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CN-121975243-A - Anti-aging expandable polystyrene particles and preparation process thereof

CN121975243ACN 121975243 ACN121975243 ACN 121975243ACN-121975243-A

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to anti-aging expandable polystyrene particles and a preparation process thereof. The flame retardant comprises, by weight, 100-120 parts of styrene, 200-300 parts of deionized water, 7-10 parts of a composite flame retardant, 0.3-0.6 part of an initiator, 1.5-3.0 parts of a nucleating agent, 0.7-1.2 parts of a composite toughening agent, 6-8 parts of a foaming agent, 0.2-0.8 parts of a dispersing agent and 0.01-0.05 part of an emulsifying agent, wherein the composite flame retardant is prepared by mixing modified graphene/boron nitride, ammonium polyphosphate and modified silicon dioxide. The components are precisely distributed and interacted on the nanometer scale, so that the material has excellent flame retardant property, ageing resistance, heat conducting property and mechanical strength.

Inventors

  • WANG KAI
  • LI GANG
  • LI PENG
  • LIU QI
  • Si Mingqian
  • LI XIAOBO
  • LI FENG

Assignees

  • 苏豪丽天(辽宁)高分子材料有限公司
  • 沈阳理工大学

Dates

Publication Date
20260505
Application Date
20260302

Claims (10)

  1. 1. The anti-aging expandable polystyrene particles are characterized by comprising, by weight, 100-120 parts of styrene, 200-300 parts of deionized water, 7-10 parts of a composite flame retardant, 0.3-0.6 part of an initiator, 1.5-3.0 parts of a nucleating agent, 0.7-1.2 parts of a composite toughening agent, 6-8 parts of a foaming agent, 0.2-0.8 part of a dispersing agent and 0.01-0.05 part of an emulsifying agent, wherein the composite flame retardant is prepared by mixing modified graphene/boron nitride, ammonium polyphosphate and modified silicon dioxide, and the mass ratio of the modified graphene/boron nitride, the ammonium polyphosphate and the modified silicon dioxide is 5:7-9:0.5-1.0; the preparation method of the modified silicon dioxide comprises the following steps: (1) Dispersing silicon dioxide in absolute ethyl alcohol by ultrasonic, then dropwise adding 3-aminopropyl triethoxysilane under the condition of nitrogen atmosphere and stirring, raising the temperature to 75-85 ℃, reacting for 20-30h, cooling to room temperature, filtering, washing and drying to obtain aminated silicon dioxide; (2) Uniformly mixing the aminated silicon dioxide, phosphorus oxychloride, tetrahydrofuran and triethylamine, adding 4,4' -diaminodiphenyl methane after ultrasonic treatment, stirring at room temperature for reaction for 20-30h, purifying and drying to obtain the product.
  2. 2. The anti-aging expandable polystyrene particles according to claim 1, wherein the volume ratio of the absolute ethyl alcohol to the 3-aminopropyl triethoxysilane in the step (1) is 150:10-20, and the addition amount of the silica in the absolute ethyl alcohol is 0.010-0.013g/mL.
  3. 3. The anti-aging expandable polystyrene particles according to claim 1, wherein the mass ratio of the aminated silica, phosphorus oxychloride, triethylamine, 4' -diaminodiphenyl methane in the step (2) is 5:2.5-3.5:2-3:6-7, and the mass-volume ratio of the aminated silica to the tetrahydrofuran is 0.010-0.015g/mL.
  4. 4. The anti-aging expandable polystyrene particles of claim 1, wherein the modified graphene/boron nitride is prepared by the following method: Step S1, dispersing boron nitride in a sodium hydroxide aqueous solution, stirring and reacting for 20-30 hours at 70-90 ℃, cooling to room temperature, and filtering, washing, drying and grinding to obtain hydroxylated boron nitride; S2, dispersing hydroxylated boron nitride and graphene in an ethanol water solution, carrying out ultrasonic treatment for 50-70min, adding 3-aminopropyl triethoxysilane, introducing nitrogen for protection, stirring at 80-100 ℃ for reaction for 7-11h, cooling to room temperature, and filtering, washing and drying to obtain silanized graphene/boron nitride; and S3, dispersing the silanized graphene/boron nitride in an ethanol water solution, performing ultrasonic treatment for 0.5-1.5h, adding dopamine hydrochloride, adjusting the pH to 8-9, stirring for 5-7h at 75-95 ℃, cooling to room temperature, filtering, washing, drying and crushing to obtain the graphene/boron nitride composite material.
  5. 5. The expandable polystyrene particles of claim 4, wherein the mass to volume ratio of said boron nitride to aqueous sodium hydroxide solution in step S1 is 1:8-12, and the concentration of aqueous sodium hydroxide solution is 4-6mol/L.
  6. 6. The anti-aging expandable polystyrene particles according to claim 4, wherein the mass ratio of the hydroxylated boron nitride, graphene, 3-aminopropyl triethoxysilane, and aqueous ethanol solution in step S2 is 0.1:0.2-0.3:2.5-3.5:20-25, the mass fraction of ethanol in the aqueous ethanol solution is 85-95%, the ultrasonic power is 100-300W, and the ultrasonic frequency is 20-40kHz.
  7. 7. The anti-aging expandable polystyrene particles according to claim 4, wherein the mass ratio of the silanized graphene/boron nitride, dopamine hydrochloride and ethanol aqueous solution in step S3 is 4:0.8-1.2:400-600, the mass fraction of ethanol in the ethanol aqueous solution is 45-55%, the ultrasonic power is 150-250W, and the ultrasonic frequency is 20-30kHz.
  8. 8. The anti-aging expandable polystyrene particles according to claim 1, wherein the initiator is one or more of benzoyl peroxide, dicumyl peroxide and tert-butyl peroxybenzoate, the nucleating agent is polyethylene wax, the foaming agent is isopentane or n-pentane, the dispersing agent is one or more of active calcium phosphate, polyvinyl alcohol, sodium dodecyl benzene sulfonate and hydroxyethyl cellulose, and the emulsifying agent is calcium dodecyl benzene sulfonate.
  9. 9. The anti-aging expandable polystyrene particles according to claim 1, wherein the composite toughening agent is prepared by mixing a styrene-ethylene-butylene-styrene block copolymer, cellulose nanofiber and castor oil polyoxyethylene ether, and the mass ratio of the styrene-ethylene-butylene-styrene block copolymer to the cellulose nanofiber to the castor oil polyoxyethylene ether is 2:0.5-1.0:0.5-1.0.
  10. 10. The process for preparing the anti-aging expandable polystyrene particles according to any one of claims 1 to 9, comprising the steps of adding a dispersing agent into deionized water, stirring for 20 to 40 minutes, sequentially adding styrene, a composite flame retardant and an emulsifier, continuing stirring for 30 to 60 minutes, increasing the temperature to 45 to 55 ℃, then adding a nucleating agent, a composite toughening agent and an initiator, continuing to increase the temperature to 88 to 92 ℃ after uniform mixing, stirring for 5 to 6 hours, adding a foaming agent, continuing stirring, increasing the temperature to 120 to 125 ℃, reacting for 3.3 to 5.5 hours, and discharging after cooling.

