高分子材料与工程专业英语重点句型.docVIP

1：That, quantity, low, saturation, bottom, much, absorbFor one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt.首先，他们是合成物和大分子，而且不同于低分子化合物，譬如说普通的盐。To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands.与低分子化合物不同的是，普通盐的分子量仅仅是58.5，而高聚物的分子量高于105，甚至大于106。As an example, a gaseous compound called butadiene, with a molecular weight of 54, combines nearly 4000 times and gives a polymer known as polybutadiene (a synthetic rubber) with about 200 000molecular weight.例如：气态化合物丁二烯的分子量为54，连接4000次可得到分子量大约为200000的聚丁二烯（合成橡胶）高聚物。It is essentially the “giantness” of the size of the polymer molecule that makes its behavior (different from that of a commonly known chemical compound such as benzene.)实质上正是由于聚合物的巨大分子尺寸才使其性能不同于像苯这样的一般化合物（的性能）Solid benzene, for instance, melts to become liquid benzene at 5.5 and , on further heating, boils into gaseous benzene.例如固态苯在5.5熔融成液态苯，进一步加热，煮沸成气态苯。Instead, it becomes increasingly softer and, ultimately, turns into a very viscous, tacky molten mass. Further heating of this hot, viscous, molten polymer does convert it into various gases but it is no longer polyethylene. (Fig. 1.1) .而聚合物变得越来越软，最终变成十分粘稠的聚合物熔融体。将这种热而粘稠的聚合物熔融体进一步加热，它会转变成不同气体，但它不再是聚乙烯（如图1.1）The globules of polyvinyl alcohol first absorb water, swell and get distorted in shape and after a long time go into solution. 聚乙烯醇颗粒首先吸水溶胀，发生变形，经过很长时间后，（聚乙烯醇分子）进入到溶液中。in conclusion, we can say that (1) the long time taken by polyvinyl alcohol for dissolution, (2) the absence of a saturation point, and (3) the increase in the viscosity are all characteristics of a typical polymer being dissolved in a solvent and these characteristics are attributed mainly to the large molecular size of the polymer.总之，我们可以讲（1）聚乙烯醇的溶解需要很长时间，（2）不存在饱和点，（3）粘度的增加是聚合物溶于溶液中的典型特性，这些特性主要归因于聚合物大分子的尺寸。Another striking difference with respect to the behavior of a polymer and that of a low molecular weight compound concerns the dissolution process.聚合物行为和低分子量化合物另一不同的行为为溶解过程。3：monofunctional 单官能团Many different chemical reactions may be used to synthesize polymeric materials by step-growth polymerization.通过逐步聚合可用许多不同的化学反应来合成聚合材料。All step-growth polymerization fall into two groups depending on the type of monomer(s) employed. The first involves two different polyfunctional monomers in which each monomer possesses only one type of functional group.所有的逐步聚合反应根据所使用单体的类型可分为两类。第一类涉及两种不同的官能团单体，每一种单体仅具有一种官能团。A polyfunctional monomer is one with two or more functional groups per molecule. The second involves a single monomer containing both types of functional groups.一种多官能团单体每个分子有两个或多个官能团。第二类涉及含有两类官能团的单个单体。Polyesterification, whether between diol and dibasic acid or intermolecularly between hydroxy acid molecules, is an example of a step-growth polymerization process.聚酯化反应是逐步聚合反应过程的一个例子。反应可能在二元酸和二元醇之间或羟基酸分子间进行。The esterification reaction occurs anywhere in the monomer matrix where two monomer molecules collide, and once the ester has formed, it, too, can react further by virtue of its still-reactive hydroxyl or carboxyl groups. 酯化反应出现在单体本体中两个单体分子相碰撞的位置，且酯一旦形成，依靠酯上仍有活性的羟基或羧基还可以进一步进行反应。The net effect of this is that monomer molecules are consumed rapidly without any large increase in molecular weight.酯化的结果是单体分子很快地被消耗掉，而分子量却没有多少增加。6：Most important mechanical properties depend on and vary considerably with molecular weight.最重要的力学性能取决于分子量，而且随着分子量变化而发生很大的变化。Thus, strength of polymer does not begin to develop until a minimum molecular weight of about 5000 10 000 is achieved.因此,直到最小分于量增大到大约5 00010 000 以后, 聚合物的强度才开始显示出来.Above that size, there is a rapid increase in the mechanical performance of polymers as their molecular weight increases; the effect levels off at still higher molecular weights. Level off达到平衡，变平缓，趋缓分子量大于这个值的时候，随着分子量的增加，聚合物的机械性能快速增加;达到更高的分子量的时候，这种效应才变平缓。In most instances, there is some molecular weight range in which a given polymer property will be optimum for a particular application. 在大多数情况下，对于某种特定的应用来说，某种聚合物存在着某一个分子量范围。When one speaks of the molecular weight of a polymer, one means something quite different from that which applies to small-sized compounds.