(307c) Hdpe/Al2o3 Nanocomposites Prepared by Extruding Al2o3 Coated Hdpe Particles

Authors: 
Hakim, L. F., University of Colorado
Spencer, J. A., ALD NanoSolutions, Inc.
Buechler, K. J., ALD NanoSolutions, Inc.
George, S. M., University of Colorado
Weimer, A. W., University of Colorado at Boulder
Liang, X., University of Colorado, Boulder
King, D. M., University of Colorado, Boulder


Micron-sized High Density Polyethylene (HDPE) particles were coated with ultrathin alumina (Al2O3) films by Atomic Layer Deposition (ALD) in a Fluidized Bed Reactor (FBR) at 77 ºC. The deposition of Al2O3 on the polymer particle surface has been confirmed by Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS). Conformal coatings of Al2O3 have been confirmed by Transmission Electron Microscopy (TEM). The results of Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP-AES) suggested that there was a nucleation period, after which, the Al2O3 films grew linearly with an increase of coating cycles. The results of Scanning Electron Microscope (SEM), particle size distribution and surface area of the uncoated and nanocoated particles showed that there was no aggregation of particles during the coating process. The coated HDPE particles were extruded to crush the Al2O3 shell and form HDPE/Al2O3 nanocomposite film. Cross section TEM indicated that nanoscale Al2O3 shells were homogeneously dispersed in the polymer matrix. The extruded HDPE/Al2O3 nanocomposite film displayed lower gas diffusion rates than blank HDPE films. Mechanical analysis data showed the nanocomposite film had higher tensile strength. Thermal Gravimetric Analyzer (TGA) was used to evaluate the thermal behavior of the composites and the results showed that the nanocomposite film had improved thermal stability.