A high-strength and high-modulus PPS reinforced resin and its preparation method

Abstract

The present invention belongs to the technical field of polymer materials, and particularly relates to a high-strength and high-modulus PPS reinforced resin and a preparation method thereof. The high-strength and high-modulus PPS reinforced resin comprises the following components in parts by weight: 35-45 parts of PPS resin, 5-10 parts of calcium carbonate, 30-40 parts of modified chopped glass fiber, 10-20 parts of long glass fiber, 10-12 parts of EEA, and 1-3 parts of lubricant; wherein, the mass ratio of the modified chopped glass fiber to the long glass fiber is 2-4:1. On the basis of PPS resin, the present invention adds calcium carbonate, modified chopped glass fiber, long glass fiber, EEA, and lubricant filler, reduces the use cost of PPS resin, and simultaneously obtains a high-strength and high-modulus PPS reinforced resin with high flexural modulus, high tensile strength, and good appearance. The preparation method has low production cost, is easy to operate, is suitable for large-scale production, and has good market prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a high-strength and high-modulus PPS reinforced resin and a preparation method thereof. Background Art

[0002] Polyphenylene sulfide (PPS) is a thermoplastic resin with a phenylthio group in the main chain of the molecule. It is a crystalline polymer with advantages such as high mechanical strength, high temperature resistance, weather resistance, corrosion resistance, flame retardancy and excellent electrical properties. It has a wide range of applications in the fields of electronics, automobiles, machinery and chemicals, and is called one of the six major special engineering plastics together with polyetheretherketone (PEEK), polysulfone (PSF), polyimide (PI), polyarylate (PAR), and liquid crystal polymer (LCP).

[0003] The bending modulus of pure PPS is only 3300 MPa, and the tensile strength is 70 MPa. Moreover, it has the disadvantages of brittle performance, poor toughness and high price (the price of domestic polyphenylene sulfide resin is 60 yuan / kg, and the import price is more than 100 yuan / kg). Therefore, it is necessary to add other fillers to modify PPS to improve its mechanical properties and reduce its production cost at the same time, so as to expand its application range and reduce its use cost. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a high-strength and high-modulus PPS reinforced resin, which has high strength, high bending modulus, a smooth and flat product surface, and no floating fiber phenomenon.

[0005] Another purpose of the present invention is to provide a preparation method of a high-strength and high-modulus PPS reinforced resin. The preparation method is simple, easy to operate, has low production cost, and the prepared product has good stability, is suitable for large-scale production, and has good economic benefits.

[0006] The first purpose of the present invention is to provide a high-strength and high-modulus PPS reinforced resin, which comprises the following components by weight: 35-45 parts of PPS resin, 5-10 parts of calcium carbonate, 30-40 parts of modified chopped glass fiber, 10-20 parts of long glass fiber, 10-12 parts of EEA, and 1-3 parts of lubricant;

[0007] Among them, the mass ratio of the modified chopped glass fiber to the long glass fiber is 2-4:1;

[0008] The preparation method of the modified chopped glass fiber is as follows: add chopped glass fiber into a 15%-35% oxalic acid solution and stir for 2-3 h, wash the precipitate with deionized water 3-4 times, then add an aqueous solution of a silane coupling agent with a volume 3-4 times that of the precipitate, and perform ultrasonic dispersion at 50-80 kHz for 0.5-1 h to obtain the modified chopped glass fiber.

[0009] Based on PPS resin, the present invention enhances its flexural modulus and tensile strength by adding various fillers, while reducing the production cost of PPS resin. Among them, ethylene-ethyl acrylate copolymer (EEA) is a copolymer of ethylene and ethyl acrylate, which has good low-temperature and non-plasticized softness, good heat resistance stability during processing, excellent resistance to flexural cracking and environmental stress cracking, high elasticity and good dispersibility. The inventor found that EEA has good compatibility with PPS resin, and at the same time can promote the good dispersion and flow of modified chopped glass fiber and long glass fiber in PPS resin. EEA has a polar functional group (C2H5OCO)-, so it has good adhesion with the inorganic filler calcium carbonate and does not affect the physical properties of EEA itself, while the calcium carbonate filler itself can improve the mechanical strength of PPS resin.

