Preparation method of high-toughness PPS plate

Abstract

The present application relates to a kind of preparation methods of high toughness PPS plate, PPS raw material is completely melted after hot pressing, first with the rate of 5~20 ℃ / min cooling to 230~250 ℃, then immediately heated to 285~335 ℃ under the condition of pressurization, finally cooling makes PPS fully crystallize solidification, and high toughness PPS plate is prepared;PPS raw material is PPS film or PPS powder;The unnotched izod impact strength of the high toughness PPS plate prepared is 235.0~254.0J / m, and the tensile strength is 82.3~84.1MPa.The preparation method of the high toughness PPS plate of the present application can realize the enhancement of PPS toughness by only the regulation of crystalline structure without adding additional additives, and the strength does not decrease.

Description

Technical Field

[0001] This invention belongs to the field of polymer material processing technology and relates to a method for preparing high-toughness PPS sheets. Background Technology

[0002] Polyphenylene sulfide (PPS) is the sixth largest engineering plastic and the largest specialty engineering plastic. The PPS molecular chain consists of alternating benzene rings and para-sulfur atoms, resulting in a relatively simple molecular structure. Its unique composition and rigid structure give PPS excellent thermal, electrical, flame-retardant, and corrosion-resistant properties, along with good mechanical properties and dimensional stability. It is widely used in electronics, petrochemicals, automobiles, machine parts, electronic component packaging, insulating films, and corrosion-resistant fabrics. However, PPS lacks toughness and is prone to breakage, limiting its application range. Therefore, improving the toughness of polyphenylene sulfide is crucial.

[0003] To enhance the toughness of polyphenylene sulfide, existing technologies often employ physical or chemical modification methods:

[0004] There are generally three methods in physical modification:

[0005] (1) By adding elastomer particles to PPS, the difference in modulus between the elastomer particles and the matrix is ​​utilized to cause the blend to deform as stress concentration points when subjected to impact, forming micropores or cavities inside the material, reducing external impact energy, and at the same time inducing shear yielding or the formation of crazes in the matrix, causing the matrix to undergo a brittle-tough transition, thereby achieving the purpose of toughening; for example: Reference 1 (Research on the reinforcement and toughening of polyphenylene sulfide [J]. Plastics Industry, 2009, 37(4):19-21.) added a novel multifunctional elastomer EMG (high molar mass ethylene-maleic anhydride-glycidyl methacrylate terpolymer) to glass fiber reinforced PPS composite material. The results showed that the elastomer EMG had a good toughening effect on PPS. When its mass fraction reached 12%, the notched impact strength of the blend system reached 18.2 kJ / m 2 However, the tensile strength decreased to some extent.

[0006] (2) Blending polyolefins with PPS introduces strong interactions between different polymer chains, thereby improving the toughness of the material. For example, in reference 2 (Poly(phenylene sulfide) and low-density polyethylene reactive blends: morphology, tribology, and moldability[J]. Polymer Journal, 2000, 32(4): 555-559), ethylene-glycidyl methacrylate random copolymer (PE-GMA) was used as a compatibilizer for PPS and maleic anhydride-grafted low-density polyethylene (LDPE-g-MAH). The study found that PE-GMA exists between the two phases, which significantly reduces the size of the LDPE-g-MAH phase in the blend, improves the dispersion, increases the notched impact strength to 38 J / m, and increases the toughness by 65.2%. However, this method leads to a decrease in the mechanical properties of the material, with a decrease of 4.1%-13.5%.

[0007] (3) PPS is blended with other special engineering plastics to form a semi-interpenetrating polymer network transition layer between the two phases, which strengthens the two-phase interface, improves the processing performance of the material, and enhances the rheological and mechanical properties of the material. For example, Reference 3 (Mechanical properties and failure modes of toughened polyphenylene sulfide [J]. Polymer Materials Science and Engineering, 1994(01):69-72.) shows that physical modification was carried out by mixing PSF / PEK-C powder and PPS powder in dichloroethane and then allowing the solvent to evaporate at room temperature, which increased the notched impact strength of PPS to 8.49 KJ / m. 2 Increased to 13.6 KJ / m 2 However, this method requires the use of dichloroethane, a toxic solvent with potential carcinogenicity, and is not suitable for mass production.

