft maleic anhydride-boron ester (bio-based content ≥85%) onto starch, with an amount of 4% of the total mass of bio-based ABS. Simultaneously, during the emulsion grafting polymerization stage, the bio-based dynamic crosslinking agent is added when the monomer conversion rate reaches 75%, and the reaction temperature and time are controlled. The maleic anhydride groups react with the hydroxyl groups of the SAN segments in the bio-based ABS through esterification, forming a dissociable-recombinable dynamic crosslinked network. The reaction temperature is set at 67.5℃, the reaction time at 1.25 hours, and the degree of crosslinking is controlled at 17.5%. S2, Preparation of shell ternary composite modified calcium terephthalate: S21, Preparation of bio-based UV absorber (BA-UV): Prepared by esterification reaction of ferulic acid and starch-derived polyol; wherein, the bio-based content is ≥90%, and it has both ultraviolet shielding and interface compatibility functions; S22, Synthesis of Ternary Composite Shell: Graphene dispersion (concentration set at 0.75 mg / mL), bio-based UV absorber dispersion (concentration set at 0.4 mg / mL), and calcium terephthalate precursor solution were mixed at a mass ratio and ultrasonically dispersed (power set at 450 W, time set at 30 minutes). The pH was adjusted to 7.0 to allow calcium terephthalate to precipitate in the form of nanosheets. Simultaneously, the carboxyl groups in the ferulic acid molecules react with… Coordination bonds are formed to achieve in-situ composite of graphene, bio-based UV absorber and calcium terephthalate, resulting in a ternary composite shell material; wherein the mass ratio of graphene dispersion, bio-based UV absorber dispersion and calcium terephthalate precursor solution is set to 1:0.25:6.5. S3, Core-shell interface pretreatment and composite particle synthesis: S31, Core layer pretreatment: After the bio-based ABS emulsion polymerization is completed, a bio-based coupling agent (BCA) is added to graft γ-aminopropyltriethoxysilane (bio-based content ≥75%) onto cellulose. The concentration is controlled at 0.9 mg / mL, and the pH is adjusted to 8.25 to hydrolyze the coupling agent to generate silanol groups, which form covalent bonds with the carboxyl groups on the surface of the bio-based ABS. The mixture is then kept at a temperature of 32.5 minutes to complete the functional modification of the core layer surface. S32, Synthesis of Core-Shell Composite Particles: An in-situ coating method was used to introduce a ternary composite shell dispersion into a pretreated bio-based ABS system, utilizing the silanol groups on the core surface to... The secondary coordination bond, combined with the original carboxyl group - Coordination acts to construct a dual-interface bond of covalent and coordination bonds, ultimately forming a core-shell composite particle. S4, PVC blend modification: Mix 80 parts of PVC resin with 20 parts of this modifier, add heat stabilizer and lubricant, and extrude and granulate through a twin-screw extruder at an extrusion temperature of 170℃ and a screw speed of 300rpm to obtain modified PVC granules. Example 3:
[0025] This invention provides a bio-based modifier for PVC, wherein the modifier is a core-shell composite particle comprising a core layer and a shell layer. The core layer is dynamically cross-linked bio-based ABS, and the surface of the core layer is pretreated with a bio-based coupling agent (BCA) to enhance the core-shell interface bonding through a dual action of "covalent bond + coordination bond". The shell layer is a ternary composite nanosheet of graphene-bio-based UV absorber (BA-UV)-calcium terephthalate (CaTP).
[0026] The mass ratio of the core layer to the shell layer is set to 1:0.5, and the shell layer thickness is set to 30 nm.