[0010] The compatibility of ordinary chopped glass fiber and PPS resin is poor, resulting in poor fluidity, and the glass fiber is easy to float out of the material surface, making the surface prone to burrs. Therefore, it is selected to use oxalic acid solution to remove the impurities on the surface of the chopped glass fiber, and then add a silane coupling agent to modify its surface to increase the activity of the chopped glass fiber and improve the compatibility of the chopped glass fiber with PPS resin and long glass fiber. The present invention adds the modified chopped glass fiber and long glass fiber to the PPS resin according to a mass ratio of 2-4:1, so that the modified chopped glass fiber and long glass fiber can be fully filled in the PPS resin and form a dense space network structure, which can better transfer the external load to the reinforcing fiber under the action of the external load, thereby improving the overall performance of the PPS resin composite material.

[0011] Further, the lubricant is at least one of white oil, paraffin wax, and microcrystalline wax.

[0012] Further, the diameter of the chopped glass fiber is 9-13μm, and the diameter of the long glass fiber is 13-16μm.

[0013] Too fine glass fiber is easily sheared by the screw into fibers with too small length, reducing the reinforcing effect of the glass fiber; too thick glass fiber is not easy to bond with other substrates, resulting in loss of mechanical properties.

[0014] Further, the mass-volume ratio (g:mL) of the chopped glass fiber to the oxalic acid solution is 1:3-4.

[0015] Further, the concentration of the aqueous solution of the silane coupling agent is 1%-3%.

[0016] The second object of the present invention is to provide a preparation method of the above high-strength and high-modulus PPS reinforced resin, including the following steps:

[0017] S11. Add the formulated amount of PPS resin, calcium carbonate, EEA and lubricant into a high-speed mixer, and mix for 10-15 minutes to obtain a premix;

[0018] S12. Add the premix obtained in S11 and the long glass fiber into the twin-screw extruder from the main feeding port of the first zone, add 1 / 2 weight of the modified chopped glass fiber from the first side feeding port, and add the remaining 1 / 2 weight of the modified chopped glass fiber from the second side feeding port, then extrude and pelletize to obtain the high-strength and high-modulus PPS reinforced resin.

[0019] Further, the length-diameter ratio of the twin-screw extruder is 40:1. The twin-screw extruder includes eleven temperature control zones, namely: temperature control zones 1-4 are 290-310 °C, temperature control zones 5-10 are 280-300 °C, and temperature control zone 11 is 310-330 °C.

[0020] Further, the main feeding port of the first zone is located in zone 1, the first side feeding port is located in zone 7, and the second side feeding port is located in zone 9.

[0021] The modified chopped glass fiber is fed from the side feeding port and added in two times to avoid agglomeration that is likely to occur when added at one time. At the same time, when feeding, it should not be too early or too late. Being too early will cause overmixing of the modified chopped glass fiber and affect the overall strength, and being too late will cause insufficient mixing of the modified chopped glass fiber and result in too much floating fiber, affecting the appearance of the high-strength and high-modulus PPS reinforced resin.

[0022] Further, the screw rotation speed of the twin-screw extruder is 260-300 rpm.

[0023] Further, the rotation speed of the high-speed mixer is 1000-1200 rpm.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. Based on the PPS resin, by adding calcium carbonate, modified chopped glass fiber, long glass fiber, EEA, and lubricant filler, the present invention reduces the use cost of the PPS resin, and at the same time obtains a high-strength and high-modulus PPS reinforced resin with high flexural modulus, high tensile strength, and good appearance.

