聚合物化学英语翻译

1、第三章 Polymer StructureThis chapter is concerned with aspects of the structure of polymeric materials outside those of simple chemical composition. The main topics covered are polymer stereochemistry, crystallinity, and the character of amorphous polymers including the glass transition. These may be t

2、hought of as arising from the primary structure of the constituent molecules in ways that will become clearer as the chapter progresses.本章所关注的这些简单的化学成分之外的高分子材料的结构方面。主要内容包括：聚合物立体化学，结晶，包括无定形聚合物的玻璃化转变的特征。这些可能被认为是章进展变得更为清晰的方式，将组成分子的一级结构所产生的。Before proceeding, a word on nomenclature is necessary. Polymer

3、 chemists, following the example of P.J. Flory, have tended to use the words configuration and conformation in a sense that differs from that conventionally employed within organic chemistry. In this book, by contrast, I intend to go along with F. W. Billmeyer, and use these words in the way that th

4、ey apply more widely throughout chemistry. Thus configuration is the term given to an arrangement of atoms that cannot be altered except by breaking chemical bonds, while conformation is the term applied to the individual, recognisable arrangement of atoms that can be altered by simple rotation arou

5、nd a single bond. Configurations include head-to-tail arrangements, described in the previous chapter, conformations include trans versus gauche arrangements of successive carbon-carbon bonds along the backbone of an individual macromolecule.在继续之前，一个命名的话是必要的。高分子化学家，例如pj的弗洛里，往往使用的话在一定意义上，从传统的有机化学内聘用不

6、同配置和构象。相比之下，在这本书中，我打算走与固件Billmeyer ，并使用这些话的方式，它们适用于更广泛的整个化学。因此，配置给安排的，不能改变，除非打破化学键，而构象是适用于个人，在一个单一的债券，可以通过简单的旋转改变原子的识别安排的长期原子一词。配置包括头部到尾部的安排，在前面的章节中描述，构包括连续的碳 - 碳沿个人大分子的骨干债券跨与笨拙的安排。Polymer stereochemistryMonosubstituted vinyl monomers form polymers containing a series of asymmetric carbon atoms alon

7、g the molecule. The precise arrangement of these asymmetric carbons gives rise to three different possible stereochemical arrangements. 单取代乙烯基单体形成聚合物含有一个不对称碳原子，分子沿。这些不对称的碳原子的精确安排产生三种可能的立体安排。Firstly，where all asymmetric carbon atoms adopt identical configurations, the resulting polymer is described a

8、s isotactic. Secondly, where there is a regular alternating arrangement of asymmetric carbon atoms, the polymer is described as syndioiactic. Lastly, where there is no regularity at all in the arrangement of asymmetric carbon atoms, the resulting structure is known as atactic. These three steric arr

9、angements are illustrated in Figure 3.1.首先，不对称碳原子采用相同的配置，由此产生的聚合物被描述为等规。其次，那里是经常交替不对称碳原子的排列，聚合物作为syndioiactic描述。最后，那里没有在不对称碳原子的排列规律，由此产生的结构被称为无规。这三个立体安排在图3.1所示。The synthesis of isotactic and syndiotactic polymers has been achieved for a number of polymers. For example poiy(methy1 methacrylate) can b

10、e prepared in either isotactic or syndiotactic configurations depending on the details of the polymerisation conditions.Polymer stereochemistry, sometimes referred to as lacticity, is not the only source of variation in polymer configuration. For the monosubstiiuted butadiene isoprene, the structure

11、s shown in Figure 3.2 are possible.已经取得了聚合物的等规和间规聚合物的合成。例如poiy （甲基丙烯酸甲酯） ，可以准备在任何配置等规或间规聚合条件的细节而定。聚合物的立体，有时也被称为lacticity来，是不是变异在聚合物配置的唯一来源。为monosubstiiuted丁二烯异戊二烯，在图3.2所示的结构是可能的。Polymers containing each of these configurations are known, the most common being the qy?.4- and the trans- ,4-isomers. Th

12、e first o( these, poly(cis-l,4-isoprene), is the macromolecular constituent of natural rubber; the second is the material known as gutta percha. The latter, unlike natural rubber, has no elasto mcric properties, but has a leathery texture. It has been used for diverse applications such as golf-ball

