PP prices down, other commodities up in a turbulent March Print Polypropylene was the odd resin out in March, with North American prices falling, while prices for other commodity resins in the region saw increases. PP prices fell an average of 12.5 cents per pound in March. Demand for the material remained strong across many end markets. The price decline was the result of a demand drop for propylene monomer feedstock. Propylene demand was down as many PP resin plants were struggling to come back from outages caused by Winter Storm Uri, which hit Texas in mid-February. Regional propylene monomer prices were down 18.5 cents per pound in March.