[0026] 2. In the present invention, EEA has good low-temperature and non-plasticized flexibility, relatively good heat resistance stability during processing, excellent resistance to flexural cracking and environmental stress cracking, high elasticity and good dispersibility. The inventor found that EEA has good compatibility with PPS resin, and at the same time can promote the good dispersion and flow of modified chopped glass fibers and long glass fibers in PPS resin. EEA has a polar functional group (C2H5OCO)-, so it has good adhesion with the inorganic filler calcium carbonate and does not affect the physical properties of EEA itself. The calcium carbonate filler itself can improve the mechanical strength of PPS resin. In the present invention, the modified chopped glass fibers and long glass fibers are added to PPS resin in a mass ratio of 2-4:1, so that the modified chopped glass fibers and long glass fibers can be fully filled in PPS resin and form a dense spatial network structure, which can better transfer the external load to the reinforcing fibers under the action of external load, thereby improving the overall performance of the PPS resin composite material.

[0027] 3. The present invention also provides a preparation method of high-strength and high-modulus PPS reinforced resin, mainly using the melt blending method of a mixer and the extrusion molding method of a twin-screw extruder. Among them, the modified chopped glass fibers are fed from the side feeding port and added in two times to avoid agglomeration phenomenon caused by one-time addition. At the same time, when feeding, it should not be too early or too late. Too early will cause over-mixing of the modified chopped glass fibers and affect the overall strength, and too late will cause insufficient mixing of the modified chopped glass fibers and result in too many floating fibers, affecting the appearance of the high-strength and high-modulus PPS reinforced resin. At the same time, by controlling the length-diameter ratio, rotation speed and temperature of the twin-screw extruder, the dispersion of materials is further promoted and the degradation of polymer materials is prevented. This preparation method has low production cost, simple operation, is suitable for large-scale production, and has good market prospects. Specific embodiments

[0028] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention.

[0029] Example 1: Modified chopped glass fibers

[0030] The chopped glass fibers are added to 30% oxalic acid solution and stirred for 2.5 h. The mass-volume ratio (g:mL) of the chopped glass fibers to the oxalic acid solution is 1:3.5. The precipitate is washed 3 times with deionized water, and then 3.5 times the volume of 2% aqueous solution of silane coupling agent is added, and ultrasonic dispersion is carried out at 65 kHz for 0.5 h to obtain modified chopped glass fibers.

[0031] Example 2: Modified chopped glass fibers

[0032] Add the chopped glass fiber into 15% oxalic acid solution and stir for 2 h. The mass-to-volume ratio (g:mL) of the chopped glass fiber to the oxalic acid solution is 1:3. Wash the precipitate with deionized water three times, then add an aqueous solution of silane coupling agent with a concentration of 1% and a volume four times that of the precipitate, and ultrasonically disperse it at 50 kHz for 45 min to obtain the modified chopped glass fiber.

[0033] Example 3: Modified Chopped Glass Fiber

[0034] Add the chopped glass fiber into 35% oxalic acid solution and stir for 3 h. The mass-to-volume ratio (g:mL) of the chopped glass fiber to the oxalic acid solution is 1:4. Wash the precipitate with deionized water three times, then add an aqueous solution of silane coupling agent with a concentration of 3% and a volume three times that of the precipitate, and ultrasonically disperse it at 80 kHz for 1 h to obtain the modified chopped glass fiber.

[0035] Example 4: Preparation of High Strength and High Modulus PPS Reinforced Resin

[0036] A preparation method of high strength and high modulus PPS reinforced resin includes the following steps:

[0037] S11. Add 40 parts of PPS resin, 8 parts of calcium carbonate, 11 parts of EEA, and 2 parts of lubricant into a high-speed mixer, and mix for 15 min to obtain a premix.

[0038] S12. Add the premix obtained in S11 and 15 parts of long glass fiber into the twin-screw extruder from the main feeding port of the first zone, add 20 parts of the modified chopped glass fiber prepared in Example 1 from the first side feeding port, and add 20 parts of the modified chopped glass fiber prepared in Example 1 from the second side feeding port, then extrude and pelletize to obtain the high strength and high modulus PPS reinforced resin.

