High‐density polyethylene pipe resins

Efficient catalyst systems and an appropriate polymerization technology are required for the production of pipe resins which must exhibit both high stiffness and excellent service lifetimes (i.e. resistance to environmental stress cracking). The problem is that these requirements are contradictory but recently a polymer alloy has been developed with an elastic modulus over 1000 MPa and a failure time two orders of magnitude higher than that of standard materials.