高分子材料工程專業(yè)英語第二版課文翻譯基本全了[共31頁]

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1、高分子專業(yè)英語選講課文翻譯資料 A 高分子化學(xué)和高分子物理 UNIT 1 What are Polymer? 第一單元 什么是高聚物？ What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt. To contrast the difference, the molecular weight of common salt is only 58.5

2、, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands. These big molecules or ‘macro-molecules’ are made up of much smaller molecules, can be of one or more chemical compounds. To illustrate, imagine that a set of rings has the same size and is made

3、of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound. Alternatively, individual rings could be of different sizes and materials, and interlinked to represent a polymer from molecules of different com

4、pounds. 什么是高聚物？首先，他們是合成物和大分子，而且不同于低分子化合物，譬如說普通的鹽。與低分子化合物不同的是，普通鹽的分子量僅僅是58.5，而高聚物的分子量高于105，甚至大于106。這些大分子或“高分子”由許多小分子組成。小分子相互結(jié)合形成大分子，大分子能夠是一種或多種化合物。舉例說明，想象一組大小相同并由相同的材料制成的環(huán)。當(dāng)這些環(huán)相互連接起來，可以把形成的鏈看成是具有同種分子量化合物組成的高聚物。另一方面，獨(dú)特的環(huán)可以大小不同、材料不同，相連接后形成具有不同分子量化合物組成的聚合物。 This interlinking of many units has given th

5、e polymer its name, poly meaning ‘many’ and mer meaning ‘part’ (in Greek). 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. The low molecul

6、ar weight compounds from which the polymers form are known as monomers. The picture is simply as follows: 許多單元相連接給予了聚合物一個(gè)名稱，poly意味著“多、聚、重復(fù)”，mer意味著“鏈節(jié)、基體”（希臘語中）。例如：稱為丁二烯的氣態(tài)化合物，分子量為54，化合將近4000次，得到分子量大約為200000被稱作聚丁二烯（合成橡膠）的高聚物。形成高聚物的低分子化合物稱為單體。下面簡單地描述一下形成過程： butadiene + butadiene + ??? + butadiene-

7、-→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 weight as 54 grow to become a giant molecule (polymer) of (544 000≈)200 000 molecular weight. It is essentially the ‘giantness’ of the size of the polymer molecule tha

8、t makes its behavior different from that of a commonly known chemical compound such as benzene. Solid benzene, for instance, melts to become liquid benzene at 5.5℃ and , on further heating, boils into gaseous benzene. As against this well-defined behavior of a simple chemical compound, a polymer lik

9、e polyethylene does not melt sharply at one particular temperature into clean liquid. 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 pol

10、yethylene. (Fig. 1.1) . 因而能夠看到分子量僅為54的小分子物質(zhì)（單體）如何逐漸形成分子量為200000的大分子（高聚物）。實(shí)質(zhì)上，正是由于聚合物的巨大的分子尺寸才使其性能不同于象苯這樣的一般化合物。例如，固態(tài)苯，在5.5℃熔融成液態(tài)苯，進(jìn)一步加熱，煮沸成氣態(tài)苯。與這類簡單化合物明確的行為相比，像聚乙烯這樣的聚合物不能在某一特定的溫度快速地熔融成純凈的液體。而聚合物變得越來越軟，最終，變成十分粘稠的聚合物熔融體。將這種熱而粘稠的聚合物熔融體進(jìn)一步加熱，不會轉(zhuǎn)變成各種氣體，但它不再是聚乙烯（如圖1.1）。 固態(tài)苯——→液態(tài)苯——→氣態(tài)苯 加熱，5.5℃ 加熱

11、，80℃ 固體聚乙烯——→熔化的聚乙烯——→各種分解產(chǎn)物-但不是聚乙烯 加熱 加熱 圖1.1 低分子量化合物（苯）和聚合物（聚乙烯）受熱后的不同行為 Another striking difference with respect to the behavior of a polymer and that of a low molecular weight compound concerns the dissolution process. Let us take, for example, sodium chloride and add it