[0039] The length-to-diameter ratio of the twin-screw extruder is 40:1. The twin-screw extruder includes eleven temperature control zones, namely: temperature control zones 1-4 are at 290-310 °C, temperature control zones 5-10 are at 280-300 °C, and temperature control zone 11 is at 310-330 °C. The main feeding port of the first zone is located in zone 1, the first side feeding port is located in zone 7, and the second side feeding port is located in zone 9.

[0040] Example 5: Preparation of High Strength and High Modulus PPS Reinforced Resin

[0041] A preparation method of high strength and high modulus PPS reinforced resin includes the following steps:

[0042] S11. Add 35 parts of PPS resin, 5 parts of calcium carbonate, 10 parts of EEA, and 1 part of lubricant into a high-speed mixer, and mix for 10 min to obtain a premix.

[0043] S12. Add the premix obtained in S11 and 10 parts of long glass fiber into the twin-screw extruder from the main feeding port of the first zone, add 10 parts of the modified chopped glass fiber prepared in Example 2 from the first side feeding port, and add 10 parts of the modified chopped glass fiber prepared in Example 2 from the second side feeding port, then extrude and pelletize to obtain the high-strength and high-modulus PPS reinforced resin.

[0044] The length-diameter ratio of the twin-screw extruder is 40:1. The twin-screw extruder includes eleven temperature control zones, namely: temperature control zones 1-4 are 290-310 °C, temperature control zones 5-10 are 280-300 °C, and temperature control zone 11 is 310-330 °C. The main feeding port of the first zone is located in zone 1, the first side feeding port is located in zone 7, and the second side feeding port is located in zone 9.

[0045] Example 6: Preparation of high-strength and high-modulus PPS reinforced resin

[0046] A preparation method of high-strength and high-modulus PPS reinforced resin includes the following steps:

[0047] S11. Add 45 parts of PPS resin, 10 parts of calcium carbonate, 12 parts of EEA and 3 parts of lubricant into a high-speed mixer, mix for 15 min to obtain a premix;

[0048] S12. Add the premix obtained in S11 and 20 parts of long glass fiber into the twin-screw extruder from the main feeding port of the first zone, add 30 parts of the modified chopped glass fiber prepared in Example 3 from the first side feeding port, and add 30 parts of the modified chopped glass fiber prepared in Example 3 from the second side feeding port, then extrude and pelletize to obtain the high-strength and high-modulus PPS reinforced resin.

[0049] The length-diameter ratio of the twin-screw extruder is 40:1. The twin-screw extruder includes eleven temperature control zones, namely: temperature control zones 1-4 are 290-310 °C, temperature control zones 5-10 are 280-300 °C, and temperature control zone 11 is 310-330 °C. The main feeding port of the first zone is located in zone 1, the first side feeding port is located in zone 7, and the second side feeding port is located in zone 9.

[0050] Comparative Example 1:

[0051] On the basis of Example 4, replace EEA with EVA, and the others are the same as Example 4.

[0052] Comparative Example 2:

[0053] On the basis of Example 4, do not add EEA, and the others are the same as Example 4.

[0054] Comparative Example 3:

[0055] On the basis of Example 4, do not add long glass fiber, and the others are the same as Example 4.

[0056] Comparative Example 4:

[0057] Based on Example 4, without adding modified chopped glass fiber, and the others are the same as Example 4.

[0058] Comparative Example 5:

[0059] S11. Add 40 parts of PPS resin, 8 parts of calcium carbonate, 11 parts of EEA and 2 parts of lubricant into a high-speed mixer, and mix for 15 minutes to obtain a premix.

[0060] S12. Add the premix obtained in S11 and 15 parts of long glass fiber from the main feeding port of the first zone into a twin-screw extruder. Add 5 parts of the modified chopped glass fiber prepared in Example 1 from the first side feeding port, and add 5 parts of the modified chopped glass fiber prepared in Example 1 from the second side feeding port, then extrude and pelletize to obtain a high-strength and high-modulus PPS reinforced resin.