[0008] Chemical modification enhances the toughness of polyphenylene sulfide (PPS) by altering its synthesis method. For example, synthesizing highly branched PPS can improve the toughness issues of linear PPS. Reference 4 (Synthesis and Application of Hyperbranched Polyphenylene Sulfide [J]. Polymer Materials Science and Engineering, 2008, (03): 122-124+128.) demonstrates this by preparing hyperbranched PPS, where the chain segments become entangled, resulting in a ductile fracture morphology compared to the brittle fracture morphology of pure PPS. However, this method is cumbersome, requiring redesign of the synthesis scheme and the use of numerous chemical reagents such as dichlorobenzene, chlorosulfonic acid, anhydrous lead acetate, and tetrahydrofuran, which increases production costs.

[0009] In summary, while physical blending improves toughness, it reduces the material's strength, which is unacceptable in material applications. Secondly, it requires adding additional materials during production, increasing both production and environmental costs. Furthermore, these techniques are only applicable to the preparation of PPS granules. Chemical modification methods, on the other hand, are time-consuming, costly, and challenging. Summary of the Invention

[0010] The purpose of this invention is to solve the above-mentioned problems existing in the prior art and to provide a method for preparing high-toughness PPS sheets.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] A method for preparing a high-toughness PPS sheet involves hot-pressing a PPS raw material until it is completely melted, then cooling it to 230-250°C at a rate of 5-20°C / min, then immediately heating it to 285-335°C under pressure, and finally cooling it to allow the PPS to fully crystallize and solidify, thereby obtaining a high-toughness PPS sheet.

[0013] The cooling rate after hot pressing and melting affects the crystallization temperature. If the cooling rate is below 5°C, the crystallization temperature will rise, causing premature and complete solidification. If the cooling rate is above 20°C, the crystallization temperature will decrease, preventing PPS from crystallizing at 230°C and thus failing to reach a semi-solidified state. If the cooling temperature is above 250°C, the material may still be in a viscous flow state without crystallization. If the cooling temperature is below 230°C, the material may have already fully crystallized, making it impossible to form a crystalline morphology with spherulites and microcrystals coexisting through subsequent steps.

[0014] The impact strength of the unnotched cantilever beam of the high-toughness PPS sheet is 235.0–254.0 J / m, and the tensile strength is 82.3–84.1 MPa.

[0015] As a preferred technical solution:

[0016] The method for preparing a high-toughness PPS sheet as described above uses PPS film or PPS powder as the PPS raw material.

[0017] The specific steps of the preparation method of the high-toughness PPS sheet described above are as follows:

[0018] (1) PPS raw material is laid into a mold and placed in a molding press. Under pressure, the temperature is initially raised to 290-350℃ to completely melt the PPS raw material, and the temperature and pressure are maintained for a period of time. If the hot pressing temperature is less than 290℃, PPS cannot completely melt, and the remaining unmelted part acts as crystal nuclei, affecting the subsequent crystallization structure. If the hot pressing temperature is greater than 350℃, PPS may undergo complex thermal oxidation behavior, such as cross-linking and degradation, which changes the molecular chain structure and leads to a decrease in material properties.

[0019] (2) Cool the mold to 230-250°C at a rate of 5-20°C / min to keep the resin melt in the mold in a semi-solidified state; at this time, some spherulites are formed in the material, but the overall phase transformation is not completely completed and it is in an intermediate state.

