Quick Comparison While both are members of the “Poly” family (polyolefins), they offer distinct advantages depending on temperature, chemical exposure, and physical stress. Feature Polyethylene (PE / HDPE) Polypropylene (PP) Max Temp Up to 140°F (60°C) Up to 180°F – 212°F (100°C) Impact Resistance Excellent (Flexible) Good (More Rigid) Cold Weather Remains flexible in freezing… Continue reading Choosing the Right Tank Material: Polyethylene vs Polypropylene