苯乙烯(C_6H_5·CHCH_2)是合成聚苯乙烯的单体,是塑料工业的重要原料,为无色、透明、具有气味的液体。于20℃时,比重为0.903,沸点为146℃,水溶性极小(20℃为0.03重量％),易溶于苯、乙醚、四氯化碳、甲醇、乙醇、丙酮及二硫化碳等。其蒸气压,在摄氐33°、40°、48°及52°时,分別为10、14、20及28毫米汞柱。在化学特性方面,易被聚合,尤其在光和高溫条件下,更易发生聚合作用,但其揮发性較小,仅相当于苯的十四分之一。 Styrene (C_6H_5 · CHCH_2), a monomer of synthetic polystyrene, is an important raw material in the plastics industry. It is a colorless, transparent and odoriferous liquid. At 20 ℃, the specific gravity is 0.903, the boiling point is 146 ℃, the water solubility is very small (0.03% by weight at 20 ℃), easily soluble in benzene, ether, carbon tetrachloride, methanol, ethanol, acetone and carbon disulfide. The vapor pressure was 10, 14, 20 and 28 mm Hg at 33 °, 40 °, 48 ° and 52 °, respectively. In terms of chemical properties, it is easy to be polymerized, especially under light and high temperature conditions, but its volatility is smaller, which is only equivalent to one-fourteenth of benzene.