Preparation method and application of high-efficiency migration-resistant hindered phenol antioxidant

Abstract

The invention discloses a preparation method and application of an efficient migration-resistant hindered phenol antioxidant. The preparation method comprises the following steps: dissolving a hindered phenolic compound and an epoxy compound in a solvent to carry out ring-opening reaction, and then further reacting the carboxyl-activated hindered phenolic compound with a ring-opened product to obtain the novel antioxidant with 4-6 hindered phenolic hydroxyl groups in the structure. According to the novel antioxidant disclosed by the invention, on the basis of fully utilizing the capability of capturing free radicals by hindered phenolic hydroxyl, the oxidation resistance of the antioxidant is improved by changing a para-substituent structure, the migration resistance of the antioxidant is improved by changing the molecular weight and the molecular structure, and the service life of the antioxidant in a high polymer material is prolonged. The novel antioxidant has the advantages of simple process preparation, high efficiency, migration resistance and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material anti-aging, and specifically designs a preparation method and application of a high-efficiency migration-resistant hindered phenol antioxidant. Background Art

[0002] High-density polyethylene (HDPE) is a highly crystalline, non-polar thermoplastic resin with good wear resistance, electrical insulation, toughness and cold resistance; it has good chemical stability, is insoluble in any organic solvent at room temperature, is resistant to corrosion by acids, alkalis and various salts, and has low water absorption; however, high-density polyethylene has poor aging resistance and environmental stress cracking resistance, especially thermal oxidation will significantly reduce its performance, so antioxidants must be added to the resin to improve this deficiency.

[0003] Plastic aging is usually caused by radiation, high temperature and contact with oxygen, which lead to the generation of active free radicals in the molecular chain, thus triggering a series of chain reactions and reducing the molecular weight. Therefore, the methods of anti-oxidation can be divided into three types: capturing free radicals generated by photoaging, decomposing hydroperoxides generated by photoaging, and anti-oxidation synergy to reduce the source of molecular chain reactions. However, the antioxidants commonly used in the market have a narrow scope of application and a single function.

[0004] Hindered phenol antioxidants are one of the most widely used phenolic antioxidants. Among them, 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid is a common basic raw material for the synthesis of hindered phenolic antioxidants. It is an excellent hydrogen donor and works by donating phenolic hydrogen to free radicals generated by molecular chains. The generated phenoxy free radicals are resonance-stabilized and have the ability to further capture other free radicals, thereby destroying the chain reaction produced by free radical oxidation during polymer aging.

[0005] Traditional hindered phenol antioxidants have a small molecular weight, are easy to migrate and volatilize during processing, storage and use, and have poor extraction resistance. Not only do they have poor antioxidant properties, but they also cause environmental pollution. However, antioxidants with excellent performance are not all due to their high molecular weight, because too high a molecular weight is not conducive to the dispersion of antioxidants in polymers, but affects the use of materials. Therefore, the ideal molecular weight of a general hindered phenol antioxidant is between 500 and 2000, and it has good compatibility with the polymer matrix.

[0006] The present invention has found that the antioxidant effect of the hindered phenol antioxidant is closely related to the chemical structure of the antioxidant. The number and type of substituents on the benzene ring of the hindered phenol antioxidant determine the antioxidant activity of the hindered phenol antioxidant. For example, 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid is a hindered phenol antioxidant with a good effect. Furthermore, the antioxidant performance of the antioxidant is mainly related to the number of phenolic hydroxyl groups and the electronegativity of the para-substituent of the phenolic hydroxyl group. The more the number of phenolic hydroxyl groups of the antioxidant and the weaker the electronegativity of the para-substituent, the greater the activity and the stronger its antioxidant performance. Summary of the invention

[0007] In order to solve the problems of small molecular weight, easy migration, migration out of material surface and low antioxidant efficiency of antioxidants in the prior art, the present invention uses hindered phenol compounds as raw materials, uses chemical reactions to react them with polyepoxy group compounds, changes the structure of the para-substituted group of the phenolic hydroxyl group on the benzene ring, changes the original electron-withdrawing group into an electron-donating group, increases the electron cloud density of the oxygen atom on the phenolic hydroxyl group, makes the hydrogen atom on the phenolic hydroxyl group have a lower dissociation energy, improves the ability of the hindered phenolic hydroxyl group to capture free radicals generated by aging of polymer materials, and provides a preparation method and application of a high-efficiency, migration-resistant hindered phenolic antioxidant with multiple hindered phenol groups in structure, moderate molecular weight, good compatibility and significant antioxidant effect.

