Controllable Microwave-Assisted Polycarbonate Waste Chemical Recycling

Abstract

A simple, convenient and novel method was developed for the recovery of bisphenol-A from polycarbonate wastes under microwave irradiation. In this study bisphenol-A was recovered at a 100% yield by using a mixture of glycerol/water as the green solvent and sodium hydroxide as the catalyst, respectively. This methodology can overcome the disadvantages existing in traditional methods such as long reaction times, high energy consumptions, use of harmful reagents and environmental problems, and is applicable to all types of polycarbonates.

Current approaches to waste polymer utilization and minimization: a review

“…Other chemical recycling methods involves photodegradation, ultrasound degradation, degradation in microwave reactor, etc. Despite all its advantages, unfortunately, chemical recycling is not a widespread method, mainly because of energy costs .…”

“…Recycling of condensation polymers such as PET and Nylon by these methods yields monomer units (de-polymerization or monomer recycling) in a relatively short time. 32 Other chemical recycling methods involves photodegradation, [45][46][47] ultrasound degradation, [48][49][50][51][52][53] degradation in microwave reactor, [54][55][56][57][58][59] etc. Despite all its advantages, unfortunately, chemical recycling is not a widespread method, mainly because of energy costs.…”

Ultrasonic Degradation of Polystyrene for Tailoring Molecular Weight and Polydispersity of Polystyrene Fragments

“…The application of the listed tertiary recycling methods depends especially on the respective synthesis process of the polymer. Additional interesting chemical recycling methods are photodegradation [12,13], ultrasound degradation [14][15][16][17][18][19][20][21][22] as well as microwave degradation [23][24][25]. These methods are not directly linked to a specific polymer synthesis method.…”

Performance of Fe3O4@SiO2 as the recyclable heterogeneous catalyst in the bisphenol A recovery from polycarbonate wastes

“…Due to increased polycarbonate (PC) production and therefore to recycle the end used PC wastes, demands for finding some adequate and environmentally benign methods for recycling these polymeric wastes have increased dramatically, and as a result, researchers are conducting experiments to find economical, green, and simple methods for chemical recycling. 1 In recent years, several methods have been presented for chemical recycling of PC wastes involving hydroglycolysis, 2,3 hydrolysis, 4,5 glycolysis, [6][7][8] methanolysis in ionic liquids, 9 pyrolysis, 10 alcoholysis in supercritical conditions, 11 and aminolysis, 12 all of which have their own merits and drawbacks. Homogeneous catalysts such as sodium hydroxide (NaOH) have higher catalytic activity than heterogeneous catalysts because of its solubility in the reaction media, which increases catalytic site accessibility for the substrate, but recycling and reusing of this catalyst is difficult, costly, and often time-consuming.…”