Low-temperature-resistant nylon composite material and preparation method thereof

Abstract

The application relates to the technical field of high polymer materials, and discloses a low-temperature-resistant nylon composite material and a preparation method thereof. The nylon composite material prepared by the application comprises the following raw materials in parts by weight: nylon 6 45-55 parts, nylon 66 15-25 parts, castor oil-based reinforcing agent 2-5 parts, glass fiber 7-10 parts, toughening agent 5-10 parts, dispersing agent 0.5-1 part, lubricant 0.5-2 parts, antioxidant 0.7-1.5 parts, and coupling agent 1-2 parts. The nylon composite material is prepared by taking nylon 6 and nylon 66 as main raw materials and adding functional additives such as the toughening agent and the castor oil-based reinforcing agent, so that the low-temperature resistance and impact toughness of the composite material are improved, and the generation of low-temperature brittleness is reduced. The toughening agent and the castor oil-based reinforcing agent significantly improve the low-temperature resistance through plastic-toughening synergistic action and dynamic-elastic network complementation mechanisms.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a low-temperature resistant nylon composite material and its preparation method. Background Technology

[0002] Nylon (polyamide, PA), a semi-crystalline engineering plastic, is widely used in the automotive, electronics, machinery, and aerospace industries due to its excellent mechanical properties, wear resistance, chemical corrosion resistance, and ease of processing. However, traditional nylons (such as PA6 and PA66) are prone to brittle fracture at low temperatures (typically below -20°C), resulting in a significant decrease in their notched impact strength, which severely limits their application in cold regions or extreme conditions. With the increasing demand for low-temperature resistance in modern industries (such as low-temperature battery components for new energy vehicles, polar equipment, and cold chain equipment), the development of high-performance low-temperature resistant nylon composite materials has become an important research direction in materials science.

[0003] In existing technologies, to improve the low-temperature resistance of nylon materials, a flexible phase is typically introduced by blending thermoplastic elastomers. The elastomer particles induce crazing and shear banding to absorb impact energy. However, excessive addition leads to a decrease in material rigidity, and the poor interfacial compatibility between the elastomer and the nylon matrix makes phase separation prone to occur at low temperatures. Adding small-molecule plasticizers (such as N-butylbenzenesulfonamide) or cold-resistant agents can lower the glass transition temperature of nylon and improve chain segment mobility. However, small-molecule plasticizers are prone to migration and precipitation, leading to performance degradation with long-term use and potentially causing environmental safety issues. Therefore, researchers still need to develop a low-temperature resistant nylon composite material with excellent overall performance to meet practical application requirements. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a low-temperature resistant nylon composite material and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A low-temperature resistant nylon composite material comprises the following raw materials in parts by weight: 5-55 parts of nylon 64, 15-25 parts of nylon 66, 2-5 parts of castor oil-based reinforcing agent, 7-10 parts of glass fiber, 5-10 parts of toughening agent, 0.5-1 part of dispersant, 0.5-2 parts of lubricant, 0.7-1.5 parts of antioxidant, and 1-2 parts of coupling agent;

[0007] Furthermore, the toughening agent is maleic anhydride-grafted POE, the dispersant is silicone powder, the lubricant is oleic acid amide, the antioxidant is one of antioxidant 1010 or antioxidant 1076, and the coupling agent is one of silane coupling agents KH550, KH560 or KH570.

[0008] The castor oil-based reinforcing agent is prepared by the following steps:

[0009] Step A1: Under nitrogen atmosphere, isophorone diisocyanate and dibutyltin dilaurate are mixed and stirred evenly in N,N-dimethylformamide, castor oil is added and heated to 60-70℃, stirred and reacted for 2-3 hours, and then distilled under reduced pressure to obtain isocyanate-based castor oil.

[0010] Further, in step A1, the ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, and N,N-dimethylformamide is 0.15-0.153 mol: 3-4 mL: 0.05 mol: 200 mL.

