Hydrolysis Degradation of Polycarbonate Using Different Co–solvent Under Microwave Irradiation

Depolymerization of poly(bisphenol A carbonate) under mild conditions by solvent-free alcoholysis catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-ene as a recyclable organocatalyst: a route to chemical recycling of waste polycarbonate

“…Pyrolysis shows the main disadvantage of low BPA selectivity due to the large production of byproducts. [8][9][10] Other options are based on the cleavage of carbonate bond through a chemical reaction such as, for instance, hydrolysis, [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] aminolysis, 22,23 alcoholysis, [11][12][13][14][15][16]29,[45][46][47][48] or also glycolysis. [17][18][19][20][21] In principle, a few of these approaches not only allow the regeneration of the monomer (BPA), but can also afford useful coproducts, for instance organic carbonates, or carbamates and ureas, if the polymer is reacted, respectively, with alcohols or amines.…”

Synthesis of dianols or BPA through catalytic hydrolyisis/glycolysis of waste polycarbonates using a microwave heating

“…[34] They 394 reported the formation of (1) as the sole product but analyses of the reaction mixture was not done, so if by 395 products were present they were not identified. 396…”

Concerning Synthesis of New Biobased Polycarbonates with Curcumin in Replacement of Bisphenol A and Recycled Diphenyl Carbonate as Example of Circular Economy

“…Recrystallization of the residue from chloroform and hexane gave DPC as a white solid in 98% of yield. (6). The depolymerization yield was calculated as previously described [12].…”

“…Plastic wastes can be considered a valuable resource that can be recycled by means of retro-polymerization to monomers obtaining two major advantages: the possibility of conserving large amounts of manufacturing energy which are trapped in the in polymer molecules and the possibility of obtaining virgin grade plastics at the end of the recycling process [ 5 ]. Alcoholysis, aminolysis, and hydrolysis are common procedures for depolymerization, typically performed under drastic conditions such as high pressure and temperatures, as well as high concentration of acids or bases during long time processing [ 6 , 7 ]. Polycarbonate (PC) is a thermoplastic polymer produced by the condensation reaction between bisphenol A (BPA) and a carbonyl source, generally phosgene or diphenyl carbonate (DPC) [ 8 ].…”