Recovery of Monomer from Nylon Waste Powder for its Recycling

Investigation of the decomplexation of polyamide/CaCl2 complex toward a green, nondestructive recovery of polyamide from textile waste

“…8 The strategy for chemical recycling of polyester focuses on the depolymerization of polyester, yielding its precursor monomers, for example, terephthalic acid and ethylene glycol, 3 for example by thermal and catalytic decomposition, 9,10 hydrolysis 11 or methanolysis. 12 Different strategies have also been proposed for polyamides including hydrolysis, [13][14][15] supercritical fluids, [16][17][18] ionic liquids under microwave irradiation, 19 and ring-closing reactions to produce N-acetylcaprolactam. 20 While the depolymerization strategy works best for single polymer synthetic products, it requires, however, extensive purification steps to separate and isolate the different monomers before repolymerization in the case of fiber mixtures as very often observed in textiles.…”

“…The strategy for chemical recycling of polyester focuses on the depolymerization of polyester, yielding its precursor monomers, for example, terephthalic acid and ethylene glycol, 3 for example by thermal and catalytic decomposition, 9,10 hydrolysis 11 or methanolysis 12 . Different strategies have also been proposed for polyamides including hydrolysis, 13–15 supercritical fluids, 16–18 ionic liquids under microwave irradiation, 19 and ring‐closing reactions to produce N ‐acetylcaprolactam 20 …”

Microwave Assisted Selective Hydrolysis of Polyamides from Multicomponent Carpet Waste

“…[ 4 , 5 ] An increasing number of countries are legislating against landfills, and incineration does not retain the intrinsic material value of the polymeric materials which is a waste of resources. [ 6 ] Synthetic carpets usually consist of a multicomponent system, where several different polymeric materials constitute the fibers and backing, respectively. The advantage of the multicomponent system is the specific properties and performances of the different polymers.…”

“…[ 7 , 8 ] This calls for new techniques to recycle carpet waste to respond to environmental and economic concerns and to generate valuable products from the waste. [ 6 , 9 , 10 , 11 , 12 ]…”

“…[7,8] This calls for new techniques to recycle carpet waste to respond to environmental and economic concerns and to generate valuable products from the waste. [6,[9][10][11][12] Many synthetic multicomponent carpets comprise of polyamide (PA) fibers (polyamide-6 (PA-6) and/or polyamide-66 (PA-66)) with a polypropylene (PP) backing, as well as an adhesive to ensure that the fibers are well connected to the backing. Additives such as dyes, repellents, and inorganic fillers (e.g., calcium carbonate, CaCO 3 ) are also commonly added.…”