[0011] Step A2: Stir isocyanate-based castor oil and dibutyltin dilaurate in toluene until homogeneous, then add 1,5-pentanediamine hydrochloride, heat to 70°C, and react under nitrogen for 1.5-2.5 hours. Rotary evaporate and dry to obtain amino-terminated castor oil.

[0012] Further, in step A2, the ratio of isocyanate-based castor oil, 1,5-pentanediamine hydrochloride, dibutyltin dilaurate, and toluene is 0.01 mol: 0.03-0.032 mol: 0.5-1 mL: 100 mL;

[0013] Step A3: Mix polyethylene glycol monomethyl ether glycidyl ether (number average molecular weight of 1000) and mercaptoethylamine in ethanol until homogeneous, stir and reflux for 12 h, add n-hexane and stir for 10 min, let stand, collect the lower layer product, and rotary evaporate to obtain mercapto-modified polyethylene glycol derivative.

[0014] Furthermore, in step A3, the ratio of polyethylene glycol monomethyl ether glycidyl ether, mercaptoethylamine, ethanol, and n-hexane is 0.1 mol: 0.1 mol: 100 mL: 300 mL.

[0015] Step A4: Mix and stir the amino-terminated castor oil, mercapto-modified polyethylene glycol derivative and photoinitiator 1173 until homogeneous, transfer to UV lamp for 2.5-3.5 h, add ethyl acetate and stir for 5 min, wash, dry, filter and rotary evaporate to obtain castor oil-based reinforcing agent;

[0016] Furthermore, in step A4, the molar ratio of the carbon-carbon double bond in the amino-terminated castor oil to the thiol group in the thiolized polyethylene glycol derivative is 1-2:1;

[0017] Further, in step A4, the photoinitiator 1173 accounts for 1.5 wt%-2 wt% of the total reactants, and the ethyl acetate accounts for 10 wt%-20 wt% of the total reactants.

[0018] A method for preparing a low-temperature resistant nylon composite material includes the following steps:

[0019] Weigh the raw materials according to the weight parts, dry nylon 6 and nylon 66, add castor oil-based reinforcing agent, glass fiber, toughening agent, dispersant, lubricant, antioxidant and coupling agent, mix and stir evenly, then transfer to a twin-screw extruder for plasticizing, extrusion and pelletizing to obtain low temperature resistant nylon composite material;

[0020] Furthermore, the screw temperature of the twin-screw extruder is 260-280℃, and the screw speed is 150-250 r / min.

[0021] The beneficial effects of this invention are:

[0022] The nylon composite material prepared by this invention uses nylon 6 and nylon 66 as the main raw materials, and adds functional additives such as toughening agents and castor oil-based reinforcing agents to improve the low-temperature resistance and impact toughness of the composite material and reduce the occurrence of low-temperature brittleness. Among them, the toughening agents and castor oil-based reinforcing agents significantly improve the low-temperature resistance through plasticizing-toughening synergistic effect and dynamic-elastic network complementarity.

[0023] The nylon composite material prepared in this invention incorporates a castor oil-based reinforcing agent, which significantly improves the low-temperature resistance of the composite material and prevents it from migrating and precipitating out of the matrix. This is because the polyether segments in the castor oil-based reinforcing agent possess excellent flexibility, which, when introduced into the matrix, increases the mobility of the molecular chains, thereby reducing low-temperature brittleness. The long-chain fatty acid structure of castor oil itself also acts as an internal lubricant, reducing frictional resistance between nylon molecular chains, improving deformation capacity at low temperatures, and inhibiting crack propagation. The urethane and urea bonds possess highly polar NH groups, which can react with the amide groups in the nylon molecular chains. The formation of a hydrogen bond network enhances the interfacial adhesion between the castor oil-based reinforcing agent and the nylon matrix, ensuring uniform stress distribution at low temperatures and preventing brittle fracture caused by localized stress concentration. Simultaneously, the dynamic hydrogen bond network formed by urea bonds and urethane absorbs energy through reversible fracture during low-temperature deformation, further reducing brittleness. Polyether segments and long-chain fatty acid structures can also embed themselves within the neatly arranged nylon molecular chain structure, weakening intermolecular forces, increasing molecular chain mobility, and thus reducing the crystallinity of the molecular chain segments. This reduced crystallinity decreases the material's brittleness at low temperatures. Furthermore, the dynamic hydrogen bond network formed by urea bonds and urethane (short-term energy dissipation) complements the toughening agent elastomer network (long-term deformation recovery), enabling the material to rapidly dissipate energy and maintain structural integrity after low-temperature impact. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: Castor oil-based reinforcing agent was prepared by the following steps:

