Abstract: A method of recycling polyester fabric includes following steps. A polyester fabric including polyethylene terephthalate and dyes is provided. An extraction process including using ethylene glycol as an extraction solvent, immersing the polyester fabric in the extraction solvent, and extracting under a temperature of 80° C. to 180° C. is performed to remove the dyes from the polyester fabric. A depolymerization process including using a chemical depolymerization solution to depolymerize the polyester fabric treated with the extraction process to obtain a product including BHET is performed. The chemical depolymerization solution is ethylene glycol. A purification process is performed to remove impurities of the product obtained by the depolymerization process and to obtain a purified BHET. A solvent recycling process is performed.

Abstract: A method for isomerizing methyltetrahydrophthalic anhydride includes the following processes. A liquid reactant is provided. Under a condition of injecting nitrogen gas, an alkaline catalyst is added into the liquid reactant for an isomerization reaction, so as to obtain an isomerization product. The liquid reactant includes 3-methyltetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride. Based on a total weight of the isomerization product being 100 wt %, an amount of a methyltetrahydrophthalic anhydride dimer is lower than 1.6 wt %.

Abstract: A decolorization method of a polyester fabric, including the following steps, is provided. A first extraction treatment is performed on the polyester fabric using a recycled solvent, so that a first portion of a dye in the polyester fabric moves into the recycled solvent. A first filtering treatment is performed on the recycled solvent and the polyester fabric to obtain a treated polyester fabric. A second extraction treatment is performed on the treated polyester fabric using a fresh solvent, so that a second portion of the dye in the treated polyester fabric moves into the fresh solvent. A second filtering treatment is performed to obtain a decolored polyester fabric and the recycled solvent.

Abstract: A plasticizer and a method for producing the same are provided. The method for producing the plasticizer includes: reacting a reaction mixture at each of a plurality of temperature holding stages in a heating process to form a semi-finished product; and purifying the semi-finished product at each of a plurality of low pressure stages of a decompression process to obtain a plasticizer. A temperature range of the heating process is from 140° C. to 220° C., a pressure range of the decompression process is from 750 Torr to 20 Torr, and the reaction mixture contains dibasic acid (e.g., adipic acid), diol (e.g. 1,4-butanediol), monohydric alcohol (e.g., 2-ethylhexanol), and catalyst (e.g., titanium catalyst).

Abstract: A disposal method for recyclate of the disclosure including: providing recyclable containing polyester; performing a first depolymerization step, including mixing the recyclable and o-BHET for reaction and extrusion depolymerization to at least obtain or produce p-BHET; and performing a second depolymerization step, including mixing the p-BHET and a depolymerization solution for chemically depolymerization to at least obtain or produce m-BHET.

Abstract: A method for manufacturing methyltetrahydrophthalic anhydride is provided, which includes steps as follows. Maleic anhydride is added into a reactor. Piperylene is added into the reactor, so that the piperylene and the maleic anhydride undergo a first addition reaction. When a conversion rate of the maleic anhydride is more than 25%, the first addition reaction is completed. Isoprene is added into the reactor, so that the isoprene and the maleic anhydride undergo a second addition reaction to obtain a methyltetrahydrophthalic anhydride product. The methyltetrahydrophthalic anhydride product contains 3-methyltetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride.

Abstract: A method for producing polyphenylene ether amine includes following steps. In step (a), a hydrogenation reaction tank is provided; a guided gas stirrer is disposed in the hydrogenation reaction tank. In step (b), a reaction solution is placed in the hydrogenation reaction tank, and the reaction solution is nitro polyphenylene ether dissolved in a solvent. In step (c), a hydrogenation catalyst is added to the reaction solution. In step (d), a hydrogen gas is introduced into the hydrogenation reaction tank. In step (e), the guided gas stirrer is activated. In step (f), a hydrogenation reaction is carried out on the conditions that a reaction temperature is 50-200 degrees Celsius and a reaction time is 1-20 hours, so as to hydrogenate the nitro polyphenylene ether in the reaction solution to polyphenylene ether amine. In step (g), the reaction solution is cooled down to a room temperature; the hydrogenation catalyst is removed.