当人们谈到聚合物分子量的时候，他所指的是和(适用于)低分子化合物的分子量完全不同的另一回事。Polymers differ from the small-sized compounds in that they are polydisperse or heterogeneous in molecular weight. 聚合物与小分子量化合物的不同在于聚合物的分子量是多分散性的或不均匀的。Both the average molecular weight and the exact distribution of different molecular weights within a polymer are required in order to fully characterize it. 为了充分地表征聚合物，不仅要求平均分子量，而且也要求聚合物内不同分子量的确切的分布情况。7：mean-square end-to-end distance 均方末端距Dissolving a polymer is a slow process that occurs in two stages. 溶解高分子需要一个缓慢的过程，这个过程分两步发生。First, solvent molecules slowly diffuse into the polymer to produce a swollen gel. 溶剂分子缓慢地扩散到高分子中产生溶胀凝胶。This may be all that happens if，for example，the polymer-polymer intermolecular forces are high because of crosslinking，crystallinityor strong hydrogen bonding.例如, 如果因交联，结晶和很强的氢键而形成很大的分子间力，(聚合物的溶解过程)有可能就只停留在这一阶段。But if these forces can be overcome by the introduction of strong polymer-solvent interactions, the second stage of solution can take place. Here the gel gradually disintegrates into a true solution.但是如果这些力被强的高分子-溶剂之间相互作用克服，溶解的第二阶段就会发生。能（在水中）崩解的即，凝胶逐渐变成一个真正的溶液。As specified in the literature，the arrangements of the polymer chain differing by reason of rotations about single bands are termed conformations.正如在文献中所定义的那样，由于围绕着单键的旋转而导致的聚合物链不同的空间排布叫做构象。The importance of the random-coil nature of the dissolved, molten, amorphous, and glassy states of high polymers cannot be overemphasized. 我们无论怎样强调溶解的，熔融的，无定形的，玻璃态的高分子无规线团性质的重要性都不过分。Many important physical as well as thermodynamic properties of high polymers result from this characteristic structural feature. 高分子的许多重要的物理及热力学性质都是这个结构特征引起的。10：An ordinary rubber ball if cooled below -70C becomes so hard and brittle that it will break into pieces like a glass ball falling on a hard surface!一个普通的橡胶球被冷却到零下70度以下，就会变得又硬又脆，掉在硬表面上就会像玻璃球一样破碎成碎片。This is because there is a “temperature boundary” for almost all amorphous polymers (and many crystalline polymers) only above which the substance remains soft, flexible and rubbery and below which it becomes hard, brittle and glassy. 这是因为几乎所有无定型聚合物(及许多结晶聚合物)都有一个“温度边界”，温度高于这个边界，材料保持软的柔韧的及橡胶状的，而高于这个边界，材料则变成硬的，脆的，玻璃状的。Depending on the temperature, the molecules of a low molecular weight substance either move apart as a whole or do not move at all. i. e., there is a definite temperature (melting point Tm) below which the molecules do not move and above which they do move.根据温度, 低分子量的物质要么整个分子移开，要么根本不运动。有一个特定的温度(熔点Tm)在低于这一温度时分子不运动，而在高于这一温度时分子则在运动。In the case of polymers, there is indeed an intermediate state. 尽管分子的一些链段在动，分子整体是不动的。聚合物有一个中间状态。If the temperature ranges between Tg and Tf, the localized mobility is activated, but the overall mobility is not. 如果温度在Tg 和Tf之间，局部的运动被激活，而整体的运动则没有。The local segments, where mobility is already activated, correspond to the liquid state, while the molecule as a whole, where mobility is forbidden, is in the solid state. This state, which is really a combination of liquid and solid, is called the rubbery state. correspond to: 相当于局部链段的运动被激活，对应着液态，而整个分子的运动性受到限制，则仍处于固态。这个状态，实际上是液态和固态的结合，叫做橡胶态。Under the influence of an applied stress, it exhibits properties of a viscous fluid as well as an elastic solid and undergoes what is called viscoelastic deformation.在外加应力的作用下，聚合材料既显示出粘性液体的性质，也显示出弹性固体的性质，而经历的过程叫做粘弹形变。The Tg value along with the Tm value gives an indication of the temperature region at which a polymeric material transforms from a rigid solid to a soft viscous stateTg值和Tm值表明了一个温度范围，在这个范围内聚合材料由刚性固体转化为柔软的粘流态。11：Functional polymers are macromolecules to which chemically functional groups are attached; they have the potential advantages of small molecules with the same functional groups. 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。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.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.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。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).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。”