A process for chemically recycling polyethylene terephthalate (PET) which utilizes a microwave absorber to optimize glycolytic depolymerization of PET via microwave irradiation. The method of chemically degrading PET to its reactive intermediate, bis(2-hydroxyethyl) terephthalate (BHET), is carried out by: (a) combining PET with ethylene glycol and a catalytic system comprising a catalyst and a microwave absorber to produce a heterogeneous reaction mixture; and then (b) heating by microwave irradiating the reaction mixture to a temperature sufficient to produce a reaction product comprising BHET. The BHET monomer then can be purified and re-polymerized to form new, virgin PET.

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

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

Disclosed herein are methods for degrading polyurethane foam from mounted polyurethane foam-containing tires, methods for separating a wheel from a mounted polyurethane foam-containing tire, methods for preparing a degradable foam-containing tire, and degradable foam-containing tires. The methods include applying a solution comprising at least one phosphorous oxoacid or an ester thereof to the polyurethane foam inside of a tire, incorporating a degradant comprising at least one phosphorous oxoacid or an ester thereof into the polyurethane foam, or both, and then heating to degrade the foam. Degradation of the foam allows for separation of the wheel from the rubber carcass of the tire.

Disclosed herein are methods for degrading polyurethane foam from mounted polyurethane foam-containing tires, methods for separating a wheel from a mounted polyurethane foam-containing tire, methods for preparing a degradable foam-containing tire, and degradable foam-containing tires. The methods include applying a solution comprising at least one phosphorous oxoacid or an ester thereof to the polyurethane foam inside of a tire, incorporating a degradant comprising at least one phosphorous oxoacid or an ester thereof into the polyurethane foam, or both, and then heating to degrade the foam. Degradation of the foam allows for separation of the wheel from the rubber carcass of the tire.

A method for recycling polyester fabrics with use of an ionic liquid catalyst is provided, which includes: providing a recycled polyester fabric; and using a chemical de-polymerization liquid to chemically de-polymerize the recycled polyester fabric and form a de-polymerization product that includes bis-2-hydroxylethyl terephthalate (BHET). The chemical de-polymerization liquid is used to chemically de-polymerize the recycled polyester fabric in an environment where a de-polymerization catalyst exists, and the de-polymerization catalyst is the ionic liquid catalyst in a solid state.

A method for recycling polyester fabrics with use of an ionic liquid catalyst is provided, which includes: providing a recycled polyester fabric; and using a chemical de-polymerization liquid to chemically de-polymerize the recycled polyester fabric and form a de-polymerization product that includes bis-2-hydroxylethyl terephthalate (BHET). The chemical de-polymerization liquid is used to chemically de-polymerize the recycled polyester fabric in an environment where a de-polymerization catalyst exists, and the de-polymerization catalyst is the ionic liquid catalyst in a solid state.

Compositions of and methods for producing a modified polyimide-containing compound with an alkyl or acyl group, one method including selecting and preparing a polyimide-containing compound to undergo a Friedel-Crafts alkylation or acylation reaction; carrying out the Friedel-Crafts alkylation or acylation reaction on the polyimide-containing compound to bond an alkyl group or acyl group to a reactive site on an aromatic compound of the polyimide-containing compound; cleaving the polyimide-containing compound to produce modified monomers comprising the alkyl group or the acyl group; and using the modified monomers in a reaction to produce the modified polyimide-containing compound, wherein the alkyl group or the acyl group is present in the modified polyimide-containing compound.

Compositions of and methods for producing a modified polyimide-containing compound with an alkyl or acyl group, one method including selecting and preparing a polyimide-containing compound to undergo a Friedel-Crafts alkylation or acylation reaction; carrying out the Friedel-Crafts alkylation or acylation reaction on the polyimide-containing compound to bond an alkyl group or acyl group to a reactive site on an aromatic compound of the polyimide-containing compound; cleaving the polyimide-containing compound to produce modified monomers comprising the alkyl group or the acyl group; and using the modified monomers in a reaction to produce the modified polyimide-containing compound, wherein the alkyl group or the acyl group is present in the modified polyimide-containing compound.

A method for improving hue of recycled bis-2-hydroxylethyl terephthalate by using ionic liquids including providing a recycled polyester fabric; using a chemical de-polymerization liquid to chemically de-polymerize the recycled polyester fabric to form a de-polymerization product; mixing the de-polymerization product with water to form an aqueous phase liquid; dispersing an ionic liquid impurity adsorption material into the aqueous phase liquid to adsorb impurities originally present in the recycled polyester fabric.