川大高分子考研專外復習提綱

1、A brief review for FINALDec. 1st. 2012 10:00AMZHONG Ganji (鐘 淦 基) 西區(qū)四教422c，1. MaterialPolyethylene（PE）, polypropylene（PP）, polyamide（PA）, polyester（聚酯）Polystyrene（PS）, polycarbonate(PC), polyvinyl chloride(PVC), polymethyl methacrylate(PMMA)Synthesis(合成), polymerization（聚合）, catalyst（催化劑）, chemical

2、reactivity（化學反應）, monomer（單體）Thermoplastic（熱塑性）, thermoset（熱固性）, elastomer（彈性體）2. Structuredouble bond（雙鍵）, repeat unit（重復單元）, conformation（構象）, pendant group（側基）, branch chain（支鏈）, coil（線團）number average molecular weight （數(shù)均分子量）intermolecular attraction（分子間作用力）, hydrogen bonding（氫鍵）, entanglement（纏

3、結）, orientation（取向）Amorphous（非晶的）, crystalline（結晶的）, crosslinked （交聯(lián)）Nucleation（成核）, folded chain model（折疊連模型）, spherulite （球晶）Blend（混合）, composite（合成的）, morphology（形態(tài)學）, composition（合成物）, component（零部件）, matrix phase（基體相）Infrared spectroscopy （紅外光譜）differential scanning calorimetry（DSC）X-ray diffra

4、ction（X衍射）3. Propertyglass transition temperature（玻璃化溫度）, melting point（熔點）, decomposition（分解）, degradation（降解）, thermal stability（熱穩(wěn)定性）, coefficient of thermal expansion（熱膨脹系數(shù)）impact toughness（沖擊韌性）, tensile strength（拉伸強度）, reinforcement（增強）, melt index（熔融指數(shù)）Modulus（模量）, stress-strain curve（應力-應變曲線

5、）, elongation at break（斷裂伸長率）, deformation（形變）Creep（蠕變）, stress relaxation（應力松弛）, annealing（退火）shear-thinning / thickening（剪切變稀/增稠）Pseudoplastic（假塑性）, viscoelasticity（粘彈性）4. Processingtwin-screw extruders（雙螺桿擠出機）injection molding（注塑成型）Die（模具）, mold（模具、制模）, cavity（中空的）processing aids / additives（加工助劑

6、）, filler（填料）Melt（融化）, plasticizing（增塑）, solidify（固化）Because of the close connection between the terms resins, plastics, and polymers, they are sometimes used interchangeably, although correctly used there are differences. To summarize, polymers are any material made up of molecular chains; plastics

7、 are synthetic（合成的）, long-chain polymers that can be or have been shaped; and resins are solids or liquids that are subsequently shaped into a plastic part.（因為樹脂、塑料和高分子緊密的聯(lián)系，它們時常被混用，雖然它們被正確使用但仍有不同?？偨Y起來，高分子是所有由分子鏈組合起來的材料；塑料是合成的，可以被或已經(jīng)被塑形的長鏈高分子；樹脂是隨后會被塑形為塑料部分的固體或液體。）As opposed to thermoplastics in whi

8、ch molding and shaping only involves freezing the hot (melted) material, in thermosets the molding and shaping involve a chemical reaction that causes the material to harden and take a permanent shape.The complexity in polymers arises because solid polymeric materials can exist, in two very distinct

9、 types of structure. In one type, the polymer molecules are randomly coiled about each other with entanglement（纏結）. This structure type is called amorphous. In the second type, the polymer molecules can pack together into regular, repeating structural patterns. These regularly packed regions are cal

10、led crystals or crystalline regions. （高分子很復雜因為固體高分子材料存在兩種不同的結構。一種形態(tài)，高分子隨機相互纏結。這種形態(tài)稱作無定形態(tài)。第二種形態(tài)，高分子有規(guī)律地以重復結構模式地折疊。這種有規(guī)律排列的區(qū)域被稱作結晶區(qū)。）The most important (but not the only) feature of a polymer that determines whether it will be amorphous or crystalline is the shape of the polymer repeat unit. If the re

11、peat unit is complex, especially with large pendant groups, the polymer cannot pack tightly together and will be amorphous. Some of the most common amorphous polymers are polystyrene, acrylic（丙烯酸）, polycarbonate, and most copolymers（共聚物）. （決定高分子是非晶還是結晶最重要的（但不是唯一的）特征是高分子重復單元的形態(tài)。如果重復單元復雜，特別是有龐大側基的，高分子

12、不能緊密排列所以是非晶的。最常見的一些非晶高聚物是PS、丙烯酸、PC和大部分共聚物。）In addition to these structural factors, the crystallinity of polymers also depends upon molding or processing conditions. Crystallization in polymers takes time to occur. Therefore, factors such as cooling rate can have strong influences on the amount of t

