发布时间 : 星期日 文章河北科技大学高分子材料专业外语翻译更新完毕开始阅读
的基体中“永久地结晶”。这些结晶力实际上以交联方式作用，产生高拉伸强度和高初始模量的材料，即纤维。因此，可以制成纤维的聚合物将不成其为纤维，除非经受一个抽丝拉伸过程，即一个可以形成分子间高度取向的过程。
Crosslinked species are found in all three categories and the process of crosslinking may change the cited characteristics of the categories. Thus, plastics are known to possess[p?zes] a marked range of deformability in the order of 100 to 200%; they do not exhibit this property when crosslinked, however. Rubber, on vulcanization, changes its properties from low modulus, low tensile strength, low hardness, and high elongation to high modulus, high tensile strength, high hardness, and low elongation. Thus, polymers may be classified as noncrosslinked and crosslinked, and this definition agrees generally with the subclassification in thermoplastic and thermoset polymers. From the mechanistic point of view, however, polymers are properly divided into addition polymers and condensation polymers. Both of these species are found in rubbers, plastics, and fibers.
交联的种类在所有三种类型（塑料，橡胶，纤维）中找到，而交联过程可以改变各类的典型特征。因此，我们熟知塑料具有的形变能力大约在100-200%范围内，然而当交联发生时塑料不能展示这个性能。对橡胶而言，硫化可以改变其性质，从低模量，低拉伸强度，低硬度及高拉伸率到高模量，高拉伸强度，高硬度及低拉伸率。这样，聚合物可以分为非交联和交联的，这个定义与把聚合物细分为热塑性和热固性聚合物相一致。然而，从反应机理的观点看，聚合物可以分成加聚物和缩聚物。这些种类聚合物在塑料，橡胶和纤维中都可以找得到。
In many cases polymers are considered from the mechanistic point
of view. Also, the polymer will be named according to its source whenever it is derived from a specific hypothetical monomer, or when it is derived from two or more components which are built randomly into the polymer. This classification agrees well with the presently used general practice. When the repeating unit is composed of several monomeric components following each other in a regular fashion, the polymer is commonly named according to its structure.
在许多情况下，聚合物可以从反应机理的角度考虑分类。也可以根据聚合物的的来源来命名,无论来源是一个假想单体，或来自于两个或两个以上无规构建聚合物的组分。这种分类方法与目前实际情况相符合。当重复单元由几个单体组分规则排布时，聚合物通常根据它的结构来命名。
It must be borne in mind that, with the advent of Ziegler-Natta mechanisms and new techniques to improve extend crystallinity, and the cIoseness of packing of chains, many older data given should be critically considered in relation to the stereoregular and crystalline structure. The properties of polymers are largely dependent on the type and extent of both stereoregularity and crystallinity. As an example, the densities and melting points of atactic and isotactic species are presented in Table 9.1.
“必须记住，随着Ziegler-Natta机理的，以及提高结晶度和链堆砌紧密度新技术的出现， 许多与立构规整和晶体结构相关的旧数据应当批判地接受。聚合物的性质主要依靠立体规整性和结晶度的类型和程度。表9.1列出无规立构和全同立构物质的密度和熔点。
UNIT 11 Functional Polymers 第十一单元 功能聚合物
Functional polymers are macromolecules to which chemically
functional groups are attached; they have the potential advantages of small molecules with the same functional groups. Their usefulness is related both to the functional groups and to the nature of the polymers whose characteristic properties depend mainly on the extraordinarily large size of the molecules.
功能聚合物是具有化学功能基团的大分子，这些聚合物与具有相同功能基团的小分子一样具有潜在的优点。它们(功能聚合物)之所以具有使用价值不仅与所带的官能团有关，而且与由巨大的分子尺寸所决定的聚合物的特性有关。
The attachment of functional groups to a polymer is frequently the first step towards the preparation of a functional polymer for a specific use. However, the proper choice of the polymer is an important factor for successful application. In addition to the synthetic aliphatic and aromatic polymers, a wide range of natural polymers have also been functionalized and used as reactive materials. Inorganic polymers have also been modified with reactive functional groups and used in processes requiring severe[si’vi?] service conditions. In principle, the active groups may be part of the polymer backbone or linked to a side chain as a pendant group either directly or via[vai?] a spacer[s’peis?] group. A required active functional group can be introduced onto a polymeric support chain (1) by incorporation during the synthesis of the support itself through poJymerization or copolymerization monomers containing the desired functional groups, (2) by chemical modification of a non-functionalized performed support matrix and (3) by a combination of (1) and (2). Each of the two approaches has its own advantages and disadvantages, and one approach may be preferred for the preparation of a particular functional polymer when the other would be totally impractical. The choice between the two ways to the synthesis of functionalized polymers depends mainly
on the required chemical and physical properties of the support for a specific application. Usually the requirements of the individual system must be thoroughly examined in order to take full advantage of each of the preparative techniques.
把功能基团连接到聚合物上常常是制备特殊用途功能高分子的第一步。然而，对成功应用而言，选择适当的聚合物是一个重要因素。除了合成的脂肪族和芳香族聚合物之外，许多天然高分子也被功能化，被用做反应性材料。无机聚合物也已经用反应功能基团改性，被用于要求耐用条件的场合。理论上讲，活基团可以是聚合物主链上的一部分，直接作为侧基或者通过隔离基团连接到侧链。可以用如下三种方法将所需要的活性官能团引入到聚合物主链上：(1)在合成主链聚合物时通过带有所需官能团的单件的均聚或共聚，使聚合物带上官能团；(2)将预先制成的未功能化的主链聚合物进行化学改性；(3)将(1)和(2)两种方法结合起来。” 两种途径中的每一种都有自身的优点和缺点，对特殊功能聚合物的制备而言，所选的方法或许是合适的，而另一种方法无法实现。功能聚合物合成的两种方法中，如何选择主要取决于特殊应用要求的主链聚合物的化学和物理性质。必须考虑不同体系的要求来充分利用不同制备方法。
Rapid progress in the utilization of functionalized polymeric materials has been noted in the recent past. Interest in the field is being enhanced due to the possibility of creating systems that combine the unique properties of conventional active moieties and those of high molecular weight polymers. The successful utilization of these polymers are based on the physical form, solvation behavior, porosity, chemical reactivity and stability of the polymers. The various types of functionalized polymers cover a broad range of chemical applications, including the polymeric reactants, catalysts, carriers, surfactants,