writer：Ran SY, Guo ZH*, Han LG, Fang ZP.
keywords：Graphene Nanoplatelets; Friedel-Crafts reaction; Dispersion; Thermal properties; Flame retardance
source：期刊
specific source：Polym. Int., 2014.10, 63(10): 1835-1841
Issue time：2014年
Brominated flame-retarded high-density polyethylene (HDPE) composites containing graphene nanoplatelets (GNPs) were prepared (HDPE/BPS/GNPs) via melt blending. Lewis acid catalyst, aluminum chloride anhydrous (AlCl3) was added to initiate Friedel-Crafts reaction for promoting the dispersion of GNPs in polymer matrix. Transmission electron microscope (TEM) images and Raman spectroscopy revealed that GNPs have been partly unfolded and the domains became smaller in the presence of AlCl3. The electrostatic attraction between the macrocarbocation formed by Friedel-Crafts reaction and π electron of graphene sheets caused the better dispersive states of GNPs. Limited oxygen index (LOI) and microscale combustion calorimeter (MCC) showed that the incorporation of AlCl3 into HDPE reduced flammability and slowed down heat release rate. The resultes of thermogravimetric (TG) analysis and char residue proved that the uniform dispersion of GNPs was crucial for forming continuous and compact carbon layer making for isolating the underlying materials from the flame and preventing heat transfer.