Ultra high molecular weight polyethylene comprising refractory particles

The present invention pertains to ultra-high molecular weight polyethylene comprising 0.001 to 10 weight% of refractory particles, wherein the refractory particles have an average particle size (D50) below 300 nm. In one embodiment the average particle size is at least 5 nm, in particular at least 10 nm, and/or at most 150 nm, in particular at most 100 nm, more in particular at most 80 nm. In one embodiment the particles are oftransformation toughened zirconia. Shaped objects based on this material, and ballistic materials are also claimed.