Various methods of reshaping and recycling thermoset polymers and composites containing thermoset polymers are provided. The methods involve the bond exchange reaction of exchangeable covalent bonds in the polymer matrix with a suitable small molecule solvent in the presence of a catalyst. In some aspects, the methods are applied to a carbon fiber reinforced polymer or a thermoset polymer where the thermoset polymer matrix includes a plurality of ester bonds. Using a small molecule alcohol, the methods provide for recycling one or both of the carbon fiber and the polymer, for welding two surfaces, or for repairing a damaged surface in the materials.

The present disclosure relates to the formation of dimethyl terephthalate (DMT) and mono ethylene glycol (MEG). The present invention also relates to the depolymerization of polyethylene terephthalate (PET) and the recovery of dimethyl terephthalate (DMT) and mono ethylene glycol (MEG) using sodium methoxide as a catalyst.

The present disclosure relates to the formation of dimethyl terephthalate (DMT) and mono ethylene glycol (MEG). The present invention also relates to the depolymerization of polyethylene terephthalate (PET) and the recovery of dimethyl terephthalate (DMT) and mono ethylene glycol (MEG) using sodium methoxide as a catalyst.

The invention relates to a process for depolymerizing a polyester feedstock comprising PET, said process comprising, prior to the step of depolymerization by glycolysis and to the step of purification of the depolymerization effluent, an improved step of conditioning the feedstock in which the polyester feedstock is conditioned in terms of temperature and pressure and then mixed with a diol effluent in a static or dynamic mixer in order in particular to substantially reduce the viscosity of the feedstock.

The invention relates to a process for depolymerizing a polyester feedstock comprising PET, said process comprising, prior to the step of depolymerization by glycolysis and to the step of purification of the depolymerization effluent, an improved step of conditioning the feedstock in which the polyester feedstock is conditioned in terms of temperature and pressure and then mixed with a diol effluent in a static or dynamic mixer in order in particular to substantially reduce the viscosity of the feedstock.

Apparatuses and processes may be utilized for mixing used polyester into a polyester melt. In some processes an intermediate product stream is branched off from an intermediate stage in a virgin polyester production process. The intermediate product stream is then mixed with recycled polyester flakes in a dynamic mixer, where not more than 60% of a melting energy required to melt all the recycled polyester flakes is generated and/or supplied in the dynamic mixer. The mixture produced in this way is fed into a subsequent stage downstream of the intermediate stage and converted up to the desired degree of polycondensation. In this way, it is possible to physically reutilize used polyester or polyester waste.

The invention relates to a method for recovering raw materials from polyurethane products, having the steps of: (A) providing a polyurethane product based on an isocyanate component and a polyol component; (B) reacting the polyurethane product with an alcohol in the presence of a catalyst, wherein a first product mixture containing alcohol, polyols, carbamates, and optionally water is obtained; (C) preparing the first product mixture, having the steps of: (C.I.) mixing the first product mixture obtained in step (B) with an organic solvent, which can be mixed with the alcohol used in step (B), optionally followed by a separation of solid components, thereby obtaining a second product mixture; (C.II) washing the second product mixture obtained in step (C.I) using an aqueous washing fluid, wherein carbamates contained in the second product mixture are hydrogenated partly while releasing amines and alcohol, and carrying out a phase separation into a first solvent phase, containing the organic solvent used in step (C.I) and polyols, and a first aqueous phase, containing water, alcohol, carbamates, and amines; and (C.III) processing the first solvent phase, thereby obtaining the polyols; and optionally (D) processing the first aqueous phase, thereby obtaining an amine which corresponds to an isocyanate of the isocyanate component.

The invention relates to a method for recovering raw materials from polyurethane products, having the steps of: (A) providing a polyurethane product based on an isocyanate component and a polyol component; (B) reacting the polyurethane product with an alcohol in the presence of a catalyst, wherein a first product mixture containing alcohol, polyols, carbamates, and optionally water is obtained; (C) preparing the first product mixture, having the steps of: (C.I.) mixing the first product mixture obtained in step (B) with an organic solvent, which can be mixed with the alcohol used in step (B), optionally followed by a separation of solid components, thereby obtaining a second product mixture; (C.II) washing the second product mixture obtained in step (C.I) using an aqueous washing fluid, wherein carbamates contained in the second product mixture are hydrogenated partly while releasing amines and alcohol, and carrying out a phase separation into a first solvent phase, containing the organic solvent used in step (C.I) and polyols, and a first aqueous phase, containing water, alcohol, carbamates, and amines; and (C.III) processing the first solvent phase, thereby obtaining the polyols; and optionally (D) processing the first aqueous phase, thereby obtaining an amine which corresponds to an isocyanate of the isocyanate component.

A biaxially oriented polyester film having the following physical property is provided: when cooled from the molten state at a cooling rate of 20° C./min, an observed recrystallization temperature is 175° C.-200° C. The biaxially oriented polyester film is formed by a thick sheet before bidirectional stretching that is melted and extruded by an extruder and then cooled and formed on a casting roll. The thick sheet before stretching having the following physical property as analyzed by differential scanning calorimetry: a crystallization rate is less than 10%.

A method of producing a thiourethane resin raw material, the method comprising a reaction step of generating a thiourethane resin raw material by contacting a composition X, which comprises a thiourethane resin and a foreign material, and an active hydrogen compound with each other, and thereby reacting the thiourethane resin in the composition X, and the active hydrogen compound, with each other.