[0008] One of the purposes of the present invention is to provide a method for preparing a highly efficient migration-resistant hindered phenolic antioxidant, which comprises the following steps:

[0009] (1) The hindered phenol compound and the polyepoxy group compound are dissolved in a solvent, and a catalyst is added dropwise under nitrogen atmosphere protection and condensation reflux conditions to carry out a ring-opening reaction.

[0010] (2) Dissolve the hindered phenol compound and thionyl chloride in an organic solvent, heat to 30° C. under a nitrogen atmosphere, drop triethylamine, and stand for 6 hours under condensation reflux conditions, and then treat the tail gas. After the reaction is completed, distill under reduced pressure to remove the solvent and unreacted thionyl chloride to obtain an acyl chloride hindered phenol compound.

[0011] (3) slowly dripping the acyl chloride hindered phenol compound into the solution of step (1) under ice bath, and then dropping the catalyst triethylamine at room temperature ten minutes later to react overnight. After the reaction is completed, the mixture is extracted, washed, centrifuged, and vacuum dried to obtain the high-efficiency migration-resistant hindered phenol antioxidant. The reaction formula is as follows:

[0012]

[0013] The reaction formula only takes the reaction of a single epoxy group as an example. The molecular structure of polyepoxides contains two or more epoxy groups. By selecting different epoxy compounds, hindered phenol antioxidants with different molecular weights and numbers of phenolic hydroxyl groups can be obtained.

[0014] Furthermore, the hindered phenol compound is 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid.

[0015] Furthermore, in step (1), the solvent is any one of tetrahydrofuran, dimethyl sulfoxide, and N,N-dimethylformamide.

[0016] Furthermore, the polyepoxy group compound in step (1) is any one of propylene glycol triglycidyl ether, ethylene glycol diglycidyl ether, isocyanuric acid triglycidyl ester, and adipic acid diglycidyl ester.

[0017] Furthermore, in step (1), the catalyst is any one of 2,2′-diamino-N-methyldiethylamine, triphenylphosphine, and N,N,N′,N′-tetramethylethylenediamine.

[0018] Furthermore, the molar ratio of the hindered phenol compound, the polyepoxy compound and the catalyst used in step (1) is 2-3:1:0.005-0.01, and the molar ratio of the hindered phenol compound and the polyepoxy compound used in step (3) is 2-3:1.

[0019] Furthermore, the reaction temperature in step (1) is 60°C to 125°C.

[0020] Furthermore, the reaction time in step (1) is 12 to 24 hours.

[0021] The second purpose of the present invention is to protect the high-efficiency migration-resistant hindered phenolic antioxidant prepared by the above method. The high-efficiency migration-resistant hindered phenolic antioxidant prepared by the present invention has a molecular weight of 1218-1863, is migration-resistant, and is not easy to move out of the material surface. The molecular structure has multiple phenolic hydroxyl groups that provide hydrogen acceptors for free radicals. Under the premise of ensuring the long-term stability and effectiveness of the antioxidant, it can achieve high-efficiency free radical capture ability and achieve significant antioxidant effect.

[0022] The third purpose of the present invention is to protect the application of the high-efficiency migration-resistant hindered phenolic antioxidant in the preparation of aging-resistant polymer materials such as high-density polyethylene materials.

[0023] Furthermore, 0.5 wt% of the hindered phenol antioxidant of the present invention is added into the high-density polyethylene material, and its anti-oxidation effect is remarkable.

[0024] In addition to the aging resistance of high-density polyethylene materials, the hindered phenol antioxidant obtained by the present invention is also suitable for the preparation of other aging-resistant polymer materials.

