Large-diameter polyphenyl ether monofilament spinning special material and preparation method and application thereof

Abstract

The invention relates to the technical field of modified resin technology, in particular to a special material for large-diameter polyphenyl ether monofilament spinning and a preparation method and application thereof, and the special material for spinning is composed of 85-95 wt% of polyphenyl ether resin and 5-15 wt% of polydimethylsiloxane modified nano silicon dioxide. In the polydimethylsiloxane modified nano silicon dioxide synthesized by the invention, the content of the polydimethylsiloxane in percentage by mass is 30-50%. The nano silicon dioxide plays a role in fixing the polydimethylsiloxane, migration of the polydimethylsiloxane is inhibited, and the melt viscosity of the polyphenyl ether resin is reduced due to introduction of the polydimethylsiloxane, so that the melt fluidity of the polyphenyl ether resin meets the spinning requirement of large-diameter monofilaments.

Description

Technical Field

[0001] The invention relates to the technical field of modified resin technology, and in particular to a special material for large-diameter polyphenylene ether monofilament spinning, and a preparation method and application thereof. Background Art

[0002] Polyphenylene ether is a high-performance thermoplastic engineering plastic. With its excellent physical and mechanical properties, electrical properties, heat resistance, water resistance, chemical corrosion resistance and dimensional stability, it has been widely used in the fields of electronics, automobile manufacturing, machinery industry, aerospace, etc. However, the main disadvantage of polyphenylene ether is poor melt fluidity and difficult processing and molding. Therefore, its modified materials are often used in practical applications, such as polystyrene or high-impact polystyrene to modify polyphenylene ether, which can greatly improve processing performance and reduce costs. However, the melt fluidity of polyphenylene ether resin modified in this way is still poor and cannot meet the requirements of melt spinning. In order to meet the requirements of melt spinning, the molecular weight of polyphenylene ether can only be reduced, but the mechanical properties of the fiber prepared thereby are reduced. It is even more difficult to meet the preparation of monofilaments with higher requirements for raw materials. Therefore, by deeply modifying conventional resins, further improving the melt fluidity of polyphenylene ether can help solve the preparation of polyphenylene ether melt-spinning monofilaments, thereby giving polyphenylene ether resins better application prospects.

[0003] Polydimethylsiloxane has the characteristics of heat resistance, cold resistance, thermal conductivity, hydrophobicity, and lubricity. Taking advantage of the self-lubricating properties of polydimethylsiloxane, adding it to the polymer can help reduce the friction between resin molecules and greatly improve the melt fluidity of the resin. However, polydimethylsiloxane has low surface energy, poor compatibility with polyphenylene ether resin, and is difficult to disperse.

[0004] Nano addition can significantly improve the thermal stability of polymers, delay the thermal degradation process, and enable them to maintain excellent performance in high temperature environments. In addition, the addition of nanoparticles can significantly improve the mechanical properties of polymers, including tensile strength, elastic modulus and stiffness. However, due to the high surface energy and high chemical activity of nanoparticles, they are easy to agglomerate and have poor dispersion in polymers. If introduced into the resin, it may further reduce the melt fluidity of the material. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings existing in the prior art, and propose a large-diameter polyphenylene ether monofilament spinning special material and its preparation method and application. First, polydimethylsiloxane modified nano-silicon dioxide is prepared by ring-opening polymerization of octamethylcyclotetrasilane and its reaction with silanol groups on the surface of nano-silicon dioxide. Since silicon dioxide is an inorganic substance and polydimethylsiloxane is fixed on the surface of nano-silicon dioxide, this method can effectively disperse the modified nano-silicon dioxide uniformly inside the polyphenylene ether resin and inhibit the migration of polydimethylsiloxane in the polyphenylene ether resin. On the one hand, the problem of dispersibility of nanoparticles in polymers is solved, and the problem of difficulty in dispersing polydimethylsiloxane and incompatibility with polymers is solved; on the other hand, the self-lubricating property of polydimethylsiloxane can be used to greatly improve the melt fluidity of polyphenylene ether resin, so that polyphenylene ether resin can be used to prepare large-diameter polyphenylene ether monofilaments by melt spinning.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A special spinning material for large-diameter polyphenylene ether monofilaments, the spinning material comprising 85-95wt% of polyphenylene ether resin and 5-15wt% of polydimethylsiloxane-modified nano-silicon dioxide;

[0008] The polydimethylsiloxane-modified nano-silica is prepared by ring-opening polymerization of nano-silica and octamethylcyclotetrasilane.

