As against this well-defined behavior of a simple chemical compound, a polymer like polyethylene does not melt sharply at one particular temperature into clean liquid. 与这类简单化合物明确的行为相比，像聚乙烯这样的聚合物不能在某一特定的温度快速地熔融成纯净的液体。
Also, we can add a very large quantity of the polymer to the same quantity of water without the saturation point ever being reached. 同样地，我们可以将大量的聚合物加入到同样量的水中，不存在饱和点。
While linear polymers are important, they are not the only type of molecules possible. 线状聚合物是很重要的,他们不是唯一可能类型的分子。
Substituent groups such as methyl or phenyl groups on the repeat units are not considered branches. Branching is generally introduced into a molecule by intentionally adding some monomer with the capability of serving as a branch. Let us consider the formation of a polyester. The presence of difunctional acids and difunctional alcohols allows the polymer chain to grow. These difunctional molecules are incorporated into the chain with ester linkage
s at both ends of each. Trifunctional acids or alcohols, on the other hand, produce a linear molecule by reacting two of their functional groups. If the third reacts and the resulting chain continues to grow, a branch has been introduced into the original chain. Adventitious branching sometimes occurs as a result of an atom being abstracted from the original linear molecule, with chain growth occurring from the resulting active site. Molecules with this kind of accidental branching are generally still called linear, although the presence of significant branching has profound effects on some properties of the polymer, most notably the tendency to undergo crystallization.
The polymerization is a chain reaction in two ways: because of the reaction kinetic and because as a reaction product one obtains a chain molecule. 聚合反应是链式反应的原因有两种：因为反应动力学和因为作为反应产物它是一种链式分子。
Thus, molecular weight increases slowly even at high levels of monomer conversion, and it will continue to increase until the viscosity build-up makes it mechanically too difficult to remove water of esterification or for reactive end groups to find each other. 因此，聚合反应
将以逐步的方式继续进行，其每一步酯化反应的反应速率和反应机理均与初始单体的酯化作用相同。因此，分子量缓慢增加直至高水平的单体转化率，而且分子量将继续增加直到粘度的增加使其难以除去酯化反应的水或难以到相互反应的端基。
If some monofunctional impurity is present, its reaction will limit the molecular weight by rendering a chain end inactive. Similarly, high-purity monomers are necessary in the A-B type of polycondensation and it follows that high-yield reactions are the only practical ones for polymer formation, since side reactions will upset the stoichiometric balance. 假如存在一些但官能团杂质，由于链的端基失活，反应将使分子量减少。同样，在A-B类的缩聚反应中高纯度的单体是必要的，而且可以归结高收率的反应仅是形成聚合物的实际反应，因为副反应会破坏当量平衡。
Chain termination takes place only through impurities, or through the addition of certain compounds such as water, alcohols, acids, amines, or oxygen, and in general through compounds which can react with polymerization ions under the formation of neutral compounds or inactive ionic species. 链终止反应仅仅通过杂质而发生，或者说通过和某些
像水、醇、酸、胺或氧这样的化合物进行加成而发生，且一般来说（链终止反应）可通过这样的化合物来进行，这种化合物在中性聚合物或没有聚合活性的离子型聚合物生成的过程中可以和活性聚合物离子进行反应。
Above that size, there is a rapid increase in the mechanical performance of polymers as their molecular weight increase; the effect levels off at still higher molecular weights. 以上尺寸,有迅速增长的力学性能,增加聚合物作为他们的分子量影响;从更高层次分子量。
The reason for the polydispersity of polymers lies in the statistical variations present in the polymerization processes. 原因在于分子量分布聚合物的统计变化出现在聚合过程。
Different average molecular weights are obtained because the properties being measured are biased differently toward the different sized polymer molecules in a polymer sample. 平均分子量不同性能得到被测因为有偏见对不同大小不同的聚合物分子在聚合物样品。
The purification effect of the extraction is in most cases rather slight because in many instances the impurity is held to the polymer by strong secondary valence forces. 萃取净化效果在很多情况下都不大,因为在许多情况下,杂质被聚合物由强大的二次价的力量。
Methanol is a sort of general precipitating agent in which most polymers, both the benzene-soluble ones and the water-soluble polymers, are insoluble. 甲醇是一种一般沉淀剂在聚合物两大部分,benzene-soluble孩子、水溶性高分子化合物,是无法解决的。
Initiators and other additives, such as emulsifying agents and protective colloids,are also selected wherever possible in such a way that they can remain in the polymer without causing problems. 发起人和其它添加剂,如乳化剂和保护胶体特性,也尽可能选择这样一种方式,他们保持在聚合物而不引起的问题。
react to翻译
In solution, a polymer molecule is a randomly coiling mass most of whose conformations occupy many times the volume of its segments alone. 在溶液中,聚合物分子质量的随机盘绕占据最多次采样体积的部分独自一人。
The folded-chain lamella theory arose in the late 1950's when polymer single crystals in the form of thin platelets termed lamella were grown from polymer solutions. folded-chain薄板理论的兴起于1950年代后期当聚合物单晶硅薄血小板的形式被称为薄板种植从聚合物溶液。
Amorphous polymers are usually considered to be a random tangle of molecules. It is, however, apparent that completely random packing cannot occur. This follows even from simple arguments based on the comparatively high density but there is no distinct structure as, for example, revealed by X-ray diffraction techniques. 非晶态聚合物通常被认为是一个随机纠缠不清的分子。不过,很明显的,不能完全随机的包装发生。这跟甚至从简单的论点基于密度较高,但没有明显的层次性,如经x -射线衍射技术显示。
Many polymers, including polyethylene terephthalate, also crystallize if they are cooled slowly from the melt. In this case we may say that they are crystalline but oriented. 许多聚合物动态,包括聚乙烯,如果他们被冷却结晶慢慢地从融化。在这个例子中,我们可以说他们是水晶但导向。

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