Bio-based nylon / polycarbonate alloy and preparation method thereof

Abstract

The invention relates to the technical field of materials, and discloses a bio-based nylon / polycarbonate alloy and a preparation method thereof.The bio-based nylon / polycarbonate alloy is prepared from bio-based nylon, polycarbonate, modified mullite fibers, an antioxidant and a lubricant through mixing and extrusion granulation, wherein the modified mullite fiber is prepared by modifying the surface of the mullite fiber with a macromolecular substance with a polybutadiene-bis (glycidoxymethyl) methoxyl front-section alternating structure, and a large number of epoxy groups in the macromolecular substance structure can play a role of a compatilizer, so that the structural compatibility of bio-based nylon and polycarbonate is improved, and the mechanical properties of the bio-based nylon and the polycarbonate are improved. The bio-based nylon and the polycarbonate are mutually combined to generate complementary advantages, molecular chains among the high-molecular substance, the bio-based nylon and the polycarbonate can form a mutually-wound cross-linked network structure, the mullite fiber serves as a cross-linked network core, and the mechanical strength of the alloy can be improved by utilizing the unique effect of a fiber reinforcing agent of the mullite fiber.

Description

Technical Field

[0001] The invention relates to the technical field of materials, and in particular to a bio-based nylon / polycarbonate alloy and a preparation method thereof. Background Art

[0002] Bio-based nylon is an important branch of nylon. It is generally made from renewable biomass resources. It uses biological, chemical and physical means to manufacture monomers for synthesizing polyamides (such as bio-based lactams, bio-based dibasic acids, bio-based diamines, etc.), and then synthesizes polymer materials through polymerization reactions. Bio-based nylon has the advantages of good oil resistance, high biocompatibility and simple processing, so it is gradually being used in practice. However, the defects of bio-based nylon are also obvious. On the one hand, it has poor toughness and low mechanical strength, which cannot meet the use requirements of high-strength plastic parts. At the same time, its high temperature resistance is poor, and it cannot be used in high temperature environments. These defects have created major obstacles to its further practical application. Therefore, it is of great significance to enhance and modify bio-based nylon.

[0003] The use of other polymer resins to compound with bio-based nylon, such as polycarbonate, can take advantage of their own excellent comprehensive properties, achieve complementary advantages, and prepare composite materials with excellent comprehensive properties. However, the compatibilizer between bio-based nylon and polycarbonate is poor. Simple physical mixing is not only difficult to produce complementary advantages, but may also cause other properties of the material to be greatly reduced due to phase separation. Therefore, it is necessary to add a compatibilizer to improve the compatibility between each other. However, it has been found through research that the addition of epoxy compatibilizers will lead to poor mechanical properties of bio-based nylon / polycarbonate. Based on this, the present invention provides a bio-based nylon / polycarbonate alloy that can solve the problems existing in the prior art. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a bio-based nylon / polycarbonate alloy and a preparation method thereof.

[0006] (II) Technical solution

[0007] A method for preparing a bio-based nylon / polycarbonate alloy, characterized in that the alloy is made of the following raw materials measured in parts by weight:

[0008] 60-75 parts of bio-based nylon, 30-50 parts of polycarbonate, 3-6.5 parts of modified mullite fiber, 0.5-1.5 parts of antioxidant, 0.5-1 parts of lubricant;

[0009] The preparation method comprises the following steps:

[0010] Step 1: Add bio-based nylon and polycarbonate into a mixing kettle according to parts by weight, stir and mix evenly, then add modified mullite fiber, antioxidant and lubricant into the mixing kettle, and continuously stir to form a uniform mixture;

[0011] Step 2: Put the mixture into a twin-screw extruder, control the rotation speed at 300 - 500 r / min and the temperature at 230 - 250 °C, and carry out melt extrusion granulation, then it's done.

