1、The low molecular weight compounds from which the polymers form are known as monomers. The picture is simply as follows:形成高聚物的低分子化合物称为单体。下面简单地描述一下形成过程:butadiene + butadiene + + butadiene-polybutadiene(4 000 time)丁二烯 丁二烯丁二烯聚丁二烯(4000次)One can thus see how a substance (monomer) with as small a molecule
2、 weight as 54 grow to become a giant molecule (polymer) of (544 000)200 000 molecular weight.能够知道分子量仅为54的小分子物质(单体)如何逐渐形成分子量为200000的大分子(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
3、 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。As against this well-defined behavior of a simple chemical compound, a polymer like polyethylene doe
4、s 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。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
5、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)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。 Le
6、t us take, for example, sodium chloride and add it slowly to fixed quantity of water. The salt, which represents a low molecular weight compound, dissolves in water up to a point (called saturation point) but, thereafter, any further quantity added does not go into solution but settles at the bottom
7、 and just remains there as solid.例如,将氯化钠慢慢地添加到定量的水中。盐作为一种低分子量化合物,在水中溶解直到某一点(叫饱和点),但进一步添加, 盐不进入溶液中却沉到底部而保持原有的固体状态The viscosity of the saturated salt solution is not very much different from that of water. But if we take a polymer instead, say, polyvinyl alcohol, and add it to a fixed quantity of wate
8、r, the polymer does not go into solution immediately.饱和盐溶液的粘度与水的粘度接近.但是,如果我们用聚合物,如聚乙烯醇添加到定量水中,聚合物不是马上进入到溶液中。 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。Also, we can add a very
9、 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。As more and more quantity of polymer is added to water, the time taken for the dissolution of the polymer obviously increases and the mix ultimately assumes a
10、soft, dough-like consistency.将越来越多的聚合物加入水中,认为聚合物溶解的时间明显地增加,最终呈现柔软像面团一样粘稠的混合物。Another peculiarity is that, in water, polyvinyl alcohol never retains its original powdery nature as the excess sodium chloride does in a saturated salt solution. 另一个特点是,在水中聚乙烯醇不会像过量的氯化钠在饱和盐溶液中那样能保持其初始的粉末状态。In conclusion,
11、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
12、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。The behavior of a low molecular weight compound and that of a polymer on dissolution are illustrated in Fig.1.2.总如图1.2说明了低分子量化合物和聚合物的溶解行为。Polymer: 高分子,聚合物.(repeat units)polymericpolymerization“poly-”: 多的
13、,聚合的. Polygon, 聚醚?聚酯?聚酰胺?聚乙烯?多官能团?polyfunctional “-mer”: part. Isomer, 同分异构体Macromolecule: 大分子,高分子Macro-: 大 (反义词?)Molecule, 分子 - Atom, 原子Molecular Weight, 分子量Micro-: 显微的。显微镜?Microscope. MicrosoftMonomer: 单体“mono-”: 单个 . Monocrystalline,monodisperse,monofunction“di-, bi-”: 双. “tri-”: 三个. “tetra-”:四个R
14、epeat Unit, 重复单元 - Monomer unit,单体单元Synthetic, 合成的, 如Synthetic RubberSynthesis, n, 合成 -Syntheses, vt, 合成Butadiene: 丁二烯。 Butyl-:丁基。-ene:烯。-yne:炔。乙烯?Ethylene . 1-丁烯?Butylene. 乙炔?Ethyne.Polyethylene: 聚乙烯. Ethyl-:乙基。 Ethylene: 乙烯。Ethane:乙烷 synthetic: 合成的。名词?动词?Viscous:粘的。Plastics, 塑料 - Rubber, 橡胶 - Fibe
15、r, 纤维Adhesive, 黏合剂 - Paints, 涂料Polybutadiene, 聚丁二烯Polyvinyl alcohol, 聚乙烯醇Polyvinyl chloride, 聚氯乙烯Polyester, 聚酯Polystyrene, 聚苯乙烯Polypropylene, 聚丙烯Polyethylene, 聚乙烯Polyamide, 聚酰胺Polyether:聚醚Thermoplastics, 热塑性塑料Thermosetting resin, 热固性树脂Elastomers, 弹性体Thermoelastomers, 热塑性弹性体Homopolymers and copolymer
