A toughening antioxidant, preparation method and application in modified engineering plastics

Abstract

The present invention discloses antioxidants including 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (AMBHP), 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate-styrene copolymer (PAS) and 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate-N-phenylmaleimide copolymer (PAN). The antioxidants are characterized by having structural formulas of: #imgabs0#, wherein n=10-100. The three antioxidants have good resistance to thermal oxidative aging and have a similar structure to polyamide 6. They can be used as antioxidant modifiers and toughening agents for polyamide 6 with good effects.

Description

Technical Field

[0001] The invention relates to the preparation of three antioxidants and modified nylon 6 thereof, and particularly belongs to the field of synthesis of resin raw materials and pharmaceutical pesticide intermediates. Background Art

[0002] During service, nylon 6 is susceptible to oxidation and fracture, generating a series of highly reactive free radicals. These free radicals continuously undergo a self-oxidation chain reaction, leading to a decline in nylon 6 material performance and an increased likelihood of brittle fracture. To improve the service life and performance of nylon 6, adding antioxidants is one of the most direct and effective methods to prevent its thermal oxidative aging. Currently reported antioxidants include antioxidant 264, antioxidant 246, antioxidant 1135, antioxidant AO, antioxidant 1010, and antioxidant 1098. While these antioxidants are widely used and perform well in the service life of most plastics, they still have some drawbacks, primarily in two areas: first, their antioxidant properties still need to be improved, and second, their ability to maintain the toughness of plastics is poor. With the advancement of society and technology, improving the aging resistance and toughness of nylon 6 remains a pressing challenge for many researchers in the industry. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an antioxidant of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and to obtain two copolymerized antioxidants by reacting the antioxidant with styrene and N-phenylmaleimide, respectively, so as to solve the limitation of single function of antioxidants in the prior art.

[0004] The technical solution of the present invention is: a toughening antioxidant, wherein the antioxidant is a 2-acrylamidoethyl propionate containing a functional group 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, a binary or ternary copolymer.

[0005] The antioxidant is 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, or a copolymer thereof with styrene and N-phenylmaleimide.

[0006] The antioxidants are 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (AMBHP), 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate-styrene copolymer (PAS) and 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate-N-phenylmaleimide copolymer (PAN), and their specific structural formulas are:

[0007]

[0008] Wherein, n=10-100.

[0009] The reaction formula of the AMBHP is as follows:

[0010]

[0011] The preparation method of the antioxidant AMBHP comprises the following reaction steps:

[0012] (1) Cooling a water bath to 0-5°C, adding a dichloromethane solution of N-(2-hydroxyethyl)acrylamide and 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid into a reactor, introducing nitrogen, and stirring at this temperature for 15-30 minutes;

[0013] (2) adding a dichloromethane solution of N,N'-dicyclohexylcarbodiimide dropwise over a period of 15-30 minutes;

[0014] (3) Add 4-dimethylaminopyridine, stir, heat to 10-30°C, and react for 12-24 hours to obtain a crude product;

[0015] (4) The crude product was purified with an eluent of ethyl acetate:cyclohexane = 1:1-9, the eluent was evaporated under reduced pressure, and the obtained product was vacuum dried at 40-100°C for 4-24 hours to obtain a yellow viscous oil sample, which was the small molecule antioxidant AMBHP.

[0016] The reaction formula of the PAS is as follows:

[0017]

[0018] The preparation method of the antioxidant PAS comprises the following reaction steps:

[0019] (1) Heat an oil bath to 50-100°C, add a xylene solution of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and styrene to the reactor, and stir at this temperature for 20-60 minutes. Then, introduce N2 gas, stir, add initiator azobisisobutyl, and heat to 90-130°C for reaction for 5-10 hours.

[0020] (2) Pour the reaction solution into petroleum ether while hot and stir to obtain a crude product;

[0021] (3) dissolving the crude product in ethanol and reprecipitating with petroleum ether;

[0022] (4) The obtained product is vacuum dried at 60-100° C. for 4-24 h to obtain a powdery binary copolymer sample, namely, the macromolecular antioxidant PAS.

[0023] The reaction formula of PAN is shown below:

[0024]

[0025] The preparation method of the antioxidant PAS comprises the following reaction steps:

[0026] (1) Heat an oil bath to 50-100°C, add a cyclohexanone solution of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and N-phenylmaleimide to the reactor, and stir at this temperature for 20-60 minutes. Then, introduce N2 gas, stir, add initiator, heat to 90-130°C, and react for 3-5 hours.

