聚丙烯

polypropylene

to congregate / to assemble / to mass / to gather together / to amass / to polymerize

third of the ten Heavenly Stems 十天干[shi2 tian1 gan1] / third in order / letter "C" or Roman "III" in list "A, B, C", or "I, II, III" etc / ancient Chinese compass point: 165° / propyl

propylene C3H6

alkene