[0026] Step A1: Under nitrogen atmosphere, isophorone diisocyanate and dibutyltin dilaurate are mixed and stirred evenly in N,N-dimethylformamide. Castor oil is added and heated to 60°C. The mixture is stirred and reacted for 2 hours. The mixture is then distilled under reduced pressure to obtain isocyanate-based castor oil. The ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, and N,N-dimethylformamide is 0.15 mol: 3 mL: 0.05 mol: 200 mL.

[0027] Step A2: Isocyanate-based castor oil and dibutyltin dilaurate are stirred evenly in toluene, then 1,5-pentanediamine hydrochloride is added, heated to 70°C, and reacted under nitrogen for 1.5 h. The mixture is then rotary evaporated and dried to obtain amino-terminated castor oil. The ratio of isocyanate-based castor oil, 1,5-pentanediamine hydrochloride, dibutyltin dilaurate, and toluene is 0.01 mol: 0.03 mol: 0.5 mL: 100 mL.

[0028] Step A3: Mix polyethylene glycol monomethyl ether glycidyl ether (number average molecular weight of 1000) and mercaptoethylamine in ethanol until homogeneous, stir and reflux for 12 h, add n-hexane and stir for 10 min, let stand, collect the lower layer product, and rotary evaporate to obtain the mercapto-modified polyethylene glycol derivative. The ratio of polyethylene glycol monomethyl ether glycidyl ether, mercaptoethylamine, ethanol and n-hexane is 0.1 mol: 0.1 mol: 100 mL: 300 mL.

[0029] Step A4: Mix and stir the amino-terminated castor oil, mercapto-modified polyethylene glycol derivative, and photoinitiator 1173 until homogeneous. Irradiate under a UV lamp for 2.5 h, add ethyl acetate and stir for 5 min. Wash, dry, filter, and rotary evaporate to obtain the castor oil-based reinforcing agent. The molar ratio of carbon-carbon double bonds in the amino-terminated castor oil to mercapto groups in the mercapto-modified polyethylene glycol derivative is 1:1. The photoinitiator 1173 accounts for 1.5 wt% of the total reactants, and ethyl acetate accounts for 10 wt% of the total reactants.

[0030] Example 2: Castor oil-based reinforcing agent was prepared by the following steps:

[0031] Step A1: Under nitrogen atmosphere, isophorone diisocyanate and dibutyltin dilaurate are mixed and stirred evenly in N,N-dimethylformamide. Castor oil is added and heated to 65°C. The mixture is stirred and reacted for 2.5 hours. The mixture is then distilled under reduced pressure to obtain isocyanate-based castor oil. The ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, and N,N-dimethylformamide is 0.151 mol: 3.5 mL: 0.05 mol: 200 mL.

[0032] Step A2: Isocyanate-based castor oil and dibutyltin dilaurate are stirred evenly in toluene, then 1,5-pentanediamine hydrochloride is added, heated to 70°C, and reacted under nitrogen for 2 hours. The mixture is then rotary evaporated and dried to obtain amino-terminated castor oil. The ratio of isocyanate-based castor oil, 1,5-pentanediamine hydrochloride, dibutyltin dilaurate, and toluene is 0.01 mol: 0.031 mol: 0.75 mL: 100 mL.

