Polyethylene Resins Slow Crack Growth Testing based on Strain Hardening Modulus and Crystallinity

The Strain Hardening Modulus method (SH) was proposed to evaluate the Slow Crack Growth (SCG) rank of five different PE resins by comparing the average strain hardening modulus $\overline {\left\langle {{\text{Gp}}} \right\rangle } $. The test result shown that, it could be accurately evaluated when the SCG of PE resins were large different (such as PE 100-RC and PE100), but when the SCG resistance were similar (such as the same grade PE 100 resins), due to the influence of the test accuracy and external factors, the evaluate result were exist offset by comparing $\overline {\left\langle {{\text{Gp}}} \right\rangle } $. Exteriorly, By testing the crystallinity of the five different PE resins and combining the strain hardening modulus to comprehensive evaluated the SCG resistance of the five different PE resins, the evaluated result were more accurate, and it can overcome the difficulty of the SH method in evaluating PE resins with similar SCG.