12、slowly to s fixed quantity of water. The salt, which represents a low molecular weight compound, dissolves in water up to s point (called saturation point) but, thereafter, any further quantity added does not go into solution but settles at the bottom and just remains there as solid. The viscosity o

13、f 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 water, the polymer does not go into solution immediately. The globules of polyvinyl alcohol first absorb water, swell and get disto

14、rted in shape and after a long time go into solution. Also, we can add a very large quantity of the polymer to the same quantity of water without the saturation point ever being reached. As more and more quantity of polymer is added to water, the time taken for the dissolution of the polymer obvious

15、ly increases and the mix ultimately assumes a soft, dough-like consistency. 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. In conclusion, we can say that (1) the long time taken by po

16、lyvinyl 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. The behavior of a low m

17、olecular weight compound and that of a polymer on dissolution are illustrated in Fig.1.2. 發(fā)現(xiàn)另一種不同的聚合物行為和低分子量化合物行為是關(guān)于溶解過程。例如，讓我們研究一下，將氯化鈉慢慢地添加到固定量的水中。鹽，代表一種低分子量化合物，在水中達(dá)到點(diǎn)（叫飽和點(diǎn)）溶解，但，此后，進(jìn)一步添加鹽不進(jìn)入溶液中卻沉到底部而保持原有的固體狀態(tài)。飽和鹽溶液的粘度與水的粘度不是十分不同，但是，如果我們用聚合物替代，譬如說，將聚乙烯醇添加到固定量的水中，聚合物不是馬上進(jìn)入到溶液中。聚乙烯醇顆粒首先吸水溶脹，發(fā)生形變，經(jīng)過很

18、長的時(shí)間以后進(jìn)入到溶液中。同樣地，我們可以將大量的聚合物加入到同樣量的水中，不存在飽和點(diǎn)。將越來越多的聚合物加入水中，認(rèn)為聚合物溶解的時(shí)間明顯地增加，最終呈現(xiàn)柔軟像面團(tuán)一樣粘稠的混合物。另一個(gè)特點(diǎn)是，在水中聚乙烯醇不會像過量的氯化鈉在飽和鹽溶液中那樣能保持其初始的粉末狀態(tài)?？傊覀兛梢灾v（1）聚乙烯醇的溶解需要很長時(shí)間，（2）不存在飽和點(diǎn)，（3）粘度的增加是典型聚合物溶于溶液中的特性，這些特性主要?dú)w因于聚合物大分子的尺寸。如圖1.2說明了低分子量化合物和聚合物的溶解行為。 氯化鈉晶體加入到水中——→晶體進(jìn)入到溶液中.溶液的粘度不是十分不同于 充分?jǐn)嚢? 水的粘度——→形成飽和溶液.剩余的

19、晶體維持不溶解狀態(tài). 加入更多的晶體并攪拌 氯化鈉的溶解 聚乙烯醇碎片加入到水中——→碎片開始溶脹——→碎片慢慢地進(jìn)入到溶液中 允許維持現(xiàn)狀 充分?jǐn)嚢? ——→形成粘稠的聚合物溶液.溶液粘度十分高于水的粘度 繼續(xù)攪拌 聚合物的溶解 圖1.2 低分子量化合物（氯化鈉）和聚合物（聚乙烯醇）不同的溶解行為 ——Gowariker VR, Viswanathan N V, Sreedhar J. Polymer Science. New York: John Wiley & Sons, 1986.6 UNIT 2 Chain Polymerizati

20、on 第二單元 鏈?zhǔn)骄酆戏磻?yīng) Many olefinic and vinyl unsaturated compounds are able to form chain-0like 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. Such react

21、ions 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. In the same way by means of a chain reaction, one monomer molecule after the other is added (2000~20000 monomer

22、s per second) until the active state is terminated through a different type of reaction. 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. The length of the chain molecule is proportional to the kinetic

