WO2002051910A1

WO2002051910A1 - The high-density high-molecular linear polyphenylene sulfide polymers and the processes of preparing the polymers

Info

Publication number: WO2002051910A1
Application number: PCT/CN2001/001637
Authority: WO
Inventors: Qigao Gu
Original assignee: Qigao Gu
Priority date: 2000-12-27
Filing date: 2001-12-20
Publication date: 2002-07-04
Also published as: CN1309142A; CN1095481C

Abstract

The high-density high-molecular linear polyphenylene sulfide polymers and the processes of preparing the polymers. The melting points of the polyphenylene sulfide polymers are between 280oC and 298oC, the melt flow rates 20-700g/316oC-5kg-10min, particle diameters more than 0.1mm, average molecular weight in the range from 28000 to 64000, the density in the range from 1360 to 1430kg/m3, and the average molecular weight of the polymers is controllable, and the polymers have regular linear structure. The invention includes using Na¿2?S9H2O as sulfur source, mixing sulfur source with additive and solvent to produce complex compound, and condensation polymerization with chlorobenzene to give the end-product. The advantages of the invention are easily available raw material, low cost, and high molecular weight with marrow distribution.

Description

High-density linear high molecular weight polyphenylene sulfide and preparation method thereof

The invention relates to a polyphenylene sulfide and a preparation method thereof, and more particularly to a high-density linear high molecular weight polyphenylene sulfide having a regular linear structure and a narrow molecular weight distribution, and a preparation method thereof. Background technique

Methods for the preparation of arylene sulfides from aromatic compounds are described in U.S. patents 3354129, 3919177, Japanese patents Sho 58-47026, Sho 58-125721, Sho 61-7332, including the use of a sulfur source, p-dihalobenzene, The organic amide, the base and the alkali metal carboxylate together form a composition, and at least a portion of the composition is kept to form a polymer under polymerization conditions. One example of this is to add sodium sulfide and N-methylpyrrolidinone to a high-pressure stirred tank, and then slowly heat the mixture to 202 ° C under the protection of nitrogen for 2 hours, distill the water, and cool to 175 ° C. 1.4-dichlorobenzene (DCB) dissolved in NMP was added to the reactor, heated at a pressure of 30 Psig for 20 minutes, the temperature reached 245 V, heated at a pressure of 80 to 220 Psig for 3 hours, and then cooled, washed and dried. Dark gray solid polyphenylene sulfide.

A method for preparing a sulfur-containing polymer is described in Chinese patent CN-1225106A, which comprises dissolving sodium sulfide trihydrate in N-methylpyrrolidone (NMP), distilling off the condensate, and then dissolving it in Dichlorobenzene (DCB) in N-methylpyrrolidinone was added, and prepolymerized at 230 ° C for 1 hour, and then the reaction kettle was returned to normal pressure. Sodium sulfide trihydrate was added, water was distilled off, and the mixture was heated to 230 ° C. 5 小时。 In addition, dichlorobenzene dissolved in N-methylpyrrolidone was added, at 230 ° C, the mixture was polymerized for 1.5 hours.

In Chinese patent CN-1145376A, a method for preparing linear high molecular weight polyarylene sulfide is described, which uses industrial sodium sulfide as a sulfur source, a high boiling point aprotic polar organic compound as a solvent, and a multi-component compound The catalyst or auxiliary is partially dehydrated in a short-time kettle at normal pressure, and is directly polymerized with the polyhalogenated aromatic compound in stages to obtain a white granular polyarylene sulfide resin. The polymerization was carried out in two stages, the first stage temperature was 100 ~ 210 ° C, time 0.5 ~ 6 hours, the second stage temperature was 200 ~ 280 ° C, time 0.5 ~ 6 hours, yield 92%, The viscosity is 1500 poise.