[0012] As a further scheme of the present invention, the preparation method of the modified mullite fiber includes the following steps:

[0013] Step S1: Carry out silanization modification on mullite fiber to obtain organic mullite fiber, and the modification reagent is selected as amino silane coupling agent;

[0014] Step S2: Use toluene as the medium, disperse the organic mullite fiber in the medium, then add isocyanate-terminated polybutadiene and metal tin catalyst. After adding, introduce dry nitrogen for protection, raise the temperature to 60 - 70 °C, stir for 2 - 4 h, then continue to add 3-[bis(glycidyl oxymethyl)methoxy]-1,2-propanediol. After adding, raise the temperature to 70 - 80 °C, keep warm and stir for 12 - 18 h, then cool down and discharge to obtain the modified mullite fiber.

[0015] As a further scheme of the present invention, the amino silane coupling agent is 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane.

[0016] As a further scheme of the present invention, the preparation method of the isocyanate-terminated polybutadiene is as follows:

[0017] Add hydroxyl-terminated polybutadiene into tetrahydrofuran, stir and mix evenly to form a uniform reaction solution, then add isocyanation reagent and pyridine into the reaction solution. Then, raise the temperature to 40 - 50 °C, keep warm and stir for 4 - 8 h, then remove the solvent by rotary evaporation under reduced pressure, and separate the product to obtain isocyanate-terminated polybutadiene.

[0018] As a further scheme of the present invention, the number-average molecular weight of the hydroxyl-terminated polybutadiene is 4000.

[0019] As a further scheme of the present invention, the isocyanation reagent is 4-isocyanatobenzoyl chloride or 3-isocyanatobenzoyl chloride.

[0020] As a further scheme of the present invention, the molar ratio of the hydroxyl-terminated polybutadiene to the isocyanation reagent is 1:2.

[0021] As a further solution of the present invention, the metal tin catalyst is any one of dibutyltin dilaurate, dibutyltin diacetate or stannous octoate.

[0022] In the above technical solution, first, the mullite fiber is surface-modified with an amino silane coupling agent to introduce active amino substituents on the surface of the mullite fiber to obtain an organic mullite fiber. Then, using isocyanate-terminated polybutadiene as a bridging agent, under the action of a metal tin catalyst, the mullite fiber is connected with 3-[bis(glycidoxy methyl)methoxy]-1,2-propanediol, and the isocyanate-terminated polybutadiene in the system can continuously carry out an amidation reaction with 3-[bis(glycidoxy methyl)methoxy]-1,2-propanediol, so as to modify a polymer substance with an alternating structure of polybutadiene-bis(glycidoxy methyl)methoxy front segment on the surface of the mullite fiber, and a modified mullite fiber is obtained.

[0023] Among them, the isocyanate-terminated polybutadiene is prepared by using hydroxyl-terminated polybutadiene and an isocyanation reagent as reactants, controlling the addition amount, and using a catalyst pyridine for catalysis through an esterification condensation reaction.

[0024] As a further solution of the present invention, the antioxidant is at least one of antioxidant 1010, antioxidant 168 or antioxidant 1076; the lubricant is montan wax or polyethylene wax.

[0025] A bio-based nylon / polycarbonate alloy is prepared by using the above preparation method.

[0026] (III) Beneficial technical effects

[0027] In the present invention, by preparing a modified mullite fiber by modifying a polymer substance with an alternating structure of polybutadiene-bis(glycidoxy methyl)methoxy front segment on the surface of the mullite fiber, a large number of epoxy groups in the polymer substance structure can react with the terminal amino groups in the bio-based nylon structure and the terminal carboxyl groups in the polycarbonate structure simultaneously during the subsequent melt extrusion process. Therefore, it can play the role of a compatibilizer. On the one hand, it improves the compatibility between the bio-based nylon and polycarbonate structures, enabling them to better combine with each other to form complementary advantages. On the other hand, after the polymer substance interacts with the bio-based nylon and polycarbonate, the molecular chains among the three will form an intertwined cross-linked network structure. The presence of the polybutadiene rubber molecular chain can improve the elasticity of the cross-linked network and the mechanical properties of the alloy, and the mullite fiber, as the core of the cross-linked network, can utilize the unique effect of its own fiber reinforcing agent to improve the mechanical strength of the alloy. Specific embodiments