23、 chain length. Staudinger第一個(gè)發(fā)現(xiàn)一例現(xiàn)象，許多烯烴和不飽和烯烴通過打開雙鍵可以形成鏈?zhǔn)酱蠓肿?。二烯烴以同樣的方式聚合，然而，僅限于兩個(gè)雙鍵中的一個(gè)。這類反應(yīng)是通過單體分子首先加成到引發(fā)劑自由基或引發(fā)劑離子上而進(jìn)行的，靠這些反應(yīng)活性中心由引發(fā)劑轉(zhuǎn)移到被加成的單體上。以同樣的方式，借助于鏈?zhǔn)椒磻?yīng)，單體分子一個(gè)接一個(gè)地被加成（每秒2000～20000個(gè)單體）直到活性中心通過不同的反應(yīng)類型而終止。聚合反應(yīng)是鏈?zhǔn)椒磻?yīng)的原因有兩種：因?yàn)榉磻?yīng)動力學(xué)和因?yàn)樽鳛榉磻?yīng)產(chǎn)物它是一種鏈?zhǔn)椒肿?。鏈分子的長度與動力學(xué)鏈長成正比。 One can summarize the proces

24、s as follow (R. is equal to the initiator radical): 鏈?zhǔn)椒磻?yīng)可以概括為以下過程（R相當(dāng)與引發(fā)劑自由基）：略 One thus obtains polyvinylchloride from vinylchloride, or polystyrene from styrene, or polyethylene from ethylene, etc. 因而通過上述過程由氯乙烯得到聚氯乙烯，或由苯乙烯獲得聚苯乙烯，或乙烯獲得聚乙烯，等等。 The length of the chain molecules, measured by mea

25、ns of the degree of polymerization, can be varied over a large range through selection of suitable reaction conditions. 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. Thi

26、s 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 molecules of different degrees of polymerization. 借助于聚合度估算的分子鏈長，在一個(gè)大范圍內(nèi)可以通過選擇適宜的反應(yīng)條件被改變

27、。通常，通過大量地制備和利用聚合物，聚合度在1000～5000范圍內(nèi)，但在許多情況下可低于500、高于10000。這不應(yīng)該把所有聚合物材料的分子量理解為由500，或1000，或5000個(gè)單體單元組成。在幾乎所有的事例中，聚合物材料由不同聚合度的聚合物分子的混合物組成。 Polymerization, a chain reaction, occurs according to the same mechanism as the well-known chlorine-hydrogen reaction and the decomposition of phosegene. 聚合反應(yīng)，鏈?zhǔn)椒磻?yīng)

28、，依照與眾所周知的氯（氣）-氫（氣）反應(yīng)和光氣的分解機(jī)理進(jìn)行。 The initiation reaction, which is the activation process of the double bond, can be brought about by heating, irradiation, ultrasonics, or initiators. The initiation of the chain reaction can be observed most clearly with radical or ionic initiators. These are energy

29、-rich compounds which can add suitable unsaturated compounds (monomers) and maintain the activated radical, or ionic, state so that further monomer molecules can be added in the same manner. For the individual steps of the growth reaction one needs only a relatively small activation energy and there

30、fore through a single activation step (the actual initiation reaction) a large number of olefin molecules are converted, as is implied by the term “chain reaction”. Because very small amounts of the initiator bring about the formation of a large amount of polymeric material (1:1000 to 1:1000), it is

31、 possible to regard polymerization from a superficial point of view as a catalytic reaction. For this reason, the initiators used in polymerization reactions are often designated as polymerization catalysts, even though, in the strictest sense, they are not true catalysts because the polymerization

32、initiator enters into the reaction as a real partner and can be found chemically bound in the reaction product ,i.e. ,the polymer, In addition to the ionic and radical initiators there are now metal complex initiators (which can be obtained, for example, by the reaction of titanium tetrachloride or

33、titanium trichloride with aluminum alkyls), which play an important role in polymerization reactions (Ziegler catalysts) ,The mechanism of their catalytic action is not yet completely clear. 雙鍵活化過程的引發(fā)劑反應(yīng)，可以通過熱、輻射、超聲波或引發(fā)劑產(chǎn)生。用自由基型或離子型引發(fā)劑引發(fā)鏈?zhǔn)椒磻?yīng)可以很清楚地進(jìn)行觀察。這些是高能態(tài)的化合物，它們能夠加成不飽和化合物（單體）并保持自由基或離子活性中心 以致單體可以

