Polypropylene or Polyethylene is the two diferent types of resin used when producing plastically corrugated. The most common throughout the plastic corrugated industry is PP when producing products or sheets in I-Beam(also known as H-Beam) structure material. The I-Beam plastic corrugated material can also be produced in PE when required. When producing containers or sheets in plastic corrugated laminated(Wave-Beam) structure it will always be made from polyethylene. The most common thickness for PE laminated(Wave-Beam) is 4mm.

Polypropylene vs Polyethylene Plastic Corrugated

Depending on how you are going to use your product. PE is less affected by extreme cold applications. When the temperatures reach 10℃ or lower PP will begin to have a tendency or at least more likely to racture or crack when it takes an impact or when flexed or folded in this cold environment.
PE is also softer, so it may be selected or rejected for the project because of this factor. The warmer the environment the softer polyethylene will become.
PE plastic corrugated sheet more "shinning and smooth"than PP plastic corrugated sheet.
Both materials have their benefits and deficits. So each project needs to be evaluated before making a decision.