Is polypropylene a good option for my aggressive chemical application?
Polypropylene (PPL) has very similar chemical resistance properties to those of polyethylene. The advantages of PPL are its resistance to chlorinated hydrocarbons and its temperature rating of 200 degrees F (vs. polyethylene at 140 degrees F). The downside to PPL in rotational molded products is that it has poor impact resistance, which makes a PPL tank very fragile. It is not uncommon for a PPL tank to crack if dropped or impacted by external force or water hammer. The larger the tank, the higher the probability of impact damage, due to the weight and geometry of a larger part. Peabody highly recommends that you use polyethylene whenever possible and if you must use PPL tanks larger than 15 gallons, we recommend that you have us put a fiberglass overwrap on it for you. This will make it far more durable and protect the wall from impact damage. The fiberglass is rated to 210 degrees F, so your tank will also handle higher operating temperatures as well.
Source: FAQs - Peabody