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新托福阅读背景知识：polymer gels

2018-08-01 11:42:57来源：网络

　　托福阅读复习中，一项重要的备考任务就是了解阅读的背景知识。这对于提升我们文章的阅读效率有着重要的影响。新东方在线托福网为大家整理了一些比较常考的背景知识，供大家参考学习。

【点击查看新托福阅读背景知识汇总】

　　polymer gels一种聚合凝胶

　　The following information was part of our display for the SET96 and SET98 Scientific Power to the People Exhibition, The Galleries, Bristol, 20th and 21st March 1998.

　　A POLYMER is a very long molecule rather like a very long piece of string.

　　The borax joins two molecules together to make a large network - rather like flexible scaffolding. This is cross-linking.

　　This turns the fluid dissolved polymer into a GEL.

　　In oil wells water is pushed down to push oil up. If this breaks through to the production well bore, the well will just produce water. A solution is to block the rock pores with polymer gel to make the well produce oil again. These gels can be made from naturally occurring sugar-based polymers such as Guar and they can be cross-linked with Cobalt or Chromium.

　　Other everyday examples of polymer gels are to be found in non-drip emulsion paints, foods, car tires and agrochemicals.

　　The polymer that we are using is POLYVINYL ALCOHOL and we are joining the strands together with BORAX. This gel, when colored, is sold in toyshops as SLIME.

　　以上就是为大家整理的“新托福阅读背景知识：polymer gels”，更多精彩内容请关注新东方在线托福频道!


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