Abstract: This disclosure relates to a method for preparing polyarylene sulfide having reduced iodine content while having excellent thermal stability, specifically to a method comprising polymerization reacting a composition comprising diiodide aromatic compounds, sulfur compounds, and a polymerization terminator. The preparation method may effectively reduce iodine content of polyarylene sulfide to prevent corrosion of post processing equipment, improve properties of polyarylene sulfide such as thermal stability, and the like, and thus, it may be usefully applied in the industrial field relating to preparation of polyarylene sulfide.

Abstract: The present invention relates to a polyarylene sulfide that is prepared from a composition including 100 parts by weight of solid sulfur, 500 to 10,000 parts by weight of iodinated aryl compounds, and 0.03 to 30 parts by weight of a sulfur-containing polymerization terminator with respect to 100 parts by weight of the solid sulfur, and has a melting temperature (Tm) of 255 to 285° C., and luminosity of 40 or higher as defined by the CIE Lab color model, and a process of preparing the same. The PAS resin is prepared from a composition including a sulfur-containing polymerization terminator and thus has excellent thermal properties and luminosity.

Abstract: The present invention relates to a method for preparing polyarylene sulfide, in which the polyarylene sulfide is prepared by a polymerization reaction of reactants including a diiodo aromatic compound and a sulfur compound, the method including: further adding 0.01 to 10.0 wt. % of diphenyl disulfide with respect to the weight of the polyarylene sulfide to the reactants to form the polyarylene sulfide having a melting point of 265 to 320° C. The diphenyl disulfide included in the reactants according to the present invention costs far less than other conventional polymerization inhibitors to dramatically lower the production cost, and the polyarylene sulfide prepared using the diphenyl disulfide exhibits low iodine content and very excellence in thermal stability.

Abstract: The present invention relates to a polyarylene sulfide that is prepared from a composition including 100 parts by weight of solid sulfur, 500 to 10,000 parts by weight of iodinated aryl compounds, and 0.03 to 30 parts by weight of a sulfur-containing polymerization terminator with respect to 100 parts by weight of the solid sulfur, and has a melting temperature (Tm) of 255 to 285° C., and luminosity of 40 or higher as defined by the CIE Lab color model, and a process of preparing the same. The PAS resin is prepared from a composition including a sulfur-containing polymerization terminator and thus has excellent thermal properties and luminosity.

Abstract: A method for preparing polyarylene sulfide having reduced iodine content and excellent thermal stability is described. The method includes reacting a composition comprising diiodide aromatic compounds, sulfur compounds, and a polymerization terminator. The preparation method may effectively reduce iodine content of polyarylene sulfide to prevent corrosion of post processing equipment, improve properties of polyarylene sulfide such as thermal stability, and the like, and thus, it may be usefully applied in the industrial field relating to preparation of polyarylene sulfide.

Abstract: A method for preparing fatty acid alkyl ester for bio-diesels is disclosed, wherein fatty acid, specifically fatty acid distillate reacts with alcohol in the presence of metal catalyst instead of conventional acid or solid acid catalyst. The method does not require the glycerin purification process, and has the superior conversion ratio of fatty acid. The method for preparing fatty acid alkyl ester comprises the step of carrying out an esterification reaction of fatty acid raw material with alcohol in the presence of metal catalyst. Preferably, the esterification reaction is carried out at the temperature of 200 to 350° C. and the pressure of atmospheric pressure to 10 bar, and the metal catalyst is a compound containing metal selected from the group consisting of cobalt, iron, manganese, zinc, titanium and mixture thereof.

Abstract: This disclosure relates to a method for preparing polyarylene sulfide having reduced iodine content while having excellent thermal stability, specifically to a method comprising polymerization reacting a composition comprising diiodide aromatic compounds, sulfur compounds, and a polymerization terminator. The preparation method may effectively reduce iodine content of polyarylene sulfide to prevent corrosion of post processing equipment, improve properties of polyarylene sulfide such as thermal stability, and the like, and thus, it may be usefully applied in the industrial field relating to preparation of polyarylene sulfide.