[0020] (3) Under pressure, the mold is heated again to 285-335℃ to melt the solidified PPS and keep it at the same temperature and pressure for a period of time. This melts the spherulites formed in step (2) to form tiny grains and locally ordered regions, which become nucleation sites for the next crystallization. This can promote the crystallization of PPS at higher temperatures, but this promoting effect only exists in the regions where spherulites are formed in step (2). At this time, the uncrystallized parts in step (2) will not be affected by the heating process in step (3) and will still maintain the original crystallization behavior of the polymer. Therefore, there will be two regions with different molecular chain topologies in the melt formed by PPS in step (3). If the temperature is greater than 335℃, the spherulites will completely melt, and the locally ordered regions will be destroyed by the thermal motion of the molecular chains, thus becoming disordered and unable to become self-nucleation sites for the next crystallization. If the temperature is less than 285℃, the spherulites will not melt and can only undergo annealing to form irregular spherulites, which cannot form self-nucleation sites.

[0021] (4) Cool the mold back to room temperature to allow the molten PPS in the mold to recrystallize and solidify. Open the mold and remove the high-toughness PPS sheet.

[0022] In the preparation method of a high-toughness PPS sheet as described above, the initial heating rate in step (1) is 5-100℃ / min, and the heat preservation and pressure holding time is 30-45min.

[0023] In the preparation method of a high-toughness PPS sheet as described above, the hot pressing pressure in step (1) is 0.8 to 1 MPa.

[0024] In the preparation method of a high-toughness PPS sheet as described above, the heating rate in step (3) is 10-40℃ / min, and the heat preservation and pressure holding time is 30-45min.

[0025] In the preparation method of a high-toughness PPS sheet as described above, the hot pressing pressure in step (3) is 0.8 to 1 MPa.

[0026] In the preparation method of a high-toughness PPS sheet as described above, the cooling rate in step (4) is 5-20℃ / min.

[0027] Invention principle:

[0028] The polymer crystallization process consists of two steps: nucleation and growth.

[0029] The polymer crystallization growth process involves polymer chains in the melt diffusing towards the crystal nucleus, then adsorbing, folding, and fixing themselves at the crystallization growth front, thus allowing the crystal to grow. This process takes time. Furthermore, the rate of crystallization is affected by temperature. The lower the temperature, the higher the viscosity of the resin and the slower the molecular chain movement.

[0030] Since polymer crystallization takes time, the start and stop of crystallization can be controlled by adjusting the temperature. Therefore, a suitable cooling rate and cooling temperature range need to be selected during processing. This invention creatively sets the cooling rate after hot pressing and melting to 5–20 °C / min, and the cooling range to 230–250 °C, thereby achieving a semi-solidified state in which PPS exhibits both melt and crystal coexistence.

[0031] If the cooling rate is too slow (less than 5℃ / min), the molecular chains have sufficient time to diffuse, adsorb, and adjust, thus increasing the crystallization temperature. This results in full crystallization before the temperature reaches 250℃, preventing the formation of a semi-solid state. Conversely, if the cooling rate is too fast (greater than 20℃ / min), the movement and diffusion rate of the molecular chains slows down, making it difficult for the polymer chains to complete their ordered arrangement within a limited time. This leads to a decrease in the crystallization temperature, with crystallization not occurring even at 230℃, leaving PPS in a fully molten state.

[0032] Once the semi-solidified state is formed, the semi-solidified PPS is immediately heated. During the heating process, the crystallization process almost stops. Upon reaching the melting temperature, the previously formed crystals are melted. At this point, there are two structural regions in the melt: one is a completely disordered melt (regions that have not crystallized after the first heating and cooling. Because the resin melts during the first heating, no crystalline structure is formed during the subsequent cooling process, and it remains in a molten state. At this time, the molecular chains in the melt have not formed a folded structure and are still in a disordered conformation. Therefore, during the second heating, the molecular chains maintain this disordered conformation under the action of their own thermal motion), and the other is a locally ordered melt (regions that have crystallized after the first heating and cooling. When the first heating and cooling forms a crystalline structure, the molecular chains have a folded chain lamellar structure. During the second melting, it will undergo a process of desorption, relaxation, interdiffusion, and reentanglement. Because the crystalline molecular chains are restricted by the amorphous regions near the crystallization and cannot diffuse, there are residual grains and regions with ordered molecular chain structures within the second melting temperature range). During the second cooling process, the locally ordered melt generated by the second heating process promotes polymer nucleation due to the presence of its low-entropy ordered structure, which increases the nucleation density in the region and preferentially forms microcrystalline structures; subsequently, the completely disordered melt crystallizes to form spherulite structures.

