Fullerene decorated by iron compound (C 60-Fe) was fabricated via solution reaction and characterized by X-ray photoelectron spectra and wide-angle X-ray diffraction. By a partial replacement of intumescent flame retardant (IFR) in flame retarded polyethylene (PE) by C 60-Fe, the flame retardant properties of PE/IFR composites were increased dramatically. When 2 wt% IFR was substituted by C 60-Fe, a compact and continuous char barrier was formed, resulting in the reduction of the peak of heat release rate (PHRR) and the total heat released (THR). Also, the ignition time (t ign) prolonged form 67 to 114 s and the time to PHRR (t PHRR) prolonged form 208 to 455 s. The improvement on flame retardancy of PE/IFR/C 60-Fe composites was due to the synergistic influence between the catalytic charring ability of Fe and the free radical trapping effect of C 60 .

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Chitosan has received extensive attention as a biomedical material; however, the poor solubility of chitosan is the major limiting factor in its utilization. In this study, chitosan-based biomaterials with improved aqueous solubility were synthesized. Two molecular weights (750 Da and 2000 Da) of methoxypoly(ethylene glycol) (mPEG) were grafted onto chitosan (mPEG-g-chitosan) to form a 100-lm-thick plastic film as a wound dressing. The chemical structures of the mPEG-g-chitosan copolymers were confirmed using Fourier transform infrared spectroscopy (FTIR), and the thermal properties were characterized using thermogravimetry analysis (TGA). Their microstructures were observed using scanning electron microscopy (SEM). The other properties were analyzed via the swelling ratio, tensile strength, elongation, and water vapor transmission rate (WVTR). Biocompatibility evaluations through biodegradability, cytotoxicity, and antimicrobial effect studies were also performed. The obtained mPEG-g-chitosan copolymers were soluble in slightly acidic aqueous solutions (pH6.5) at a concentration of 10 wt %. The optimal mPEG-g-chitosan hydrogels had swelling ratios greater than 100% and WVTRs greater than 2000 g/m 2 /day. Their performance against Staphylococcus aureus will be subjected to further improvements with respect to medical applications.

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