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CN-122011710-A - Wear-resistant environment-friendly plastic for children toys and preparation method thereof

CN122011710ACN 122011710 ACN122011710 ACN 122011710ACN-122011710-A

Abstract

The invention belongs to the technical field of high polymer materials, and in particular relates to wear-resistant environment-friendly plastic for children toys and a preparation method thereof, wherein the wear-resistant environment-friendly plastic for children toys comprises the following components of 100 parts of polylactic acid, 15-40 parts of polycaprolactone, 6-25 parts of composite wear-resistant agent, 5-15 parts of reactive compatibilizer, 0.2-1 part of antioxidant and 0.2-1 part of lubricant. The preparation method of the wear-resistant environment-friendly plastic for the children toys comprises the steps of mixing the weighed materials at a high speed to obtain a uniform premix, carrying out melt blending extrusion on the premix, granulating the extruded materials through water-cooling braces, and drying to obtain the wear-resistant environment-friendly plastic for the children toys. The plastic disclosed by the invention can form a chemical bonding network in a polylactic acid and polycaprolactone blend system, and simultaneously realizes excellent wear resistance and impact resistance.

Inventors

  • PAN XIUDONG
  • Teng Minmin
  • ZHANG XIAOHUA
  • LEI ZHIYONG

Assignees

  • 奇特乐集团有限公司

Dates

Publication Date
20260512
Application Date
20260320

Claims (10)

  1. 1. The wear-resistant environment-friendly plastic for the children toys is characterized by comprising the following components in parts by weight: 100 parts of polylactic acid; 15 to 40 parts of polycaprolactone; 6 to 25 parts of composite wear-resistant agent; 5 to 15 parts of a reactive compatibilizer; 0.2 to 1 part of antioxidant; 0.2 to 1 part of a lubricant; The composite wear-resistant agent is a complex formed by polyformaldehyde whisker, fullerene and phytic acid modified hydroxyapatite through calcium ion coordination, and the reactive compatibilizer is a triblock copolymer of polylactic acid-polycaprolactone-glycidyl methacrylate.
  2. 2. The wear-resistant environment-friendly plastic for children toys according to claim 1 is characterized in that the preparation process of the composite wear-resistant agent comprises the steps of dispersing polyformaldehyde whiskers and fullerene in absolute ethyl alcohol, conducting ultrasonic dispersion for 30 to 60 minutes to obtain mixed dispersion liquid, dispersing phytic acid modified hydroxyapatite in absolute ethyl alcohol, conducting ultrasonic dispersion for 20 to 40 minutes to obtain hydroxyapatite dispersion liquid, slowly dropwise adding the hydroxyapatite dispersion liquid into the mixed dispersion liquid, simultaneously adding a calcium chloride ethanol solution, wherein the addition amount of calcium chloride is 1 to 5% of the mass of the phytic acid modified hydroxyapatite, stirring and reacting for 3 to 6 hours at the temperature of 50 to 70 ℃, conducting centrifugal separation after the reaction, washing 3 to 5 times with absolute ethyl alcohol, collecting solid products, and conducting vacuum drying for 8 to 12 hours at the temperature of 60 to 80 ℃ to obtain the composite wear-resistant agent.
  3. 3. The wear-resistant environment-friendly plastic for children toys of claim 2, wherein the mass ratio of the polyoxymethylene whisker to the fullerene is 1:0.3-0.6, and the mass ratio of the phytic acid modified hydroxyapatite to the polyoxymethylene whisker is 0.5-2:1; the length-diameter ratio of the polyformaldehyde whisker is 20:1-50:1, the diameter is 0.5-2 microns, the length is 10-100 microns, the fullerene is C60, and the average particle size is 10-100 nanometers.
  4. 4. The wear-resistant environment-friendly plastic for children toys according to claim 2, wherein the phytic acid modified hydroxyapatite is obtained by dispersing nano hydroxyapatite in water to prepare a suspension with a mass concentration of 5-10%, adding phytic acid, stirring and reacting for 2-4 hours at a temperature of 40-60 ℃, then centrifugally separating, washing for 2-4 times with deionized water, collecting a solid product, and vacuum drying for 6-10 hours at a temperature of 50-70 ℃.
  5. 5. The wear-resistant environment-friendly plastic for children toys of claim 4, wherein the addition amount of the phytic acid is 2 to 8 percent of nano-hydroxyapatite.
  6. 6. The wear-resistant environment-friendly plastic for children toys according to claim 1, wherein the reactive compatibilizer is obtained by adding polylactic acid monomer and polycaprolactone monomer into a reaction kettle according to a mass ratio of 1:0.3-1, adding stannous octoate as a catalyst, wherein the adding amount of the catalyst is 0.1-0.5% of the total mass of the monomers, and reacting for 4-8 hours at a temperature of 130-150 ℃ and a gauge pressure of-0.08-0.1 MPa to obtain polylactic acid-polycaprolactone diblock prepolymer; dissolving the polylactic acid-polycaprolactone diblock prepolymer in toluene, adding glycidyl methacrylate and azodiisobutyronitrile, reacting for 6 to 10 hours at the temperature of 70 to 90 ℃ under the protection of nitrogen, cooling to room temperature after the reaction is finished, precipitating with absolute methanol, collecting precipitate and drying in vacuum for 12 to 24 hours at the temperature of 40 to 60 ℃ to obtain the triblock copolymer of polylactic acid-polycaprolactone-glycidyl methacrylate.
  7. 7. The wear-resistant environment-friendly plastic for children toys of claim 6, wherein the catalyst is added in an amount of 0.1 to 0.5 percent of the total mass of polylactic acid monomers and polycaprolactone monomers, the glycidyl methacrylate is added in an amount of 5 to 15 percent of the diblock prepolymer, and the azodiisobutyronitrile is added in an amount of 1 to 3 percent of the glycidyl methacrylate.
  8. 8. The wear-resistant environment-friendly plastic for children toys of claim 1, wherein the antioxidant comprises hindered phenol antioxidants and phosphite antioxidants, wherein the hindered phenol antioxidants are antioxidant 1010, the phosphite antioxidants are antioxidant 168, and the mass ratio of the antioxidant 1010 to the antioxidant 168 is 1-3:1; The lubricant is calcium stearate.
  9. 9. A method for preparing the wear-resistant environment-friendly plastic for the children's toys according to any one of claims 1-8, which is characterized by comprising the steps of weighing polylactic acid, polycaprolactone, a reactive compatibilizer, a composite wear-resistant agent, an antioxidant and a lubricant, mixing the materials at a high speed to obtain a uniform premix, carrying out melt blending extrusion on the premix, granulating the extruded material through a water-cooling brace, and drying to obtain the wear-resistant environment-friendly plastic for the children's toys.
  10. 10. The method for preparing the wear-resistant environment-friendly plastic for children toys according to claim 9, wherein the specific parameters of the high-speed mixing are that polylactic acid, polycaprolactone, a reactive compatibilizer, a composite wear-resistant agent, an antioxidant and a lubricant are mixed for 5 to 15 minutes at a temperature of 25 to 40 ℃ at a rotating speed of 500 to 1500 revolutions per minute; The specific parameters of the melt blending extrusion are that premix is added into a double-screw extruder, the screw rotating speed is 200 to 400 revolutions per minute, the feeding rotating speed is 20 to 40 revolutions per minute, and the gauge pressure is-0.06 to-0.1 MPa in the extrusion process; the drying is to granulate the extruded material by water-cooling, and then collect the obtained granules, and keep the granules at the temperature of 60-80 ℃ for 2-4 hours.