[0033] When a material is subjected to impact, the strain rate is very high, and the material's internal structure cannot adapt quickly enough. The resulting strain often exceeds the load-bearing capacity of the molecular structure. This can lead to molecular chain breakage, expansion of defects between grains, and crystal fragmentation.

[0034] The above-described process introduces spherulitic structures into a uniform microcrystalline structure. Due to the relatively perfect spherulitic structure, it exhibits high strength. When an impact-induced crack encounters spherulites during propagation, the high strength of the spherulites resists crack propagation and deflects the crack propagation path, thereby increasing the material's absorption of destructive energy. The role of the microcrystals is to achieve a more uniform distribution of internal stress under external loads through their more uniform distribution. Simultaneously, the microcrystalline region contains more grain boundaries, increasing the crack propagation path. Through this spherulitic-microcrystalline coexistence structure, the PPS material's toughness is improved without compromising its strength.

[0035] Beneficial effects:

[0036] The present invention provides a method for preparing high-toughness PPS sheets, which can enhance the toughness of PPS by regulating the crystal structure without adding any additional additives, and maintain the strength without any decrease. Attached Figure Description

[0037] Figure 1The image shows a polarized light microscope image of PPS at 50 μm in Example 1. (a) shows the initial spherulite morphology formed during the first cooling process, where the area without spherulites is still in a molten state. (b) and (c) show the process of forming a coexistence of microcrystals and spherulites during the second cooling process.

[0038] Figure 2 This is a comparison chart of the impact strength of the unnotched cantilever beam of PPS in Comparative Example 7 and Example 3.

[0039] Figure 3 This is a comparison chart of the tensile strength of PPS in Comparative Example 7 and Example 3. Detailed Implementation

[0040] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0041] The testing method used in this invention is as follows:

[0042] Unnotched cantilever beam impact strength: According to ASTM D256 standard, PPS material was prepared into cuboid specimens of 64mm×12.7mm×3.2mm. The specimens were tested for unnotched cantilever beam impact strength using a cantilever beam impact testing machine (XJUD-5.5, JinJian-Test, China). The specimens were impacted with an impact energy of 1J. Specimens that completely fractured upon impact were recorded as valid specimens.

[0043] Tensile strength: PPS specimens were prepared according to ASTM D638 standard, and tensile properties were tested at room temperature using a general-purpose tensile testing machine at a cross speed of 1 mm / min. Tensile stress was determined by dividing the tensile load by the initial cross-sectional area, and tensile strain was calculated by the ratio of the length increment between the clamps to the initial gauge length. The maximum stress was the tensile strength.

[0044] In the embodiments of the present invention, the PPS film manufacturer is Zhejiang Xinhecheng Co., Ltd., and the trade name is 3518. The PPS powder is made by crushing the PPS film.

[0045] Example 1

[0046] A method for preparing a high-toughness PPS sheet, the specific steps of which are as follows:

[0047] (1) Lay the PPS film into the mold, put it into the molding machine, and heat it to 290°C for the first time at a rate of 5°C / min under 0.8MPa, and keep it at the temperature and pressure for 30min.

[0048] (2) Cool the mold to 230℃ at a rate of 5℃ / min;

[0049] (3) Immediately heat the mold to 285°C at a rate of 10°C / min under a pressure of 0.8MPa, and keep it at the temperature and pressure for 30min;

[0050] (4) Cool the mold to room temperature again at a rate of 5℃ / min, open the mold and take out the high-toughness PPS sheet.