[0009] Preferably, the polyphenylene ether resin is poly-2,6-dimethyl-1,4-phenylene ether.

[0010] Preferably, in the polydimethylsiloxane-modified nano-silica, the mass percentage content of polydimethylsiloxane is 30-50%.

[0011] Preferably, the particle size of the nano-silicon dioxide is 50 nm.

[0012] The present invention also provides a method for preparing a special material for large-diameter polyphenylene ether monofilament spinning, comprising the following steps:

[0013] Step 1: Preparation of polydimethylsiloxane-modified nano-silica

[0014] Octamethylcyclotetrasilane, nano-silica, xylene and tetramethylammonium hydroxide were added to a three-necked flask equipped with a reflux condenser and a mechanical stirrer; the temperature was then raised to 100°C and the reaction was carried out at this temperature for a certain period of time; after the system was cooled, the product was centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process was repeated twice, and vacuum dried at 100°C to obtain polydimethylsiloxane-modified nano-silica;

[0015] Step 2: Preparation of special materials for large diameter polyphenylene ether monofilament spinning

[0016] The polydimethylsiloxane-modified nano-silica and polyphenylene ether resin prepared in step one are added into a high-speed mixer according to a proportion and mixed evenly; extruded by a twin-screw extruder, and the seven-stage temperatures of the extruder are set to 180° C., 270° C., 280° C., 290° C., 300° C., 300° C. and 300° C.; the large-diameter polyphenylene ether monofilament spinning material is obtained by cooling the drawing and extruding granulation.

[0017] Preferably, in step 1, the mass ratio of octamethylcyclotetrasilane, nano-silicon dioxide and xylene is 1:(0.4-1):10, and the amount of tetramethylammonium hydroxide used is 1.5wt% of the mass of octamethylcyclotetrasilane.

[0018] Preferably, in step 1, the reaction time is 40-80 minutes.

[0019] The present invention also provides an application of the large diameter polyphenylene ether monofilament spinning material obtained by the above preparation method in the preparation of large diameter polyphenylene ether monofilaments, specifically: the large diameter polyphenylene ether monofilament spinning material is melt-spinned to prepare large diameter polyphenylene ether monofilaments.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention introduces polydimethylsiloxane into polyphenylene ether resin, which greatly reduces the melt viscosity of the polyphenylene ether resin and improves the melt fluidity, so that the high molecular weight polyphenylene ether resin meets the spinning fluidity requirements of large diameter monofilaments, thereby being able to smoothly prepare large diameter polyphenylene ether monofilaments by melt spinning.

[0022] 2. The present invention utilizes the ring-opening polymerization of octamethylcyclotetrasilane and its reaction with the silanol group on the surface of nano-silicon dioxide to graft polydimethylsiloxane onto the surface of nano-silicon dioxide. On the one hand, polydimethylsiloxane can be fixed inside the polyphenylene ether resin by using nano-silicon dioxide, thereby reducing migration and aggregation, improving the dispersion uniformity of polydimethylsiloxane, and improving the problem of incompatibility between polydimethylsiloxane and polyphenylene ether. On the other hand, due to the lubricity of polydimethylsiloxane on the surface of nano-silicon dioxide, the addition of nanoparticles does not cause a decrease in the fluidity of the polyphenylene ether resin, and simultaneously also plays a compensatory role in the mechanical properties of the polyphenylene ether. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the protection scope of the present invention. The embodiments described in the present invention are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0024] The invention provides a special material for large-diameter polyphenylene ether monofilament spinning, which is composed of 85-95wt% polyphenylene ether resin and 5-15wt% polydimethylsiloxane-modified nano-silica. The polydimethylsiloxane-modified nano-silica is prepared by ring-opening polymerization of nano-silica and octamethylcyclotetrasilane. The polyphenylene ether resin is poly-2,6-dimethyl-1,4-phenylene ether, the mass percentage content of polydimethylsiloxane in the polydimethylsiloxane-modified nano-silica is 30-50%, and the particle size of the nano-silica is 50nm.