[0028] For ease of understanding the present invention, the present invention will be described more comprehensively below. Preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0029] Example 1

[0030] A bio-based nylon / polycarbonate alloy is made of the following raw materials by weight:

[0031] 60 parts of bio-based nylon, 30 parts of polycarbonate, 3 parts of modified mullite fiber, 0.5 part of antioxidant 168, and 0.5 part of lubricant montan wax;

[0032] The preparation method of the alloy includes the following steps:

[0033] Step 1: Add bio-based nylon and polycarbonate to a mixing kettle according to the weight parts, stir and mix evenly, then add modified mullite fiber, antioxidant 168 and montan wax to the mixing kettle, and continuously stir to form a uniform mixture;

[0034] Step 2: Put the mixture into a twin-screw extruder, control the rotation speed at 300 r / min, and the temperatures of each zone are as follows: the temperature of zone 1 is 230 °C, the temperature of zone 2 is 230 °C, the temperature of zone 3 is 235 °C, the temperature of zone 4 is 240 °C, the temperature of zone 5 is 240 °C, the temperature of zone 6 is 240 °C, the temperature of zone 7 is 240 °C, the temperature of zone 8 is 250 °C, the temperature of zone 9 is 240 °C, and the temperature of the die head is 245 °C, and carry out melt extrusion granulation to obtain the product.

[0035] Example 2

[0036] A bio-based nylon / polycarbonate alloy is made of the following raw materials by weight:

[0037] 65 parts of bio-based nylon, 40 parts of polycarbonate, 6 parts of modified mullite fiber, 1 part of antioxidant 1010, and 0.6 part of lubricant montan wax;

[0038] The preparation method of the alloy includes the following steps:

[0039] Step 1: Add bio-based nylon and polycarbonate to a mixing kettle according to the weight parts, stir and mix evenly, then add modified mullite fiber, antioxidant 1010 and montan wax to the mixing kettle, and continuously stir to form a uniform mixture;

[0040] Step 2: Put the mixture into a twin-screw extruder, control the rotation speed at 300 r / min, and the temperatures of each zone are as follows: the temperature of zone 1 is 230 °C, the temperature of zone 2 is 230 °C, the temperature of zone 3 is 235 °C, the temperature of zone 4 is 240 °C, the temperature of zone 5 is 240 °C, the temperature of zone 6 is 240 °C, the temperature of zone 7 is 240 °C, the temperature of zone 8 is 250 °C, the temperature of zone 9 is 240 °C, and the temperature of the die head is 245 °C. Then carry out melt extrusion granulation, and that's it.

[0041] Example 3

[0042] A bio-based nylon / polycarbonate alloy is made from the following raw materials by weight:

[0043] 75 parts of bio-based nylon, 50 parts of polycarbonate, 6.5 parts of modified mullite fiber, 1.5 parts of antioxidant 1076, and 1 part of lubricant montan wax;

[0044] The preparation method of the alloy includes the following steps:

[0045] Step 1: According to the weight parts, add bio-based nylon and polycarbonate into a mixing kettle, stir and mix evenly, then add modified mullite fiber, antioxidant 1076 and montan wax into the mixing kettle, and continuously stir to form a uniform mixture;

[0046] Step 2: Put the mixture into a twin-screw extruder, control the rotation speed at 300 r / min, and the temperatures of each zone are as follows: the temperature of zone 1 is 230 °C, the temperature of zone 2 is 230 °C, the temperature of zone 3 is 235 °C, the temperature of zone 4 is 240 °C, the temperature of zone 5 is 240 °C, the temperature of zone 6 is 240 °C, the temperature of zone 7 is 240 °C, the temperature of zone 8 is 250 °C, the temperature of zone 9 is 240 °C, and the temperature of the die head is 245 °C. Then carry out melt extrusion granulation, and that's it.