34、以同樣的方式進(jìn)一步加成。對于增長反應(yīng)的各個(gè)步驟，每一步僅需要相當(dāng)少的活化能，因此通過一步簡單的活化反應(yīng)（即引發(fā)反應(yīng)）即可將許多烯類單體分子轉(zhuǎn)化成聚合物，這正如連鎖反應(yīng)這個(gè)術(shù)語的內(nèi)涵那樣。因?yàn)樯倭康囊l(fā)劑引發(fā)形成大量的聚合物原料（1：1000～1：10000），從表面上看聚合反應(yīng)很可能是催化反應(yīng)。由于這個(gè)原因，通常把聚合反應(yīng)的引發(fā)劑看作是聚合反應(yīng)的引發(fā)劑，但是，嚴(yán)格地講它們不是真正意義上的催化劑，因?yàn)榫酆戏磻?yīng)的催化劑進(jìn)入到反應(yīng)內(nèi)部而成為一部分，同時(shí)可以在反應(yīng)產(chǎn)物，既聚合物的末端發(fā)現(xiàn)。此外離子引發(fā)劑和自由基引發(fā)劑有的是金屬絡(luò)合物引發(fā)劑（例如，通過四氯化鈦或三氯化鈦與烷基鋁的反應(yīng)可以得到），Z引發(fā)劑

35、在聚合反應(yīng)中起到了重要作用，它們催化活動的機(jī)理還不是十分清楚。 UNIT 3 Step-Growth Polymerization 第三單元 逐步聚合 Many different chemical reactions may be used to synthesize polymeric materials by step-growth polymerization. These include esterification, amidation, the formation of urethanes, aromatic substitution, etc. Polymerizat

36、ion proceeds by the reactions between two different functional groups, e.g., hydroxyl and carboxyl groups, or isocyanate and hydroxyl groups. 許多不同的化學(xué)反應(yīng)通過逐步聚合可用于合成聚合材料。這些反應(yīng)包括酯化、酰胺化、氨基甲酸酯、芳香族取代物的形成等。通過反應(yīng)聚合反應(yīng)在兩種不同的官能團(tuán)，如，羥基和羧基，或異氰酸酯和羥基之間。 All step-growth polymerization fall into two groups depending o

37、n the type of monomer(s) employed. The first involves two different polyfunctional monomers in which each monomer possesses only one type of functional group. A polyfunctional monomer is one with two or more functional groups per molecule. The second involves a single monomer containing both types o

38、f functional groups. The synthesis of polyamides illustrates both groups of polymerization reactions. Thus, polyamides can be obtained from the reaction of diamines with diacids 所有的逐步聚合反應(yīng)根據(jù)所使用單體的類型可分為兩類。第一類涉及兩種不同的官能團(tuán)單體，每一種單體僅具有一種官能團(tuán)。一種多官能團(tuán)單體每個(gè)分子有兩個(gè)或多個(gè)官能團(tuán)。第二類涉及含有兩類官能團(tuán)的單種單體。聚酰胺的合成說明了聚合反應(yīng)的兩個(gè)官能團(tuán)。因此聚酰胺可

39、以由二元胺和二元酸的反應(yīng)或氨基酸之間的反應(yīng)得到。 nH2N-R-NH2+nHO2C-R’-CO2H→ H-(-NH-R-NHCO-R’-CO-)n-OH+(2n-1)H2O (3.1) or from the reaction of amino acids with themselves nH2R-CO2H→ H-(-NH-R-CO-)n-OH+(n-1)H20 (3.2) The two groups of reactions can be represented in a general manner by the equations as follows