[0027] It also includes a preparation method, the specific steps of which are as follows: S1, Preparation of bio-based ABS with dynamic cross-linking of the core layer: S11 is a basic bio-based ABS prepared by emulsion graft polymerization using starch-derived bio-based styrene-acrylonitrile copolymer (SAN) as the hard segment and bio-based butadiene rubber as the soft segment. Bio-based raw materials account for 80% of the total mass of ABS. Starch-derived SAN is obtained by copolymerizing styrene monomers with acrylonitrile monomers prepared by starch fermentation. The carbon footprint is reduced by 40% compared to petroleum-based SAN. S12, a bio-based dynamic crosslinking agent (BDC) is introduced to graft maleic anhydride-boron ester (bio-based content ≥85%) onto starch, with an amount of 5% of the total mass of bio-based ABS. Simultaneously, during the emulsion grafting polymerization stage, the bio-based dynamic crosslinking agent is added when the monomer conversion rate reaches 80%, and the reaction temperature and time are controlled. The maleic anhydride groups react with the hydroxyl groups of the SAN segments in the bio-based ABS through esterification, forming a dissociable-recombinable dynamic crosslinked network. The reaction temperature is set at 70℃, the reaction time at 1.5 hours, and the degree of crosslinking is controlled at 20%. S2, Preparation of shell ternary composite modified calcium terephthalate: S21, Preparation of bio-based UV absorber (BA-UV): Prepared by esterification reaction of ferulic acid and starch-derived polyol; wherein, the bio-based content is ≥90%, and it has both ultraviolet shielding and interface compatibility functions; S22, Synthesis of Ternary Composite Shell: Graphene dispersion (concentration set at 1.0 mg / mL), bio-based UV absorber dispersion (concentration set at 0.5 mg / mL), and calcium terephthalate precursor solution were mixed at a mass ratio and ultrasonically dispersed (power set at 500 W, time set at 35 minutes). The pH was adjusted to 7.5 to allow calcium terephthalate to precipitate in the form of nanosheets. Simultaneously, the carboxyl groups in the ferulic acid molecules react with… Coordination bonds are formed to achieve in-situ composite of graphene, bio-based UV absorber and calcium terephthalate, resulting in a ternary composite shell material; wherein the mass ratio of graphene dispersion, bio-based UV absorber dispersion and calcium terephthalate precursor solution is set to 1:0.3:8. S3, Core-shell interface pretreatment and composite particle synthesis: S31, Core layer pretreatment: After the bio-based ABS emulsion polymerization is completed, a bio-based coupling agent (BCA) is added to graft γ-aminopropyltriethoxysilane (bio-based content ≥75%) onto cellulose. The concentration is controlled at 1.0 mg / mL, and the pH is adjusted to 8.5 to hydrolyze the coupling agent to generate silanol groups, which form covalent bonds with the carboxyl groups on the surface of the bio-based ABS. The mixture is then kept at a temperature of 35 minutes to complete the functional modification of the core layer surface. S32, Synthesis of Core-Shell Composite Particles: An in-situ coating method was used to introduce a ternary composite shell dispersion into a pretreated bio-based ABS system, utilizing the silanol groups on the core surface to... The secondary coordination bond, combined with the original carboxyl group - Coordination acts to construct a dual-interface bond of covalent and coordination bonds, ultimately forming a core-shell composite particle. S4, PVC Blending Modification: Mix 80 parts of PVC resin with 20 parts of this modifier, add heat stabilizer and lubricant, and extrude and granulate through a twin-screw extruder at an extrusion temperature of 180℃ and a screw speed of 300rpm to obtain modified PVC granules.
[0028] The following data were obtained by comparing the modifiers prepared in Examples 1-3 above:
[0029] As shown in the table above, the modifiers prepared in Examples 1-3 all showed good performance in terms of impact strength retention rate after UV aging, impact strength retention rate after 3 recycling cycles, and carbon footprint reduction rate. After use, Example 2 showed the best results.
[0030] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A biobased modifier for PVC, characterized in that, The modifier is a core-shell composite particle, the core-shell composite particle comprises a core layer and a shell layer, the core layer is a dynamic crosslinking bio-based ABS, and the surface of the core layer is pretreated by a bio-based coupling agent; the shell layer is a ternary composite nanosheet layer of graphene-bio-based UV absorber-calcium terephthalate.
2. A biobased modifier for PVC according to claim 1, characterized in that, The mass ratio of the core layer and the shell layer is set to 1:0.3-1:0.
5.