16、s, 均聚物和共聚物Homo- :均匀的。Homogenous:均相的 Hetero-:异的,不同的 heterogenous: 异相的Block copolymers,嵌段共聚物Random copolymers,无规共聚物Alternating copolymers,交替共聚物Terpolymers,三元共聚物Graft copolymers,接枝共聚物Polyvinyl alcohol: 聚乙烯醇。 Vinyl:乙烯基Sodium chloride, 氯化钠,potassium sulfate, 硫酸钾;sulfuric acid, 硫酸Settle,使(液体)澄清,沉淀,沉降Preci
17、pitate, 使沉淀,使凝结Precipitant,沉淀剂Stir, 搅拌Saturation, 饱和 - Unsaturation, 不饱和Dissolution, n,溶解 -Dissolve, vt, 溶解solution n 溶液; solution polymerizationsolubility n 溶解度,溶解性solvent n 溶剂, solvent effectViscous, a, 粘稠的 -Viscosity, 粘度(性) Clean, 完全的,彻底的;sharply, 明显地,精明地,敏锐地,突然地,急剧地Increasingly, 越来越.,Striking, 显
18、著的, 引人注目的,with respect to 关于,就而论Thereafter,此后Distort,畸变,扭变,变形。Consistency, 一致性,坚固性。Peculiarity, 独特性,特色,特质,特殊的东西,怪癖。issue from, 由.产生,由得出.Adventitious dventiSs,外来的,偶然的,abstract, 分离,转移profound,意义深远的,深刻的,notably,显著的,著名的,这个句型很有用 just as it is not necessary for to be , it is also not necessary for to be 正
19、不一定是.一样, .也不一定是.The moment, 一.就.Segment, 链段Backbone, 主链,骨架(脊骨,脊柱)/skeleton, 骨骼,骨架(建筑),骷髅Skeleton atom (structure),骨架原子(结构)substituent, substituted group,取代基side(pendant,lateral)group,侧基/end group,端基Side chain, 侧链,支链Side reaction, 副反应Linear polymers, 线型高分子/Nonlinear polymers,非线型高分子Branched polymers,支
20、化高分子Crosslinked polymers,交联高分子Stars and dendrimers,星型高分子及树枝状高分子Ladder polymers,梯型高分子Cyclolinear polymers,线型环聚合物/Cyclomatrix polymer,体型聚合物Telechelic polymers,远鳌聚合物,遥爪聚合物Mono-telechelic polymer,单遥爪聚合物Di-telechelic polymer,双遥爪聚合物Amorphous polymers,无定形高分子/Crystalline polymers,结晶高分子Unit 2 Chain Polymeriz
21、ationMany olefinic and vinyl unsaturated compounds are able to form chain-like macromolecules through elimination of the double bond, a phenomenon first recognized by Staudinger. Diolefins polymerize in the same manner, however, only one of the two double bonds is eliminated.Staudinger首先发现许多烯烃和不饱和烯烃
22、通过打开双键可以形成链式大分子。二烯烃以同样的方式聚合,但仅消除两个双键中的一个。 Such reactions occur through the initial addition of a monomer molecule to an initiator radical or an initiator ion, by which the active state is transferred from the initiator to the added monomer.这类反应是通过单体分子首先加成到引发剂自由基或引发剂离子上而进行的,靠这些反应活性中心由引发剂转移到被加成的单体上。In
23、 the same way by means of a chain reaction, one monomer molecule after the other is added (200020000 monomers per second) until the active state is terminated through a different type of reaction.单体分子通过链式反应以同样的方式一个接一个地加上(每秒200020000个单体)直到活性中心通过不同的反应方式终止。The polymerization is a chain reaction in two
24、ways: because of the reaction kinetic and because as a reaction product one obtains a chain molecule. The length of the chain molecule is proportional to the kinetic chain length.聚合反应成为链式反应的两种原因:反应动力学和作为链式反应产物分子。链分子的长度与动力学链长成正比。One can summarize the process as follow (R. is equal to the initiator ra
25、dical):链式反应可以概括为以下过程(R相当与引发剂自由基):略One thus obtains polyvinylchloride from vinylchloride, or polystyrene from styrene, or polyethylene from ethylene, etc.因而通过上述过程由氯乙烯得到聚氯乙烯,或由苯乙烯获得聚苯乙烯,或乙烯获得聚乙烯,等等。The length of the chain molecules, measured by means of the degree of polymerization, can be varied over
26、 a large range through selection of suitable reaction conditions.分子链长通过聚合度测量,可以通过选择适宜的反应条件大为改变Usually, with commercially prepared and utilized polymers, the degree of polymerization lies in the range of 1000 to 5000, but in many cases it can be below 500 and over 10000.商业制备和使用的聚合物,聚合度通常在10005000范围内,但在许多情况下可低于500或高于10000。This should not be interpreted to mean that all molecules of a certain polymeric material consist of 500, or 1000, or 5000 monomer units. In almost all cases, the polymeric material consists of a mixture of polymer
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