propylene glycol      
noun [ U ]  chemistry specialized uk/ˌprəʊ.pɪ.liːn ˈɡlaɪ.kɒl/ us/ˌproʊ.pɪ.liːn ˈɡlaɪ.kɑːl/
 丙二醇
a chemical compound used mainly for making polymers (= chemical substances consisting of large molecules made from smaller molecules) and in food production