However, the above existing technologies all have at least the following problems:

1. The sulfur source used in the preparation of polyaryl sulfide, especially polyphenylene sulfide (PPS), the methods described in Chinese patents CN-1225106A, CN-1145376A are using anhydrous sodium sulfide, Chinese patent CN- The method described in 1145376A uses aqueous industrial sodium sulfide containing 0.5 to 7 water molecules, and the method described in Chinese patent CN-1225106A uses aqueous sodium sulfide containing 3 water molecules. Industrial scale production of anhydrous sulfur sulfide or sodium sulfide containing partially crystallized water not only has high production costs, but also has problems such as process, equipment, storage, and more serious. Crystalline sodium sulfide loses some or all of it at high temperatures After crystallizing water, the color becomes darker and even red Brown, forming solid amorphous particles. The reaction with halobenzene can only take place on the surface of the particles, and the activity is very low.

2. In the methods described in Japanese Patent Laid-Open No. 6-192422 (1994), Japanese Patent Laid-Open No. 6-192423 (1994), Japanese Patent Laid-Open No. 7-3022 (1995), etc., the synthesis of polyarylsulfide, especially For polyphenylene sulfide, the reaction process is a heterogeneous process. Generally, a two-stage reaction is used: In the first stage of the reaction, solid sodium sulfide particles and a halogenated state in the form of droplets (oil beads) dispersed in a strongly polar organic solvent Benzene reaction for 2 ~ 12 hours, the formation of prepolymers with extremely uneven molecular weights and a viscosity of 0.5 ~ 30P. AS, such prepolymers with very different molecular weights, it is very bad to enter the second-stage polycondensation reaction; In the second stage, the reaction temperature is 20 ~ 60 ° C, and the reaction is performed for 4 ~ 8 hours, so that the polycondensation reaction continues between the prepolymer particles. As the above two important reaction processes are performed in a heterogeneous state, especially in the second-stage reaction process, there is no significant difference in the interface reaction speed of various prepolymers with greatly different molecular weights. Polyphenylene sulfide resins prepared under process conditions differ in physical properties from several to ten times and have a wide molecular weight distribution. Strict refining is required to remove 15-25% of the total resin with molecular weight below 10,000 g / mol. Oligomer.

3. Due to the above-mentioned problems in the prior art, the prepared polymers differ greatly in color and luster (white, gray, tan), and the particles are not uniform. 'Most of them are powdery, with a bulk density of only 115 to 280 kg / ^m3 and a density of only It reaches 1150 ~ 1320 kg / ^m3 .

4. Regarding the polyphenylene sulfide prepared by the above method, whether it is granules or powder, its density is very small, and storage and transportation are inconvenient. Generally, the post-processing should be pre-pelletized with a twin-screw extruder, and then filled. Strong, such as adding glass fiber, carbon fiber, inorganic materials, etc. for secondary granulation, for industrial scale preparation of various compositions, the cost is very high. Summary of the Invention

The object of the present invention is to provide a high-density linear high-molecular-weight polyphenylene sulfide, which has readily available raw materials, is inexpensive, has uniform particles, has a linear molecular structure, has a high molecular weight, and has a narrow molecular weight distribution.

Another object of the present invention is to provide a method for preparing a high-density linear high-molecular-weight polyphenylene sulfide.

These and other objects of the present invention will be further embodied and illustrated by the following detailed description and description.

The high-density linear high molecular weight polyphenylene sulfide of the present invention has a melting point of 280 ~ 298 ° C and a melt flow rate of

2 ~ 700 g / 316 ° C—5 kg for 10 minutes, particle size is greater than 0.1 mm, average molecular weight is 28000 ~ 84000, density is 1360 ~ 1430 kg / ^m3 , and it has a regular linear structure.

Preferably, the high-density linear high-molecular-weight polyphenylene sulfide of the present invention has a melting point of 280 to 298 ° C, and a melt flow rate of 20 to 200 g / 316 ° C-5 kg to 10 minutes, and the particle size More than 0.1 mm, average molecular weight is 45000 ~ 72000, molecular weight can be controlled, density is 1360 ~ 1430 kg / ^m3 , and it has a regular linear structure. Most preferably, the high-density linear high molecular weight polyphenylene sulfide of the present invention has a melting point of 280 ~ 298 ° C, a melt flow rate of 50 ~ 100 g / 316Ό-5 kg for 10 minutes, and a particle size greater than 0. 1 mm, average molecular weight is 55,000 ~ 64000, molecular weight can be controlled, density is 1360 ~ 1430 kg / ^m3 , and it has a regular linear structure.