13、he material that crystallizes, since below certain temperatures there is not sufficient molecular motion to allow the molecules to rearrange（重排） into a close packing configuration. （除了這些結構因素，高聚物的結晶度同樣決定于成型或加工條件。高聚物的的結晶的出現(xiàn)需要時間。因此，像冷卻速率這樣的因素對于材料的結晶率有很大的影響，因此在特定溫度下沒有足夠的分子運動使分子重排為最接近的折疊構象。）Most polymer

14、materials have some characteristics that are similar to viscous liquids and some that are similar to elastic solids. These materials are therefore known as viscoelastic. Viscoelastic materials can be either liquid or solid, although the distinction between liquids and solids in these materials is no

15、t a clear one. The time dependence of viscoelastic materials is an important consideration that significantly affects their behavior. Most polymer viscoelastic liquids exhibit shear-thinning, and many are thixotropic（觸變的）.（大部分高分子材料有一些類似粘性液體或彈性固體的特征。這類材料因此因粘彈性而被知道。粘彈性材料既可能是固體也可能是液體，雖然在這類材料中液體和固體的區(qū)別并不

16、明顯。粘彈性材料的時間依賴性是一個重要的、顯著影響它們行為的性質。大部分高分子粘彈性液體表現(xiàn)出剪切變稀，很多是觸變性流體。）The viscous nature of a polymer solid can be associated with long-range movements. The viscous material will move more freely than an elastic solid when a force is imposed, and all the energy input into the material may not be returned be

17、cause of permanent deformations or the creation of internal heating（內加熱）. The long-range movements require more energy to activate than do the short-range movements. Hence, above a certain level of internal energy, the behavior of the material will more likely be dominated（支配） by long-range movement

18、s, and below this characteristic energy level, the material will exhibit only short-range movements. （高分子固體的粘性可以被聯(lián)系到長程運動。當有外力被施加時，粘性材料比塑性材料運動更自由，而且被加入到材料里的能量可能不會被釋放因為永久性變和內部升溫。長程運動要求更多的能量來激活相對于短程運動。因此，在一定的內部能量下，材料的行為更多的是被長程運動支配，在這個特征能量以下，材料只會表現(xiàn)出短程運動。）The molecular interpretation（解釋）of elastic and pl

19、astic behavior is that in the elastic region the strain results from recoverable movement-stretching out of the twisted molecules in the amorphous regions and minor deformations in the crystalline regions. At the yield point, nonrecoverable movements begin that result in permanent deformation. Some

20、of the most common are disentanglement of the molecules, slip of one molecule past another in a way that the slip could not be recovered, slip along a crystal plane, and formation of a crack.（塑性和彈性現(xiàn)象的分子解釋是在彈性區(qū)，應變是可回復的、在非晶區(qū)纏繞分子外的伸展運動和晶區(qū)次要的運動的結果。在屈服點，不可回復的運動開始了并造成了永久性變。最常見的是分子的解纏，一個分子從另一個上不可回復地滑移，滑移順著

21、結晶平面，然后出現(xiàn)缺陷。）High molecular weight favors high toughness. This results from the combination of higher strength and better sharing of the impact force along the polymer chain by causing more atoms to rotate, vibrate（振動）, and stretch to absorb the energy of the impact. Crystallinity gives higher stren

22、gth but lower toughness unless the nature of the backbone（主鏈） changes. Crosslinking of a brittle polymer will usually decrease toughness because of the increased limitation of motion within the polymer mass caused by the intermolecular（分子間） bonds.（大的分子量帶來高硬度。這結果來自于更大的強度的結合和更好地分子鏈之間的力的分配。這種更優(yōu)的分子鏈間力的分

23、配源自于使更多的原子旋轉，振動，和伸展以吸收相互擠壓的能量。結晶高聚物會有更高的強度但是更低的硬度除非改變其主鏈結構。交聯(lián)高分子通常會減弱其硬度因為隨著高分子分子量增大，分子運動的限度增加。這種限度來源于分子間的物理作用。）The differences between the commodity thermoplastics arise from the differences caused by the substitution of one functional group (atom) on the carbon-carbon double bond. One of the most

24、important effects is steric（空間排列的）, that is, the consequences of differences in the size of the functional groups. When the functional groups are small (such as hydrogen), little steric hindrance（空間位阻） (interference because of size) is encountered（遇到）. Without steric hindrance the polymers are relat