[0047] The modified mullite fiber in the above examples is prepared by the following method:

[0048] Step S1: Disperse 1.4 g of mullite fiber in an ethanol aqueous solution with a volume fraction of 70%, then add 0.9 g of 3-aminopropyltriethoxysilane to the formed dispersion, stir and mix evenly, then raise the temperature to 70 °C, continuously stir for 6 h, then cool and discharge, separate the solid matter, and after washing and vacuum drying treatment, obtain organic mullite fiber;

[0049] Step S2, using toluene as a medium, dispersing 1.2g of organic mullite fiber in the medium, then adding 2.5g of isocyanate-terminated polybutadiene and dibutyltin dilaurate, after the addition, introducing dry nitrogen protection, raising the temperature to 65°C, stirring for 3h, and then adding 0.2g of 3-[bis(glycidyloxymethyl)methoxy]-1,2-propylene glycol, after the addition, raising the temperature to 75°C, continuing to keep warm and stir for 16h, cooling and discharging, centrifuging the solid material, washing, and vacuum drying to obtain modified mullite fiber.

[0050] The preparation method of isocyanate-terminated polybutadiene is as follows:

[0051] 1.5 g of hydroxy-terminated polybutadiene with a number average molecular weight of 4000 is added to tetrahydrofuran, and the mixture is stirred to form a uniform reaction liquid. Then, 0.14 g of 3-isocyanatobenzoyl chloride and 0.01 g of pyridine are added to the reaction liquid. Then, the temperature is raised to 45° C., and the mixture is stirred for 6 hours. The solvent is removed by vacuum rotary evaporation, and the product is separated to obtain isocyanate-terminated polybutadiene.

[0052] Comparative Example 1

[0053] A bio-based nylon / polycarbonate alloy is prepared from the following raw materials measured in parts by weight:

[0054] 65 parts of bio-based nylon, 40 parts of polycarbonate, 6 parts of E44 epoxy resin, 10101 parts of antioxidant, and 0.6 parts of lubricant montan wax;

[0055] The preparation method of the alloy comprises the following steps:

[0056] Step 1: Add bio-based nylon and polycarbonate to a mixing kettle according to weight proportions, stir and mix evenly, then add E44 epoxy resin, antioxidant 1010 and montan wax to the mixing kettle, continue stirring to form a uniform mixture;

[0057] Step 2: put the mixture into a twin-screw extruder, control the speed to 300r / min, and the temperatures of each zone are: zone 1 temperature 230°C, zone 2 temperature 230°C, zone 3 temperature 235°C, zone 4 temperature 240°C, zone 5 temperature 240°C, zone 6 temperature 240°C, zone 7 temperature 240°C, zone 8 temperature 250°C, zone 9 temperature 240°C, and die head temperature 245°C, and perform melt extrusion granulation.

[0058] Test Case

[0059] The alloys in the embodiments and comparative examples were made into test specimens and performance tests were performed. The results are shown in the following table:

[0060] Tensile strength / MPa Elongation at break / % <![CDATA[Impact strength / KJ / m 2 > Heat distortion temperature / °C Example 1 90 132 68 86 Example 2 91 135 71 87 Example 3 91 133 70 86 Comparative Example 1 62 107 46 83

[0061] According to the standard ASTM D38-1997, the tensile property test was carried out at a tensile rate of 50 mm / min;

[0062] According to the standard ASTM D256-1997, the impact property test was carried out;

[0063] According to the standard ASTM D648-2007, the heat distortion temperature test was carried out.

[0064] According to the analysis of the test results, it can be seen that the effect of using the epoxy compatibilizer E44 epoxy resin to compatibilize bio-based nylon and polycarbonate is not good. On the contrary, for the alloy prepared by adding the modified mullite fiber of the present invention, the mechanical properties and high-temperature resistance are significantly more excellent.

