Preparation process of high-toughness flame-retardant nylon material

Abstract

The application relates to the technical field of nylon, and discloses a preparation process of high-toughness flame-retardant nylon material, wherein water, potassium titanate whiskers and cationic polyamide flame-retardant agent are added into a reaction kettle, modified by heating and stirring, dried to remove water, then the mixture is mixed with nylon resin, extruded, granulated, and high-toughness flame-retardant nylon material is obtained. The cationic polyamide flame-retardant agent is modified on the surface of the potassium titanate whiskers, the compatibility between the potassium titanate whiskers and the nylon is improved, the interface bonding strength between the potassium titanate whiskers and the nylon resin is enhanced, the potassium titanate whiskers play a better toughening and reinforcing role, and the impact strength and the bending strength of the nylon material are obviously improved. The cationic polyamide flame-retardant agent contains a large number of phosphoramide flame-retardant groups, forms a nitrogen-phosphorus flame-retardant system, and obviously improves the limiting oxygen index and the flame-retardant performance of the nylon material.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of nylon, in particular to a preparation process of high-toughness flame-retardant nylon material. BACKGROUND

[0002] Nylon is a kind of polyamide resin with excellent performance, which is widely applied in the fields of plastics, fibers, concrete and the like. The traditional nylon resin has the problems of low impact strength, poor toughness and the like, and the nylon resin is easy to burn and has poor flame retardancy, thereby limiting the practical application of the nylon resin. It is of great significance to toughen the nylon and improve the flame retardancy of the nylon. Generally, a rubber elastomer, nano-silicon dioxide, potassium titanate whisker and the like toughening agent, and antimony trioxide, nitrogen phosphorus and the like halogen-free flame retardant are added into the nylon.

[0003] The potassium titanate whisker is a fibrous crystal material with high mechanical strength and heat resistance, and is widely applied in the filling modification of plastics such as nylon, polyurethane and polyformaldehyde. The research difficulty lies in the surface modification of the potassium titanate whisker and the improvement of the compatibility of the potassium titanate whisker with a resin matrix such as nylon. Commonly used modifiers include silane coupling agents, titanate coupling agents and epoxy resins, but these modifiers cannot improve the flame retardancy of the resin material such as nylon. SUMMARY

[0004] The application solves the problems of poor toughness and poor flame retardancy of the nylon material.

[0005] The technical scheme of the application is as follows: a preparation process of high-toughness flame-retardant nylon material:

[0006] (1) dichloromethane, triethylamine, N, N-dimethylethylenediamine and phenyl dichlorophosphate are added into a reaction bottle, and stirring reaction is carried out at 30-45 DEG C for 6-10 h; dichloromethane is removed by rotary evaporation; after water washing, the product is dried and recrystallized in dichloromethane to obtain phenyl dichlorophosphate di (N, N-dimethylethylenediamine). The reaction formula is as follows:

[0007]

[0008] (2) ethanol, phenyl dichlorophosphate di (N, N-dimethylethylenediamine) and N, N'-bis (chloroacetyl) diamine monomer are added into a reaction bottle provided with a condensation reflux pipe; heating and stirring reaction are carried out; ethanol is removed by rotary evaporation; petroleum ether washing and drying are carried out to obtain a cationic polyamide flame retardant. The reaction formula is as follows:

[0009]

[0010] (3) adding water, potassium titanate whisker, cationic polyamide flame retardant into a reaction kettle, modifying by heating and stirring, drying to remove water, then mixing the mixture with nylon resin in a mixer, then extruding in a twin-screw extruder, granulating to obtain high-toughness flame-retardant nylon material.

[0011] Preferably, the ratio of triethylamine, N,N-dimethylethylenediamine and dichlorophenyl phosphate in (1) is (2-2.8) mol:(2-2.4) mol:1 mol.

[0012] Preferably, the temperature during stirring reaction in (2) is 75-85 DEG C, and the reaction time is 24-36 h.

[0013] Preferably, the ratio of dichlorophenyl phosphate di(N,N-dimethylethylenediamine) and N,N'-bis(chloroacetyl) diamine monomer in (2) is (0.9-1.1) mol:1 mol.

[0014] Preferably, the structural formula of N,N'-bis(chloroacetyl) diamine monomer is a is any integer from 2 to 8.

[0015] Preferably, the ratio of cationic polyamide flame retardant, potassium titanate whisker and nylon resin in (3) is (8-20) g:(30-60) g:100 g.