[0025] Compared with the prior art, the present invention has the following significant advantages:

[0026] (1) The high-efficiency migration-resistant hindered phenol antioxidant provided by the present invention uses commonly used 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid and epoxy compounds as raw materials, has a simple preparation process, mild conditions and low production cost.

[0027] (2) The molecular weight of the high-efficiency migration-resistant hindered phenol antioxidant provided by the present invention is 1218-1863, which is the optimal molecular weight for use as an antioxidant for polymer materials. The molecular structure is symmetrical and is not easy to migrate or move out of the material surface. It has good compatibility with the polymer matrix and can be used for aging modification of various polyolefin resins.

[0028] (3) The high-efficiency migration-resistant hindered phenol antioxidant provided by the present invention has 4 to 6 phenolic hydroxyl groups with free radical capture ability in its molecular structure, has high antioxidant efficiency and strong antioxidant performance, and is suitable for industrial promotion and application.

[0029] (4) The high-efficiency migration-resistant hindered phenolic antioxidant provided by the present invention has a counter-substituent group that is changed from the electron-withdrawing group -COOH of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid to the electron-donating group -OCOR, which further enhances the electron cloud density of the oxygen atom on the phenolic hydroxyl group through the conjugation effect, making it easier for the hydrogen atom to dissociate. The electrons on the phenolic hydroxyl group are then transferred to the counter-substituent group through the inductive effect, thereby avoiding the coupling formed by hydrogen bonding between the phenolic hydroxyl groups in molecules. Finally, the reaction between the hydrogen atoms on the phenolic hydroxyl group and the free radicals is accelerated, achieving the effect of faster free radical capture, thereby improving the antioxidant effect.

[0030] (5) The high-density polyethylene pipe provided by the present invention containing 0.5% by mass of hindered phenol antioxidant has excellent antioxidant properties, which does not reduce or even exceeds the physical and chemical properties of the high-density polyethylene itself, and can be widely promoted and applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The free radical scavenging ability diagram of different concentrations of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid and antioxidants prepared in examples.

[0032] Figure 2 This is the infrared spectrum of the antioxidant prepared in Example 1.

[0033] Figure 3 This is a molecular structure diagram of the antioxidant prepared in Example 1.

[0034] Figure 4 This is the molecular structure diagram of the antioxidant prepared in Example 2.

[0035] Figure 5 This is the molecular structure diagram of the antioxidant prepared in Example 3.

[0036] Figure 6 This is the molecular structure diagram of the antioxidant prepared in Example 4.

[0037] Figure 7 A line graph of the change in tensile strength of the blank sample, comparative example 1, and examples 1-4 was prepared before and after aging.

[0038] Figure 8 A line graph showing the change in elongation at break of the blank sample, comparative example 1, and examples 1-4 before and after aging.

[0039] Fig. 9 A line graph of the impact strength variation of the blank sample, comparative example 1 and examples 1-4 was prepared before and after aging.

[0040] Fig.10 This is a scanning electron microscope image of the cross section of the HDPE material impact specimen before aging.

[0041] Fig.11 This is a scanning electron microscope image of the cross section of the HDPE material impact specimen after aging for 300 hours.

[0042] Fig.12 This is a scanning electron microscope image of the cross section of the impact specimen of Comparative Example 1 after aging for 300 hours.

[0043] Fig.13 This is a scanning electron microscope image of the cross section of the impact specimen of Example 1 after aging for 300 hours. DETAILED DESCRIPTION

[0044] A high-efficiency migration-resistant hindered phenol antioxidant, the preparation method of which comprises the following steps:

[0045] (1) The hindered phenol compound and the polyepoxy group compound are dissolved in a solvent, and a catalyst is added dropwise under nitrogen atmosphere protection and condensation reflux conditions to carry out a ring-opening reaction.

[0046] (2) Dissolve the hindered phenol compound and thionyl chloride in an organic solvent, heat to 30° C. under a nitrogen atmosphere, drop triethylamine, and stand for 6 hours under condensation reflux conditions, and then treat the tail gas. After the reaction is completed, distill under reduced pressure to remove the solvent and unreacted thionyl chloride to obtain an acyl chloride hindered phenol compound.