40、 A+B-B →–[-A-A-B-B-]-A-B→–[-A-B-]- 兩種官能團(tuán)之間的反應(yīng)一般來說可以通過下列反應(yīng)式表示 反應(yīng)式略 Reaction (3.1) illustrates the former, while (3.2) is of the latter type. 反應(yīng)（3.1）說明前一種形式，而反應(yīng)（3.2）具有后一種形式。 圖3.1 逐步聚合的示意圖 未反應(yīng)單體；（b）50%已反應(yīng)；（c）83.3%已反應(yīng)；(d) 100%已反應(yīng)（虛線表示反應(yīng)種類） Polyesterification, whether between diol and dibasic

41、 acid or intermolecularly between hydroxy acid molecules, is an example of a step-growth polymerization process. 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-rea

42、ctive hydroxyl or carboxyl groups. The net effect of this is that monomer molecules are consumed rapidly without any large increase in molecular weight. Fig. 3.1 illustrates this phenomenon. Assume, for example, that each square in Fig. 3.a represents a molecule of hydroxy acid. After the initial di

43、mmer molecules from (b), half the monomer molecules have been consumed and the average degree of polymerization (DP) of polymeric species is 2. As trimer and more dimer molecules form (c), more than 80% of the monomer molecules have reacted (d), DP is 4. But each polymer molecule that forms still ha

44、s reactive end groups; hence the polymerization reaction will continue in a stepwise fashion, with each esterification of monomers. 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 t

45、oo difficult to remove water of esterification or for reactive end groups to find each other. 聚酯化，是否在二元酸和二元醇或羥基酸分子間進(jìn)行，是逐步聚合反應(yīng)過程的一個(gè)例子。酯化反應(yīng)出現(xiàn)在單體本體中兩個(gè)單體分子相碰撞的位置，且酯一旦形成，依靠酯上仍有活性的羥基或羧基還可以進(jìn)一步進(jìn)行反應(yīng)。酯化的結(jié)果是單體分子很快地被消耗掉，而分子量卻沒有多少增加。圖3.1說明了這個(gè)現(xiàn)象。例如，假定圖3.1中的每一個(gè)方格代表一個(gè)羥基酸分子。（b）中的二聚體分子，消耗二分之一的單體分子聚合物種類的聚合度（DP）是2。（c

46、）中當(dāng)三聚體和更多的二聚體形成，大于80%的單體分子已反應(yīng)，但DP僅僅還是2.5。（d）中當(dāng)所有的單體反應(yīng)完，DP是4。但形成的每一種聚合物分子還有反應(yīng)活性的端基；因此，聚合反應(yīng)將以逐步的方式繼續(xù)進(jìn)行，其每一步酯化反應(yīng)的反應(yīng)速率和反應(yīng)機(jī)理均與初始單體的酯化作用相同。因此，分子量緩慢增加直至高水平的單體轉(zhuǎn)化率，而且分子量將繼續(xù)增加直到粘度的增加使其難以除去酯化反應(yīng)的水或難以找到相互反應(yīng)的端基。 It can also be shown that in the A-A+B-B type of polymerization, an exact stoichiometric balance is n

47、ecessary to achieve high molecular weights. 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 o

48、nly practical ones for polymer formation, since side reactions will upset the stoichiometric balance. 在A-A+B-B的聚合反應(yīng)中也可以看到，精確的當(dāng)量平衡是獲得高分子量所必需的。假如存在一些但官能團(tuán)雜質(zhì)，由于鏈的端基失活，反應(yīng)將使分子量減少。同樣，在A-B類的縮聚反應(yīng)中高純度的單體是必要的，而且可以歸結(jié)高收率的反應(yīng)僅是形成聚合物的實(shí)際反應(yīng)，因?yàn)楦狈磻?yīng)會破壞當(dāng)量平衡。 -------Stevens M P. Polymer Chemistry. London: Addison-Wesley

49、 Publishing Company, 1975. 13 UNIT 4 Ionic Polymerization 第四單元 離子聚合反應(yīng) Ionic polymerization, similar to radial polymerization, also has the mechanism of a chain reaction. The kinetics of ionic polymerization are, however, considerably different from that of radical polymerization. 離子聚合反應(yīng)，與自由基聚合反