Further, the high-density linear high molecular weight polyphenylene sulfide of the present invention has a tensile strength greater than 100 MPa, a breaking elongation greater than 32%, a flexural strength greater than 160 MPa, and a notched Izod impact strength greater than 12 kg / m.

In the present invention, a crystal of sodium sulfide containing nine molecules of water is used as a sulfur source. Further, a crystal of sodium sulfide containing nine molecules of water can be used as a sulfur source.

The high-density linear high-molecular-weight polyphenylene sulfide of the present invention can be prepared according to the following method, including the following steps:

A. Weigh out the reactants according to the following proportions and add them to the reaction kettle:

The molar ratio of sulfide, phosphate and solvent is: 1. 0: (0. 2 ~ 0. 3): (0. 5 ~ 2. 5), at a temperature of 120 ~

Reaction at 240 ° C for 60 ~ 220 minutes, complexes are formed, and excess low-boiling substances are discharged at the same time;

B. Add a halogenated aromatic compound dissolved in a solvent to the complex, and react at a temperature of 140 ~ 260 ° C for 5 ~ 60 minutes to form a prepolymer;

C, and then the temperature of the reaction kettle was raised to 180 ~ 280 ° C, and the reaction was performed at a pressure of 0.05 to 0.6MPa for 30 to 190 minutes;

D. Cool to below 80 ° C and centrifuge to separate the granular polymer.

Preferably, the high-density linear high-molecular-weight polyphenylene sulfide of the present invention can be prepared by the following method, including the following steps −

The molar ratio of sulfide, phosphonate and solvent is: 1. 0: (0. 2 ~ 0. 25): (1. 0 ~ 1. 8), at a temperature of 150 ~

Reaction at 220 ° C for 90 ~ 150 minutes, complexes are formed, and excess low boiling point substances are discharged at the same time;

B. Add a halogenated aromatic compound dissolved in a solvent to the complex, and react at a temperature of 180 ~ 240 ° C for 10 ~ 40 minutes to form a prepolymer;

C, and then the temperature of the reaction kettle was raised to 200 ~ 260 ° C, and the reaction was carried out at a pressure of 0.1 to 0.6MPa for 40 to 180 minutes;

D. Cool to below 80 ° C, centrifugally separate the granular polymer, wash with hot water until neutral, and then wash it twice with hot deionized water, then dry under reduced pressure at 120 ° F for 6 hours to obtain the final product.

Most preferably, the high-density linear high-molecular-weight polyphenylene sulfide of the present invention can be prepared by the following method, including the following steps:

The molar ratio of sulfide, phosphate and solvent is: 1. 0: (0. 2 ~ 0. 25): (1. 2 ~ 1. 6), at a temperature of 150 ~ Reaction at 220 ° C for 90 ~ 120 minutes, complexes are formed, and excess low boiling point substances are discharged at the same time;

B. Adding a halogenated aromatic compound dissolved in a solvent to the complex, and reacting at a temperature of 190 to 22 ° C. for 15 to 30 minutes to form a prepolymer;

C, and then the temperature of the reaction kettle was raised to 220 ~ 240 ° C, and the reaction was performed for 60 ~ 160 minutes under a pressure of 0.1 to 0.4 MPa;

D. Cool to below 80 ° C, centrifugally separate the granular polymer, wash it with hot water to neutrality, wash it twice with hot deionized water, and then dry it under reduced pressure at 120 ° C for 6 hours to obtain the final product.

In the preparation method of the high-density linear high molecular weight polyphenylene sulfide of the present invention, the molar ratio of the complex to the halogenated aromatic compound is 1.0: (0. 3 ~ 0. 6), more It is good that the molar ratio of the complex to the halogenated aromatic compound is 1.0: (0.4 to 0.5); the molar ratio of the solvent to the halogenated aromatic compound is 1: (0.2 to 0 5).