[0047] (3) slowly dripping the acyl chloride hindered phenol compound into the solution of step (1) under ice bath, and then adding the catalyst triethylamine at room temperature after ten minutes to react overnight. After the reaction is completed, the product is extracted, washed, centrifuged, and vacuum dried to obtain the said high-efficiency migration-resistant hindered phenol antioxidant.

[0048] Wherein, the polyepoxy group compound is any one of glycerol triglycidyl ether, isocyanuric acid triglycidyl ether, ethylene glycol diglycidyl ether, and adipic acid diglycidyl ester.

[0049] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments.

[0050] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0051] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0052] The raw materials used in the following examples of the present invention are described as follows:

[0053] The hindered phenol compound, polyepoxy group compound, catalyst, solvent and raw materials are all commercially available conventional products.

[0054] The determination methods of tensile strength, elongation at break, impact strength and plastic aging test involved in the following embodiments of the present invention are specifically described as follows:

[0055] The test methods for tensile strength and elongation at break shall comply with the relevant provisions of GB / T 1040.2-2006, the test methods for impact strength shall comply with the relevant provisions of ISO 179-1:2000, and the test methods for plastic aging tests shall comply with the relevant provisions of GB / T16422.2.

[0056] Example 1

[0057] A preparation method and application of a high-efficiency migration-resistant hindered phenol antioxidant, comprising the following steps:

[0058] (1) Pour 40 ml of N,N-dimethylformamide solvent into a beaker, add 8.3 g of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid and 2.6 g of propylene glycol triglycidyl ether, and sonicate for 10 min to completely dissolve. Pour the dissolved solution into a 100 ml three-necked round-bottom flask, add 0.003 g of triphenylphosphine, pass nitrogen atmosphere for protection, condense and reflux, stir at 500 r / min, heat to 125°C, and keep the temperature for reaction for 24 h.

[0059] (2) Weigh 10 g of 3,5-di-tert-butyl-4-hydroxybenzene propionic acid and dissolve it in a 250 ml three-necked flask filled with 100 ml of dichloromethane. Take 8 ml of thionyl chloride and slowly add it to the solution. Heat it to 30° C. under a nitrogen atmosphere, drop 0.1 g of triethylamine, and let it stand for 6 hours under condensation reflux conditions. Then, treat the tail gas. After the reaction is completed, distill under reduced pressure to remove the solvent and unreacted thionyl chloride to obtain the reaction intermediate 3,5-di-tert-butyl-4-hydroxybenzene propionyl chloride.

[0060] (3) 9 g of 3,5-di-tert-butyl-4-hydroxyphenylpropionyl chloride was dissolved in 30 ml of N,N-dimethylformamide and slowly added to the three-necked flask in step (1) under an ice bath at 0°C. After reacting for ten minutes, the mixture was moved to room temperature and 1.2 g of triethylamine was added dropwise to react overnight. The reaction solution was extracted, washed, centrifuged and vacuum dried to obtain a dark green esterified product, which was the target product of the hindered phenol antioxidant.

[0061] (4) 100 parts by weight of HDPE 5000S resin and 0.5 parts by weight of hindered phenol antioxidant were put into a torque rheometer, kneaded at 200°C and 90 r / min for 8 minutes to make them uniform, and then pulverized and dried in a 60°C oven overnight to obtain an aging-resistant high-density polyethylene material.

[0062] Example 2

[0063] A preparation method and application of a hindered phenol antioxidant, comprising the following steps:

[0064] (1) Pour 50 ml of dimethyl sulfoxide solvent into a beaker, add 5.56 g of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid and 1.74 g of ethylene glycol diglycidyl ether, and sonicate for 20 min to completely dissolve. Pour the dissolved solution into a 500 ml three-necked round-bottom flask, add 0.012 g of 2,2′-diamino-N-methyldiethylamine, pass nitrogen atmosphere for protection, condense and reflux, stir at 500 r / min, heat to 120°C, and keep the temperature for reaction for 12 h.

