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匿名使用者 發問時間: 社會與文化語言 · 1 0 年前

翻譯英文(一篇有關聚合物的文章)

POLYURETHANE

This important class of condensation polymers is formed by the polymerization of a diisocyanate (whose

molecules contain two –NCO groups) and a dialcohol (two –OH groups). The polymer chain is linked by urethane groups (–O–CO–NH–). The –NH– portion of the urethane group can react similarly to an –OH group, producing cross-linking between polymer chains. Polyurethane is spun into elastic fibers, called spandex, and sold under the trade name Lycra. Polyurethane can also be foamed. Soft polyurethane foams are used in upholstery, and hard foams are used structurally in light aircraft wings and sail boards. The formation of some polyurethane (and polystyrene) foams exploits the exothermic nature of the polymerization reaction. A liquid with a low boiling point, called a blowing agent, is added to the monomers before the polymerization starts. As the polymerization proceeds, it releases enough heat to boil the liquid. The boiling liquid produces bubbles that create a foam. In the past, the most commonly used low-boiling liquids were chlorofluorocarbons. However, the damaging effect of chlorofluorocarbons on the stratospheric ozone layer has eliminated their use. Other low-boiling liquids have other disadvantages, such as flammability. Therefore, most polyurethane and polystyrene foams are manufactured by forcing a pressurized gas, such as nitrogen or carbon dioxide, into the polymerizing mixture. [For more information about this polymer, see Ibid., Volume 1, page 216.]

請不要直接用翻譯軟體翻~~很急~謝謝

1 個解答

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  • 1 0 年前
    最佳解答

    聚氨酯結露聚合物這重要組由分子包含二個的聚化diisocyanate 形成(- NCO 小組) 並且dialcohol (二- OH 小組) 。聚合物鏈子由氨基甲酸脂小組連接(- O-CO-NH -) 。- 氨基甲酸脂小組的NH- 部份能相似地起反應與- OH 小組, 導致cross-linking 在聚合物鏈子之間。聚氨酯轉動入有彈性纖維, 叫做斯潘德克斯彈性纖維, 和被賣以商標Lycra 。聚氨酯可能並且起泡沫。軟的聚氨酯起泡沫被使用在室內裝飾品裡, 和艱苦起泡沫結構地被使用在輕的航空器翼和風帆板。一些聚氨酯(和多苯乙烯的) 形成起泡沫盤剝聚化反應的放熱本質。液體以低沸點, 稱一個吹的代理, 增加來單體在聚化開始之前。當聚化進行, 它發布足夠的熱煮沸液體。煮沸的液體生產創造泡沫的泡影。從前, 最常用的低沸點液體是含氟氯□。但是, 含氟氯□的殘損的作用在同溫層的臭氧層消滅了他們的用途。其它低沸點液體有其它不利, 譬如燃燒性。所以, 多數聚氨酯和多苯乙烯起泡沫由強迫製造被加壓的氣體, 譬如氮氣或二氧化碳, 入聚合的混合物。[ 對於關於這個聚合物的更多資訊, 參見Ibid., 容量1, 頁216 。

    希望幫到你^^

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