13、covers and as an insulating material for the trans-Atlanlic cables of the late nineteenth century.聚合物含有这些配置是众所周知的，最常见的是在QY .4 - ？和跨 ,4-异构体。第一O（其中，聚（CIS -L ,4-异戊二烯） ，是天然橡胶的大分子成分;二是后者称为杜仲胶材料，不像天然橡胶，具有无弹mcric属性，但有。 ，革的质感。它已被用于各种应用，如高尔夫球球作为十九世纪末的的跨Atlanlic电缆绝缘材料的封面和。 POLYMER CRYSTALLINITYThe essential r

14、equirement for crystallinity in polymers is some sort of stereoregularity.This is not to say that the entire collection of macromolecuJes within the sample needs to be all isotactic or syndiotactic; however, it is essential that regions along the backbone of a significant number of the macromolecule

15、s do have such regularity.聚合物的结晶的基本要求是一些stereoregularity.This ，并不是说整个集合的样本内的macromolecuJes需要所有的全同或间同，但是，它是必不可少的，地区沿线的一个显着数量的骨干大分子也有这样的规律。Many polymers show partial crystallinity. This is apparent from the study of X-ray diffraction patterns, which for polymers generally show both the sharp features

16、associated with crystalline regions a$ well as less well-defined features which are characteristic of disordered substances with liquid-like arrangements of molecules. The coexistence of crystalline and amorphous regions is typical of the behaviour of 'crystalline' polymers.许多聚合物的结晶部分。从X-射线衍

17、射图案，一般为聚合物同时显示美元以及较差的定义特征是无序的物质分子的液体状的安排的特点与结晶区的尖锐特征的研究，这是明显的。结晶和非晶区共存，是典型的“结晶”聚合物的行为。The reason for the existence of both phases in polymers is quite straightforward. Crystalline regions are formed from the stereo-regular components of the macromolecules, which, given the nature of the polymerisati

18、on processes from which the macromolecules are built up, represent only a proportion of the overall material. There is often the possibility that an essentially isotactic polymer will contain a syndiotactic segment and vice versa. Chain branching may also occur, thereby reducing local regularity in

19、structure and inhibiting crystallisation. Occasionally copolymerisation is the reason for the co-existence of the amorphous regions with the crystalline phases. For example, the inclusion of a small amount of isoprene in what is mainly poly (isobutylene), so-called butyl rubber, limits the extent of

20、 possible crystallisation bui duejj not prevent its occurrence completely.在聚合物中的两个阶段的存在的原因很简单。结晶区形成大分子的立体正规的组件，其中，建立了从大分子聚合过程的性质，只占整体材料的比例。往往是有本质等规聚合物的可能性将包含间同段，反之亦然。支链也可能会发生，从而减少地方在结构和抑制结晶规律。偶尔共聚与晶相的非晶区共存的原因。例如，什么是主要聚（异丁烯） ，所谓的丁基橡胶，少量的异戊二烯列入限制可能结晶BUI duejj的程度并不完全防止其发生。Non-crystalline polymers are t

21、hose which include high levels of irregularity within their structure. Typical sources of such irregularity are copolymerisation with significant amounts of at least two co-monomers and also complete absence of stereoregularity, i.e. atactic polymers.Among the polymers which contain clear crystallin

22、e phases are poly (ethylene) and PTFE. Their properties, however, are very different from those usually associated with crystalline solids; in particular, they tend to exhibit low rigidity and at ambient temperatures are soft and deformable rather than brittle. This is because, unlike say sodium chl

23、oride or copper sulphate, crystalline polymers include both amorphous and crystalline regions.非结晶聚合物，其中包括在它们的结构不规则的高层次。这种不规则的典型来源至少有两个共同的单体，也完全没有立构规整性，即无规聚合物的重要共聚。其中含有明显的晶相聚合物聚（乙烯）和聚四氟乙烯。然而，它们的属性，通常结晶固体的非常不同，尤其是他们往往表现出刚性低，在常温下是柔软和变形，而不是脆。这是因为，不像说氯化钠或硫酸铜，结晶聚合物包括无定形和结晶区。X-Ray studies of crystalline po

24、lymers have shown that the crystallites are very small，of the order of tens of nanometres. This is much less than the end-to-end distance of a high molar mass polymer, a fact which was originally interpreted as implying that an individual polymer molecule actually passed through several crystallites

