蜡
相关tags:
蜡(wax)
一类来源於动物、植物、矿物的或合成的柔顺性物质中的任何一种,和脂肪相比它较不油腻、较软也更脆。蜡包含了大部分高分子量(脂肪酸、醇和饱和烃)的化合物。有不少蜡类可在高温(即35~100℃)熔化,形成可以擦得很亮的膜,使它们成为用於一系列擦亮剂的理想材料。动物蜡和植物蜡属脂肪酸的酯类,这些醇类可以是一组称为固醇(例如胆固醇)的醇类,或者是一种在直链中的醇(例如十六烷醇)。羊毛蜡、蜂蜡属动物蜡,用於制药和化妆品。鲸油和鲸蜡都取自抹香鲸,在常温下是液体,主要用作润滑剂。植物蜡主要是巴西棕榈蜡、小烛树蜡和甘蔗蜡都用作擦亮剂。工业用蜡中约有90%是由石油中回收的。一般分为三种主要类型︰石蜡、微晶蜡和石蜡脂。石蜡广泛用於蜡烛、蜡笔和工业用擦亮剂。它还用作电器的绝缘组分和用於防水木材及其他材料中。微晶蜡主要用於包装纸涂层。石蜡脂用於药膏和化妆品制造。合成蜡通常与石油蜡混合,制得种种产品。
English version:
wax
Any of a class of pliable substances, organic compounds of animal, plant, mineral, or synthetic origin, less greasy, harder, and more brittle than fats. Waxes contain mostly compounds of high molecular weight (fatty acids, alcohols, and saturated hydrocarbons). Many melt at moderate temperatures and form hard films that can take a high polish. Animal and plant waxes are esters of fatty acids and either a sterol (see steroid) or a straight-chain higher alcohol (e.g., cetyl alcohol). Animal waxes include beeswax; wool wax (lanolin), used in pharmaceuticals and cosmetics; and sperm oil and spermaceti (from sperm whales), used as lubricants. Plant waxes include carnauba wax, candelilla wax, and sugarcane wax, used in polishes. About 90% of the waxes in commerce are recovered by dewaxing petroleum. There are three main types: paraffin (used in candles, crayons, paper coating, and industrial polishes and as a protective sealant, lubricant, insulating agent, and antifrothing agent), microcrystalline wax (used in paper coating), and petrolatum (used in ointments and cosmetics). Synthetic waxes (carbowaxes), derived from ethylene glycol, are commonly blended with petroleum waxes.