In the present invention, the phosphate is sodium phosphate, and the solvent hexamethylphosphoryl triamine; the halogenated aromatic compound is dichlorobenzene, and the dichlorobenzene is 1.4-Xinch dichlorobenzene and 1 . The mixture of 3-dichlorobenzene, the molar ratio of p-dichlorobenzene and m-dichlorobenzene is 3: 2 ~ 19: 1, the molar ratio of p-dichlorobenzene and m-dichlorobenzene is 9: 1 ~ 16: lo

In the present invention, other compounds or auxiliaries can also be added to further improve the product's

Quality, including the use of dimethylformamide (DMF), N-methylpyrrolidone (NMP) or tetrahydrofuran instead of hexamethylphosphoryltriamine (HPT); dihalobenzenes including diiodobenzene, Dibromobenzene partially (more than 10%) or completely replace dichlorobenzene; In addition to sodium phosphate, other phosphates can be used, including phosphites, metaphosphates, and hypophosphites. Besides sodium, potassium, lithium, etc. can also be used. The raw materials of the product of the invention are easily available, the cost is low, the polymer produced has a high molecular weight, a narrow molecular weight distribution, and a density of 1360 to 1430 kg / m ³ , which is suitable for industrial scale preparation of polyphenylene sulfide.

In the present invention, crystalline sodium sulfide containing nine molecules of crystalline water is used as a sulfur source. Because sodium sulfide nine hydrate is a prism-shaped crystal, it has stable properties, easy storage, simple industrial preparation, and low cost. Of course, if necessary, crystalline sodium sulfide containing not nine molecules may be used as the sulfur source, including sodium sulfide using six molecules or three molecules of crystal water as the sulfur source.

In the method of the present invention, a complex of sodium sulfide and phosphate with a polar solvent is prepared. In the range of 80 ~ 250 ° C, sodium sulfide, sodium phosphate and solvent form complexes, which are red in the range of 80 ~ 125 ° C and dark blue in the range of 140 ~ 230 ° C. The complex has a certain composition : NS: HPT: (NaO) ₃ P0 = 1: 1: 0.2. Under the process conditions of the present invention, the complex is in a metastable state and has a high reactivity. Since the complex is metastable, the temperature has a great influence on it. When the temperature is higher than 180 ° C, the complex has good activity. The reaction speed of benzene mixture is very fast, and the size of the prepolymer produced is uniform; when the temperature is lower than 130Ό, the activity of the complex is low, the prepolymerization reaction time is long, and the molecular weight of the prepolymer produced is greatly different, which significantly affects the synthesis product. The yield and quality are unfavorable.

In the present invention, a halogenated aromatic compound which is highly dispersed in a polar solvent is reacted with active sulfur in the complex at 180 ~ 230 ° C to form a prepolymer. ) In the system, so the reaction speed is very fast, can be completed in 5 to 30 minutes. What's more important is that the molecular size of the prepolymers produced by the reaction is basically the same, which is of great significance for further polymerization into linear polymers with high molecular weight and narrow distribution range.

In the present invention, a halogenated aromatic mixture is used, when the amount of 1.4 pairs of dichlorobenzene and 1.3-m-dichlorobenzene is in the range of 3: 2 ~ 19 _: 1, and preferably 9: 1 ~ 16: 1: 1 range, the solubility of the prepolymer in a polar solvent (such as hexamethylphosphoryl triamine) is very large, and then the product performance indicators obtained through polycondensation are significantly improved compared to the single use of 1.4 pairs of dichlorobenzene . The prepolymer system was rapidly increased to 180 ~ 28 (TC range for polycondensation in accordance with the program temperature increase method, and the process conditions were extremely stable. Because the prepolymer molecules were basically the same size and the reaction speed was fast, 0.5 to 3 hours was completed, The polymer with the expected linear molecular structure and molecular weight and concentrated molecular weight distribution is obtained. The polymer is characterized by high whiteness, uniform particles, particle size of 1 mm, bulk density of 450 ~ 700 kg / ^m3 , and density of 1360-1430. Kg / ^m3 high-quality polyphenylene sulfide resin can be directly used in high-strength injection products, high-toughness film products, fiber products and electrical components with excellent performance.

