Zero shear viscosity and molecular weight between entanglements (M_e) are determined from dynamic oscillatory shear experiments. Lower M_e value means higher number of entanglements in the system and is associated with increasing strain hardening stiffness. With the understanding that strain hardening is related to environmental stress cracking resistance (ESCR) of high density polyethylene (HDPE), M_e is then related to the ESCR of several resins in this study. The inversely proportional relationship between M_e and ESCR indicates that low network mobility due to an increasing number of chain entanglements increases the ESCR of HDPE.

Environment stress cracking of HDPE products is quite common due to its semi crystalline nature which gets attacked due to chemicals present in the environment. The stress cracking is more severe with detergent, bleach, motor oil and some industrial chemical packaging. ESCR problems get more pronounced in the summer, because of several factors related to increased heat and humidity. To overcome these challenges, a new simpler and faster method was developed by SABIC to assess ESCR for high density polyethylene (HDPE) materials. In this method, the resistance of slow crack growth or environmental stress cracking is predicted from simple tensile measurement at a.

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