[0051] like Figure 1 As shown, by controlling the first cooling rate and the first cooling temperature, PPS reaches a semi-solidified state. Subsequently, after undergoing a second cooling and heating process, PPS forms a structure in which microcrystalline spherulites coexist.

[0052] The high-toughness PPS sheet obtained has an unnotched cantilever beam impact strength of 235.2 J / m and a tensile strength of 82.6 MPa.

[0053] Comparative Example 1

[0054] A method for preparing PPS board is basically the same as in Example 1, except that the cooling rate in step (2) is 2℃ / min.

[0055] The unnotched cantilever beam impact strength of the prepared PPS sheet is 210.4 J / m, and the tensile strength is 82.5 MPa.

[0056] Compared with Example 1, the impact strength of the unnotched cantilever beam in Comparative Example 1 is reduced because the cooling rate in step (2) is too slow, causing PPS to fully crystallize and solidify before reaching the specified temperature range of 230-250°C, and failing to form the semi-solidified state required by the present invention. Therefore, the impact strength is not improved.

[0057] Comparative Example 2

[0058] A method for preparing PPS board is basically the same as in Example 1, except that the cooling rate in step (2) is 40℃ / min.

[0059] The unnotched cantilever beam impact strength of the prepared PPS sheet is 194.5 J / m, and the tensile strength is 78.6 MPa.

[0060] Compared with Example 1, the impact strength of the unnotched cantilever beam in Comparative Example 2 is reduced. This is because the cooling rate in step (2) is too fast, which causes the molecular chain mobility of PPS to decrease rapidly during the cooling process, making it unable to complete crystal nucleation and growth. Therefore, PPS is still in a molten state at this time and has not formed the semi-solidified state required by the present invention. Therefore, the impact strength is not improved.

[0061] Comparative Example 3

[0062] A method for preparing PPS sheets is basically the same as in Example 1, except that the temperature is lowered to 200°C in step (2).

[0063] The unnotched cantilever beam impact strength of the prepared PPS sheet is 206.2 J / m, and the tensile strength is 83.5 MPa.

[0064] Compared with Example 1, the impact strength of the unnotched cantilever beam in Comparative Example 3 is reduced because the cooling temperature in step (2) is too low, below the temperature range specified in this invention. As a result, PPS has fully crystallized and solidified when it reaches 200°C, and has not formed the semi-solidified state required by this technology. Therefore, the impact strength is not improved.

[0065] Comparative Example 4

[0066] A method for preparing PPS sheets is basically the same as in Example 1, except that the temperature is lowered to 270°C in step (2).

[0067] The unnotched cantilever beam impact strength of the prepared PPS sheet is 189.5 J / m, and the tensile strength is 77.6 MPa.

[0068] Compared with Example 1, the impact strength of the unnotched cantilever beam in Comparative Example 4 is reduced. This is because the temperature reached by cooling in step (2) is higher than the temperature range required to form a semi-solidified state. At this time, PPS still remains in a molten state and does not crystallize. Therefore, it is impossible to form the semi-solidified state required by this invention, resulting in no improvement in impact strength.

[0069] Comparative Example 5

[0070] A method for preparing PPS board is basically the same as in Example 1, except that the temperature is raised to 350°C in step (3).

[0071] The high-toughness PPS sheet obtained has an unnotched cantilever beam impact strength of 183.3 J / m and a strength of 73.4 MPa.

[0072] Compared with Example 1, the impact strength of the unnotched cantilever beam in Comparative Example 5 was reduced. This is because the melting temperature reached in step (3) was too high, and the molecular chain mobility was too strong, which destroyed the residual grains and local ordered regions of the crystal in the semi-solidified state in step (2) in the melt of the second heating. This structure is the key to improving the nucleation density of PPS and then forming microcrystals in step (4). Because the heating temperature in step (3) was too high, the structure of coexistence of microcrystals and spherulites could not be formed, resulting in no improvement in impact strength.