The resin density of the invention reaches 1360 ~ 1430 kg / ^m3 , which is convenient for storage and transportation, and can be easily added with glass fiber, carbon fiber, and inorganic materials for reinforcement without pre-granulation treatment.

The polymerization reaction of the present invention is carried out at a low pressure of 0.1 to 0.6 MPa, which does not have high requirements for reactor manufacture. The polymerization reaction is more stable than the atmospheric polymerization conditions of the prior art, and the medium and high pressure polymerization conditions are adopted compared to foreign patents. The equipment investment is significant. Lower, which is good for preparing polyphenylene sulfide on an industrial scale. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an infrared spectrum of a product of the present invention.

Figure 2 is an infrared spectrum of another product of the present invention.

Figure 3 is the infrared spectrum of a famous foreign company's products.

A simple comparison between FIG. 1 and FIG. 2 and FIG. 3 shows that the molecular structure of the product of the present invention is regular. Tables 1 and 2 compare the products of the present invention with those of a foreign company. Table 1

Note-The above five important indicators are better than a foreign company, the other ten indicators are basically the same, but the products of a foreign company contain a crosslinked structure. The high density linear high molecular weight polyphenylene sulfide of the present invention does not need to be crosslinked.联处理的。 Processing. Table 4

Note: The currently available solvents are 40-50 yuan / kg. Reducing solvent consumption is an important factor in reducing the cost of polyphenylene sulfide and reducing environmental pollution. detailed description

The following further describes the present invention through specific examples, but the examples are only for illustration, and cannot limit the scope of the present invention.

All raw materials used in the present invention are commercially available.

In the present invention, unless otherwise specified, all amounts and percentages are weight units.

Example 1:

In a 2500 liter stainless steel reactor, 3.0 kilomoles of crystalline sodium sulfide nonahydrate, 0.666 kilomoles of sodium phosphate, 800 kilograms of hexamethylphosphoryltriamine were added, and the temperature was increased to 180 ° C under stirring for 2 hours to produce a blue color. Complex, while discharging low-boiling substances (including water, hydrogen sulfide, by-products generated during the complexation process); adding 1.4 pairs 2.75 kilomoles of dichlorobenzene, 0.31 kilomoles of 1.3-m-dichlorobenzene, 400 kg of hexamethylphosphoryltriamine, and the temperature was rapidly raised to 200 ° C, and the reaction was allowed to proceed for 10 minutes. The temperature was further increased to 225 ° C, and the reaction was allowed to proceed for 2 hours, and then cooled The granulated polymer was centrifuged below 80 ° C, washed with 80 ° C hot water to neutrality, then washed twice with 80 ° C deionized water, and then dried under reduced pressure at 12CTC for 6 hours to obtain all white granular polymerization. 311.5 kg, yield 96%, see Table 1 and Table 2 for polymer performance index.

(2) Using a new low-pressure polymerization process, a 200-ton / year polyphenylene sulfide (PPS) resin production device was built, with a reactor capacity of 2500 liters, and a continuous feeding test was carried out to achieve the following indicators-production capacity: 800 kg / day, synthesis cycle: 4 ~ 8 hours / cauldron

Feeding capacity of a single kettle: 2000 kg (raw materials, additives, solvents)

Recovery rate: 95 ~ 98%

Solvent consumption: <300 kg / ton PPS resin (hexamethylphosphoryl triamine)

Product quality: melting point 295 ~ 298 ° C, melt flow rate: 2 ~ 700g / 316 ° C- 5kg-10min, density 1360-1430kg / ^m3

Resin appearance: All white granules, particle size 0.1 mm.

Pure resin properties: average molecular weight MV61000 ~ 64000, tensile strength 100¾ «¾, elongation at break 30%, flexural strength> 150¾ ^ ¾, cantilever notched impact strength> 12J / M, heat distortion temperature> 112 ° C, volume resistance 4.2 Χ10 ¹⁶ ΩΜ, surface resistivity 6.2 × ^{10 15} Ω.