25、ively free to rotate, bend, and pack together. （商品熱塑性塑料的差異來源于碳碳雙鍵上的功能基團（原子）被代替。其中一個重要影響是空間排列，即功能基團排布的不同帶來的后果。當功能基團很小（如氫原子），會遇到小的空間位阻（因為尺寸帶來的阻礙）。沒有了空間位阻高分子會相對自由地旋轉、彎曲和折疊在一起。）The majority of engineering thermoplastics are similar in many respects. They are generally strong and have, a high use tempera

26、ture, good impact strength, good dimensional（尺寸） stability over a wide range of temperatures, generally good resistance to environmental conditions, and are much more moldable than the metal, ceramic, or wood parts that they often replace. Most engineering resins can also be made into fibers, films（

27、薄膜）, and coatings（涂料）, which is beyond the capability of most metals.（主要的工程熱塑性材料在很多方面相似。它們通常有高強度，并且有高的使用溫度，高的擠壓強度，在大的溫度范圍內有良好的尺寸穩(wěn)定性，通常能較好地抵抗環(huán)境條件，比常常更換的金屬、陶瓷和木制品更容易塑型。大部分工程樹脂可以被制成纖維、薄膜、涂料，這是超出了大部分金屬的能力。）In addition to the shaping of parts, extrusion（擠出） is the most efficient and widely used method fo

28、r melting plastic resin as part of the process of adding or mixing fillers, colorants, and other additives（添加劑） into the molten（熔化的） plastic. Extrusion can be used to shape the part directly after this mixing or an extruder（擠出機） can be used as the melting device that is coupled with other shaping pr

29、ocesses. When used for direct shaping, a shaping device or tool is placed directly on the end of the extrusion machine (extruder) and the process is called extrusion molding. （除了塑造的部分，擠出是最效率的也是被廣泛運用的方法使熔化樹脂成為加入或混合填料、著色劑和其添加劑到熔化的塑料里面的工藝過程。擠出可以被用來直接塑造混合后的部分的形狀，一臺擠出機也可以被用做熔化設備，和其他的塑型過程一起使用。當被用來直接塑形，一臺塑

30、性設備或工具直接被擠出機的最后部分代替，而這個過程被稱作擠出成型。）In normal plastics extrusion, plastics granules（微粒） or pellets（小球） and any other materials to be mixed with them are fed into a hopper attached to the extrusion machine. From the hopper the material falls through feed throat onto the extrusion screw（螺桿）. This screw,

31、 which turns inside the extruder barrel（桶）, conveys the plastic forward into a heated region where the combination of external（外部的） heating and heating from friction（摩擦） melts the plastic. The screw moves the molten plastic forward until it exits through a hole in the end of the extruder barrel. （對通

32、常的塑料擠出機，塑料微?；蛐∏蛞约捌渌旌显谄渲械牟牧蠒患尤氲竭B接在擠出機上的料斗。材料從料斗掉落，通過進料口到達螺桿。這個在擠出機料筒內旋轉的螺桿，將塑料傳遞到一個加熱區(qū)。在加熱區(qū)，外部的加熱和內部的摩擦會熔化掉塑料。螺桿會推動熔化的塑料向前運動直到它從擠出機料筒最后的部分的洞中出去。）The extruder screw has several important functions to perform such as (1) conveying the resin through the extruder, (2) imparting（賦予） mechanical energy as

33、 part of the melting process, (3) mixing ingredients together, (4) building pressure in the extruder so that the resin will be pushed through the die. One major development in screw design is the creation of twin-screw extruders, in which two screws operate together to achieve unique performance cha

34、racteristics. （螺桿擠出機有一些重要的作用表現(xiàn)在：1、在擠出機中傳遞樹脂；2、在熔融過程中賦予機械能；3、將原料混合；4、在擠出機中給予壓力，以使樹脂被推到模具中。在螺桿設計中的一個主要的發(fā)展是雙螺桿擠出機。在雙螺桿擠出機上兩個螺桿同時操作以實現(xiàn)特殊的性能表現(xiàn)。）In contrast to the extrusion process, which makes continuous parts of constant（恒定的、常數(shù)） cross section（截面）, injection molding makes discrete（不連續(xù)的） parts that can h

35、ave complex and variable cross sections as well as a range of surface textures（紋理） and characteristics. The wide variety in the types of parts that can be made by injection molding is a key reason that more injection molding machines are used for plastics processing than any other type of molding equipment. Almost all thermoplastics and some thermosets can be injection molded, thus adding to the flexibility（靈活性） of the process. （與能夠制造連續(xù)的、恒定截面零件的擠出工藝相對的，注射成型制造不連續(xù)的、有復雜的和易變截面的、一定范圍表面紋理和特性的零件。大范圍種類的的零件可以被注射成型是相對于其他成型設備，注射成型被更多的運用于塑料制造工