25、 as well as through a number of amorphous regions. The process of crystallisation was viewed as occurring by the coming together of bundles of regular segments from different molecules to form a close packed crystalline array at localised points within the material see Figure 3.3 (a). This theory, w

26、hich is to be found described in older books and papers in polymer science, is known as the fringed micelle theory.X射线结晶聚合物的研究已经表明，晶粒非常小，几十纳米的顺序。这是高摩尔质量的聚合物，最初被解释为暗示，一个单独的聚合物分子实际上通过非晶区的数量，以及通过几个晶粒月底到年底的距离比少得多。结晶过程，被视为发生撞在了一起，从不同的分子定期分部的束在材料内部的局部点形成密切包装的晶体阵列见图3.3 （一） 。这个理论，这是老年人在高分子科学的书籍和论文中描述的被发现，被称

27、为作为流苏胶束理论。The fringed micelle theory has been less favoured recently following research on the subject of polymer single crystals. This work has led to the suggestion that polymer crystallisation lakes place by single molecules folding themselves at intervals of about 10 nm to form lamellae as shown

28、 in Figure 3.3(b). These lamellae appear to be the fundamental structures of crystalline polymers.流苏胶束理论已经不太赞成最近下列聚合物单晶的主题研究。这项工作的领导建议，每隔约10 nm ，折叠，形成片状，如在图3.3 （B）所示的单分子，聚合物结晶湖泊的地方。出现这些片状结晶聚合物的基本结构。It has proved difficult to decide which of these two theories of polymer crystallisation is correct, s

29、ince both are consistent with the observed effects of crystallinity in polymers. These effects include increased density, increased stiffness,and higher softening point. However, the balance of opinion among those working with crystalline polymers favours the latter theory, based on lamellae formed

30、by the folding of single molecules.它已被证明难以决定聚合物的结晶这两种理论是正确的，因为无论是结晶聚合物中观察到的影响是一致的。这些影响包括增加密度，增加刚度，较高的软化点。然而，舆论工作的结晶聚合物之间的平衡，有利于后者的理论，基于单分子折叠形成片状。 Orientadon and CrystallisationWhen a rubbery polymer, such as natural rubber, is stretched the molecules become aligned. This orientation leads to crystal

31、lisation. The effect of this so-called strain-induced crystallisation is to make the extended polymer stiffer than the unstrained polymer. Such crystallisation is not permanent but disappears when the sample is allowed to retract and regain its original dimensions.当橡胶的聚合物，如天然橡胶，拉伸分子成为对齐。这种倾向导致结晶。这个所

32、谓的应变诱导结晶的作用是使扩展的聚合物比无应变聚合物严厉。这种结晶是不是永久性的，但消失时样品被允许收回，并恢复其原始尺寸。Other, non-rubbery polymers can be made to increase their crystalline proportion permanently by stretching under appropriate conditions. For example, hearing nylon 6,6 to a temperature between its transition temperature and the melting po

33、int of the crystalline regions followed by stretching causes additional crystallisation with the crystallites being aligned with the direction of the extension. The oriented crystalline filaments or fibres that result are much stronger than the unoriented material and may approach 700 MPa in strengt

34、h.其他非橡胶的聚合物，可永久地伸展在适当的条件下，其结晶比例增加。例如，尼龙6,6听到其转变温度和熔点，通过拉伸结晶区之间的温度会导致额外的结晶与晶粒延伸的方向相一致。面向结晶细丝或纤维，结果是比未取向材料和可能接近700兆帕的强度。Similarly, oriented crystallisation can be induced by stretching sheets or films of polymers in two directions simultaneously. The resulting materials have biaxially oriented polymer

35、 crystals. Typical examples of such materials are biaxially stretched poly-(ethylene terephthalate), poly(vinylidene chloride)，and poly-(propylene). Since the oriented crystals do not interfere with light waves, such films combine good strength with high clarity, which makes them attractive in a num

36、ber of applications.同样，面向结晶片或聚合物薄膜在两个方向同时拉伸，可诱发。由此产生的材料具有双向拉伸聚合物晶体。这类材料的典型的例子是双向拉伸聚（对苯二甲酸乙二醇酯） ，聚偏二氯乙烯，聚（丙烯） 。由于面向晶体不干扰光波，这种薄膜结合强度好，清晰度高，这使得他们有吸引力的应用数量。 The Crystalline Melting PointUnlike conventional organic substances, crystalline polymers do not have well-defined melting points. This is because