Abstract: A manufacturing method of a polymer includes the following steps. Terephthalic acid, butanediol, adipic acid, and carboxybenzene are used as raw materials to perform an esterification reaction to obtain a reactant. A catalyst is added to the reactant, and a polymerization reaction is performed.

Abstract: A manufacturing method of a polyester for a plastic wrap at least includes the following steps. An aromatic carboxylic acid, an aliphatic carboxylic acid, and an aliphatic alcohol are provided, wherein the aromatic carboxylic acid includes at least two of a phthalic acid, an isophthalic acid, and a terephthalic acid. The aromatic carboxylic acid, the aliphatic carboxylic acid and the aliphatic alcohol are subjected to at least an esterification reaction, a pre-polymerization reaction, and a polymerization reaction in sequence, so as to obtain a polybutylene adipate terephthalate.

Abstract: A method for manufacturing a low-viscosity hardener is provided. The method includes the followings steps: providing a hardener crude product; and subjecting the hardener crude product and an alkaline catalyst to an isomerization reaction, so as to obtain the low-viscosity hardener. The hardener crude product contains 3-methyltetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride, and a weight ratio of the 3-methyltetrahydrophthalic anhydride to the 4-methyltetrahydrophthalic anhydride ranges from 7:3 to 3:7. A viscosity of the low-viscosity hardener ranges from 30 cps to 50 cps.

Abstract: A method for manufacturing methyltetrahydrophthalic anhydride is provided, which includes steps as follows. Maleic anhydride is added into a reactor. Piperylene is added into the reactor, so that the piperylene and the maleic anhydride undergo a first addition reaction. When a conversion rate of the maleic anhydride is more than 25%, the first addition reaction is completed. Isoprene is added into the reactor, so that the isoprene and the maleic anhydride undergo a second addition reaction to obtain a methyltetrahydrophthalic anhydride product. The methyltetrahydrophthalic anhydride product contains 3-methyltetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride.

Abstract: A method for preparing a low migration plasticizer of di-2-ethylhexyl terephthalate is provided. The method includes a step of adding a short chain alcohol component having 4 to 6 carbon atoms and a long chain alcohol component having 9 to 13 carbon atoms in an esterification reaction between terephthalic acid and 2-ethylhexanol, so as to obtain a modified di-2-ethylhexyl terephthalate including residues derived from the short chain alcohol component and the long chain alcohol component. The esterification reaction is carried out under a temperature from 30° C. to 225° C. and a pressure from 80 mbar to 1033 mbar.

Abstract: The disclosure provides a decolorization and purification method of BHET material, which includes the following steps. A first dose of activated carbon is added to preliminarily treat the BHET material. After the preliminary treatment, a first cooling crystallization process and filtration are performed to obtain BHET crystals. Afterwards, an oxidant is used to chemically react with the BHET crystals to destroy a dye or impurities, and then a second dose of activated carbon is added to adsorb a chemically reacted oxide. Next, a second cooling crystallization process, filtration, and drying are performed to obtain a finished product of BHET.

Abstract: A method for manufacturing polyester polyhydric alcohol is provided. The method for manufacturing the polyester polyhydric alcohol includes steps as follows. A polybasic acid and a first polyhydric alcohol are mixed for a first oligomerization reaction, so as to form a first oligomer mixture. A second polyhydric alcohol is added into the first oligomer mixture for a second oligomerization reaction when a remaining amount of the first polyhydric alcohol in the first oligomer mixture is lower than or equal to 1 mol %, so as to form a second oligomer mixture. A catalyst is added into the second oligomer mixture for a polycondensation reaction, so as to obtain a polyester polyhydric alcohol product. The polyester polyhydric alcohol product has an Alpha value of lower than 30.

