Polyethylene/synthetic boehmite alumina nanocomposites: Structure, mechanical, and perforation impact properties
Journal of Materials Science
Department of Polymer Technology, Faculty of Mechanical Engineering and Built Environment, Tshwane University of Technology, Pretoria 0001, South Africa; Institut für Makromolekulare Chemie und Freiburger Materialforschungszentrum, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Str. 31, Freiburg 79104, Germany
Synthetic boehmite alumina (BA) has been incorporated up to 8 wt% in high-density polyethylene (HDPE) and low-density polyethylene (LDPE) by melt compounding. The primary nominal particle sizes of the two BA grades used were 40 and 74 nm, respectively. The dispersion of the BA in PE matrices was investigated by scanning and transmission electron microscopy techniques (SEM and TEM). Specimens of the PE/BA nanocomposites were subjected to dynamic-mechanical thermal analysis (DMTA), static tensile and instrumented falling weight impact (IFWI) tests. It was established that BA was nanoscale dispersed in both HDPE and LDPE. According to DMTA, BA worked as reinforcing filler. This was confirmed in static mechanical tests, too. BA grades and contents influenced the static tensile and dynamic IFWI behaviors of the PE/BA nanocomposites differently. Surprisingly, BA incorporation enhanced the ductility (elongations at yield and break) of HDPE in contrast to LDPE. Unlike HDPE/BA nanocomposites, the perforation impact resistance of the LDPE/BA systems was reduced with increasing BA content at both ambient temperature and T = -30 °C. The lesser the reduction the higher the primary particle size of the BA was. © 2010 Springer Science+Business Media, LLC.
Ambient temperatures; Falling weight impact; Impact property; Melt-compounding; Nano scale; Primary particle size; Reinforcing fillers; Scanning and transmission electron microscopy; SEM and TEM; Static mechanical test; Static tensile; Thermal analysis; Dynamics; High density polyethylenes; Impact resistance; Mechanical properties; Nanocomposites; Thermoanalysis; Thermoplastics; Transmission electron microscopy; Dynamic mechanical analysis