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CN-122011510-A - Layered composite metal hydroxide and preparation method and application thereof

CN122011510ACN 122011510 ACN122011510 ACN 122011510ACN-122011510-A

Abstract

The invention belongs to the technical field of polymer functional additives, and discloses a layered composite metal hydroxide, a preparation method and application thereof, wherein the chemical expression of the layered composite metal hydroxide is M 2+ 1‑x M 3+ x (OH) 2 (A n‑ ) x/n ·mH 2 O@P;M 2+ selected from any one or two of Mg 2+ 、Zn 2+ 、Ni 2+ 、Ca 2+ 、Fe 2+ and Cu 2+ , M 3+ is selected from any one or two of Al 3+ 、Co 3+ 、Ti 3+ 、Fe 3+ and Cr 3+ , A n‑ is selected from beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) acrylate, 3, 5-di-tert-butyl-4-hydroxybenzoate or beta- (3-tert-butyl-4-hydroxy-5-methylphenyl) acrylate, x is 0.1-0.5, n is 1 or 2, M is 0.4-1.5, P is selected from chitosan, chitin, polyamino glucose, polyallylamine or polyethylene polyamine, and the content of P is 5-15wt% based on the total weight of the layered composite metal hydroxide. The layered composite metal hydroxide of the present invention has excellent migration resistance when used as a polymer antioxidant.

Inventors

  • BAI YIQING
  • XU MENG
  • GAO DALI
  • FENG YONGJUN
  • TANG PINGGUI
  • XU KAI
  • QUAN HUI
  • LV YUN

Assignees

  • 中国石油化工股份有限公司
  • 中石化(北京)化工研究院有限公司
  • 北京化工大学

Dates

Publication Date
20260512
Application Date
20241112

Claims (10)

  1. 1. A layered double hydroxide, characterized in that the chemical expression of the layered double hydroxide is M 2+ 1-x M 3+ x (OH) 2 (A n- ) x/n ·mH 2 O@P; Wherein M 2+ is selected from any one or two of Mg 2+ 、Zn 2+ 、Ni 2+ 、Ca 2+ 、Fe 2+ and Cu 2+ , preferably Mg 2+ and/or Zn 2 + ;M 3+ is selected from any one or two of Al 3+ 、Co 3+ 、Ti 3+ 、Fe 3+ and Cr 3+ , preferably Al 3+ ; A n- is selected from beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 3, 5-di-tert-butyl-4-hydroxybenzoate or beta- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, preferably beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate; x is 0.1 to 0.5, preferably 0.16 to 0.35, n is 1 or 2, and m is 0.4 to 1.5; P is selected from chitosan, chitin, polyamino glucose, polyallylamine or polyethylene polyamine, preferably chitosan, and the content of P is 5-15wt% based on the total weight of the layered composite metal hydroxide.
  2. 2. A method for preparing a layered composite metal hydroxide, comprising: (1) In the presence of a solvent, reacting divalent metal salt, trivalent metal salt, a precipitant and a guest anion compound to obtain a reaction solution; (2) And in the presence of protective gas, the reaction solution and the blocking agent solution are contacted and reacted to obtain the layered composite metal hydroxide.
  3. 3. The preparation method according to claim 2, wherein the divalent metal salt provides divalent metal ions of either or both of Mg 2+ 、Zn 2+ 、Ni 2+ 、Ca 2+ 、Fe 2+ and Cu 2+ , preferably Mg 2+ and/or Zn 2+ ; the trivalent metal ions provided by the trivalent metal salt are any one or two of Al 3+ 、Co 3+ 、Ti 3+ 、Fe 3+ and Cr 3+ , and are preferably Al 3+ ; The divalent metal salt and the trivalent metal salt are inorganic metal salts.
  4. 4. The preparation method according to claim 2, wherein the precipitant is at least one of NaOH, KOH, ammonia, hexamethylenetetramine and urea.
  5. 5. The preparation method according to claim 2, wherein the guest anionic compound is at least one of hindered phenol compound, preferably beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid, beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid sodium, beta- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionic acid sodium, 3, 5-di-tert-butyl-4-hydroxybenzoic acid and 3, 5-di-tert-butyl-4-hydroxy sodium benzoate, and further preferably beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid.
  6. 6. The preparation method according to claim 2, wherein the blocking agent is a polyamino polymer, preferably chitosan, chitin, polyamino glucose, polyallylamine or polyethylene polyamine, further preferably chitosan.
  7. 7. The preparation method according to claim 2, wherein the molar ratio of divalent metal ions to trivalent metal ions is (2-4): 1; The ratio of the sum of the molar contents of the divalent metal salt and the trivalent metal salt to the molar content of the precipitant is 1 (1.5-3); The molar ratio of the guest anion compound to the trivalent metal ion is 1 (0.5-10); The mass ratio of the blocking agent to the sum of the contents of the divalent metal salt and the trivalent metal salt is 1 (3-50).
  8. 8. The preparation method according to claim 2, wherein in the step (1), the solvent is water, and the reaction time is 5-80min; In step (2), the reaction time is 0.5-12h, and the reaction temperature is 25-180 ℃, preferably 40-180 ℃; the blocking agent solution is acetic acid aqueous solution of blocking agent.
  9. 9. A layered double hydroxide prepared by the preparation method of any one of claims 2 to 8.
  10. 10. Use of a layered double hydroxide according to claim 1 or 9 as a polymeric antioxidant, preferably polypropylene.

