Key Words:WALLED CARBON NANOTUBES; FLAME RETARDANCY; FLAMMABILITY PROPERTIES; EPOXY-RESIN; CARBONIZATION; POLYETHYLENE; PYROLYSIS; CATALYSTS; SUPPRESSION; NANOSHEETS

Abstract:To effectively mitigate the environmental and ecological impacts stemming from polymer wastes, the development of innovative recycling and reusing strategies is of utmost importance. In response to the call of "Waste-to-Wealth", this study presents a green and efficient method to convert waste polypropylene (waste protective cloths, WPC) into Ni@CNTs hybrids via catalytic carbonization. Subsequently, these Ni@CNTs hybrids are directly applied as functional nanofillers to prepare fire resistant polycarbonate (PC) composites. The experimental results demonstrated that the combined catalysts composed of NiCl2/Ni(C5H7O2)2 were efficient in catalyzing WPC into Ni@ CNTs hybrids, achieving the yield was as high as 58.6 g/100 g WPC. Leveraging the superior characteristics of Ni@CNTs hybrids, they were used as a fire retardant of polycarbonate (PC) matrix to fabricate PC/Ni@CNTs composites. The PC/3Ni@CNTs exhibited excellent fire retardancy, as evidenced by the limited oxygen index (LOI) of 30.5 %, the V0 rating in UL-94 vertical burning test, and the 64.1 % reduction in the peak of heat release rate (PHRR) in cone calorimeter test. Meanwhile, it displayed low toxicity with 75.0 % reduction in the peak of CO production (COP). The mechanism was attributed to the synergistic effects of Ni and CNTs, which combine the catalyzing carbonization and the enhanced char layer together in condensed phase. Thus, this study provides a green and sustainable strategy for the conversion of polymer wastes into high-valuable carbon/metal hybrids, and exploits their advanced application in the fabrication of fire-resistant polymer composites.

Volume:13

Issue:3

Translation or Not:no