Abstract: The present invention relates to a method for preparing polyarylene sulfide with a reduced free iodine content. More specifically, the method for preparing polyarylene sulfide includes: (a) polymerizing reactants including a diiodo aromatic compound and a sulfur compound to form a polyarylene sulfide; and (b) maintaining the polyarylene sulfide product at 100 to 260° C. for heat-setting. The preparation method of the present invention effectively reduces the free iodine content of the polyarylene sulfide to prevent potential corrosion of facilities for the subsequent process and improves the properties of the polyarylene sulfide product such as thermal stability, so the method can be usefully applied to industrial fields in regard to the preparation of polyarylene sulfide.

Abstract: The present invention relates to a method for preparing polyarylene sulfide, in which the polyarylene sulfide is prepared by a polymerization reaction of reactants including a diiodo aromatic compound and a sulfur compound, the method including: further adding 0.01 to 10.0 wt. % of diphenyl disulfide with respect to the weight of the polyarylene sulfide to the reactants to form the polyarylene sulfide having a melting point of 265 to 320° C. The diphenyl disulfide included in the reactants according to the present invention costs far less than other conventional polymerization inhibitors to dramatically lower the production cost, and the polyarylene sulfide prepared using the diphenyl disulfide exhibits low iodine content and very excellence in thermal stability.

Abstract: A method for preparing fatty acid alkyl ester for bio-diesels is disclosed, wherein fatty acid, specifically fatty acid distillate reacts with alcohol in the presence of metal catalyst instead of conventional acid or solid acid catalyst. The method does not require the glycerin purification process, and has the superior conversion ratio of fatty acid. The method for preparing fatty acid alkyl ester comprises the step of carrying out an esterification reaction of fatty acid raw material with alcohol in the presence of metal catalyst. Preferably, the esterification reaction is carried out at the temperature of 200 to 350° C. and the pressure of atmospheric pressure to 10 bar, and the metal catalyst is a compound containing metal selected from the group consisting of cobalt, iron, manganese, zinc, titanium and mixture thereof.

Abstract: The present invention relates to a polyarylene sulfide that is prepared from a composition including 100 parts by weight of solid sulfur, 500 to 10,000 parts by weight of iodinated aryl compounds, and 0.03 to 30 parts by weight of a sulfur-containing polymerization terminator with respect to 100 parts by weight of the solid sulfur, and has a melting temperature (Tm) of 255 to 285° C., and luminosity of 40 or higher as defined by the CIE Lab color model, and a process of preparing the same. The PAS resin is prepared from a composition including a sulfur-containing polymerization terminator and thus has excellent thermal properties and luminosity.

Abstract: The present invention relates to a method for refining 2,6-naphthalene dicarboxylic acid, and particularly to a method for refining 2,6-naphthalene dicarboxylic acid comprising recrystallizing crude 2,6-naphthalene dicarboxylic acid in the form of an amine salt using a solvent comprising a protic polar solvent selected from the group consisting of an alcohol, water, and a mixture thereof, and an acetate. In accordance with the invention, 2,6-naphthalene dicarboxylic acid can be obtained with excellent purity and color, and at the same time, it can be obtained in an economical and environmentally friendly way because the acetate, which is a byproduct of the oxidation process, is used as a solvent.

Abstract: The present invention relates to a method for refining 2,6-naphthalene dicarboxylic acid, and particularly to a method for refining 2,6-naphthalene dicarboxylic acid comprising recrystallizing crude 2,6-naphthalene dicarboxylic acid in the form of an amine salt using a solvent comprising a protic polar solvent selected from the group consisting of an alcohol, water, and a mixture thereof, and an acetate. In accordance with the invention, 2,6-naphthalene dicarboxylic acid can be obtained with excellent purity and color, and at the same time, it can be obtained in an economical and environmentally friendly way because the acetate, which is a byproduct of the oxidation process, is used as a solvent.