3. A biobased modifier for PVC according to claim 1, characterized in that, The thickness of the shell layer is set to 10-30 nm.
4. A biobased modifier for PVC according to claim 1, characterized in that, Also included is a preparation method, and the specific steps are as follows: S1, preparation of a core layer dynamic crosslinking bio-based ABS: S11, a bio-based styrene-acrylonitrile copolymer derived from starch is used as a hard segment, and a bio-based butadiene rubber is used as a soft segment, and a base bio-based ABS is prepared through emulsion graft polymerization; S12, a bio-based dynamic crosslinking agent is introduced to graft maleic anhydride-borate to the starch, and the amount is 3%-5% of the total mass of the bio-based ABS; at the same time, the bio-based dynamic crosslinking agent is added when the monomer conversion rate reaches 70%-80% in the emulsion graft polymerization stage, and the reaction temperature and the reaction time are controlled, and the maleic anhydride groups are esterified with the hydroxyl groups in the SAN segment of the bio-based ABS to form a dynamic crosslinking network that can be dissociated and recombined; S2, preparation of a shell layer ternary composite modified calcium terephthalate: S21, preparation of a bio-based UV absorber: prepared by esterification of ferulic acid with a starch-derived polyol; S22, ternary composite shell synthesis: the graphene dispersion liquid, the bio-based UV absorber dispersion liquid and the calcium terephthalate precursor solution are mixed according to the mass ratio, and ultrasonic dispersion is carried out, the pH value is adjusted to 6.5-7.5, the calcium terephthalate is precipitated in the form of nanosheet layer, and the coordination bond is formed through the carboxyl in the ferulic acid molecule The in-situ composite of graphene, bio-based UV absorber and calcium terephthalate is realized, and a ternary composite shell material is obtained. S3, core-shell interface pretreatment and composite particle synthesis: S31, core layer pretreatment: after the emulsion polymerization of the bio-based ABS is completed, a bio-based coupling agent is added to graft γ-aminopropyl triethoxysilane to the cellulose, the concentration is controlled to be 0.8-1.0 mg / mL, the pH is adjusted to 8.0-8.5, the coupling agent is hydrolyzed to form silanol groups, which form covalent bonds with the carboxyl groups on the surface of the bio-based ABS, and heat preservation is performed to complete the functional modification of the surface of the core layer; S32, synthesis of core-shell composite particles: using in-situ coating method, introducing ternary composite shell dispersion liquid into the pretreated bio-based ABS system, using the secondary coordination bond of the silicon hydroxyl group on the surface of the core layer and the carboxyl group on the surface of the shell layer, combining the original carboxyl group coordination action, constructing the double interface combination of covalent bond+coordination bond, and finally forming the core-shell structure composite particles. coordination action, constructing the double interface combination of covalent bond+coordination bond, and finally forming the core-shell structure composite particles. 5. A biobased modifier for PVC according to claim 4, characterized in that, In S11, the bio-based raw material accounts for 60%-80% of the total mass of the ABS.
6. A biobased modifier for PVC according to claim 4, characterized in that, In S12, the reaction temperature is set to 65-70℃, the reaction time is set to 1-1.5 hours, and the crosslinking degree is controlled to be 15%-20%.
7. A biobased modifier for PVC according to claim 4, characterized in that, In S21, the bio-based content is ≥90%.
8. A biobased modifier for PVC according to claim 4, characterized in that, In S22, the mass ratio of the graphene dispersion liquid, the bio-based UV absorber dispersion liquid, and the calcium terephthalate precursor solution is set to 1:0.2-0.3:5-8.
9. A biobased modifier for PVC according to claim 4, characterized in that, In S22, the concentration of the graphene dispersion liquid is set to 0.5-1.0 mg / mL, and the concentration of the bio-based UV absorber dispersion liquid is set to 0.3-0.5 mg / mL; at the same time, the power during ultrasonic dispersion is set to 400-500 W, and the time is set to 25-35 minutes.
10. A biobased modifier for PVC according to claim 4, characterized in that, In S31, the heat preservation time is set to 30-35 minutes.