[0027] (2) Pour the reaction solution into petroleum ether while hot and stir to obtain a crude product;

[0028] (3) dissolving the crude product in ethanol and reprecipitating with petroleum ether;

[0029] (4) The obtained product is vacuum dried at 60-100° C. for 4-24 h to obtain a powdery binary copolymer sample, namely, the macromolecular antioxidant PAS.

[0030] In the preparation method of the two antioxidants, the molar ratio of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid 2-acrylamidoethyl ester and styrene (N-phenylmaleimide) is 1:1-4; the precipitant of the first precipitation is a non-polar solvent, and the second precipitation agent is a 1:1 mixture of a non-polar solvent and a polar solvent.

[0031] The beneficial effects of the present invention are as follows: the present invention prepares a copolymerized macromolecular antioxidant of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate 2-acrylamidoethyl ester and styrene (N-phenylmaleimide); the two polymers have good resistance to thermal oxidative aging and toughening properties, and can be used as thermal oxidative aging inhibitors for engineering plastics such as PA6 and PA56 with good effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The stress-strain curve results of the product obtained in Example 2 after adding nylon 6 (PA6);

[0033] Figure 2 This is the infrared spectrum of the antioxidant in this application. DETAILED DESCRIPTION

[0034] The present invention is further described below by way of specific examples, but the examples do not limit the scope of protection of the present invention.

[0035] Example 1

[0036] Preparation of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate: Cool a water bath to 0-5°C, dissolve 0.8625g of N-(2-hydroxyethyl)acrylamide and 2.088g of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid in 20ml of dichloromethane, add the mixed solution to a reactor, introduce nitrogen, and stir at this temperature for 20 minutes; dissolve 2.3175g of N,N'-dicyclohexylcarbodiimide in 10ml of dichloromethane and add dropwise to the reaction vessel over a period of 15-30 minutes; add 0.0916g of 4-dimethylaminopyridine, stir, heat to 20°C, and react for 24 hours to obtain a crude product; purify the crude product with an eluent of ethyl acetate:cyclohexane = 1:1, evaporate the eluent under reduced pressure, and dry the obtained product at 60°C in vacuum for 24 hours to obtain a small molecule antioxidant.

[0037] 2-Acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and styrene(N-phenylmaleimide) are polycondensed to obtain a binary copolymer product. The preparation method is as follows:

[0038] Heat an oil bath to 76°C, dissolve 1.876g of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 0.52g of styrene (0.8656g of N-phenylmaleimide) in 20mL of cyclohexanone; transfer the solution to a 250ml four-necked flask equipped with a stirrer, condenser, thermometer, and gas guide tube, introduce N2 gas, and stir at this temperature for 30min, add 0.0657g of azobisisobutylene, heat to 100°C and react for 5h; pour the reaction solution into 100ml of petroleum ether while hot, stir to obtain a crude product; dissolve the crude product in 20ml of ethanol and reprecipitate with 100ml of petroleum ether to remove small molecules; and dry the obtained product in vacuum at 80°C for 24h to obtain a powdery binary copolymer resin sample, i.e., antioxidant PAS (PAN).

[0039] Example 2

[0040] Preparation of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate: Cool a water bath to 0-5°C, dissolve 8.625g of N-(2-hydroxyethyl)acrylamide and 20.88g of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid in 200ml of dichloromethane, add the mixed solution to a reactor, introduce nitrogen, and stir at this temperature for 20 minutes; dissolve 23.175g of N,N'-dicyclohexylcarbodiimide in 100ml of dichloromethane and add dropwise to the reaction vessel over a period of 15-30 minutes; add 0.916g of 4-dimethylaminopyridine, stir, heat to 20°C, and react for 24 hours to obtain a crude product; purify the crude product with an eluent of ethyl acetate:cyclohexane = 1:1, evaporate the eluent under reduced pressure, and dry the obtained product at 60°C in vacuum for 24 hours to obtain a small molecule antioxidant.

[0041] 2-Acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and styrene(N-phenylmaleimide) are polycondensed to obtain a binary copolymer product. The preparation method is as follows:

[0042] Heat an oil bath to 76°C, dissolve 18.76g of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 5.2g of styrene (8.656g of N-phenylmaleimide) in 200mL of cyclohexanone; transfer the solution to a 500ml four-necked flask equipped with a stirrer, condenser, thermometer, and gas guide tube, introduce N2 gas, and stir at this temperature for 30min, add 0.657g of azobisisobutylene, heat to 100°C and react for 5h; pour the reaction solution into 1000ml of petroleum ether while hot, stir to obtain a crude product; dissolve the crude product in 200ml of ethanol and reprecipitate with 1000ml of petroleum ether to remove small molecules; and dry the obtained product in vacuum at 80°C for 24h to obtain a powdery binary copolymer resin sample, i.e., antioxidant PAS (PAN).

