Thermal Stability and Dynamic Mechanical Behavior of Exfoliated Graphite Nanoplatelets-LLDPE Nanocomposites

The objective of this research was to investigate thermal stability and dynamic mechanical behavior of Exfoliated graphite nanoplatelets (xGnP (TM))-Linear Low-Density Poly Ethylene (LLDPE) nanocomposites with different xGnP loading content. The xGnP-LLDPE nanocomposites were fabricated by solution and melt mixing in various screw rotating systems such as co-, counter-, and modified-corotating. The storage modulus (E') of the composites at the starting point of -50 degrees C increased as xGnP contents increased. E' of the nanocomposite with only 7 wt% of xGnP was 2.5 times higher than that of the control LLDPE. Thermal expansion and the coefficient of thermal expansion of xGnP-loaded composites were much lower than those of the control LLDPE in the range of 45-80 degrees C (299.8 x 10(-6)/degrees C) and 85-100 degrees C (365.3 x 10(-6)/degrees C). Thermal stability of the composites was also affected by xGnP dispersion in LLDPE matrix. The xGnP-LLDPE nanocomposites by counter-rotating screw system showed higher thermal stability than ones by co-rotating and modified-corotating system at 5 wt% and 12 wt% of xGnP. xGnP had a great effect on high thermal stability of xGnP-LLDPE composites to be applied as tube and film for electrical materials. POLYM. COMPOS., 31:755-761, 2010. (C) 2009 Society of Plastics Engineers