Ultrahigh molecular-weight polyethylene-chalk composites resulting from in situ polymerization

Ethylene polymerization on chalk surface under the action of TiCl4–organoaluminium compound systems yields filled composites possessing high stress–strain properties and preserving their ductility up to the chalk content of 60–70 wt %. The kinetics of the process and the properties of the composites have been investigated, as well as the interrelation between catalyst fixation technique, polymerization rate, and the ductile properties of composites containing 50 wt % of chalk. The conditions leading to the formation of “homogeneous” composites with a high ductility are examined. The possible causes of the formation of composites with a low value of elongation at break are analyzed. The principal regularities of the mechanical behavior of composites are considered for the case when the process is taking place on the filler surface and leads to “homogeneous” composites.