Environmental stress cracking tendency: which polyethylene grade is most prone to stress-cracking under typical service conditions?

Introduction / Context:
Environmental stress cracking (ESC) is a key failure mode in polyethylenes. Recognising which grade is more susceptible guides material selection for detergents, hydrocarbons, and long-term load exposure.

Given Data / Assumptions:

• HDPE is stiffer and more crystalline, often with lower ESCR than certain LDPE/LLDPE grades unless stabilised.
• Cross-linked PE improves crack resistance.

Concept / Approach:
Higher crystallinity can raise notch sensitivity and reduce resistance to ESC in aggressive environments. LLDPE is designed for improved ESCR relative to HDPE in many packaging applications.

Step-by-Step Solution:
Compare ESCR trends: HDPE tends to be more prone than LDPE/LLDPE without additives.Select HDPE as most prone among the listed choices.

Final Answer:
High-density polyethylene (HDPE)