[0043] The mass spectrometry data of the antioxidant prepared in this application are as follows:

[0044] AMBHP

[0045] 1H NMR(400MHz,Chloroform-d)δ7.13(s,2H),6.41(d,J=18.4Hz,1H),6.17(s,1H),6.03(s,1H), 5.76(s,1H),5.26(s,1H),4.34(s,2H),3.72(s,2H),3.01(s,2H),2.77(s,2H),1.56(s,18H).

[0046] PAS

[0047] 1H NMR (400MHz, Chloroform-d) δ6.97 (s, 13H), 5.08 (s, 1H), 3.95 (d, J = 68.0Hz, 4H), 2.82 (s, 3H), 2.54 (s, 3H), 2.31 (s, 1H), 1.75 (s, 5H), 1.43 (s, 26H).

[0048] PAN

[0049] 1H NMR(400MHz,Chloroform-d)δ7.22(s,12H),6.91(s,3H),5.05(s,1H),4.03(s,4H),3.31(s,4H ),2.93(s,1H),2.86(s,1H),2.71(s,2H),2.46(s,2H),2.34(s,1H),1.92(s,2H),1.37(s,18H).

[0050] The product obtained in Example 2 was added to nylon 6 (PA6), and the composite material was subjected to thermal oxidative aging performance research. The results of thermal oxidative aging at 150°C for 2 days were as follows:

[0051]

[0052]

[0053] Note: No. 1 in the table has no antioxidant added, No. 2 has 1% AMBHP added, No. 3 has 1% PAN added, and No. 4 has 1% PAS added.

[0054] The product obtained in Example 2 was added to nylon 6 (PA6), and the composite material was subjected to thermal oxidative aging performance research. The stress-strain curve results were as follows: Figure 1 shown.

[0055] Professionals can associate it with binary, ternary and higher copolymers containing 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate through common sense, which are also within the scope of protection.

Claims

1. A toughening antioxidant characterized by: The antioxidant is 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate binary copolymer or 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate ternary copolymer.

2. The toughening antioxidant according to claim 1, wherein: The antioxidant is 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, a copolymer of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and styrene, or a copolymer of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and N-phenylmaleimide.

3. The toughening antioxidant according to claim 1, wherein: The antioxidant is 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate , 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate-styrene binary copolymer or 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate-N-phenylmaleimide copolymer ; where n=10-100.

4. A method for preparing 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, characterized by: The reaction steps are as follows: (1) Cooling a water bath to 0-5°C, adding a dichloromethane solution of N-(2-hydroxyethyl)acrylamide and 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid into a reactor, introducing nitrogen, and stirring at this temperature for 15-30 minutes; (2) adding a dichloromethane solution of N,N'-dicyclohexylcarbodiimide dropwise over a period of 15-30 minutes; (3) Add 4-dimethylaminopyridine, stir, heat to 10-30°C, and react for 12-24 hours to obtain a crude product; (4) The crude product was purified with an eluent of ethyl acetate:cyclohexane = 1:1-9, the eluent was evaporated under reduced pressure, and the obtained product was vacuum dried at 40-100°C for 4-24 hours to obtain a yellow viscous oil sample.

5. A method for preparing a 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate-styrene binary copolymer, characterized by: The reaction steps are as follows: (1) Heat the oil bath to 50-100°C, add the xylene solution of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and styrene to the reactor, and stir at this temperature for 20-60 minutes. Then, introduce N2 gas, stir, add the initiator azobisisobutyronitrile, heat to 90-130°C, and react for 5-10 hours. (2) Pour the reaction solution into petroleum ether while hot and stir to obtain a crude product; (3) dissolving the crude product in ethanol and reprecipitating with petroleum ether; (4) The obtained product was vacuum dried at 60-100° C. for 4-24 h to obtain a powdery binary copolymer sample.

6. A method for preparing a binary copolymer of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and N-phenylmaleimide, characterized by: The reaction steps are as follows: (1) Heat the oil bath to 50-100°C, add the cyclohexanone solution of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and N-phenylmaleimide to the reactor, and stir at this temperature for 20-60 minutes. Then, introduce N2 gas, stir, add the initiator, heat to 90-130°C, and react for 3-5 hours. (2) Pour the reaction solution into petroleum ether while hot and stir to obtain a crude product; (3) dissolving the crude product in ethanol and reprecipitating with petroleum ether; (4) The obtained product was vacuum dried at 60-100° C. for 4-24 h to obtain a powdery binary copolymer sample.

7. The preparation method according to claim 6, characterized in that: The molar ratio of 2-acrylamidoethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate to N-phenylmaleimide is 1:1-4.

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