37、they are effectively mixtures, comprising components of a range of relative molar masses, the individual components of which melt at different temperatures. Thus low relative molar mass homopolymers melt at lower temperatures than high relative molar mass species. The size of the crystallites themse

38、lves also influences the range of the melting temperature, since smaller and less perfect crystallites melt before larger ones as the temperature is raised.不同于传统的有机物质，结晶聚合物没有明确的熔点。这是因为它们是有效的混合物，包括范围相对摩尔群众，其中熔体在不同温度下的各个组成部分的组成部分。因此，相对低摩尔质量均聚物熔体在较低的温度比相对高摩尔质量品种。大小的晶粒本身也影响熔融温度范围内，因为更小，更完美的晶体融化温度较大的前提出。

39、Other factors which influence the value of the range of temperature over which melting takes place are (a) the presence of comonomers in the polymer and (b) the presence of traces of solvent or plasticiser in the polymer. The first of these, involving copolymerisation, lowers the melting point by sh

40、ortening the length of crystallisation sequences within the individual polymer molecules. The latter does so by increasing the relative mobility of the polymer molecules in the material. Thereby reducing the energy necessary to take them into the liquid phase.其他因素的影响而融化发生的温度范围内的值是（一）在聚合物中存在的单体及（b）在聚

41、合物中的溶剂或增塑剂的痕迹存在。这些第一，涉及共聚，降低内个别的聚合物分子的结晶序列的长度缩短的熔点。后者则使材料中的聚合物分子的相对流动性增加。从而减少了所需的能量，他们考虑到液相。 PolyblendsIn the design of new materials there is currently less emphasis on producing new polymers than on producing novel combinations of polymers by blending, socalled polyblends. The polymers involved in

42、 polyblends generally have very different properties so that typically a brittle, glassy polymer would be blended with a rubbery polymer, thereby producing a material of good rigidity and toughness. Such a combination of properties tends to beacking in most polymers. A good example of a polyblend is

43、 high-impact poly (styrene), in which rubber particles are blended with the base polymer, as described in Chapter 1.在新材料的设计，目前还不太强调生产比新的聚合物生产勾兑，所谓的共混的新型聚合物组合。在共混聚合物通常有很大的不同性能，所以通常是脆，玻璃状聚合物将与橡胶聚合物混合，从而产生良好的刚性和韧性的材料。这种属性的组合，往往在大多数聚合物beacking 。一个共混的好例子是高冲击聚（苯乙烯），其中橡胶颗粒与基聚合物混合，如第1章中所述。The morphology of

44、polyblends tends to be the same as that shown by high-impact poly (styrene), i.e. a dispersion of rubbery particles in a matrix of the glassy component. This kind of arrangement is responsible for the improvement in mechanical properties observed. One particular change associated with the polyblends

45、 is that a significant difference develops between the crazing stress and the fracture stress. In glassy polymers with no rubbery fillerr, crazing occurs just before fracture, and the stresses are very close in value. In polyblends, crazing occurs well before the sample actually undergoes fracture.

46、This phenomenon ap-pears to occur because the rubber particles are large enough to bridge the craze in the glassy matrix and become load bearing, as illustrated in Figure 3.4. Such a mechanism explains the fact that there is an optimum size range for the rubber particles which bring about the increa

47、se in fracture strength. For example, for high impact poly(styrene) the best results are obtained with rubber particles in ihe size range 1-10 m .共混形态往往是高冲击聚（苯乙烯）中所示的相同，即在玻组件矩阵的橡胶颗粒分散。这种安排是负责观察力学性能的改善。一个与共混相关的特定的变化是一个显着区别的开裂应力和断裂应力的发展。在玻璃状聚合物没有橡胶fillerr的，龟裂发生骨折之前，讲价值非常接近。在共混，裂纹发生之前的样品实际上经历了骨折。 AP-梨，