[0025] A method for preparing a large-diameter polyphenylene ether monofilament spinning material, comprising the following steps:

[0026] Step 1: Preparation of polydimethylsiloxane-modified nano-silica

[0027] Octamethylcyclotetrasilane, nano-silica, xylene and tetramethylammonium hydroxide are added to a three-necked flask equipped with a reflux condenser and a mechanical stirrer. Then the temperature is raised to 100°C and the reaction is carried out at this temperature for 40-80 minutes. The mass fraction ratio of octamethylcyclotetrasilane, nano-silica and xylene is 1: (0.4-1): 10, and the amount of tetramethylammonium hydroxide is 1.5wt% of the mass of octamethylcyclotetrasilane. After the system is cooled, the product is centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process is repeated twice, and vacuum dried at 100°C to obtain polydimethylsiloxane-modified nano-silica.

[0028] Step 2: Preparation of a special material for large-diameter polyphenylene ether monofilament spinning

[0029] The polydimethylsiloxane modified nano-silica and polyphenylene ether resin prepared in step 1 are added into a high-speed mixer according to the proportion and mixed evenly. The mixture is extruded by a twin-screw extruder, and the seven-stage temperature of the extruder is set to 180°C, 270°C, 280°C, 290°C, 300°C, 300°C and 300°C. The large-diameter polyphenylene ether monofilament spinning material is obtained by cooling the strands and extruding and granulating.

[0030] Melt viscosity test: A rotational rheometer was used to test the melt viscosity of the material. The test temperature was 285°C, and the composite viscosity at a frequency of 0.1 rad / s was taken as the melt viscosity of the material.

[0031] Example 1

[0032] Step 1: Preparation of polydimethylsiloxane-modified nano-silica

[0033] 40g of octamethylcyclotetrasilane, 40g of nano-silicon dioxide, 400g of xylene and 0.6g of tetramethylammonium hydroxide were added to a 2L three-necked flask equipped with a reflux condenser and a mechanical stirrer. The temperature was then raised to 100°C and the reaction was carried out at this temperature for 40 minutes. After the system was cooled, the product was centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process was repeated twice, and vacuum dried at 100°C to obtain modified nano-silicon dioxide with a mass percentage of polydimethylsiloxane of 30%.

[0034] Step 2: Preparation of special materials for large diameter polyphenylene ether monofilament spinning

[0035] The polydimethylsiloxane modified nano-silica and polyphenylene ether resin prepared in step 1 are added to a high-speed mixer in a ratio of 10:90 and mixed evenly. Extruded by a twin-screw extruder, the seven-stage temperature of the extruder is set to 180°C, 270°C, 280°C, 290°C, 300°C, 300°C and 300°C. After cooling and drawing, extrusion and granulation are obtained to obtain a large-diameter polyphenylene ether monofilament spinning material. Spinning at 320°C by a single-screw extruder to obtain a large-diameter polyphenylene ether monofilament with a diameter of 3 mm.

[0036] Example 2

[0037] Step 1: Preparation of polydimethylsiloxane-modified nano-silica

[0038] 40g of octamethylcyclotetrasilane, 32g of nano-silicon dioxide, 400g of xylene and 0.6g of tetramethylammonium hydroxide were added to a 2L three-necked flask equipped with a reflux condenser and a mechanical stirrer. The temperature was then raised to 100°C and the reaction was carried out at this temperature for 50 minutes. After the system was cooled, the product was centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process was repeated twice, and vacuum dried at 100°C to obtain modified nano-silicon dioxide with a mass percentage of polydimethylsiloxane of 35%.

[0039] Step 2: Preparation of special materials for large diameter polyphenylene ether monofilament spinning

[0040] The polydimethylsiloxane modified nano-silica and polyphenylene ether resin prepared in step 1 are added to a high-speed mixer in a ratio of 10:90 and mixed evenly. The mixture is extruded by a twin-screw extruder, and the seven-stage temperature of the extruder is set to 180°C, 270°C, 280°C, 290°C, 300°C, 300°C and 300°C. After cooling and drawing the strands, a large-diameter polyphenylene ether monofilament spinning material is obtained by extrusion granulation. The large-diameter polyphenylene ether monofilament with a diameter of 3 mm is obtained by spinning at 320°C by a single-screw extruder.

[0041] Example 3

[0042] Step 1: Preparation of polydimethylsiloxane-modified nano-silica

[0043] 40g of octamethylcyclotetrasilane, 26g of nano-silicon dioxide, 400g of xylene and 0.6g of tetramethylammonium hydroxide were added to a 2L three-necked flask equipped with a reflux condenser and a mechanical stirrer. The temperature was then raised to 100°C and the reaction was carried out at this temperature for 60 minutes. After the system was cooled, the product was centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process was repeated twice, and vacuum dried at 100°C to obtain modified nano-silicon dioxide with a mass percentage of polydimethylsiloxane of 40%.