[0016] Preferably, the temperature during stirring modification in (3) is 65-80 DEG C, and the modification time is 6-12 h.

[0017] Preferably, the temperature of zone 1-6 of the twin-screw extruder in (3) is 210-270 DEG C, and the screw rotation speed is 100-200 r / min.

[0018] The application has the beneficial technical effects that: dichlorophenyl phosphate di(N,N-dimethylethylenediamine) and N,N'-bis(chloroacetyl) diamine monomer are subjected to quaternary ammonium polymerization reaction to obtain cationic polyamide flame retardant, which contains quaternary ammonium salt cation, can have ion exchange action with K + ions in potassium titanate whisker, thereby modifying the cationic polyamide flame retardant on the surface of potassium titanate whisker. The molecular main chain of the polyamide flame retardant contains a large number of amide bonds, which are similar to the structure of the polyamide molecular chain of nylon resin, and the compatibility between them is good, thereby improving the compatibility between the potassium titanate whisker and the nylon, enhancing the interface bonding strength between the potassium titanate whisker and the nylon resin, making the potassium titanate whisker play a better toughening and reinforcing role, and significantly improving the impact strength and bending strength of the nylon material.

[0019] The cationic polyamide flame retardant of the present application contains a large amount of phosphoramide flame retardant groups, forms a nitrogen-phosphorus flame retardant system, pyrolyzes to form phosphoric acid substances at high temperature combustion, promotes the dehydration of the nylon matrix into carbon, and at the same time generates nitrogen-containing non-combustible gas, dilutes oxygen, inhibits combustion, and has a very good flame retardant effect, significantly improving the limiting oxygen index and flame retardant performance. DETAILED DESCRIPTION

[0020] The technical solutions of the present application will be further specifically described below through specific examples. It should be understood that the implementation of the present application is not limited to the following examples, and any form of variation and / or change made to the present application will fall within the scope of protection of the present application.

[0021] The following nylon resin brand is 1030U2, purchased from Shanghai Hengpeng Plastic Co., Ltd. The potassium titanate whisker specification is 5-10um, purchased from Hubei Yamide Biological Medicine Co., Ltd.

[0022] According to the method of the journal "Inorganic Chemistry" 2014, 53, 13, 6698-6707, the literature "Bispidine Dioxotetraaza Macrocycles: A New Class of Bispidines for 64 The N,N'-bis(chloroacetyl)ethylenediamine monomer and the N,N'-bis(chloroacetyl)propylenediamine monomer are prepared according to the method of the journal "Inorganic Chemistry" 2014, 53, 13, 6698-6707, the literature "Bispidine Dioxotetraaza Macrocycles: A New Class of Bispidines for

[0023] In an ice water bath, 22.5 mL of dichloromethane, 29.95 mmol of ethylenediamine, 74.88 mmol of potassium carbonate, 17.5 mL of water were added to the reaction bottle, 59.90 mmol of chloroacetyl chloride was added dropwise, stirred for 1 h, then stirred at 25℃ for 12 h, rotary evaporation to remove dichloromethane, water washing after filtration, the product was dried and recrystallized in acetonitrile to obtain N,N'-bis(chloroacetyl)ethylenediamine monomer, the structural formula is

[0024]

[0025] In an ice water bath, 22.5 mL of dichloromethane, 29.95 mmol of ethylenediamine, 74.88 mmol of potassium carbonate, 17.5 mL of water were added to the reaction bottle, 59.90 mmol of chloroacetyl chloride was added dropwise, stirred for 1 h, then stirred at 25℃ for 12 h, rotary evaporation to remove dichloromethane, water washing after filtration, the product was dried and recrystallized in acetonitrile to obtain N,N'-bis(chloroacetyl)ethylenediamine monomer, the structural formula is

[0026]

[0027] Example 1:

[0028] (1) Add 100 mL of dichloromethane, 80 mmol of triethylamine, 80 mmol of N,N- dimethylethylenediamine, 40 mol of phenylphosphorodichloridate to the reaction bottle, stir for 10 h at 30 °C, remove dichloromethane by rotary evaporation, dry the product after washing with water, recrystallize in dichloromethane to obtain phenylphosphorodiamidate.