50、應(yīng)相似，也有鏈反應(yīng)的機(jī)理。但是，離子聚合的動力學(xué)明顯地不同于自由基聚合反應(yīng)。 (1) The initiation reaction of ionic polymerization needs only a small activation energy. Therefore, the rate of polymerization depends only slightly on the temperature. Ionic polymerizations occur in many cases with explosive violence even at temperature. bel

51、ow 50℃(for example, the anionic polymerization of styrene at –70℃ in tetrahydrofuran, or the cationic polymerization of isobutylene at –100℃ in liquid ethylene ). (1)離子聚合的引發(fā)反應(yīng)僅需要很小的活化能。因此，聚合反應(yīng)的速率僅對溫度有較少的依賴性。在許多情況下離子聚合猛烈地發(fā)生甚至低于50℃（例如，苯乙烯的陰離子聚合反應(yīng)在-70℃在四氫呋喃中，或異丁烯的陽離子聚合在-100℃在液態(tài)乙烯中）。 (2) With ionic po

52、lymerization there is no compulsory chain termination through recombination, because the growing chains can not react with each other. 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

53、 through compounds which can react with polymerization ions under the formation of neutral compounds or inactive ionic species. If the initiators are only partly dissociated, the initiation reaction is an equilibrium reaction, where reaction in one direction gives rise to chain initiation and in the

54、 other direction to chain termination. （2）對于離子聚合來說，不存在通過再結(jié)合反應(yīng)而進(jìn)行的強(qiáng)迫鏈終止，因?yàn)樯L鏈之間不能發(fā)生鏈終止。鏈終止反應(yīng)僅僅通過雜質(zhì)而發(fā)生，或者說通過和某些像水、醇、酸、胺或氧這樣的化合物進(jìn)行加成而發(fā)生，且一般來說（鏈終止反應(yīng)）可通過這樣的化合物來進(jìn)行，這種化合物在中性聚合物或沒有聚合活性的離子型聚合物生成的過程中可以和活性聚合物離子進(jìn)行反應(yīng)。如果引發(fā)劑僅僅部分地離解，引發(fā)反應(yīng)即為一個(gè)平衡反應(yīng)，在出現(xiàn)平衡反應(yīng)的場合，在一個(gè)方向上進(jìn)行鏈引發(fā)反應(yīng)，而在另一個(gè)方向上則發(fā)生鏈終止反應(yīng)。 In general ionic polymeri

55、zation polymerization can be initiated through acidic or basic compounds. For cationic polymerization, complexes of BF3, AlCl3, TiCl4, and SnCl4 with water, or alcohols, or tertiary oxonium salts have shown themselves to be particularly active. The positive ions are the ones that cause chain initiat

56、ion. For example: 通常離子聚合反應(yīng)能通過酸性或堿性化合物被引發(fā)。對于陽離子聚合反應(yīng)來說，BF3,AlCl3,TiCl4和SnCl4與水、或乙醇，或叔烊鹽的絡(luò)合物提供了部分活性。正離子是產(chǎn)生鏈引發(fā)的化合物。例如：(反應(yīng)略) 三乙基硼氟酸烊 However, also with HCl, H2SO4, and KHSO4, one can initiate cationic polymerization. Initiators for anionic polymerization are alkali metals and their organic compounds,

57、 such as phenyllithium, butyllithium, phenyl sodium, and triphenylmethyl potassium, which are more or less strongly dissociated in different solvents. To this group belong also the so called Alfin catalysts, which are a mixture of sodium isopropylate, allyl sodium, and sodium chloride. 然而，BF3也可以與HC

58、l、H2SO4和KHSO4引發(fā)陽離子聚合反應(yīng)。陰離子聚合反應(yīng)的引發(fā)劑是堿金屬和它們的有機(jī)金屬化合物，例如苯基鋰、丁基鋰和三苯甲基鋰，它們在不同的溶劑中或多或少地強(qiáng)烈分解。所謂的Alfin催化劑就是屬于這一類，這類催化劑是異丙醇鈉、烯丙基鈉和氯化鈉的混合物。 With BF3 (and isobutylene as the monomer), it was demonstrated that the polymerization is possible only in the presence of traces of traces of water or alcohol. If one