Description

Anti-aging expandable polystyrene particles and preparation process thereof Technical Field The invention belongs to the technical field of high polymer materials, and particularly relates to anti-aging expandable polystyrene particles and a preparation process thereof. Background Polystyrene is used as a general thermoplastic plastic, and is widely applied to the fields of packaging, construction, electronic appliances and the like due to the advantages of excellent electrical insulation, transparency, processability, low cost and the like. However, the traditional polystyrene material has obvious limitations, including problems of flammability, high brittleness, poor heat resistance, easy aging and the like, and severely restricts the application thereof in the high-end field. In particular, in the scenes of building thermal insulation materials, electronic element packaging and the like, higher requirements are put on the flame retardance, mechanical properties and long-term durability of the materials. In recent years, the modification research on polystyrene at home and abroad mainly focuses on two aspects of flame retardant property and mechanical enhancement. In the aspect of flame retardant modification, although the effect of the traditional halogen flame retardant is obvious, but the environmental risk exists, the current research hot spot is shifted to a halogen-free flame retardant system, such as an Intumescent Flame Retardant (IFR), a phosphorus-nitrogen flame retardant and a nano filler compounding technology. For example, ammonium polyphosphate (APP) and melamine derivatives can form a carbon layer blocking effect, but are easy to migrate and poor in compatibility with a matrix when being singly used, and the problem that the nano particles are easy to agglomerate is not thoroughly solved due to the unique lamellar structure and high thermal stability of two-dimensional nano materials such as graphene, boron nitride (h-BN) and the like. In the field of anti-aging modification, ultraviolet radiation and thermo-oxidative aging are major factors that cause molecular chain breakage, yellowing and performance degradation of polystyrene. Conventional antioxidants such as hindered phenols (e.g., BHT) and light stabilizers (e.g., benzotriazole) have some effects but have the problem of small molecule migration loss. In recent years, a long-acting stable system is built by using dopamine bionic modified nano materials to become a new idea, and the catechol structure of Polydopamine (PDA) can effectively quench free radicals, and meanwhile, the adhesion characteristic of the catechol structure is favorable for enhancing the interface binding force. Mechanical property modification is usually performed by elastomer toughening (such as SEBS) or rigid particle toughening, but a single toughening mode often leads to reduced modulus or limited toughness improvement. Cellulose Nanofibers (CNF) are considered ideal reinforcements due to their high aspect ratio and biodegradability properties, but the interfacial compatibility of hydrophilic CNF with hydrophobic polystyrene remains a technical difficulty. In the existing Expandable Polystyrene (EPS) production process, a suspension polymerization method is mostly adopted, and although a closed-cell structure can be formed by adding the foaming agent n-pentane, the uniformity and the size control of cells directly influence the compression strength and the heat insulation performance of the final product. The traditional nucleating agent such as talcum powder has low cost but limited effect on cell refinement, and the polyethylene wax (PE wax) serving as a novel nucleating agent can reduce interfacial energy, but the synergistic action mechanism of the novel nucleating agent and a flame-retardant system is not clear. In addition, the dispersion stability is critical to the particle form in the production process, and the anionic dispersing agent such as Sodium Dodecyl Benzene Sulfonate (SDBS) is easily influenced by electrolyte and needs to be compounded with a high polymer dispersing agent for use. Despite the attempts made to combine the above-mentioned modification approaches, multicomponent synergistic effects have not yet been fully exploited, and in particular flame-toughening-anti-aging multifunctional integrated designs lack systematic solutions. For example, the compounding ratio of CNF and SEBS, the surface functionalization degree of the modified nanofiller, and the law of influence of polymerization process parameters on the final performance have not been established as a quantization model. Therefore, development of a polystyrene composite material with high-efficiency flame retardance, long-acting aging resistance, excellent mechanical properties and controllable foaming structure still needs innovation from three dimensions of molecular design, interface engineering and process optimization. Disclosure of Invention Aiming at the defects of the