Examples 2-6

Change the process parameters and operate according to Example 1. The results are shown in Table 3 and Table 4.

Comparative example:

In a 5 liter titanium-lined reactor, 5.0 mol of sodium sulfide trihydrate, 1.0 mol of sodium phosphate, and 1250 g of hexamethylphosphoryl triamine were added. The temperature was raised to 120 ° C under stirring, and the reaction was continued for 2.5 hours. At the same time, excess water was discharged. 1.4 one pair of dichlorobenzene 4.4 mol, 1.3-m-dichlorobenzene 0.5 mol, quickly heated to 220 ° C, and reacted for 10 minutes; then quickly heated to 250 ° C, reacted for 4 hours, cooled to 80 ° C, suction filtered, Rinse with 80Ό hot water to neutrality, wash twice with 80 ° C deionized water, and dry under reduced pressure at 120 ° C for 12 hours to obtain 421 g of beige powdery polymer, yield 78%, polymer properties The indicators are shown in Table 3 and Table 4.

Comparative Examples 2-5

Change the process parameters and operate according to Comparative Example 1. The results are shown in Table 3 and Table 4. table 3

Continued Table 3

• Import Products

The reaction temperature appearance time Yield Yield diameter ■ ¾, Example 1 225 240 311.5 96.0 white particle (° C) (min) (KG) (%) ( U) kg / m 3 Example embodiments 1,471,360 ^ 2,240,150 310.1 95.7 White particles ^ 147 1385 Example 3 230 90 312.0 96.3 White particles ^ 175 Example 4 225 210 308.0 95.0 White particles ^ 240 1430 Example 5 225 120 300.8 92.8 White particles ^ 175 1426 Example 6 225 60 310.5 95.8 White Granules 147 1410 Comparative Example 1 250 240 421.0g 78.0 Beige powder 1320 Comparative Example 2 245 280 440.0g 81.5 Beige <74 1356 Comparative Example 3 250 240 450.0g 83.4 White powder 1335 Comparative Example 4 245 210 450.5g 83.4 Beige <74 1352 Comparative example 5 255 '220 443. Og 82.0 beige powder 1300 Table 4

Note: 1. Alpha-chlorobenzene, 206 ° C

2. GB— 3682, 316 ° C, 5 kg, 10 minutes

3. 316 ° C, 5 kg, 30 minutes

4.GB/T1410

Claims

Rights request

1. A high-density linear high molecular weight polyphenylene sulfide, characterized by a melting point of 280 ~ 298 ° C, and a melt flow rate of 2 ~ 700 g / 316 ° C-5 kg for 10 minutes, with a particle size greater than 0.1 mm, the average molecular weight is

28000 ~ 84000, density is 1360 ~ 1430 kg / ^m3 , and it has a regular linear structure.

2. The high-density linear high molecular weight polyphenylene sulfide according to claim 1, characterized in that its melting point is 280 ~ 298 ° C, and the melt flow rate is 20 ~ 200 g / 316 ° C-5 kg-10 Minutes, the particle size is greater than 0.1 mm, the average molecular weight is 45000 ~ 72000, the molecular weight can be controlled, the density is 1360 ~ 1430 kg / m ³ , and it has a regular linear structure.

3. The high-density linear high molecular weight polyphenylene sulfide according to claim 1, characterized in that its melting point is 280 ~ 298 ° C, and the melt flow rate is 50 ~ 100 g / 316 ° C-5 kg-10 Minutes, the particle size is greater than 0.1 mm, the average molecular weight is 55000 ~ 64000, the molecular weight can be controlled, the density is 1360 ~ 1430 kg / m ³ , and it has a regular linear structure.

4. The high-density linear high molecular weight polyphenylene sulfide according to claim 1 to 3, characterized in that the tensile strength is greater than 100 MPa, the elongation at break is greater than 32%, the bending strength is greater than 160 MPa, and the notched Izod impact strength is greater than 12 Kg / m.

5. The high-density linear high-molecular-weight polyphenylene sulfide according to claim 1 to 3, characterized in that a crystal of sodium sulfide containing nine molecules of water is used as a sulfur source.

