The present disclosure relates to a preparation method of a monomer composition for synthesizing recycled plastic, the method comprising the steps of: subjecting a polycarbonate-based resin to a depolymerization reaction in the presence of an alcohol; monitoring a Raman spectrum of an aromatic diol compound obtained from the depolymerization reaction or alcohol in a reactor through which depolymerization reaction proceeds; and recovering the aromatic diol compound, and to a preparation device of a monomer composition for synthesizing recycled plastic, and a monomer composition for synthesizing recycled plastic, a recycled plastic and a molded product using the same.

A process for recovering a polyol substance from a polyurethane material, preferably from an end-of-life (eol) polyurethane material, is provided, wherein the process comprises alcoholising a polyurethane material by contacting the polyurethane material with an alcoholising substance, wherein during alcoholising of the polyurethane material, a mixture containing a polyol substance and an amine substance is formed, allowing the mixture to settle, wherein a phase, in particular a first phase, which is polyol substance rich, and a phase, in particular a second phase, which is alcoholising substance rich, are formed and a work-up of the phase, which is polyol substance rich, in particular the first phase, by purification of the polyol substance, wherein the purification comprises two or more of evaporation of the phase in one or more evaporators, contacting the phase with an ion exchange material and contacting the phase with an adsorbent, wherein after the work-up, the phase, which is polyol substance rich, in particular the first phase, has an acid number of 0.1 mg KOH/g or less.

A process for recovering a polyol substance from a polyurethane material, preferably from an end-of-life (eol) polyurethane material, is provided, wherein the process comprises alcoholising a polyurethane material by contacting the polyurethane material with an alcoholising substance, wherein during alcoholising of the polyurethane material, a mixture containing a polyol substance and an amine substance is formed, allowing the mixture to settle, wherein a phase, in particular a first phase, which is polyol substance rich, and a phase, in particular a second phase, which is alcoholising substance rich, are formed and a work-up of the phase, which is polyol substance rich, in particular the first phase, by purification of the polyol substance, wherein the purification comprises two or more of evaporation of the phase in one or more evaporators, contacting the phase with an ion exchange material and contacting the phase with an adsorbent, wherein after the work-up, the phase, which is polyol substance rich, in particular the first phase, has an acid number of 0.1 mg KOH/g or less.

The present disclosure relates to a method for low-temperature depolymerization of a polymer containing a urethane-functional group using a cosolvent and a method for producing polyol. More specifically, the present disclosure relates to a method of adding a compound having two or more alcohol-functional groups as a depolymerization solvent for decomposing a polymer containing a urethane-functional group, adding an aromatic compound having an alkoxy-functional group as a cosolvent to construct a reaction system for decomposing the polymer containing the urethane-functional group, thereby performing rapid depolymerization at a low temperature, and obtaining high-quality recycled polyol in high yield through a physical separation process of the reaction product generated therefrom.

The process uses specific glycolysis reactions using a unique solvent system combined with metal catalysts including zinc undecylenate to chemically convert waste flexible polyurethane foam to recycled polyol. In this process, waste polyurethane foams react with the solvent system at elevated temperatures together in the presence of the metal catalyst(s) to break the urethane bonds and release polyols.

The process uses specific glycolysis reactions using a unique solvent system combined with metal catalysts including zinc undecylenate to chemically convert waste flexible polyurethane foam to recycled polyol. In this process, waste polyurethane foams react with the solvent system at elevated temperatures together in the presence of the metal catalyst(s) to break the urethane bonds and release polyols.

Processes for recovering dialkyl terephthalates. The processes can include exposing a feedstock composition that includes one or more tetramethylcyclobutanediol (TMCD)-containing polyesters ethylene glycol, methanol, or both under depolymerization conditions thereby providing one or more depolymerization products. The one or more depolymerization products can be exposed to an alcoholysis process to recover dialkyl terephthalate.