[en] Polyethylene-layered silicate nanocomposites were prepared by the in situ intercalative polymerization of ethylene by the so-called polymerization-filling technique and analyzed by transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), differential scanning calorimetry, dynamic mechanical analysis and tensile testing. Non-modified montmorillonite and hectorite were first treated by trimethylaluminum-depleted methylaluminoxane before being contacted by a Ti-based constrained geometry catalyst. The nanocomposite was formed by addition and polymerization of ethylene. In the absence of a chain transfer agent, ultra high molecular weight polyethylene was produced. The tensile properties of these nanocomposites were poor and essentially independent of the nature and content of the silicate. Upon hydrogen addition, the molecular weight of the polyethylene was decreased with parallel improvement of the tensile and shear moduli, in relation to the filler content. The exfoliation of the layered silicates was confirmed by XRD analysis and TEM observation. The mechanical kneading of the molten nanocomposites resulted in the partial collapse of the exfoliated structure driven by the thermodynamic stability of the layered filler.
Research center :
Center for Education and Research on Macromolecules (CERM)
Disciplines :
Chemistry Materials science & engineering
Author, co-author :
Alexandre, Michaël ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Dubois, Philippe ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Sun, Tao; The Dow Chemical Company, Midland, USA
Garces, Juan M.; The Dow Chemical Company, Midland, USA
Jérôme, Robert ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Language :
English
Title :
Polyethylene-layered silicate nanocomposites prepared by the polymerization-filling technique: synthesis and mechanical properties
Dow Chemical BELSPO - SPP Politique scientifique - Service Public Fédéral de Programmation Politique scientifique The US Department of Commerce, National Institute of Standards and Technology, Advanced Technology Program, Cooperative Agreement Number 70NANB7H3028
Commentary :
The authors acknowledge Polymer (Elsevier) for allowing them to archive this paper.