48、这种现象发生，因为橡胶颗粒足够大，以弥补在玻璃基质的热潮，成为承载，如图3.4所示。这种机制解释的事实，那就是最佳的尺寸范围为断裂强度的增加带来的橡胶颗粒。例如，对于高影响聚（苯乙烯） ，得到最好的结果，在的IHE尺寸范围1-10微米的橡胶颗粒。THERMAL AND MECHANICAL PROPERTIESThree factors affect the essential nature of a polymeric material and determine whether it is glassy, rubbery, or fibre-forming under a given se

49、t of conditions. These are:(i ) the flexibility of the macromolecule,the magnitude of the forces between the molecules, andthe stereo regularity of the macromolecules.These three factors influence the ability of the polymer to crystallise, the melting point of any resulting crystalline regions, and

50、also the glass transition temperature. It is the last of these features of polymeric materials which we will concentrate on for the rest of this chapter.三个因素影响的高分子材料的基本性质，并确定它是否是给定条件下的玻璃状，橡胶，纤维形成。它们是：（一）灵活的高分子，分子之间的力量的大小，大分子的立体规律。这三个因素的影响能力的聚合物的结晶，结晶产生的任何地区的熔点，玻璃化转变温度。这是最后这些功能高分子材料，我们将集中在本章的其余部分。 Th

51、e Glass Transition Temperature,TgThe glass transition is a phenomenon observed in linear amorphous polymers, such as poly (styrene) or poly (methyl methacrylate). It occurs at a fairly well-defined temperature when the bulk material ceases to be brittle and glassy in character and becomes Jess rigid

52、 and more rubbery.玻璃化转变是线性无定形聚合物，如聚（苯乙烯）或聚（甲基丙烯酸甲酯） ，观察到一个现象。当散装物料不再是性格脆，玻璃状，并成为杰西的刚性和更多的橡胶，它发生在一个相当明确的温度。Many physical properties change profoundly at the glass transition temperature, including coefficient of thermal expansion, heat capacity, refractive index, mechanical damping, and electrical pr

53、operties. All of these are dependent on the relative degree of freedom for molecular motion within a given polymeric material and each can be used to monitor the point at which the glass transition occurs. Unfortunately, in certain cases, the values obtained from these various techniques can vary wi

54、dely. An example is the variation found in the measured values of Tg for poly (methyl methacrylate), which range from 110°C using dilato-metry (i.e. where volume changes are monitored) to 160 °C using a rebound elasticity technique. This, thought is an extreme example; despite the fact tha

55、t the measured value of Tg does vary according to the technique used to evaluate it, the variation tends to be over a fairly small temperature range.深刻地改变在许多物理性质，化学性质，玻璃化转变温度，热膨胀，热容量大，折射率，机械阻尼和电气性能系数。所有这些都是在一个给定的高分子材料的分子运动相对自由程度上依赖于每个人都可以被用来监测发生在哪个点的玻璃化转变。不幸的是，在某些情况下，从这些不同的技术中获得的值可以有很大的不同。一个例子是在聚（甲基

56、丙烯酸甲酯）的Tg测量值的变化，范围从110 ° C ，使用dilato metry （即量的变化进行监测）至160 ° C使用反弹弹性技术。这一点，思想是一个极端的例子;变化，尽管事实上， Tg的测量值会根据用于评估技术，往往是在一个相当小的温度范围内。The glass transition is a second-order transition. In this it differs from genuine phase changes that substances may undergo, such as melting or boiling, which ar

57、e known as first-order transitions. These latter transitions are characterised by a distinct volume change, by changes in optical properties (i.e. in the X-ray diffraction pattern and the infrared spectrum) and by the existence of a latent heat for the phase change in question. By contrast, no such

58、changes occur at the glass transition，though the rate of change of volume with temperature alters at the Tg as illustrated in Figure 3.5.玻璃化转变是一个二阶的过渡。在此，它不同于真正的相位变化，物质可能发生，如熔化或沸腾，这是作为第一阶跃迁。这些后者过渡的特点是一个独特的体积变化，在光学性能的变化（即中的X-射线衍射和红外光谱）和存在的一个问题的相变潜热。相比之下，没有这样的变化发生在玻璃化转变，虽然在TG率随温度的改变量的变化如图3.5所示。The gla

59、ss transition can be understood by considering the nature of the changes that occur at the temperature in question. As a materia! is heated to this point and beyond，molecular rotation around single bonds suddenly becomes significantly easier. A number of factors can affect the ease with which suchmolecular rotation takes place, and hence influence the actual value that the glass transit