[0033] Step A3: Mix polyethylene glycol monomethyl ether glycidyl ether (number average molecular weight of 1000) and mercaptoethylamine in ethanol until homogeneous, stir and reflux for 12 h, add n-hexane and stir for 10 min, let stand, collect the lower layer product, and rotary evaporate to obtain the mercapto-modified polyethylene glycol derivative. The ratio of polyethylene glycol monomethyl ether glycidyl ether, mercaptoethylamine, ethanol and n-hexane is 0.1 mol: 0.1 mol: 100 mL: 300 mL.

[0034] Step A4: Mix and stir the amino-terminated castor oil, mercaptolated polyethylene glycol derivative, and photoinitiator 1173 until homogeneous. Transfer the mixture to a UV lamp for 3 hours of irradiation. Add ethyl acetate and stir for 5 minutes. Wash, dry, filter, and rotary evaporate to obtain the castor oil-based reinforcing agent. The molar ratio of carbon-carbon double bonds in the amino-terminated castor oil to mercapto groups in the mercaptolated polyethylene glycol derivative is 1.5:1. The photoinitiator 1173 accounts for 1.75 wt% of the total reactants, and ethyl acetate accounts for 15 wt% of the total reactants.

[0035] Example 3: Castor oil-based reinforcing agent prepared by the following steps:

[0036] Step A1: Under nitrogen atmosphere, isophorone diisocyanate and dibutyltin dilaurate are mixed and stirred evenly in N,N-dimethylformamide. Castor oil is added and heated to 70°C. The mixture is stirred and reacted for 3 hours. The mixture is then distilled under reduced pressure to obtain isocyanate-based castor oil. The ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, and N,N-dimethylformamide is 0.153 mol: 4 mL: 0.05 mol: 200 mL.

[0037] Step A2: Isocyanate-based castor oil and dibutyltin dilaurate are stirred evenly in toluene, then 1,5-pentanediamine hydrochloride is added, heated to 70°C, and reacted under nitrogen for 2.5 h. The mixture is then rotary evaporated and dried to obtain amino-terminated castor oil. The ratio of isocyanate-based castor oil, 1,5-pentanediamine hydrochloride, dibutyltin dilaurate, and toluene is 0.01 mol: 0.032 mol: 1 mL: 100 mL.

[0038] Step A3: Mix polyethylene glycol monomethyl ether glycidyl ether (number average molecular weight of 1000) and mercaptoethylamine in ethanol until homogeneous, stir and reflux for 12 h, add n-hexane and stir for 10 min, let stand, collect the lower layer product, and rotary evaporate to obtain the mercapto-modified polyethylene glycol derivative. The ratio of polyethylene glycol monomethyl ether glycidyl ether, mercaptoethylamine, ethanol and n-hexane is 0.1 mol: 0.1 mol: 100 mL: 300 mL.

[0039] Step A4: Mix and stir the amino-terminated castor oil, mercaptolated polyethylene glycol derivative, and photoinitiator 1173 until homogeneous. Transfer the mixture to a UV lamp for 3.5 h, add ethyl acetate and stir for 5 min. Wash, dry, filter, and rotary evaporate to obtain the castor oil-based reinforcing agent. The molar ratio of carbon-carbon double bonds in the amino-terminated castor oil to mercapto groups in the mercaptolated polyethylene glycol derivative is 2:1. The photoinitiator 1173 accounts for 2 wt% of the total reactants, and ethyl acetate accounts for 20 wt% of the total reactants.

[0040] Example 4: A method for preparing a low-temperature resistant nylon composite material includes the following steps:

[0041] 645 parts of nylon, 15 parts of nylon 66, 2 parts of castor oil-based reinforcing agent prepared in Example 1, 7 parts of glass fiber, 5 parts of maleic anhydride-grafted POE, 0.5 parts of silicone powder, 0.5 parts of oleic acid amide, 0.7 parts of antioxidant 1010, and 1 part of silane coupling agent KH550.

[0042] The raw materials were weighed according to the weight proportions. After drying Nylon 6 and Nylon 66, the castor oil-based reinforcing agent, glass fiber, maleic anhydride grafted POE, silicone powder, oleic acid amide, antioxidant 1010 and silane coupling agent KH550 prepared in Example 1 were added and mixed evenly. Then, the mixture was transferred to a twin-screw extruder for plasticizing, extrusion and pelletizing to obtain a low-temperature resistant nylon composite material. The screw temperature of the twin-screw extruder was 260°C and the screw speed was 150 r / min.

