Environmentally friendly chemical recycling of poly(bisphenol-A carbonate) through phase transfer-catalysed alkaline hydrolysis under microwave irradiation
| Autor: | Dimitris S. Achilias, Georgia P. Tsintzou, E.V. Antonakou |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Bisphenol A
Environmental Engineering Materials science Hot Temperature Polymers Health Toxicology and Mutagenesis Industrial Waste Catalysis Phase Transition Chemical kinetics chemistry.chemical_compound Hydrolysis Spectroscopy Fourier Transform Infrared Environmental Chemistry Organic chemistry Sodium Hydroxide Recycling Polycarbonate Benzhydryl Compounds Microwaves Waste Management and Disposal Alkaline hydrolysis chemistry.chemical_classification Calorimetry Differential Scanning Molecular Structure Water Polymer Pollution Kinetics chemistry Chemical engineering visual_art visual_art.visual_art_medium Chromatography Gel Degradation (geology) |
| Zdroj: | Journal of hazardous materials. |
| ISSN: | 1873-3336 |
| Popis: | The various and widespread uses of polycarbonate (PC) polymers require a meaningful and environmentally friendly disposal method. In this study, depolymerisation of polycarbonate with water in a microwave reactor is suggested as a recycling method. Hydrolysis was investigated in an alkaline (NaOH) solution using a phase-transfer catalyst. All of the experiments were carried out in a sealed microwave reactor, in which the reaction pressure, temperature and microwave power were continuously controlled and recorded. In the hydrolysis products, bisphenol-A monomer was obtained and identified by FTIR measurements. PC degradation higher than 80% can be obtained at 160 °C after a microwave irradiation time of either 40 min or 10 min using either a 5 or 10% (w/v) NaOH solution, respectively. GPC, TGA and DSC measurements of the PC residues revealed that surface erosion is the degradation mechanism. First-order reaction kinetics were estimated by implementing a simple kinetic model. Finally, greater than 85% degradation was achieved when waste CDs were treated with the same method. The results confirm the importance of the microwave power technique as a promising recycling method for PC-based waste plastics, resulting in monomer recovery in addition to substantial energy savings. |
| Databáze: | OpenAIRE |
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