[0061] The length-diameter ratio of the twin-screw extruder is 40:1. The twin-screw extruder includes eleven temperature control zones, which are: temperature control zones 1-4 at 290-310 °C, temperature control zones 5-10 at 280-300 °C, and temperature control zone 11 at 310-330 °C. The main feeding port of the first zone is located in zone 1, the first side feeding port is located in zone 7, and the second side feeding port is located in zone 9.

[0062] Comparative Example 6:

[0063] S11. Add 40 parts of PPS resin, 8 parts of calcium carbonate, 11 parts of EEA and 2 parts of lubricant into a high-speed mixer, and mix for 15 minutes to obtain a premix.

[0064] S12. Add the premix obtained in S11 and 15 parts of long glass fiber from the main feeding port of the first zone into a twin-screw extruder. Add 40 parts of the modified chopped glass fiber prepared in Example 1 from the first side feeding port, and add 40 parts of the modified chopped glass fiber prepared in Example 1 from the second side feeding port, then extrude and pelletize to obtain a high-strength and high-modulus PPS reinforced resin.

[0065] The length-diameter ratio of the twin-screw extruder is 40:1. The twin-screw extruder includes eleven temperature control zones, which are: temperature control zones 1-4 at 290-310 °C, temperature control zones 5-10 at 280-300 °C, and temperature control zone 11 at 310-330 °C. The main feeding port of the first zone is located in zone 1, the first side feeding port is located in zone 7, and the second side feeding port is located in zone 9.

[0066] Comparative Example 7:

[0067] S11. Add 40 parts of PPS resin, 8 parts of calcium carbonate, 11 parts of EEA and 2 parts of lubricant into a high-speed mixer, and mix for 15 minutes to obtain a premix.

[0068] S12. Add the premix obtained in S11 and 15 parts of long glass fiber into the twin-screw extruder from the main feeding port of the first zone, add 20 parts of chopped glass fiber into the first side feeding port, and add 20 parts of chopped glass fiber into the second side feeding port, then extrude and pelletize to obtain high-strength and high-modulus PPS reinforced resin.

[0069] The length-diameter ratio of the twin-screw extruder is 40:1. The twin-screw extruder includes eleven temperature control zones, namely: temperature control zones 1-4 are 290-310 °C, temperature control zones 5-10 are 280-300 °C, and temperature control zone 11 is 310-330 °C. The main feeding port of the first zone is located in zone 1, the first side feeding port is located in zone 7, and the second side feeding port is located in zone 9.

[0070] Detect the physical and chemical properties of the high-strength and high-modulus PPS reinforced resin prepared in Examples 4-6 and Comparative Examples 1-7. The inspection methods for each index are shown in Table 1, and the test results are shown in Tables 1 and 2.

[0071] Table 1

[0072]

[0073] Table 2

[0074]

[0075] The flexural modulus of pure PPS is only 3300 MPa, and the tensile strength is 70 MPa. It can be seen from Table 1 that the flexural modulus of the high-strength and high-modulus PPS reinforced resin prepared in Examples 4-6 of the present invention is 176618-176847 kg / cm 2 , and the tensile strength is 1415-1435 kg / cm 2 . It can be seen that the flexural modulus is increased by more than 5 times compared with pure PPS resin, and the tensile strength is increased by more than 2 times, and the mechanical properties are greatly improved.

[0076] Compared with Example 4, in Comparative Example 1, after replacing EEA with EVA, the overall performance decreased slightly; in Comparative Example 2, after not adding EEA, the mechanical properties decreased greatly, especially the tensile strength, flexural strength, and flexural modulus performance deteriorated; in Comparative Examples 3 and 4, after not adding long glass fiber and modified chopped glass fiber respectively, the impact strength performance deteriorated; in Comparative Examples 5 and 6, when the mass ratio of modified chopped glass fiber to long glass fiber is not 2-4:1, the overall performance decreased slightly; in Comparative Example 7, after using unmodified chopped glass fiber, the overall performance decreased slightly.