[0065] (2) Weigh 10 g of 3,5-di-tert-butyl-4-hydroxybenzene propionic acid and dissolve it in a 250 ml three-necked flask filled with 100 ml of dichloromethane. Take 8 ml of thionyl chloride and slowly add it to the solution. Heat it to 30° C. under a nitrogen atmosphere, drop 0.1 g of triethylamine, and let it stand for 6 hours under condensation reflux conditions. Then, treat the tail gas. After the reaction is completed, distill under reduced pressure to remove the solvent and unreacted thionyl chloride to obtain the reaction intermediate 3,5-di-tert-butyl-4-hydroxybenzene propionyl chloride.

[0066] (3) Take 6 g of 3,5-di-tert-butyl-4-hydroxyphenylpropionyl chloride and dissolve it in 30 ml of dimethyl sulfoxide. Slowly add it to the three-necked flask in step (1) under an ice bath at 0°C. After reacting for ten minutes, move it to room temperature and add 0.8 g of triethylamine dropwise to react overnight. The reaction solution is extracted, washed, centrifuged and vacuum dried to obtain the target product.

[0067] (4) 100 parts by weight of HDPE 5000S resin and 0.5 parts by weight of hindered phenol antioxidant were put into a torque rheometer, kneaded at 200°C and 90 r / min for 8 minutes to make them uniform, and then pulverized and dried in a 60°C oven overnight to obtain an aging-resistant high-density polyethylene material.

[0068] Example 3

[0069] A preparation method and application of a hindered phenol antioxidant, comprising the following steps:

[0070] (1) Pour 60 ml of tetrahydrofuran solvent into a beaker, add 4.18 g of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid and 1.49 g of triglycidyl isocyanurate, and sonicate for 10 min to completely dissolve them. Pour the dissolved solution into a 500 ml three-necked round-bottom flask, add 0.058 g of N,N,N′,N′-tetramethylethylenediamine, pass nitrogen atmosphere for protection, condense and reflux, stir at 500 r / min, heat to 60°C, and keep the temperature for reaction for 20 h.

[0071] (2) Weigh 10 g of 3,5-di-tert-butyl-4-hydroxybenzene propionic acid and dissolve it in a 250 ml three-necked flask filled with 100 ml of dichloromethane. Take 8 ml of thionyl chloride and slowly add it to the solution. Heat it to 30° C. under a nitrogen atmosphere, drop 0.1 g of triethylamine, and let it stand for 6 hours under condensation reflux conditions. Then, treat the tail gas. After the reaction is completed, distill under reduced pressure to remove the solvent and unreacted thionyl chloride to obtain the reaction intermediate 3,5-di-tert-butyl-4-hydroxybenzene propionyl chloride.

[0072] (3) Take 9g of 3,5-di-tert-butyl-4-hydroxyphenylpropionyl chloride and dissolve it in 30ml of tetrahydrofuran. Slowly add it to the three-necked flask in step (1) under an ice bath at 0°C. After reacting for ten minutes, move it to room temperature and add 1.2g of triethylamine dropwise to react overnight. The reaction solution is extracted, washed, centrifuged and vacuum dried to obtain the target product.

[0073] (4) 100 parts by weight of HDPE 5000S resin and 0.5 parts by weight of hindered phenol antioxidant were placed in a torque rheometer, kneaded at 200°C and 90 r / min for 8 minutes to make them uniform, and then pulverized and dried in a 60°C oven overnight to obtain an aging-resistant high-density polyethylene material.

[0074] Example 4

[0075] A preparation method and application of a hindered phenol antioxidant, comprising the following steps:

[0076] (1) Pour 50 ml of N,N-dimethylformamide solvent into a beaker, add 8.34 g of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid and 2.58 g of diglycidyl adipate, and sonicate for 10 min to completely dissolve them. Pour the dissolved solution into a 500 ml three-necked round-bottom flask, then drop 0.012 g of N,N,N′,N′-tetramethylethylenediamine, pass nitrogen atmosphere for protection, condense and reflux, stir at 500 r / min, heat to 125°C, and keep the temperature for reaction for 24 h.