[0065] In this article, specific examples are used to elaborate on the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those of ordinary skill in the art in the technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of the present invention patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that have no substantial difference from the literal description of the claims, then these other embodiments should also be included within the scope of the claims.

[0066] Enlightened by the ideal embodiments of the present invention, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A preparation method of a bio-based nylon / polycarbonate alloy, characterized in that, The alloy is made of the following raw materials by weight: 60 - 75 parts of bio - based nylon, 30 - 50 parts of polycarbonate, 3 - 6.5 parts of modified mullite fiber, 0.5 - 1.5 parts of antioxidant, 0.5 - 1 part of lubricant; The preparation method includes the following steps: Step 1: Add bio - based nylon and polycarbonate into a mixing kettle according to the weight parts, stir and mix evenly, then add modified mullite fiber, antioxidant and lubricant into the mixing kettle, and continuously stir to form a uniform mixture; Step 2: Put the mixture into a twin - screw extruder, control the rotation speed at 300 - 500 r / min and the temperature at 230 - 250 °C, and carry out melt extrusion granulation to obtain the product.

2. The preparation method of a bio-based nylon / polycarbonate alloy according to claim 1, wherein, The preparation method of the modified mullite fiber includes the following steps: Step S1: Carry out silanization modification on mullite fiber to obtain organic mullite fiber, and the modification reagent is selected from amino - silane coupling agent; Step S2: Use toluene as the medium, disperse the organic mullite fiber in the medium, then add isocyanate - terminated polybutadiene and metal tin catalyst. After adding, introduce dry nitrogen for protection, raise the temperature to 60 - 70 °C, stir for 2 - 4 h, then continue to add 3 - [bis(glycidoxymethyl)methoxy]-1,2 - propanediol. After adding, raise the temperature to 70 - 80 °C, keep the temperature and stir for 12 - 18 h, then cool down and discharge to obtain the modified mullite fiber.

3. The preparation method of a bio-based nylon / polycarbonate alloy according to claim 2, characterized in that, The amino - silane coupling agent is 3 - aminopropyltrimethoxysilane or 3 - aminopropylethoxysilane.

4. The preparation method of a bio-based nylon / polycarbonate alloy according to claim 2, wherein The preparation method of the isocyanate - terminated polybutadiene is as follows: Add hydroxyl - terminated polybutadiene into tetrahydrofuran, stir and mix evenly to form a uniform reaction solution, then add isocyanation reagent and pyridine into the reaction solution. Then, raise the temperature to 40 - 50 °C, keep the temperature and stir for 4 - 8 h, then remove the solvent by rotary evaporation under reduced pressure, and separate the product to obtain isocyanate - terminated polybutadiene.

5. The preparation method of a bio-based nylon / polycarbonate alloy according to claim 4, characterized in that, The number - average molecular weight of the hydroxyl - terminated polybutadiene is 4000.

6. The preparation method of a bio-based nylon / polycarbonate alloy according to claim 4, characterized in that, The isocyanation reagent is 4 - isocyanatobenzoyl chloride or 3 - isocyanatobenzoyl chloride.

7. The preparation method of a bio-based nylon / polycarbonate alloy according to claim 4, characterized in that, The molar ratio of the hydroxyl - terminated polybutadiene to the isocyanation reagent is 1:

2.

8. The preparation method of a bio-based nylon / polycarbonate alloy according to claim 2, characterized in that, The metal tin catalyst is any one of dibutyltin dilaurate, dibutyltin diacetate or stannous octoate.

9. The preparation method of a bio-based nylon / polycarbonate alloy according to claim 1, characterized in that, The antioxidant is at least one of antioxidant 1010, antioxidant 168 or antioxidant 1076; the lubricant is montan wax or polyethylene wax.

10. A bio-based nylon / polycarbonate alloy, characterized in that, Prepared by the preparation method according to any one of claims 1 - 9.