Video 1:What is a polymer ?
电饭锅品牌Today I will introduce what a polymer is.
Polymers are everywhere. They are all around us in everyday u.
You can easily find them in your surroundings, no matter they are natural or synthetic.
For example, the rubber ud in tire of car, the plastic ud in bottles, eyeglass and cell phone cas.
今天给大家介绍-聚合物这一概念。
聚合物无处不在，我们周围聚合物随处可见。聚合物可以是天然的，也可以是合成的。例如：汽车轮胎上用的橡胶，制备饮料瓶、眼镜和手机壳用的塑料等，都是聚合物。You may know the widely ud plastics are polyethylene, Polypropylene, and Polystyrene. Every day, you wear a shirt, jacket or coat.
Your clothes are made from fibers, maybe a type of natural fiber, such as silk or cotton fiber, maybe a kind of synthetic fiber, usually a Visco fiber or Rayon, or polyester fiber.
You can check the tags attached in your clothes and find the main ingredients of the fiber for your clothes.
We can say that our life is bad on polymers.
关于聚合物，你肯定知道广泛应用的塑料：聚乙烯, 聚丙烯和聚苯乙烯。
生活中，您穿的衣服布料是各种纤维织成的，这些纤维可以是天然纤维，如丝、棉纤维等，衣用纤维也可以是黏胶、聚酯等合成纤维，您可在衣服标签上看到衣料组成。可以说，我们的生活离不开聚合物。
In fact, you are so familiar with polymers. But, do you really know what a polymer is?
波波头短发发型图片The word polymer is derived from classical Greek words: poly and meres. Poly means “many” and meres means “parts or gments.”
西藏湖泊That’s to say, a polymer contains many, many parts or gments.
聚合物polymer这个词源于古希腊语poly和meres，poly意思是很多，meres的意思是部分，这就说明聚合物包含很多部分。
Academically, a polymer is made up of many small molecular units.
We call the small molecular units monomer. T he word monomer is also come from classical Greek words: mono and meres. It means one part.
德育案例范文聚合物是有许多小分子单元结构或单体组成的。单体一词也来源于古希腊语mono and meres.意指“一个部分”。
If many monomers are linked together, a long, chainlike molecule, a polymer is formed. Compared with the common small molecules, the size of the long chain is extremely large, is very large. Thousands of small molecular units may be included in the chain. So, a polymer is also called a macro-molecule. Thus, we can say, a polymer is a large, macro-molecule, a long chain built up by the repetitions of small chemical units, by linking m any, many small molecules together.
许多单体单元连接在一起，形成长的、链式聚合物分子。中午英语怎么读>最近的英文
与小分子相比，聚合物长链的尺寸非常大，分子链中包含成千上万或更多的小分子单元。因此，聚合物也是一种大分子。
简言之，聚合物是由许多小的化学结构单元链接而成的长链大分子。
For example, joining monomer of ethylene together, we can get polyethylene, a polymer widely ud for plastic bag or film. Similarly, monomer of vinyl chloride, or styrene, are converted to polyvinyl chloride, PVC, or polystyrene, PSt.
We all know that PVC is a common polymer ud for pipe in water supply and wage systems, and PSt is usually applied for making foamed plate in building industry.
例如：由乙烯单体链接而成聚乙烯，聚乙烯已广泛用于制备各种塑料袋和薄膜。
同样，用单体氯乙烯、苯乙烯制备聚氯乙烯、聚苯乙烯。聚氯乙烯常用于生产上下水管，PSt常用来制作建筑行业用的发泡彩钢板。
From the structures of ethylene, vinyl chloride and styrene, we can e that all of them contain a double bond. Other monomers, such as acetylene乙炔，may conta in one or more triple bond.
The monomers that have double or triple covalent bonds are called unsaturated monomers. Opening the double or triple bonds under conditions, thousands of monomers become linked together, forming a long chain.
乙烯、氯乙烯、苯乙烯这些单体中都含有双键。其他的单体，如乙炔，含有三键。通常，含双键、三
键的单体称为不饱和单体。在一定条件下双键、三键打开，使单体单元连接在一起形成长链聚合物。
校园不文明现象For a saturated molecule, all bonds are single ones. If saturated molecules contain more than two functional groups, they can also be ud to produce a polymer. For example, using hexa-methylene-diamine and adipic acid, and by the reaction of amine and carboxyl group, the two monomers are joined together, producing a polymer named nylon. Or，using terephthalic acid and ethylene glycol, and by the reaction of carboxyl and hydroxyl groups, PET is synthesized.By the reaction of hydroxyl and acyl chloride groups, polycarbonate, PC is prepared.
对于只含单键的饱和单体，如果它们含有两个以上的功能基团，也可以通过功能基团间的反应来制备聚合物。例如：使用六亚甲基二氨和己二酸，通过氨基和羧基之间的反应，可制得尼龙；使用对苯二甲酸和乙二醇，通过羧基和羟基之间的反应，合成聚酯；通过羟基和酰氯反应，得到聚碳酸酯。
From the resulting structure of a polymer, such as polyethylene, we can e that the long chain is compod of structural units. The structural units are c alled repeating units. The units are successively repeated along the chain.
The repeating unit looks like the original monomer, both posss same atoms, and the atoms occupy similar relative positions. But, in fact, the structure of repeating unit is not the same as that of
the monomer.
In the ca of PE, PVC and PSt, the polymer is derived from a single monomer (ethylene, vinyl chloride, styrene), and conquently, the structural unit of polymer chain is the same as its repeating unit.
从聚乙烯等聚合物的结构来看，我们知道聚合物长链由结构单元组成。该结构单元也称为重复单元。
在聚乙烯、聚氯乙烯和聚苯乙烯等聚合物中，结构单元结构和重复单元结构一样，重复单元结构类似单体乙烯、氯乙烯、苯乙烯等，除了少许不同。
While, in the ca of nylon, the repeating unit consists of two structural units: one from the diamine, and another from adipic acid. Other polymers, including PET, polyurethane-PU, also have repeating units with more than one structural unit.
尼龙分子中，重复单元包含2结构单元，一结构单元来自二氨单体，另一结构单元来自单体己二酸。其他聚合物，如聚酯、聚氨酯等分子链中，也包含不止一个结构单元。
Simply to say, polymer is a chain-like, macromolecule consisting of many small molecular units, repeating units. In some cas, the structure of repeating unit is same as that of structural unit. In ot
her cas, the repeating unit consists of two structural units 小结：
自觉吃药打一成语聚合物是一链式大分子，包含许多的小分子重复单元；
有时，重复单元即是结构单元；有时，重复单元包含两个结构单元。