[0029] (2) Add 600 mL of ethanol, 100 mmol of phenylphosphorodiamidate, 100 mmol of N,N'- bis(chloroacetyl)ethylenediamine monomer to the reaction bottle equipped with a condenser reflux tube, heat to 85 °C, stir for 24 h, remove ethanol by rotary evaporation, wash with petroleum ether, dry to obtain a cationic polyamide flame retardant.

[0030] (3) Add 20 L of water, 300 g of potassium titanate whisker, 80 g of cationic polyamide flame retardant to the reaction kettle, heat to 80 °C, stir for 6 h, dry and remove water, then mix the mixture with 1 kg of nylon resin in a mixer, and then extrude in a twin-screw extruder, the temperature of 1-6 zones is 210 °C, 240 °C, 255 °C, 270 °C, 270 °C, 260 °C, the screw rotation speed is 100 r / min, and the granulation is obtained to obtain a high-toughness flame-retardant nylon material.

[0031] Example 2:

[0032] (1) Add 150 mL of dichloromethane, 112 mmol of triethylamine, 96 mmol of N,N- dimethylethylenediamine, 40 mol of phenylphosphorodichloridate to the reaction bottle, stir for 10 h at 40 °C, remove dichloromethane by rotary evaporation, dry the product after washing with water, recrystallize in dichloromethane to obtain phenylphosphorodiamidate.

[0033] (2) Add 500 mL of ethanol, 90 mmol of phenylphosphorodiamidate, 100 mmol of N,N'- bis(chloroacetyl)ethylenediamine monomer to the reaction bottle equipped with a condenser reflux tube, heat to 80 °C, stir for 36 h, remove ethanol by rotary evaporation, wash with petroleum ether, dry to obtain a cationic polyamide flame retardant.

[0034] (3) Add 40 L of water, 450 g of potassium titanate whisker, 140 g of cationic polyamide flame retardant to the reaction kettle, heat to 65 °C, stir for 12 h, dry and remove water, then mix the mixture with 1 kg of nylon resin in a mixer, and then extrude in a twin-screw extruder, the temperature of 1-6 zones is 210 °C, 240 °C, 255 °C, 270 °C, 270 °C, 260 °C, the screw rotation speed is 200 r / min, and the granulation is obtained to obtain a high-toughness flame-retardant nylon material.

[0035] Example 3:

[0036] (1) Add 100 mL of dichloromethane, 92 mmol of triethylamine, 84 mmol of N,N- dimethylethylenediamine, 40 mol of phenyl phosphate dichloride to a reaction bottle, stir at 45°C for 6h, remove dichloromethane by rotary evaporation, dry the product after washing with water, recrystallize in dichloromethane to obtain phenyl phosphate di(N,N-dimethylethylenediamine).

[0037] (2) Add 600 mL of ethanol, 110 mmol of phenyl phosphate di(N,N-dimethylethylenediamine), 100 mmol of N,N'-bis(chloroacetyl)propylenediamine monomer to a reaction bottle equipped with a condenser reflux tube, heat to 75°C, stir for 36h, remove ethanol by rotary evaporation, wash with petroleum ether, dry to obtain a cationic polyamide flame retardant.

[0038] (3) Add 65L of water, 600g of potassium titanate whisker, 200g of cationic polyamide flame retardant to a reaction kettle, heat to 70°C, stir for 12h, dry to remove water, then mix the mixture with 1kg of nylon resin in a mixer, then extrude in a twin-screw extruder, the temperature of 1-6 zones is 210°C, 240°C, 255°C, 270°C, 270°C, 260°C, the screw speed is 200r / min, and the granulation is obtained. A high-toughness flame-retardant nylon material is obtained.

[0039] Comparative Example 1:

[0040] (1) Extrude 1kg of nylon resin in a twin-screw extruder, the temperature of 1-6 zones is 210°C, 240°C, 255°C, 270°C, 270°C, 260°C, the screw speed is 100r / min, and the granulation is obtained. A nylon material is obtained.

[0041] Comparative Example 2:

[0042] (1) Mix 80g of cationic polyamide flame retardant, 1kg of nylon resin in a mixer, then extrude in a twin-screw extruder, the temperature of 1-6 zones is 210°C, 240°C, 255°C, 270°C, 270°C, 260°C, the screw speed is 100r / min, and the granulation is obtained. A nylon material is obtained.