[0077] (2) Weigh 10 g of 3,5-di-tert-butyl-4-hydroxybenzene propionic acid and dissolve it in a 250 ml three-necked flask filled with 100 ml of dichloromethane. Take 8 ml of thionyl chloride and slowly add it to the solution. Heat it to 30° C. under a nitrogen atmosphere, drop 0.1 g of triethylamine, and let it stand for 6 hours under condensation reflux conditions. Then, treat the tail gas. After the reaction is completed, distill under reduced pressure to remove the solvent and unreacted thionyl chloride to obtain the reaction intermediate 3,5-di-tert-butyl-4-hydroxybenzene propionyl chloride.

[0078] (3) Take 6 g of 3,5-di-tert-butyl-4-hydroxyphenylpropionyl chloride and dissolve it in 30 ml of N,N-dimethylformamide. Slowly add it to the three-necked flask in step (1) under an ice bath at 0°C. After reacting for ten minutes, move it to room temperature and add 0.8 g of triethylamine dropwise to react overnight. The reaction solution is extracted, washed, centrifuged and vacuum dried to obtain the target product.

[0079] (4) 100 parts by weight of HDPE 5000S resin and 0.5 parts by weight of hindered phenol antioxidant were put into a torque rheometer, kneaded at 200°C and 90 r / min for 8 minutes to make them uniform, and then pulverized and dried in a 60°C oven overnight to obtain an aging-resistant high-density polyethylene material.

[0080] Comparative Example 1

[0081] 100 parts by weight of HDPE 5000S resin and 0.5 parts by weight of 3,5-di-tert-butyl-4-hydroxybenzenepropionic acid were put into a torque rheometer, mixed at 200°C and 90 r / min for 8 minutes, and then crushed and dried in a 60°C oven overnight to obtain an aging-resistant high-density polyethylene material.

[0082] The free radical scavenging ability of antioxidants can be measured by the DPPH free radical scavenging method: 2 ml of DPPH solution (0.04 mg / ml) dissolved in ethanol is mixed with 2 ml of antioxidant solutions of different concentrations (2, 4, 6 and 8 mg / ml) dissolved in ethanol, and placed in the dark for 30 minutes. The free radical scavenging activity is then calculated by monitoring the change in the UV-visible light absorption intensity of DPPH at 517 nm. The calculation formula is:

[0083]

[0084] The sample is the UV-visible light intensity of 2 ml antioxidant solution of different concentrations mixed with 2 ml DPPH solution; the control is the UV-visible light absorption intensity of 2 ml antioxidant solution of different concentrations mixed with 2 ml anhydrous ethanol; DPPH is the UV-visible light absorption intensity of 2 ml DPPH solution mixed with 2 ml anhydrous ethanol.

[0085] The experiment shows that when the antioxidant concentration is 2 mg / ml, the free radical scavenging ability of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid is 83.65%. The free radical scavenging abilities of the antioxidants prepared in Examples 1-4 of the present invention are all above 90%. When the antioxidant concentration is greater than 2 mg / ml, the free radical scavenging abilities of all antioxidants are basically stable, all reaching above 92%, showing a highly effective antioxidant effect.

[0086] The parameters and test results of the high-density polyethylene pipes prepared in Examples 1-4 and the high-density polyethylene pipes prepared in Comparative Example 1 were statistically sorted out, and the results are shown in Table 1.

[0087] Table 1 Performance parameters of high-density polyethylene pipe products prepared from pure materials, comparative example 1 and examples 1-4 after different aging times

[0088]

[0089] The data shown in Table 1 show that the high-efficiency migration-resistant hindered phenolic antioxidants prepared in Examples 1-4 are applied to high-density polyethylene pipes to give them excellent antioxidant effects. After 300 hours of UV heat aging, the elongation at break of the high-density polyethylene pipe without adding antioxidants decreased from 383.97% to 5.27%, the retention rate was 1.37%, and the impact strength was increased from 105.65KJ / M 2 Reduced to 6.25KJ / M 2 , retention rate 5.91%, the material is brittle as a whole, and has no antioxidant effect; the elongation at break of the high-density polyethylene pipe prepared in Comparative Example 1 was reduced from 458.92% to 25.70%, the retention rate was 5.60%, and the impact strength was reduced from 110.68KJ / M 2 Reduced to 29.35KJ / M 2, the retention rate is 26.52%, and the long-term antioxidant effect is poor; the high-density polyethylene pipe prepared by Examples 1-4 still maintains good mechanical properties after 300h of UV heat aging, and the antioxidant effect is obvious.

