Maleated and non-maleated polyethylene-montmorillonite layered silicate blown films: creep, dispersion and crystallinity

Non-linear time dependent creep of polyethylene (PE) montmorillonite layered silicate (MLS) nanocomposites was investigated. PE grafted maleic anhydride (PE-g-MA) was used, as a coupling agent to improve the miscibility between PE and organically modified MLS. The creep and tensile response of maleated and non-maleated PE nanocomposites were determined. Tensile properties of maleated PE nanocomposites were higher than the non-maleated nanocomposites. Non-linearity in the creep response was modeled using the Burger model. A drop in the retardation time was observed for maleated PE nanocomposites. XRD, polarized optical microscopy and a differential scanning calorimeter (DSC) were used to probe crystallinity and clay dispersion in the films. The tensile and creep properties were related to dispersion due to presence of MLS. The deformation response of PE blended with PE-g-MA and each of these separately modified by MLS showed synergistic contributions of the constituents. The response was attributed to dispersion effects with marginal effects of crystallinity. (c) 2005 Elsevier Ltd. All rights reserved.