Abstract: A plasticizer and a method for manufacturing the plasticizer are provided. The method includes the following steps. A dicarboxylic acid, a diol, and a catalyst are mixed to form a reactant mixture. The reactant mixture is reacted at a temperature ranging from 130° C. to 220° C. to form a semi-product. An endcapping alcohol is added into the semi-product at a temperature ranging from 205° C. to 220° C. to form a coarse plasticizer. The coarse plasticizer is purified under a pressure ranging from 760 Torr to 5 Torr to obtain the plasticizer. The dicarboxylic acid includes succinic acid or adipic acid. The diol includes diethylene glycol and 2-methyl-1,3-propanediol. The endcapping alcohol is an ether alcohol or a fatty alcohol having a carbon number of less than or equal to 4. The dicarboxylic acid, the diol, and the endcapping alcohol have a molar ratio ranging from 1:0.6 to 0.9:0.3 to 0.6.

Abstract: A plasticizer and a method for manufacturing the plasticizer are provided. The method includes steps as follow. A dicarboxylic acid, a diol, and a catalyst are mixed to form a reactant mixture. The reactant mixture is reacted at a temperature ranging from 130° C. to 220° C. to form a semi-product. An endcapping alcohol into the semi-product at a temperature ranging from 205° C. to 220° C. to form a coarse plasticizer. The coarse plasticizer is purified under a pressure ranging from 760 Torr to 5 Torr to obtain the plasticizer. The dicarboxylic acid includes a first dicarboxylic acid and a second dicarboxylic acid, and the second dicarboxylic acid is adipic acid. The diol includes diethylene glycol and 2-methyl-1, 3-propanediol. The endcapping alcohol includes isooctyl alcohol, isodecyl alcohol, or 2-propylheptanol. A molar ratio of dicarboxylic acid:diol:the endcapping alcohol ranges from 1:0.6 to 0.9:0.3 to 0.6.

Abstract: A method for producing polyphenylene ether amine includes following steps. In step (a), a hydrogenation reaction tank is provided; a guided gas stirrer is disposed in the hydrogenation reaction tank. In step (b), a reaction solution is placed in the hydrogenation reaction tank, and the reaction solution is nitro polyphenylene ether dissolved in a solvent. In step (c), a hydrogenation catalyst is added to the reaction solution. In step (d), a hydrogen gas is introduced into the hydrogenation reaction tank. In step (e), the guided gas stirrer is activated. In step (f), a hydrogenation reaction is carried out on the conditions that a reaction temperature is 50-200° C. and a reaction time is 1-20 hours, so as to hydrogenate the nitro polyphenylene ether in the reaction solution to polyphenylene ether amine. In step (g), the reaction solution is cooled down to a room temperature; the hydrogenation catalyst is removed.

Abstract: A method for manufacturing nonylcyclohexanol is provided. The method includes steps as follows: adding a liquid phase reactant into a reactor, and the liquid phase reactant includes a molten nonylphenol and a catalyst; introducing a gas phase reactant to maintain a pressure of the gas phase reactant to be from 36.5 bar to 70 bar, and the gas phase reactant consists of hydrogen; rotating a hollow stirring shaft of the reactor at a temperature of from 100° C. to 130° C. so that the gas phase reactant is transported through a channel formed in the hollow stirring shaft into the liquid phase reactant for carrying out a reaction; obtaining a product that contains nonylcyclohexanol. A conversion rate of the nonylcyclohexanol is higher than or equal to 99.0%.

Abstract: The disclosure provides a decolorization and purification method of BHET material, which includes the following steps. A first dose of activated carbon is added to preliminarily treat the BHET material. After the preliminary treatment, a first cooling crystallization process and filtration are performed to obtain BHET crystals. Afterwards, an oxidant is used to chemically react with the BHET crystals to destroy a dye or impurities, and then a second dose of activated carbon is added to adsorb a chemically reacted oxide. Next, a second cooling crystallization process, filtration, and drying are performed to obtain a finished product of BHET.

Abstract: A disposal method for waste fabric containing polyester, nylon, and dye includes the following steps: step (a): providing a waste fabric containing polyester, nylon, and dye; and step (b): performing a first-stage treatment including acid treatment on the waste fabric to obtain a first liquid material and a first solid material. The first-stage treatment includes acid treatment with an acid liquid mixed with an oxidant. The first solid material includes recycled polyester, and/or the first liquid material includes recycled nylon or degraded nylon.