[0043] Example 5: A method for preparing a low-temperature resistant nylon composite material includes the following steps:

[0044] 650 parts of nylon, 6620 parts of nylon, 3.5 parts of castor oil-based reinforcing agent prepared in Example 2, 9 parts of glass fiber, 7.5 parts of maleic anhydride-grafted POE, 0.75 parts of silicone powder, 1 part of oleic acid amide, 10761 parts of antioxidant, and 1.5 parts of silane coupling agent KH560.

[0045] The raw materials were weighed according to the weight proportions. After drying Nylon 6 and Nylon 66, the castor oil-based reinforcing agent, glass fiber, maleic anhydride grafted POE, silicone powder, oleic acid amide, antioxidant 1076 and silane coupling agent KH560 prepared in Example 2 were added and mixed evenly. Then, the mixture was transferred to a twin-screw extruder for plasticizing, extrusion and pelletizing to obtain a low-temperature resistant nylon composite material. The screw temperature of the twin-screw extruder was 270°C and the screw speed was 200 r / min.

[0046] Example 6: A method for preparing a low-temperature resistant nylon composite material includes the following steps:

[0047] 655 parts of nylon, 6625 parts of nylon, 5 parts of castor oil-based reinforcing agent prepared in Example 3, 10 parts of glass fiber, 10 parts of maleic anhydride-grafted POE, 1 part of silicone powder, 2 parts of oleic acid amide, 1.5 parts of antioxidant 1076, and 2 parts of silane coupling agent KH570.

[0048] The raw materials were weighed according to the weight proportions. After drying Nylon 6 and Nylon 66, the castor oil-based reinforcing agent, glass fiber, maleic anhydride grafted POE, silicone powder, oleic acid amide, antioxidant 1076 and silane coupling agent KH570 prepared in Example 3 were added and mixed evenly. Then, the mixture was transferred to a twin-screw extruder for plasticizing, extrusion and pelletizing to obtain a low-temperature resistant nylon composite material. The screw temperature of the twin-screw extruder was 280°C and the screw speed was 250 r / min.

[0049] Comparative Example 1: This comparative example is a nylon composite material. The difference from Example 6 is that commercially available castor oil is used instead of the castor oil-based reinforcing agent prepared in Example 3. All other aspects are the same.

[0050] Comparative Example 2: This comparative example is a nylon composite material. The difference from Example 6 is that commercially available polyethylene glycol (molecular weight 1000) is used instead of the castor oil-based reinforcing agent prepared in Example 3. All other aspects are the same.

[0051] Comparative Example 3: This comparative example is a nylon composite material. The difference between this example and Example 6 is that the castor oil-based reinforcing agent prepared in Example 3 is added. All other aspects are the same.

[0052] The nylon composite materials prepared in Examples 4-6 and Comparative Examples 1-3 were subjected to low-temperature performance tests at 25℃, -40℃, and -50℃ according to GB / T 1043.1-2008 "Determination of Impact Properties of Simply Supported Beams in Plastics" standard; the test results are shown in Table 1.

[0053] Table 1: Performance Test Results

[0054]

[0055] As shown in Table 1, the notched impact strength of the nylon composite material prepared in this invention was tested at 25℃, -40℃, and -50℃. The notched impact strength at -40℃ was (14.9-15.8) kJ / m. 2 The notched impact strength at -50℃ is (14.1-14.8) kJ / m. 2 This indicates that the nylon composite material has excellent low-temperature resistance.

