The present disclosure relates to a monomer composition for synthesizing recycled plastic which is extremely reduced in the content of organic impurities such as formic acid and acetic acid while recovering from a (co)polymer synthesized from monomers containing terephthalic acid, a method for preparing the same, and a recycled plastic, molded product, and plasticizer composition using the same.

The present disclosure relates to a monomer composition for synthesizing recycled plastic which is extremely reduced in the content of organic impurities such as formic acid and acetic acid while recovering from a (co)polymer synthesized from monomers containing terephthalic acid, a method for preparing the same, and a recycled plastic, molded product, and plasticizer composition using the same.

A depolymerization reaction of a polyester input with an organocatalyst and an alcohol solvent produces (i) a recycled monomeric or oligomeric diester from the polyester, (ii) the organocatalyst for reuse, and (iii) the alcohol solvent, which may also be reused. The presence of volatile impurities, such as water, acetyl aldehyde, and organic solvents can interfere with the success of the depolymerization reaction. A pre-reaction distillation step removes volatile impurities from the polyester input resulting in an efficient depolymerization reaction with consistency among batches. The polyester input may be further treated with a water azeotrope to remove water from the polyester input prior to the pre-reaction distillation.

A waste polyester material is prepared for recycling by dissolving the material in a solution comprising hexafluoroisopropyl (HFIPA) and a chlorinated hydrocarbon, such as dichloromethane (DCM) and/or an aromatic hydrocarbon, such as toluene or xylene, to form a dissolved polyester sample. The dissolved polyester may be prepared for recycling by evaporation, spray drying, and/or precipitation, which produces a purified solid polyester product. The dissolution solution, which is separated from the purified solid polyester product, is also recycled through distillation with purification.

A method for recycling polyester from a polyester textile. The method comprises the steps of: providing said polyester textile soaked in a mixture comprising a solvent and a catalyst, providing and maintaining a temperature of said mixture comprising said polyester textile within a range of 80-240° C. during depolymerization of polyester in said polyester textile and wherein, in said step of providing said polyester textile soaked in said mixture, said catalyst of said mixture comprises calcium hydroxide. A catalyst may be used for depolymerization of polyester in a polyester textile, wherein the catalyst comprises calcium hydroxide. Natural fibers may b e recovered from a textile comprising polyester and natural fibers.

A method for recycling polyester from a polyester textile. The method comprises the steps of: providing said polyester textile soaked in a mixture comprising a solvent and a catalyst, providing and maintaining a temperature of said mixture comprising said polyester textile within a range of 80-240° C. during depolymerization of polyester in said polyester textile and wherein, in said step of providing said polyester textile soaked in said mixture, said catalyst of said mixture comprises calcium hydroxide. A catalyst may be used for depolymerization of polyester in a polyester textile, wherein the catalyst comprises calcium hydroxide. Natural fibers may b e recovered from a textile comprising polyester and natural fibers.

A method for producing bisphenol A (BPA) is provided. The method includes step A of degrading a polycarbonate resin in a solvent and distilling off the solvent to obtain a crude solution A; step B of subjecting acetone and phenol to dehydration condensation; step C of distilling off unreacted acetone and water to obtain a concentrated liquid C; step D of crystallizing the concentrated liquid C to obtain a slurry liquid, from which a mother liquor D is obtained; step H of obtaining a solution H1 or a solution H2 from the crude solution A and part of the mother liquor D; and step I of supplying the solution H1 or H2 to the step B or C. The solution H1 contains BPA obtained by degrading BPA contained in the crude solution A and the mother liquor D into phenol and isopropenylphenol and then rebonding phenol and isopropenylphenol, and the solution H2 contains phenol obtained by degrading BPA contained in the crude solution A and the mother liquor D into phenol and acetone.

The present disclosure relates to the formation of dimethyl terephthalate (DMT). The present invention also relates to the depolymerization of polyethylene terephthalate (PET) and the recovery of terephthalic acid and ethylene glycol.

The present disclosure relates to the formation of dimethyl terephthalate (DMT). The present invention also relates to the depolymerization of polyethylene terephthalate (PET) and the recovery of terephthalic acid and ethylene glycol.

The present disclosure relates to a monomer composition for synthesizing recycled plastic that contains a high-purity aromatic diol compound recovered through recycling by chemical decomposition of a polycarbonate-based resin, a method for preparing the same, and a recycled plastic and molded product using the same.