Siloxane-based dynamic cross-linking agent and application thereof

[0026] Example 1

[0027] Siloxane-based dynamic crosslinking agent DTSi5

[0028] (((((1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane-1,9-diyl)bis(azanediyl))bis(methylene))bis(2,1-phenylene )) Synthesis of diboronic acid):

[0029] The specific reaction equation is as follows:

[0030]

[0031] The specific implementation steps are as follows: In a round-bottom flask, add 5.8 g amino silicone oil, 6.75 g formaldehyde phenylboronic acid, and 50 mL tetrahydrofuran, and react for 3 days at room temperature under nitrogen protection. Then, 2 g of sodium borohydride was added to the reaction system to reduce the double bond formed by the condensation of aldoamine. After the product is concentrated by a rotary evaporator, it is repeatedly washed with dichloromethane and tetrahydrofuran, and then separated and purified by liquid chromatography. The yield is higher than 67%. The corresponding NMR data of the product are as follows: 1H NMR (500MHz, CD3OD): δ 7.51, 7.24, 4.12, 2.6, 0.23. 13C NM

[0032] Example 2

[0033] (1) Preparation of reversible dynamic crosslinking polyamide masterbatch:

[0034] In this example, the siloxane-based dynamic crosslinking agent DTSi5 prepared in Example 1 is used as a typical dynamic crosslinking agent for description:

[0035] Mix 2% of the antioxidant system (antioxidant 1010: antioxidant 168=1:2) into 1kg of polyamide 6, and stir evenly; add 0.2kg of the above siloxane dynamic crosslinking agent DTSi5 into the high-speed mixer , Under normal temperature conditions, fully mix for 30 minutes to obtain a mixture; the mixture is melt-mixed and pelletized in a twin-screw extruder to prepare a dynamic crosslinking agent masterbatch, and the melting temperature is controlled below 280°C.

[0036] (2) Preparation of reversibly cross-linked polyamide 6: In 5 kg of polyamide 6, add more than 1 kg of dynamic cross-linking agent masterbatch, in a high-speed mixer, fully disperse, and then extrude and granulate in a twin-screw extruder ( The melting t

[0040] Example 3 Preparation of reversibly crosslinked polyamide 66:

[0041] (1) Preparation of reversible dynamic crosslinking polyamide masterbatch:

[0042] In this example, the siloxane-based dynamic crosslinking agent DTSi5 prepared in Example 1 is used as a typical dynamic crosslinking agent for description:

[0043] Mix 2% of the antioxidant system (antioxidant 1010: antioxidant 168=1:2) into 1kg of polyamide 66, and stir evenly; add 0.2kg of the siloxane-based dynamic crosslinking agent DTSi5 into the high-speed mixer , Under normal temperature conditions, fully mix for 30 minutes to obtain a mixture; the mixture is melt-mixed and pelletized in a twin-screw extruder to prepare a dynamic crosslinking agent masterbatch, and the melting temperature is controlled below 300°C.

[0044] (2) Preparation of reversibly cross-linked polyamide 66: In 5 kg of polyamide 66, add 1 kg of the above-mentioned dynamic cross-linking agent masterbatch, disperse it fully in a high-speed mixer, and t