Description

Wear-resistant environment-friendly plastic for children toys and preparation method thereof Technical Field The invention belongs to the technical field of high polymer materials, and particularly relates to wear-resistant environment-friendly plastic for children toys and a preparation method thereof. Background In the field of children toys, plastic materials have become dominant materials for manufacturing various toys due to the characteristics of easy processing and forming, large design freedom and relatively low production cost. From bell and gutta-percha in infancy, to building blocks and model cars for preschool children, to outdoor children amusement facilities, the plastic body and shadow are ubiquitous. Along with the development of social economy and the improvement of the attention of parents to the growth environment of children, the modern toy design not only pursues interesting and educational functions, but also brings the environmental protection safety and durability of the materials at the first place. In practical use scenarios, the wear problems faced by children's toys are manifold. Taking the splicing building blocks as an example, the connecting column and the clamping groove parts of the toy bear larger friction force and extrusion force in the repeated inserting and pulling process. When a certain toy company produces a certain spliced building block, the product is found in a laboratory simulation plug test, the surface of a connecting column can be obviously worn white marks after 300 times of plug, the plug force is reduced by more than 40%, and the spliced building block is loose, so that the construction stability is influenced. More seriously, when the building blocks fall on the outdoor sand floor, deep scratches are generated on the surface due to the scratching of sand, and the microscopic ravines not only conceal dirt, but also provide a hotbed for bacteria to grow. Another type of typical product is the wheels of children's scooters and strollers. After the wheels of the baby carriage continuously run for 10 kilometers on the cement pavement, the wear depth of the wheel surface can reach 0.3 to 0.5 millimeter, and the fine powder generated by wear not only pollutes the environment, but also increases the rolling resistance after the surface of the wheels becomes rough, so that the portability of children in riding is greatly compromised. In addition, when the cambered surface of the base of some rocking toys is repeatedly rubbed with the ground, the surface layer is easy to wear, and the internal filler is exposed, so that potential safety hazards are brought. In order to solve the above problems, the prior art has been variously explored. One technical route is to add inorganic rigid fillers to the matrix resin to increase the surface hardness, such as silica, alumina or diatomaceous earth. Studies have shown that adding less than 10% diatomaceous earth to polypropylene can improve the impact strength and bending properties of the composite, but when the amount added exceeds 10%, voids are easily formed between the diatomaceous earth particles, rather decreasing the impact strength of the material. Meanwhile, the interface compatibility of the inorganic filler and the organic resin is poor, and the surface treatment is required by a silane coupling agent or a titanate coupling agent, but if the coupling agent remains or migrates, organic volatile matters can be introduced, so that the environment-friendly risk exists for the infant toy. Another technical route is to use fiber reinforcement, such as the addition of glass or carbon fibers. Research shows that the reinforcing and toughening effects can be realized by adding the modified carbon nano tube into the polylactic acid, but the adhesion and dispersion between the filler and the matrix are the difficulties to be solved urgently. Glass fiber reinforcement also has a fiber floating phenomenon, which causes roughness on the surface of the toy and may irritate the skin of children. In addition, the anisotropy of such materials makes dimensional control of precision parts difficult. In recent years, researchers have begun to focus on the development of novel wear-resistant fillers. There is a patent to use polyoxymethylene powder as an antiwear agent, and to improve the wear resistance of a material by utilizing its self-lubricating property. There are also studies on attempts to introduce fullerenes as wear-resistant fillers into polymer matrices, and to use their spherical molecular structure and excellent mechanical properties to improve the wear resistance of the material. In addition, some naturally derived materials such as micro-lint fibers, layered double hydroxides, and the like have also been explored for polymer modification. The nano hydroxyapatite has been widely applied in the biomedical material field in recent years due to good biocompatibility and mechanical property, but the application in toy mater