[0044] Step 2: Preparation of special materials for large diameter polyphenylene ether monofilament spinning

[0045] The polydimethylsiloxane modified nano-silica and polyphenylene ether resin prepared in step 1 are added to a high-speed mixer in a ratio of 10:90 and mixed evenly. The mixture is extruded by a twin-screw extruder, and the seven-stage temperature of the extruder is set to 180°C, 270°C, 280°C, 290°C, 300°C, 300°C and 300°C. After cooling and drawing the strands, a large-diameter polyphenylene ether monofilament spinning material is obtained by extrusion granulation. The large-diameter polyphenylene ether monofilament with a diameter of 3 mm is obtained by spinning at 320°C by a single-screw extruder.

[0046] Example 4

[0047] Step 1: Preparation of polydimethylsiloxane-modified nano-silica

[0048] 40g of octamethylcyclotetrasilane, 16g of nano-silicon dioxide, 400g of xylene and 0.6g of tetramethylammonium hydroxide were added to a 2L three-necked flask equipped with a reflux condenser and a mechanical stirrer. The temperature was then raised to 100°C and the reaction was carried out at this temperature for 80 minutes. After the system was cooled, the product was centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process was repeated twice, and vacuum dried at 100°C to obtain modified nano-silicon dioxide with a mass percentage of polydimethylsiloxane of 50%.

[0049] Step 2: Preparation of special materials for large diameter polyphenylene ether monofilament spinning

[0050] The polydimethylsiloxane modified nano-silica and polyphenylene ether resin prepared in step 1 are added to a high-speed mixer in a ratio of 10:90 and mixed evenly. Extruded by a twin-screw extruder, the seven-stage temperature of the extruder is set to 180°C, 270°C, 280°C, 290°C, 300°C, 300°C and 300°C. After cooling and drawing, extrusion and granulation are obtained to obtain a large-diameter polyphenylene ether monofilament spinning material. Spinning at 320°C by a single-screw extruder to obtain a large-diameter polyphenylene ether monofilament with a diameter of 3 mm.

[0051] Example 5

[0052] Step 1: Preparation of polydimethylsiloxane-modified nano-silica

[0053] 40g of octamethylcyclotetrasilane, 32g of nano-silicon dioxide, 400g of xylene and 0.6g of tetramethylammonium hydroxide were added to a 2L three-necked flask equipped with a reflux condenser and a mechanical stirrer. The temperature was then raised to 100°C and the reaction was carried out at this temperature for 50 minutes. After the system was cooled, the product was centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process was repeated twice, and vacuum dried at 100°C to obtain modified nano-silicon dioxide with a mass percentage of polydimethylsiloxane of 35%.

[0054] Step 2: Preparation of special materials for large diameter polyphenylene ether monofilament spinning

[0055] The polydimethylsiloxane modified nano-silica and polyphenylene ether resin prepared in step 1 are added to a high-speed mixer in a ratio of 15:85 and mixed evenly. Extruded by a twin-screw extruder, the seven-stage temperature of the extruder is set to 180°C, 270°C, 280°C, 290°C, 300°C, 300°C and 300°C. After cooling and drawing, extrusion and granulation are obtained to obtain a large-diameter polyphenylene ether monofilament spinning material. Spinning at 320°C by a single-screw extruder to obtain a large-diameter polyphenylene ether monofilament with a diameter of 3 mm.

[0056] Example 6

[0057] Step 1: Preparation of polydimethylsiloxane-modified nano-silica

[0058] 40g of octamethylcyclotetrasilane, 0.26g of nano-silicon dioxide, 400g of xylene and 0.6g of tetramethylammonium hydroxide were added to a 2L three-necked flask equipped with a reflux condenser and a mechanical stirrer. The temperature was then raised to 100°C and the reaction was carried out at this temperature for 60 minutes. After the system was cooled, the product was centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process was repeated twice, and vacuum dried at 100°C to obtain modified nano-silicon dioxide with a mass percentage of polydimethylsiloxane of 40%.

[0059] Step 2: Preparation of special materials for large diameter polyphenylene ether monofilament spinning

[0060] The polydimethylsiloxane modified nano-silica and polyphenylene ether resin prepared in step 1 are added to a high-speed mixer in a ratio of 5:95 and mixed evenly. The mixture is extruded by a twin-screw extruder, and the seven-stage temperature of the extruder is set to 180°C, 270°C, 280°C, 290°C, 300°C, 300°C and 300°C. After cooling and drawing the strands, a large-diameter polyphenylene ether monofilament spinning material is obtained by extrusion granulation. The large-diameter polyphenylene ether monofilament with a diameter of 3 mm is obtained by spinning at 320°C by a single-screw extruder.