Description

Layered composite metal hydroxide and preparation method and application thereof Technical Field The invention relates to the technical field of polymer functional assistants, in particular to a layered composite metal hydroxide, a preparation method and application thereof. Background Polypropylene (PP) is one of the most widely used commercial thermoplastics, has excellent characteristics of good transparency, corrosion resistance, high insulation and the like, and is widely applied to various aspects in life. However, due to the existence of a large amount of unstable alpha-H in the structure, the alpha-H can undergo automatic oxidative degradation reaction under the action of external factors such as ultraviolet rays, heat, oxygen and the like, and the molecular weight change and the mechanical property of the polymer product are directly reduced. Based on the wide demand of polypropylene and the defect of easy thermo-oxidative aging in the environment, anti-aging aids such as antioxidant and the like are needed to inhibit degradation reaction and improve long-term stability, and the polypropylene has important practical application value. The basic principle of avoiding the thermal oxidative degradation of polypropylene is to inhibit the formation of free radicals. This can be achieved using functional auxiliaries. The functional auxiliary agent is usually an organic small molecular compound, and has the main function of capturing free radicals generated in the thermal oxygen degradation process so as to cut off chain reaction, however, in the use process, the small molecular functional auxiliary agent cannot be fixed in the polymer because of low relative molecular mass, so that the functional auxiliary agent is easy to migrate to the surface of the polymer, and after the migration, the polypropylene product is yellowing and embrittled in appearance, the thermal oxygen aging resistance effect is poor, the service life is reduced, and the environment is polluted so as to cause harm to human bodies. For this reason, in order to increase the migration resistance of functional auxiliaries, in recent times, the scholars have proposed to immobilize the polymeric functional auxiliaries onto an inorganic particle carrier, thereby increasing the service life of polypropylene. Layered double hydroxide LDHs (Layered Double Hydroxides) is a two-dimensional material having a molecular structure that is a layered double hydroxide, and the chemical composition can be expressed as [ M 2+1-xM3+x(OH)2](An-)x/n·mH2O,An- is an inorganic or organic anion that is not framework charge compensated. Based on the chemical composition, the type and the number of the main body laminates, the in-layer elastic space and the interaction variability of the main body and the guest, the small molecular antioxidant is intercalated between the LDHs layers to prepare the antioxidant with an intercalated structure. Under the protection of the interaction of host and guest and lattice energy, the migration resistance of the antioxidant is obviously enhanced. The intercalation assembly has universality and is widely applied to the aspect of migration resistance functional auxiliary agents. However, in the daily use process, the antioxidants at the edge parts of the layers are always in close contact with the solvent and the air, and therefore, the situation that part of the antioxidants are extracted and exchanged out of the intercalation structure by the solvent and CO 2 is unavoidable, so that the inter-layer edges are blocked, the antioxidants at the edges are prevented from migrating out of LDHs, and the migration resistance of the antioxidants of the intercalation structure is further enhanced. At present, a method for blocking an LDHs interlayer is not reported, but a blocking structure is commonly found in a drug slow-release material, for example, a literature R.Meng,Z.Wu,Q.T.Xie,J.S.Cheng,B.Zhang,Preparation and characterization of zein/carboxymethyl dextrin nanoparticles to encapsulate curcumin:Physicochemical stability,antioxidant activity and controlled release properties,Food Chem.340(2021)127893 adopts zein and carboxymethyl dextrin, and the curcumin is coated and blocked under the electrostatic interaction, hydrogen bond and hydrophobic interaction. However, the preparation of the blocking material is complicated, and is difficult to be used for blocking the object between LDHs layers. Therefore, a method suitable for interlayer blocking of LDHs needs to be developed and researched. Disclosure of Invention The invention aims to provide a layered composite metal hydroxide, a preparation method and application thereof, and the layered composite metal hydroxide has excellent migration resistance when used as a polymer antioxidant. In order to achieve the above object, a first aspect of the present invention provides a layered double hydroxide having a chemical formula of M 2+1-xM3+x(OH)2(An-)x/n·mH2 O@P; Wherein M 2+ is selected