[0043] Comparative Example 3:

[0044] (1) Mix 300g of potassium titanate whisker, 1kg of nylon resin in a mixer, then extrude in a twin-screw extruder, the temperature of 1-6 zones is 210°C, 240°C, 255°C, 270°C, 270°C, 260°C, the screw speed is 100r / min, and the granulation is obtained. A nylon material is obtained.

[0045] Comparative Example 4

[0046] (1) Into a reaction flask equipped with a condenser reflux tube, 600 mL of ethanol, 100 mmol of di(N,N-dimethylethylene diamine) benzene phosphonate, 100 mmol of 1,4-dichlorobutane were added, heated to 85 °C, stirred for 24 h, rotary evaporated to remove ethanol, washed with petroleum ether, and dried to obtain the cationic flame retardant.

[0047] (2) Into a reaction kettle, 25 L of water, 300 g of potassium titanate whisker, 80 g of cationic flame retardant were added, heated to 80 °C, stirred for 6 h, dried to remove water, and then the mixture was mixed with 1 kg of nylon resin in a mixer, and then extruded in a twin-screw extruder, with the temperature of 1-6 zones being 210 °C, 240 °C, 255 °C, 270 °C, 270 °C, and 260 °C, and the screw rotation speed being 100 r / min to obtain the nylon material.

[0048] Comparative Example 5:

[0049] (1) Bis(hydroxyacetyl) ethylene diamine was prepared according to the method of the journal “Organic Preparations and Procedures International” Volume 32, No. 1, 2000, p. 84-88, document “Synthesis and characterization of N-alkylhydroxyacetamides”. Into a reaction flask, 1 g of ethylene diamine, 2.53 g of glycolic acid were added, stirred for 2 h at 90 °C, washed with acetone, and dried to obtain bis(hydroxyacetyl) ethylene diamine, with the structural formula being

[0050] (2) Into a reaction flask equipped with a condenser reflux tube, 100 mL of tetrahydrofuran, 100 mmol of N,N'-bis(hydroxyacetyl) ethylene diamine, 200 mmol of triethylamine were added, 100 mmol of benzene phosphonate was added in an ice water bath, stirred for 2 h at 25 °C, and then stirred for 6 h at 40 °C, the filtrate was rotary evaporated after filtration, washed with petroleum ether, and dried to obtain the polyamide flame retardant. The structural formula is as follows:

[0051]

[0052] (3) Into a reaction kettle, 25 L of water, 300 g of potassium titanate whisker, 80 g of polyamide flame retardant were added, heated to 80 °C, stirred for 6 h, dried to remove water, and then the mixture was mixed with 1 kg of nylon resin in a mixer, and then extruded in a twin-screw extruder, with the temperature of 1-6 zones being 210 °C, 240 °C, 255 °C, 270 °C, 270 °C, and 260 °C, and the screw rotation speed being 100 r / min to obtain the nylon material.

[0053] The nylon material was injection molded, and the impact strength was tested according to GB / T 1043.1-2008 standard. The bending strength was tested according to GB / T9341-2000 standard. The oxygen index was tested according to GB / T 2406.1-2008 standard.

[0054] Table 1 Properties of the nylon material

[0055]

[0056] The impact strength and bending strength of the nylon material of Comparative Example 1 were low, the toughness was poor, and the limiting oxygen index was low, and the flame retardancy was poor.

[0057] Comparative Example 2 added a cationic polyamide flame retardant, which had a large number of amide bonds in the molecular main chain, and was similar in structure to the polyamide molecular chain of the nylon resin, and had good compatibility between the two. The addition of the cationic polyamide flame retardant had little effect on the mechanical properties of the nylon material, and the impact strength and bending strength were not affected. The flame retardant contained a large number of phosphoramide flame retardant groups forming a nitrogen-phosphorus flame retardant system, pyrolyzing to form phosphoric acid substances at high temperature, promoting the dehydration of the nylon matrix to form carbon, and at the same time generating nitrogen-containing non-combustible gas, diluting oxygen, and inhibiting combustion, which had a good flame retardant effect, and significantly improved the limiting oxygen index and flame retardant properties.

[0058] Comparative Example 3 added potassium titanate whiskers, which had a certain toughening effect on the nylon material, but the compatibility of the potassium titanate whiskers with the nylon resin was poor, and the increase in the impact strength and bending strength of the material was low.

