A preparation method of a polyphenylene sulfide resin, and a polyphenylene sulfide resin prepared by the method using a sulfur-containing compound, an alkaline substance and p-dichlorobenzene as raw materials, a fatty acid as a polycondensation aid to carry out a polycondensation reaction. After purification treatment, a primary polyphenylene sulfide is obtained, which then reacts with a terminal-group adjusting agent at a high temperature to generate the polyphenylene sulfide resin resulting in high yield and low cost. The prepared polyphenylene sulfide resin has high reactivity, high melting crystallization temperature and excellent thermal stability. The resulting polyphenylene sulfide resin can be directly used for extrusion and injection molding.

A preparation method of a polyphenylene sulfide resin, and a polyphenylene sulfide resin prepared by the method using a sulfur-containing compound, an alkaline substance and p-dichlorobenzene as raw materials, a fatty acid as a polycondensation aid to carry out a polycondensation reaction. After purification treatment, a primary polyphenylene sulfide is obtained, which then reacts with a terminal-group adjusting agent at a high temperature to generate the polyphenylene sulfide resin resulting in high yield and low cost. The prepared polyphenylene sulfide resin has high reactivity, high melting crystallization temperature and excellent thermal stability. The resulting polyphenylene sulfide resin can be directly used for extrusion and injection molding.

A method for preparing polyarylene sulfide that can control a viscosity grade thereof by adjusting the molar ratio of water and amide-based compounds present in a polymerization reaction.

A method for preparing polyarylene sulfide that can control a viscosity grade thereof by adjusting the molar ratio of water and amide-based compounds present in a polymerization reaction.

The present disclosure relates to a preparation method of a polyarylene sulfide, and this method may produce a polyarylene sulfide having properties equal to or higher than those of the conventional method at a high yield by using a dihalogenated aromatic compound in a predetermined equivalent ratio with respect to a sulfur compound and performing both dehydration and polymerization under optimum conditions.

The present disclosure relates to a preparation method of a polyarylene sulfide, and this method may produce a polyarylene sulfide having properties equal to or higher than those of the conventional method at a high yield by using a dihalogenated aromatic compound in a predetermined equivalent ratio with respect to a sulfur compound and performing both dehydration and polymerization under optimum conditions.

A method for manufacturing a pre-lithiated polyphenylene sulfide with a high solid solubility of lithium includes; placing NMP, Li.sub.2S, and LiOH into a high-pressure reactor to obtain a mixture, and heating the mixture to 150-250° C. for a high-temperature dehydration for 2-5 h, and then cooling the mixture to 100° C. and adding p-DCB to the mixture for a reaction at 150-250° C. for 80-200 min; dropwise adding hydrochloric acid in an identical amount as that of the LiOH neutralize LiOH, and removing NMP and H.sub.2O by evaporation or sublimation, to obtain a dry mixed powder; and to the dry mixed powder, adding a chloride ion complexing agent to obtain a mixture, stirring the mixture to homogeneity, and placing the mixture in a sealed reactor for a reaction at 150-250° C. for 80-200 min, followed by washing and drying, to obtain the pre-lithiated polyphenylene sulfide.

The continuous dehydration method for a raw material mixture to be used in the production of PAS includes supply and dehydration of the raw material mixture and extraction of the raw material mixture having a water content reduced by the dehydration, the supply, dehydration and extraction being carried out concurrently in parallel. A dehydration efficiency index determined according to Equation (1) is not less than 0.3. In Equation (1), the dehydration time is a period of time until a moisture content per mole of the sulfur source in the raw material mixture having a reduced water content reaches not greater than 1.7 mol, including moisture consumed by the hydrolysis of the organic polar solvent.
Dehydration efficiency index=[Number of moles (mol) of the sulfur source in the raw material mixture having a reduced water content]/[Dehydration time (hr)×(Total internal volume (L) of the dehydration tanks).sup.2/3]  (1)

The continuous dehydration method for a raw material mixture to be used in the production of PAS includes supply and dehydration of the raw material mixture and extraction of the raw material mixture having a water content reduced by the dehydration, the supply, dehydration and extraction being carried out concurrently in parallel. A dehydration efficiency index determined according to Equation (1) is not less than 0.3. In Equation (1), the dehydration time is a period of time until a moisture content per mole of the sulfur source in the raw material mixture having a reduced water content reaches not greater than 1.7 mol, including moisture consumed by the hydrolysis of the organic polar solvent.
Dehydration efficiency index=[Number of moles (mol) of the sulfur source in the raw material mixture having a reduced water content]/[Dehydration time (hr)×(Total internal volume (L) of the dehydration tanks).sup.2/3]  (1)

A method of producing a polyarylene sulfide (PAS) with a high nitrogen content in the PAS, the method thereof improving the characteristics of the PAS while reducing the amount of organic by-products, and using a plurality of reaction vessels that are in communication with each other through a gas phase. In the production method, a supply step, a water removal step, a polymerizing step, and a recovering step are performed in parallel. A polar organic solvent, a sulfur source, and a dihalo aromatic compound are used as reaction raw materials. A supply amount of the polar organic solvent used as a reaction raw material is 5 mol or less per mole of the sulfur source used as a reaction raw material. The polar organic solvent has a bond represented by —RO—N—, where R is C or P.