[0073] Comparative Example 6

[0074] A method for preparing a high-toughness PPS sheet is basically the same as in Example 1, except that in step (3), the temperature is not raised immediately, but after cooling in step (2), the temperature is kept for 30 minutes before being raised again.

[0075] The high-toughness PPS sheet obtained has an unnotched cantilever beam impact strength of 201.3 J / m and a tensile strength of 82.1 MPa.

[0076] Compared with Example 1, the impact strength of the unnotched cantilever beam in Comparative Example 6 was reduced. This is because the heat preservation time after step (2) was too long. Since the crystallization of PPS takes time, the heat preservation time was too long, which caused PPS to fully crystallize and solidify, and the semi-solidified state required by the present invention was not formed. Therefore, the impact strength was not improved.

[0077] Example 2

[0078] A method for preparing a high-toughness PPS sheet, the specific steps of which are as follows:

[0079] (1) Lay the PPS film into the mold, put it into the molding machine, and heat it to 310°C at a rate of 15°C / min under 0.9MPa for the first time, and keep it at the temperature and pressure for 35min.

[0080] (2) Cool the mold to 235℃ at a rate of 10℃ / min;

[0081] (3) Immediately heat the mold to 290°C at a rate of 15°C / min under a pressure of 0.9MPa, and keep it at the temperature and pressure for 35min;

[0082] (4) Cool the mold back to room temperature at a rate of 10℃ / min, open the mold and take out the high-toughness PPS sheet.

[0083] The high-toughness PPS sheet obtained has an unnotched cantilever beam impact strength of 240.4 J / m and a tensile strength of 83.1 MPa.

[0084] Example 3

[0085] A method for preparing a high-toughness PPS sheet, the specific steps of which are as follows:

[0086] (1) Lay the PPS film into the mold, put it into the molding machine, and heat it to 320°C for the first time at a rate of 35°C / min under 1MPa, and keep it heated and pressed for 45min.

[0087] (2) Cool the mold to 240℃ at a rate of 20℃ / min;

[0088] (3) Immediately heat the mold to 300°C at a rate of 20°C / min under a pressure of 1MPa, and keep it at the temperature and pressure for 45min.

[0089] (4) Cool the mold to room temperature again at a rate of 20℃ / min, open the mold and take out the high-toughness PPS sheet.

[0090] The high-toughness PPS sheet obtained has an unnotched cantilever beam impact strength of 254.0 J / m and a tensile strength of 84.1 MPa.

[0091] Comparative Example 7

[0092] A method for preparing PPS sheet is basically the same as in Example 1, except that steps (3) and (4) are omitted, and after step (2), the temperature is lowered to room temperature at a rate of 20°C / min, and the mold is opened to take out the prepared PPS sheet.

[0093] like Figure 2 , 3 As shown, compared with Comparative Example 7, the unnotched cantilever beam impact strength of the molded PPS sheet increased by 19.2% in Example 3, and the tensile strength changed from 81.5 MPa to 84.1 MPa. This indicates that the present invention effectively improves the toughness of PPS material by constructing a crystalline structure in which microcrystalline spherulites coexist, and the tensile strength does not decrease.

[0094] Example 4

[0095] A method for preparing a high-toughness PPS sheet, the specific steps of which are as follows:

[0096] (1) PPS powder is spread into the mold and placed in the molding press. The temperature is initially raised to 330°C at a rate of 55°C / min under 0.8MPa, and kept at the temperature and pressure for 30min.

[0097] (2) Cool the mold to 245℃ at a rate of 5℃ / min;

[0098] (3) Immediately heat the mold to 310°C at a rate of 25°C / min under a pressure of 0.8MPa, and keep it at the temperature and pressure for 30min;

[0099] (4) Cool the mold to room temperature again at a rate of 5℃ / min, open the mold and take out the high-toughness PPS sheet.

[0100] The high-toughness PPS sheet obtained has an unnotched cantilever beam impact strength of 247.1 J / m and a tensile strength of 83.8 MPa.