[0061] The melt viscosity and strength of the above embodiments are shown in Table 1 below:

[0062] Table 1

[0063]

[0064] In summary, the present invention firstly prepares polydimethylsiloxane modified nano-silicon dioxide by ring-opening polymerization of octamethylcyclotetrasilane and reaction with silanol groups on the surface of nano-silicon dioxide. Since silicon dioxide is an inorganic substance and polydimethylsiloxane is fixed on the surface of nano-silicon dioxide, this method can effectively disperse the modified nano-silicon dioxide uniformly inside the polyphenylene ether resin and inhibit the migration of polydimethylsiloxane in the polyphenylene ether resin. On the one hand, the problem of dispersibility of nanoparticles in polymers is solved, and the problem of difficulty in dispersing polydimethylsiloxane and incompatibility with polymers is solved at the same time; on the other hand, the self-lubricating property of polydimethylsiloxane can be used to greatly improve the melt fluidity of polyphenylene ether resin, so that polyphenylene ether resin can be used to prepare large-diameter polyphenylene ether monofilaments by melt spinning.

[0065] The description and practice disclosed in the present invention are easy to think and understand for ordinary technicians in the technical field, and several improvements and modifications can be made without departing from the principles of the present invention. Therefore, modifications or improvements made without departing from the spirit of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A special material for large-diameter polyphenylene ether monofilament spinning, characterized in that: The spinning material comprises 85-95wt% of polyphenylene ether resin and 5-15wt% of polydimethylsiloxane-modified nano-silicon dioxide; The polydimethylsiloxane-modified nano-silica is prepared by ring-opening polymerization of nano-silica and octamethylcyclotetrasilane.

2. The large-diameter polyphenylene ether monofilament spinning material according to claim 1, characterized in that: The polyphenylene ether resin is poly-2,6-dimethyl-1,4-phenylene ether.

3. The large-diameter polyphenylene ether monofilament spinning material according to claim 1, characterized in that: In the polydimethylsiloxane-modified nano-silica, the mass percentage content of polydimethylsiloxane is 30-50%.

4. The large-diameter polyphenylene ether monofilament spinning material according to claim 1, characterized in that: The particle size of the nano silicon dioxide is 50 nm.

5. The method for preparing a large-diameter polyphenylene ether monofilament spinning material according to any one of claims 1 to 4, characterized in that: The steps include: Step 1: Preparation of polydimethylsiloxane modified nano-silica Octamethylcyclotetrasilane, nano-silica, xylene and tetramethylammonium hydroxide were added to a three-necked flask equipped with a reflux condenser and a mechanical stirrer; the temperature was then raised to 100°C and the reaction was carried out at this temperature for a certain period of time; after the system was cooled, the product was centrifuged at 8000r / min, washed with xylene and then centrifuged again, the above process was repeated twice, and vacuum dried at 100°C to obtain polydimethylsiloxane-modified nano-silica; Step 2: Preparation of special materials for large diameter polyphenylene ether monofilament spinning The polydimethylsiloxane-modified nano-silica and polyphenylene ether resin prepared in step one are added into a high-speed mixer according to a proportion and mixed evenly; extruded by a twin-screw extruder, and the seven-stage temperatures of the extruder are set to 180° C., 270° C., 280° C., 290° C., 300° C., 300° C. and 300° C.; the large-diameter polyphenylene ether monofilament spinning material is obtained by cooling the drawing and extruding granulation.

6. The method for preparing a large-diameter polyphenylene ether monofilament spinning material according to claim 5, characterized in that: In step 1, the mass ratio of octamethylcyclotetrasilane, nano-silicon dioxide and xylene is 1:(0.4-1):10, and the amount of tetramethylammonium hydroxide used is 1.5wt% of the mass of octamethylcyclotetrasilane.

7. The method for preparing a large-diameter polyphenylene ether monofilament spinning material according to claim 5, characterized in that: In step 1, the reaction time is 40-80 minutes.

8. Use of a special spinning material for large-diameter polyphenylene ether monofilaments obtained by the preparation method according to any one of claims 5 to 7 in the preparation of large-diameter polyphenylene ether monofilaments.

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