[0090] Photographed by scanning electron microscope Figure 10-13 It can be seen that due to the high crystallinity and regular molecular chains of HDPE, its impact section before aging presents a striped dense structure; under ultraviolet accelerated aging, ultraviolet radiation will cause a series of reactions such as free radical initiation, cross-linking, and branching of the molecular chain. Therefore, the impact section of the blank sample and the comparative example 1 sample after aging presents a completely irregular and disordered structure, while the impact section of the example 1 sample still maintains a roughly striped dense structure without major changes, and the antioxidant effect is obvious.

[0091] It should be noted that, although the above embodiments have been described in this article, the patent protection scope of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made using the contents of the present invention specification, directly or indirectly applying the above technical solutions to other related technical fields are all included in the patent protection scope of the present invention.

Claims

1. A method for preparing a highly efficient migration-resistant hindered phenolic antioxidant, characterized in that: The following steps are involved: (1) Dissolving a hindered phenol compound and a polyepoxy compound in a solvent, and adding a catalyst dropwise to carry out a ring-opening reaction under nitrogen atmosphere protection and condensation reflux conditions; (2) Dissolving a hindered phenol compound and thionyl chloride in an organic solvent, heating to 30° C. under a nitrogen atmosphere, dropping triethylamine, standing for 6 hours under condensation reflux conditions, and treating the tail gas. After the reaction is completed, performing reduced pressure distillation to remove the solvent and unreacted thionyl chloride to obtain an acyl chloride hindered phenol compound; (3) Slowly dripping the acyl chloride hindered phenol compound into the solution of step (1) under ice bath, and then adding the catalyst triethylamine at room temperature after ten minutes to react overnight. After the reaction is completed, the product is extracted, washed, centrifuged, and vacuum dried to obtain the said high-efficiency migration-resistant hindered phenol antioxidant.

2. The preparation method according to claim 1, characterized in that: The hindered phenol compound is 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid.

3. The preparation method according to claim 1, characterized in that: The solvent in step (1) is any one of tetrahydrofuran, dimethyl sulfoxide and N,N-dimethylformamide.

4. The preparation method according to claim 1, characterized in that: The polyepoxy compound is Any one of glycerol triglycidyl ether, isocyanuric acid triglycidyl ether, ethylene glycol diglycidyl ether, and adipic acid diglycidyl ether.

5. The preparation method according to claim 1, characterized in that: The catalyst in step (1) is any one of 2,2´-diamino-N-methyldiethylamine, triphenylphosphine, and N,N,N´,N´-tetramethylethylenediamine.

6. The preparation method according to claim 1, characterized in that: The molar ratio of the hindered phenol compound, the polyepoxy compound and the catalyst used in step (1) is 2-3:1:0.005-0.01, and the molar ratio of the acyl chloride hindered phenol compound and the polyepoxy compound used in step (3) is 2-3:

1.

7. The preparation method according to claim 1, characterized in that: The reaction temperature in step (1) is 60°C to 125°C.

8. The preparation method according to claim 1, characterized in that: The reaction time in step (1) is 12 to 24 hours.

9. A high-efficiency, migration-resistant hindered phenol antioxidant prepared by the method according to any one of claims 1 to 8.

10. Use of the high-efficiency migration-resistant hindered phenol antioxidant as claimed in claim 9 in the preparation of aging-resistant polymer materials, characterized in that: The polymer material includes a high-density polyethylene material, the density of which is 0.941 to 0.960 g / cm³ and the melt flow rate of which is 2.20 to 2.26 g / 10 min.

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