[0101] Example 5

[0102] A method for preparing a high-toughness PPS sheet, the specific steps of which are as follows:

[0103] (1) PPS powder is spread into the mold and placed in the molding press. The temperature is initially raised to 340℃ at a rate of 75℃ / min under 0.9MPa, and then kept at the temperature and pressure for 40min.

[0104] (2) Cool the mold to 250℃ at a rate of 15℃ / min;

[0105] (3) Immediately heat the mold to 320°C at a rate of 30°C / min under a pressure of 0.9MPa, and keep it at the temperature and pressure for 40min;

[0106] (4) Cool the mold back to room temperature at a rate of 15℃ / min, open the mold and take out the high-toughness PPS sheet.

[0107] The high-toughness PPS sheet obtained has an unnotched cantilever beam impact strength of 237.1 J / m and a tensile strength of 83.4 MPa.

[0108] Example 6

[0109] A method for preparing a high-toughness PPS sheet, the specific steps of which are as follows:

[0110] (1) PPS powder is spread into the mold, placed in the molding machine, and initially heated to 350°C at a rate of 100°C / min under 1MPa, and kept at the temperature and pressure for 45min.

[0111] (2) Cool the mold to 250℃ at a rate of 20℃ / min;

[0112] (3) Immediately heat the mold to 335°C at a rate of 40°C / min under a pressure of 1MPa, and keep it at that temperature and pressure for 45min.

[0113] (4) Cool the mold to room temperature again at a rate of 20℃ / min, open the mold and take out the high-toughness PPS sheet.

[0114] The high-toughness PPS sheet obtained has an unnotched cantilever beam impact strength of 235.5 J / m and a tensile strength of 82.3 MPa.

Claims

1. A method for preparing a high-toughness PPS sheet, characterized in that: After the PPS raw material is completely melted by hot pressing, it is first cooled to 230-250°C at a rate of 5-20°C / min, and then immediately heated to 285-335°C under pressure. Finally, it is cooled to allow the PPS to fully crystallize and solidify, thus obtaining a high-toughness PPS board. The hot pressing temperature is 290–350℃; The impact strength of the unnotched cantilever beam of the high-toughness PPS sheet is 235.0–254.0 J / m, and the tensile strength is 82.3–84.1 MPa.

2. The method for preparing a high-toughness PPS sheet according to claim 1, characterized in that, PPS raw material is PPS Thin film or PPS powder.

3. The method for preparing a high-toughness PPS sheet according to claim 2, characterized in that, The specific steps are as follows: (1) PPS raw material is laid into the mold and placed in the molding press. Under pressure, the temperature is initially raised to 290-350℃ to completely melt the PPS raw material, and the temperature and pressure are maintained for a period of time. (2) Cool the mold to 230-250℃ at a rate of 5-20℃ / min; (3) Under pressure, the mold is heated again to 285-335°C to melt the crystallized PPS and keep it at the temperature and pressure for a period of time. (4) Cool the mold back to room temperature to allow the molten PPS in the mold to recrystallize and solidify. Open the mold and remove the high-toughness PPS sheet.

4. The method for preparing a high-toughness PPS sheet according to claim 3, characterized in that, In step (1), the initial heating rate is 5-100℃ / min, and the holding and pressure holding time is 30-45min.

5. The method for preparing a high-toughness PPS sheet according to claim 3, characterized in that, The pressure applied in step (1) is 0.8 to 1 MPa.

6. The method for preparing a high-toughness PPS sheet according to claim 3, characterized in that, In step (3), the heating rate is 10-40℃ / min, and the holding time is 30-45min.

7. The method for preparing a high-toughness PPS sheet according to claim 3, characterized in that, The pressure applied in step (3) is 0.8 to 1 MPa.

8. The method for preparing a high-toughness PPS sheet according to claim 3, characterized in that, The rate of cooling again in step (4) is 5 to 20 °C / min.

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