13：Reactors may be categorized in a variety of ways, each appropriate to a particular perspective.反应器有许多分类方法，各自适用于特定的目的Regardless of the rate of the reaction, these are clearly low production rate devices. As scale up is desired, the most straightforward approach is to move to a larger batch reactor such as a large vat or tank.不管反应速率如何，间歇反应器生产率较低。当反应放大时，大多可直接的移至一个较大的间歇反应器进行，例如一个较大的大桶或罐。The cycle time，often a day or more，typically becomes longer as reactor volume increases in order to achieve a substantial production rate with an inherently slow reaction. 对于慢化学反应，为提高生产率必须增加反应器体积，而这往往导致反应器的循环周期变长，常常以天计算。16：The synthetic rubber industry, based on the free-radical emulsion process, was created almost overnight during World War 。合成橡胶工业，以自由基乳液过程为基础，在第二次世界大战期间几乎很快地形成。Styrene-butadiene (GR-S) rubber created at that time gives such good tire treads that natural rubber has never regained this market.那时，丁苯橡胶制造的轮胎性能相当优异，使天然橡胶在市场上黯然失色This mixture is heated with stirring and at 50 gives conversions of 5%6% per hour. Polymerization is terminated at 70%75% conversion by addition of a “short-stop”, such as hydroquinone (approximately 0.1 part), to quench radicals and prevent excessive branching and microgel formation.混合物加热搅拌，50下转化率为每小时5%6%。在转化率达70%75%时，通过加入“终止剂”如对苯二酚（大约0.1的重量百分含量）来淬灭自由基并避免过量支化和微凝胶形成，使聚合反应终止。Unreacted butadiene is removed by flash distillation, and syrene by steam-stripping in a column. After addition of an antioxidant, such as N-phenyl-naphthylamine (PBNA) (1.25 parts), the latex is coagulated by the addition of brine, followed by dilute sulfuric acid or aluminum sulfate. The coagulated crumb is washed, dried, and baled for shipment.未反应的丁二烯通过闪蒸去除，苯乙烯在塔中通过蒸汽去取。乳液在加入抗氧剂如N-甲基-萘胺（1.25的重量百分含量）后，加入盐水凝胶，然后加入稀硫酸或硫酸铝。凝胶碎片洗涤、干燥并包装装运。In the continuous process, styrene, butadiene, soap, initiator, and activator (an auxiliary initiating agent) are pumped continuously from storage tanks through a series of agitated reactors at such a rate that the desired degree of conversion is reached at the last reactor.在连续操作中，苯乙烯、丁二烯、肥皂、引发剂和活化剂（一种助引发剂）用泵从储罐通过一系列的混合反应器，泵送流率根据末釜的转化率控制。The commercial importance of such chain-transfer agents or modifiers cannot be overemphasized. Without molecular weight control the rubbers would be too tough to process.这种链转移剂或调节剂具有极其重要的商业价值。不控制分子量橡胶将过于粘稠以致难以加工。17:In large reactors, a reflux condenser is the most effective way toincrease the available cooling surface without increasing the length ratio of the reaction vessel .大型反应器中，回流冷凝器的最有效方法是提高现有冷却表面没有增加的长度比的反应釜。The reflux condenser operation envelope( a mount of reflux ,startup time for reflux )will depend on the ability of the reactor agitation system to reincorporate the refluxed monomer effectively into the polymerizing mass , and on the foaming tendency of the polymerization recipe . 回流冷凝器操作信封（安装回流，启动时间倒流）将取决于能力，反应器搅拌系统再合并回流单体有效地进聚合质量，并对发泡趋势聚合配方。It has been suspected that this type of heat-up process leads to increased wall fouling . 它一直怀疑，这种类型的加热过程导致增加壁结垢。另一种方法是使用预热过程的水。22The feed to the reactor comprises ethylene, a comonomer (1-butene or a higher alpha-olefin),hydrogen and nitrogen. These gases provide the fluidization and heat transfer media and supply reactants for the growing polymer particles. The catalyst and a cocatalyst are fed continuously to the reactor. The fluidized particles disengage from the reactant gas in the expanded top section of the reactor. The unreacted gases are combined with fresh feed streams and recycled to the base of the reactor.反应器中的进料包括：乙烯，（1丁烯或更高的长链-烯烃）共聚单体，氢气和氮气。这些气体提供了流化、传热介质和供给反应物生长所需的聚合物颗粒。催化剂和助催化剂则被连续供给到反应器中。流化的颗粒在反应器中扩大的顶部部分脱离反应气体。未反应的气体与新鲜进料流相结合，并再循环到反应器的底部（基极）Periodically, the product discharge valve near the base of the reactor opens and the fluidized product flows into a surge tank. The unreacted gas is recovered from the product that proceeds downstream for further processing and distribution.靠近反应器底部的出料阀打开，流化床产品流入缓冲罐，这一过程周期性地进行着。未反应的气体从产品中回收，产品进入下一工段进行进一步处理。The melt index and density of the polymer in the bed depend on catalyst properties, reactant gas compositio