The high-density linear high molecular weight polyphenylene sulfide according to claim 5, characterized in that sodium sulfide crystals containing nine molecules of crystal water are used as a sulfur source.

7. The method for preparing a high-density linear high-molecular-weight polyphenylene sulfide according to claim 1 to 3, comprising the following steps:

At 24CTC, reaction for 60 ~ 220 minutes, complexes are formed, and excess low boiling point substances are discharged at the same time;

D. Cool to below 80 ° C and centrifuge to separate the granular polymer.

8. The method for preparing a high-density linear high molecular weight polyphenylene sulfide according to claims 1 to 3, wherein Yu includes the following steps:

A. Weigh out the reactants according to the following proportions and add them to the reactor-the molar ratio of sulfide, phosphate and solvent is: 1. 0: (0. 2 ~ 0. 25): (1. 0 ~ 1 8), at a temperature of 150 ~ 220 ° C, a reaction of 90 ~ 150 minutes, a complex is formed, and an excessive amount of a low boiling point substance is discharged at the same time;

C, and then the temperature of the reaction kettle was raised to 200 ~ 260 Torr, and the reaction was carried out at a pressure of 0.1 to 0.6MPa for 40 to 180 minutes;

9. The method for preparing a high-density linear high-molecular-weight polyphenylene sulfide according to claims 1 to 3, further comprising the following steps:

The molar ratio of sulfide, phosphate and solvent is: 1. 0: (0. 2 ~ 0. 25): (1. 2 ~ 1. 6), at a temperature of 150 ~ 220 ° C, a reaction of 90 ~; 120 Minutes, complexes are formed, while excess low-boiling substances are discharged;

B. Add a halogenated aromatic compound dissolved in a solvent to the complex, and react at a temperature of 190 ~ 220 ° C for 15 ~ 30 minutes to form a prepolymer;

C, and then the temperature of the reactor was increased to 220 ~ 240 ° C, and the reaction was carried out at a pressure of 0.1 to 0.4 MPa for 60 to 150 minutes;

D. Cool to below 80 ° C, centrifuge to separate the granular polymer, wash with hot water until neutral, and then wash twice with hot deionized water, then dry under reduced pressure at 12CTC for 6 hours to obtain the final product.

10. The method for preparing a high-density linear high-molecular-weight polyphenylene sulfide according to claim 7 to 9, wherein the molar ratio of the complex to the halogenated aromatic compound is 1.0: (0 3 ~ 0. 6).

11. The method for preparing a high-density linear high-molecular-weight polyphenylene sulfide according to claim 7 to 9, wherein the molar ratio of the complex to the halogenated aromatic compound is 1.0: (0 4 ~ 0. 5).

12. The method for preparing a high-density linear high molecular weight polyphenylene sulfide according to claim 7 to 9, characterized in that the molar ratio of the solvent to the halogenated aromatic compound is 1: (0. 2 ~ 0 5).

The method for preparing a high-density linear high-molecular-weight polyphenylene sulfide according to claims 7 to 9, wherein the phosphate is sodium phosphate.

14. The method for preparing a high-density linear high-molecular-weight polyphenylene sulfide according to claim 7 to 9, wherein the solvent is hexamethylphosphoryl triamine.

15. The method for preparing a high-density linear high-molecular-weight polyphenylene sulfide according to claims 7 to 9, wherein the halogenated aromatic compound is dichlorobenzene.

16. The method for preparing a high-density linear high molecular weight polyphenylene sulfide according to claim 15, wherein said dichlorobenzene is 1.4 pair of dichlorobenzene and 1.3-m-dichloro For a mixture of benzene, the molar ratio of p-dichlorobenzene and m-dichlorobenzene is 3: 2 to 19: 1.

17. The method for preparing a high-density linear high molecular weight polyphenylene sulfide according to claim 15, wherein said dichlorobenzene is 1.4 pair of dichlorobenzene and 1.3-m-dichloro For a mixture of benzene, the molar ratio of p-dichlorobenzene and m-dichlorobenzene is 9: 1 to 16: 1.