A method for recycling polyester/polyurethane is provided. The method comprises adding additives containing hydroxyl or/and amino groups to polyester/polyurethane waste and performing transesterification or transcarbamoylation at 80-180° C. to form recycled new materials with different structures including polyester, polyurethane, polyamide, and polyurea.

A composition comprising a Lewis base containing depolymerization liquid and methods of using the Lewis base depolymerization liquid to depolymerize the polymer component of fiber reinforced polymers to form free fibers.

A composition comprising a Lewis base containing depolymerization liquid and methods of using the Lewis base depolymerization liquid to depolymerize the polymer component of fiber reinforced polymers to form free fibers.

This invention relates to the field of plastic waste decomposition. More specifically, the invention comprises products obtained from the decomposition of plastic waste.

Novel polymers are depolymerizable by metathesis of a cleavable unit. As an example, a series of linear and crosslinked polyurethanes were prepared that can be selectively depolymerized under mild conditions. Two unique polyols were synthesized bearing unsaturated units in a configuration designed to favor ring-closing metathesis to five- and six-membered cycloalkenes. These polyols were co-polymerized with toluene diisocyanate to generate linear polyurethanes and trifunctional hexamethylene- and diphenylmethane-based isocyanates to generate crosslinked polyurethanes. The polyol design is such that the ring-closing metathesis reaction cleaves the backbone of the polymer chain. Upon exposure to dilute solutions of Grubbs' catalyst under ambient conditions, the polyurethanes were rapidly depolymerized to low molecular weight, soluble products bearing vinyl and cycloalkene functionalities. These functionalities enabled further re-polymerization by traditional strategies for polymerization of double bonds. This general approach can be expanded to develop a range of chemically recyclable condensation polymers that are readily depolymerized by orthogonal metathesis chemistry.

A desulfurized rubber obtained by mixing a desulfurization agent and a vulcanized rubber, the desulfurization agent containing a compound represented by any one of the following formulae (1) to (4):

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wherein R.sub.1 to R.sub.8 each independently represent a hydrogen atom, an oxygen atom, or an alkyl group. It is preferable that the desulfurization agent contains at least one selected from the group consisting of 2,2′-dithiodianiline and 4,4′-dithiodianiline.

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.

Polyester-free cotton is obtained from a fabric and/or fibers containing polyester and cotton by reacting the fabric and/or fibers with an amine organocatalyst and/or carboxylic acid salt of same and an alcohol solvent. The reaction, which may be run in batches or as a continuous flow process, recovers (i) polyester-free cotton as a solid inert by-product of the reaction, (ii) the amine organocatalyst and/or carboxylic acid salt of same for reuse, (iii) a polyester monomer product, and (iv) unreacted alcohol. The reaction works on any polyester-cotton fabric and/or fibers, including those that have at least one additional material, such as polyethers polyolefins, polyurethanes, nylon, rayon, acetate, viscose, modal, acrylic, wool, and combinations thereof.

Polyester-free cotton is obtained from a fabric and/or fibers containing polyester and cotton by reacting the fabric and/or fibers with an amine organocatalyst and/or carboxylic acid salt of same and an alcohol solvent. The reaction, which may be run in batches or as a continuous flow process, recovers (i) polyester-free cotton as a solid inert by-product of the reaction, (ii) the amine organocatalyst and/or carboxylic acid salt of same for reuse, (iii) a polyester monomer product, and (iv) unreacted alcohol. The reaction works on any polyester-cotton fabric and/or fibers, including those that have at least one additional material, such as polyethers polyolefins, polyurethanes, nylon, rayon, acetate, viscose, modal, acrylic, wool, and combinations thereof.

Polyester-free magnetic and/or metallic components are obtained from a multicomponent polyester device by reacting the multicomponent polyester device with an amine organocatalyst and/or carboxylic acid salt of same and an alcohol solvent. The reaction recovers (i) the polyester-free magnetic and/or metallic components as solid inert by-products of the reaction, (ii) the amine organocatalyst and/or carboxylic acid salt of same for reuse, (iii) unreacted alcohol for reuse, and (iv) a polyester monomer product. Where the multicomponent device includes a non-polyester material, such as polystyrene, the polystyrene is fully recovered from the reaction. Where the multicomponent polyester device includes recording media, the reaction process sanitizes the inert byproducts of the recording media, thus scrubbing any personal data from the reacted recording media.