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防冻剂
维基百科,自由的 encyclopedia
防冻剂,又称阻冻剂、抗冻剂,是防止液体凝固或组成过大冰晶的物质。
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在汽车上使用时,防冻剂除了要防止它们在高于引擎最低工作温度的温度凝固,兼防止冷却系统的金属生锈。1930年代前,甲醇是最流行的防冻剂,可是它的热容量和沸点都很低,而且时间一长,它的份量会因蒸发而渐渐减少。1937年,开始使用乙二醇,其沸点高,使得它取代甲醇,直到现在仍流行。其缺点是有毒。丙二醇是没有毒性的防冻剂,它以甘油为原料。1980年代Jack Evans发现使用无水的防冻剂——乙二醇及丙二醇的混合液,其沸点超过摄氏180度。