Polypropylene rhymes with:
opaline, opaline, acetylene, aniline, ethylene, evaleen, gasoline, magdalene, maybelline, mescaline, naphthalene, opaline, polyacetylene, polybutylene, polyethylene, tourmaline, valvoline, vaseline
opaline, opaline, acetylene, aniline, ethylene, evaleen, gasoline, magdalene, maybelline, mescaline, naphthalene, opaline, polyacetylene, polybutylene, polyethylene, tourmaline, valvoline, vaseline