[0077] Visually, the surfaces of the high-strength and high-modulus PPS reinforced resin prepared in Examples 4-6 are relatively smooth. In Comparative Example 2 where EEA was not used and in Comparative Example 7 where unmodified chopped glass fiber was used, fiber floating phenomena occurred.

[0078] The above describes in detail the preferred embodiments of this patent. However, this patent is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, other different forms of changes or alterations can also be made. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A high-strength and high-modulus PPS reinforced resin, characterized in that: By weight, it includes the following components: 35-45 parts of PPS resin, 5-10 parts of calcium carbonate, 30-40 parts of modified chopped glass fiber, 10-20 parts of long glass fiber, 10-12 parts of EEA, and 1-3 parts of lubricant; Among them, the mass ratio of the modified chopped glass fiber to the long glass fiber is 2-4:1; The preparation method of the modified chopped glass fiber is as follows: Add the chopped glass fiber into a 15%-35% oxalic acid solution and stir for 2-3 h, wash the precipitate with deionized water 3-4 times, then add an aqueous solution of a silane coupling agent with a volume 3-4 times that of the chopped glass fiber, and perform ultrasonic dispersion at 50-80 kHz for 0.5-1 h to obtain the modified chopped glass fiber; Add 1 / 2 of the weight of the modified chopped glass fiber to the first side feeding port, and add the remaining 1 / 2 of the weight of the modified chopped glass fiber to the second side feeding port; The first side feeding port is located in the 7th zone, and the second side feeding port is located in the 9th zone.

2. The high-strength and high-modulus PPS reinforced resin according to claim 1, wherein: The lubricant is at least one of white oil, paraffin wax, and microcrystalline wax.

3. The high-strength and high-modulus PPS reinforced resin according to claim 1, wherein: The diameter of the chopped glass fiber is 9-13 μm, and the diameter of the long glass fiber is 13-16 μm.

4. The high-strength and high-modulus PPS reinforced resin according to claim 1, characterized in that: The mass-volume ratio (g:mL) of the chopped glass fiber to the oxalic acid solution is 1:3-4.

5. The high-strength and high-modulus PPS reinforced resin according to claim 1, wherein: The concentration of the aqueous solution of the silane coupling agent is 1%-3%.

6. The preparation method of the high-strength and high-modulus PPS reinforced resin according to any one of claims 1-5, characterized in that: It includes the following steps: S11. Add the formulated amounts of PPS resin, calcium carbonate, EEA, and lubricant into a high-speed mixer and mix for 10-15 min to obtain a premix; S12. Add the premix obtained in S11 and the long glass fiber from the main feeding port in the first zone into a twin-screw extruder, add 1 / 2 of the weight of the modified chopped glass fiber to the first side feeding port, and add the remaining 1 / 2 of the weight of the modified chopped glass fiber to the second side feeding port, extrude and pelletize to obtain a high-strength and high-modulus PPS reinforced resin.

7. The preparation method according to claim 6, characterized in that: The length-diameter ratio of the twin-screw extruder is 40:

1. The twin-screw extruder includes eleven temperature control zones, namely: temperature control zones 1-4 are 290-310 °C, temperature control zones 5-10 are 280-300 °C, and temperature control zone 11 is 310-330 °C.

8. The preparation method according to claim 6, characterized in that: The main feeding port in the first zone is located in the 1st zone, the first side feeding port is located in the 7th zone, and the second side feeding port is located in the 9th zone.

9. The preparation method according to claim 6, characterized in that: The screw speed of the twin-screw extruder is 260-300 rpm.

10. The preparation method according to claim 6, wherein: The rotation speed of the high-speed mixer is 1000-1200 rpm.

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