59、eliminates the trace of water, BF3 alone does not give rise to polymerization. Water or alcohols are necessary in order to allow the formation of the BF3-complex and the initiator cation according to the above reactions. However, one should not describe the water or the alcohol as a “cocatalyst”. B

60、F3為引發(fā)劑（異丁烯為單體），證明僅在痕量水或乙醇的存在下聚合反應(yīng)是可以進(jìn)行的。如果消除痕量的水，單純的BF3不會引發(fā)聚合反應(yīng)。按照上述反應(yīng)為了能形成BF3-絡(luò)合物和引發(fā)劑離子水或乙醇是必需的。但是不應(yīng)將水或乙醇描述成“助催化劑”。 Just as by radical polymerization, one can also prepare copolymers by ionic polymerization, for example, anionic copolymers of styrene and butadiene, or cationic copolymers of isobut

61、ylene and styrene, or isobutylene and viny ethers, etc. As has been described in detail with radical polymerization, one can characterize each monomer pair by so-called reactivity ratios r1 and r2. The actual values of these two parameters are, however, different from those used for radical copolyme

62、rization. 正與自由基聚合反應(yīng)一樣，通過離子聚合反應(yīng)也能制備共聚物，例如，苯乙烯-丁二烯陰離子共聚物，或異丁烯-苯乙烯陽離子共聚物，或異丁烯-乙烯基醚共聚物，等等。正如對自由基型聚合已經(jīng)詳細(xì)描述過那樣，人們可以用所謂的競聚率r1和r2來表征每單體對。然而，這兩個(gè)參數(shù)的實(shí)際意義不同于那些用于自由基共聚合反應(yīng)的參數(shù)。 ---Vollmert B. Polymer Chemistry. Berlin: Sping-Verlag, 1973.163 PART B 聚合反應(yīng)工程 UNIT 11 Reactor types 第十一單元 反應(yīng)器類型 Reactors

63、 may be categorized in a variety of ways, each appropriate to a particular perspective. For example, Henglein (1969) chooses a breakdown based on the source of energy used to initiate the reaction (i.e., thermal, electrochemical, photochemical, nuclear). More common breakdowns are according to the t

64、ypes of vessels and flows that exist. 反應(yīng)器可以用許多方法分類，各自適用于特定的目的。例如，Henglein（1969）基于用于產(chǎn)生反應(yīng)的能量來源，即，熱量，電化學(xué)，光化學(xué)，原子核，選擇了一種細(xì)目分類。更多普通的細(xì)目分類是按照所存在的容器和流量的類型。 Batch Reactors 1. 間歇反應(yīng)器 The batch reactor (BR) is the almost universal choice in the chemist’s laboratory where most chemical processes originate. The

65、 reason is the simplicity and versatility of the batch reactor, whether it be a test tube, a three-neck flask, an autoclave, or a cell in a spectroscopic instrument. Regardless of the rate of the reaction, these are clearly low production rate devices. As scale up is desired, the most straightforwar

66、d approach is to move to a larger batch reactor such as a large vat or tank. 間歇反應(yīng)器在化學(xué)實(shí)驗(yàn)室?guī)缀跏且话愕倪x擇，大多數(shù)的化學(xué)過程在那里產(chǎn)生。間歇反應(yīng)器的原理具簡單性和通用性，不管它是一支試管，一個(gè)三頸瓶，一個(gè)高壓釜，還是一個(gè)光譜儀器的比色皿。不管反應(yīng)比例，很清楚這些是低產(chǎn)率設(shè)備。當(dāng)要求放大反應(yīng)器時(shí)，大多直截了當(dāng)?shù)耐緩绞且浦烈粋€(gè)較大的間歇反應(yīng)器如一個(gè)較大的大桶或罐。 Commercial batch reactors can be huge, 100 000 gal or more. 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. Fabrication, shipping, or other facto