[0059] Examples 1-3 used a cationic polyamide flame retardant to modify the surface of the potassium titanate whiskers. The quaternary ammonium salt cation of the flame retardant and the K + ion in the potassium titanate whiskers underwent ion exchange, thereby modifying the cationic polyamide flame retardant on the surface of the potassium titanate whiskers. Since the polyamide flame retardant had good compatibility with the nylon resin, the compatibility between the potassium titanate whiskers and the nylon was improved, the interfacial bonding strength between the two was enhanced, the potassium titanate whiskers played a better toughening and reinforcing role, and the impact strength and bending strength of the nylon material were significantly improved.

[0060] Comparative Example 4 used di(N,N-dimethylethylenediamine) phenyl phosphate and 1,4-dichlorobutane to undergo a quaternization polymerization reaction, and the obtained cationic flame retardant could undergo ion exchange with the potassium titanate whiskers and be modified on the surface thereof. However, the cationic flame retardant did not contain a large number of amide bonds, and had poor compatibility with the nylon resin. It was difficult to effectively improve the compatibility and interfacial bonding strength between the potassium titanate whiskers and the nylon resin, resulting in low toughening and reinforcing effect of the potassium titanate whiskers, and the impact strength and bending strength were lower than those of Example 1.

[0061] The phosphoric esterification reaction of Comparative Example 5 is carried out using N,N'-bis(hydroxyacetyl)ethylenediamine and diphenyl phosphite to obtain a polyamide flame retardant, which does not contain quaternary ammonium salt cations, cannot ion exchange with potassium titanate whiskers, cannot realize surface modification of the potassium titanate whiskers, does not improve the compatibility and interfacial bonding strength of the potassium titanate whiskers with the nylon resin, and results in a lower toughening and reinforcing effect of the potassium titanate whiskers, with the impact strength and the bending strength being lower than those of Example 1.

[0062] The above description of the examples is only used to help understand the method of the present application and its core idea. It should be noted that, for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A process for the preparation of a high tenacity flame retardant nylon material, characterized in that, The preparation process comprises the following steps: (1) adding ethanol, di(N, N-dimethyl ethylenediamine) benzene phosphonate, N, N'-bis (chloroacetyl) diamine monomer into a reaction bottle, heating and stirring reaction, rotary evaporation, washing, drying to obtain a cationic polyamide flame retardant; The structural formula of the N,N'-bis(chloroacetyl)diamine monomer is , a is any integer from 2 to 8; wherein the structure of the bis(N,N-dimethylethylene diamine) phenyl phosphorodithioate is: ; (2) adding water, potassium titanate whisker, cationic polyamide flame retardant into a reaction kettle, heating and stirring modification, drying water, then mixing the mixture with nylon resin in a mixer, then extruding in a twin screw extruder, granulating to obtain a high toughness flame retardant nylon material, wherein the ratio of cationic polyamide flame retardant, potassium titanate whisker and nylon resin in (2) is (8-20) g: (30-60) g: 100 g.

2. The process for preparing high tenacity flame retardant nylon material according to claim 1, characterized in that, The temperature during stirring reaction in (1) is 75-85℃, and the reaction time is 24-36h.

3. The process for preparing high tenacity flame retardant nylon material according to claim 1, wherein, The ratio of di(N, N-dimethyl ethylenediamine) benzene phosphonate, N, N'-bis (chloroacetyl) diamine monomer in (1) is (0.9-1.1) mol: 1 mol.

4. The process for preparing high tenacity flame retardant nylon material according to claim 3, characterized in that, The preparation method of di(N, N-dimethyl ethylenediamine) benzene phosphonate is: adding dichloromethane, triethylamine, N, N-dimethyl ethylenediamine, benzene phosphonate dichloride into a reaction bottle, stirring reaction at 30-45℃ for 6-10h, rotary evaporation, washing, drying the product, recrystallization to obtain di(N, N-dimethyl ethylenediamine) benzene phosphonate.

5. The process for preparing high tenacity flame retardant nylon material according to claim 4, wherein, The ratio of triethylamine, N, N-dimethyl ethylenediamine, benzene phosphonate dichloride is (2-2.8) mol: (2-2.4) mol: 1 mol.

6. The process for preparing high toughness flame retardant nylon material according to claim 1, wherein, The temperature during stirring modification in (2) is 65-80℃, and the modification time is 6-12h.

7. The process for preparing high toughness flame retardant nylon material according to claim 1, wherein, The temperature of 1-6 zones of the twin screw extruder in (2) is 210-270℃, and the screw rotation speed is 100-200r / min.

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