[0056] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. A low-temperature resistant nylon composite material, characterized in that, The raw materials include the following parts by weight: 45-55 parts of nylon 6, 15-25 parts of nylon 66, 2-5 parts of castor oil-based reinforcing agent, 7-10 parts of glass fiber, 5-10 parts of toughening agent, 0.5-1 part of dispersant, 0.5-2 parts of lubricant, 0.7-1.5 parts of antioxidant, and 1-2 parts of coupling agent; The castor oil-based reinforcing agent is prepared by reacting amino-terminated castor oil with a mercaptolated polyethylene glycol derivative. The amino-terminated castor oil is prepared by reacting isocyanate-based castor oil with 1,5-pentanediamine hydrochloride. The isocyanate-based castor oil is prepared by reacting isophorone diisocyanate with castor oil. The mercaptolated polyethylene glycol derivative is prepared by reacting polyethylene glycol monomethyl ether glycidyl ether with mercaptoethylamine. The castor oil-based reinforcing agent is prepared by the following steps: Step A1: Under nitrogen atmosphere, isophorone diisocyanate and dibutyltin dilaurate are mixed and stirred evenly in N,N-dimethylformamide. Castor oil is added and heated to 60-70℃. The mixture is stirred and reacted for 2-3 hours. The mixture is then distilled under reduced pressure to obtain isocyanate-based castor oil. The ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, and N,N-dimethylformamide is 0.15-0.153 mol: 3-4 mL: 0.05 mol: 200 mL. Step A2: Stir isocyanate-based castor oil and dibutyltin dilaurate in toluene until homogeneous, then add 1,5-pentanediamine hydrochloride, heat to 70°C, and react under nitrogen for 1.5-2.5 hours. Rotary evaporate and dry to obtain amino-terminated castor oil. Step A3: Mix polyethylene glycol monomethyl ether glycidyl ether and mercaptoethylamine in ethanol until homogeneous, stir and reflux for 12 h, add n-hexane and stir for 10 min, let stand, collect the lower layer product, and rotary evaporate to obtain the mercapto-modified polyethylene glycol derivative. The ratio of polyethylene glycol monomethyl ether glycidyl ether, mercaptoethylamine, ethanol and n-hexane is 0.1 mol: 0.1 mol: 100 mL: 300 mL. Step A4: Mix and stir the amino-terminated castor oil, mercaptolated polyethylene glycol derivative and photoinitiator 1173 until homogeneous, transfer to UV lamp for 2.5-3.5 h, add ethyl acetate and stir for 5 min, wash, dry, filter and rotary evaporate to obtain castor oil-based reinforcing agent. The molar ratio of carbon-carbon double bonds in amino-terminated castor oil to mercapto groups in mercaptolated polyethylene glycol derivative is 1-2:

1.

2. The low-temperature resistant nylon composite material according to claim 1, characterized in that, In step A2, the ratio of isocyanate-based castor oil, 1,5-pentanediamine hydrochloride, dibutyltin dilaurate, and toluene is 0.01 mol: 0.03-0.032 mol: 0.5-1 mL: 100 mL.

3. The low-temperature resistant nylon composite material according to claim 1, characterized in that, In step A4, the photoinitiator 1173 accounts for 1.5wt%-2wt% of the total reactants, and ethyl acetate accounts for 10wt%-20wt% of the total reactants.

4. The low-temperature resistant nylon composite material according to claim 1, characterized in that, The toughening agent is maleic anhydride-grafted POE, the dispersant is silicone powder, the lubricant is oleic acid amide, the antioxidant is one of antioxidant 1010 or antioxidant 1076, and the coupling agent is one of silane coupling agents KH550, KH560 or KH570.

5. A method for preparing the low-temperature resistant nylon composite material according to any one of claims 1-4, characterized in that, Includes the following steps: Weigh the raw materials according to the weight proportions, dry nylon 6 and nylon 66, add castor oil-based reinforcing agent, glass fiber, toughening agent, dispersant, lubricant, antioxidant and coupling agent, mix and stir evenly, then transfer to a twin-screw extruder for plasticizing, extrusion and pelletizing to obtain low-temperature resistant nylon composite material.

6. The method for preparing a low-temperature resistant nylon composite material according to claim 5, characterized in that, The screw temperature of the twin-screw extruder is 260-280℃, and the screw speed is 150-250 r / min.

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