高分子材料專業(yè)英語第二版部分答案2

1、unit11.Notallpolymersarebuiltupfrombondingtogetherasinglekindofrepeatingunit.Attheotherextremeproteinmoleculesarepolyaesinwhichnaminoaciderepeatunitsarebondedtogether.Althoughwemightstillcallnthedegreeofpolymerizationint

2、hiscaseitislessusefullsinceanaminoacidunitmightbeanyoneofsome20oddmoleculesthatarefoundinproteins.Inthiscasethemolecularweightitselfratherthanthedegreeofthepolymerizationisgenerallyusedtodescribethemolecule.Whentheactual

3、contentofindividualaminoacidsisknownitistheirsequencethatisofspecialinteresttobiochemistsmolecularbiologists.并不是所有的聚合物都是由一個重復(fù)單元鏈接在一起而形成的。在另一個極端的情形中，蛋白質(zhì)分子是由n個氨基酸重復(fù)單元鏈接在一起形成的聚酰胺。盡管在這個例子中，我們也許仍然把n稱為聚合度，但是沒有意義，因為一個氨基酸單元也許是在蛋

4、白質(zhì)中找到的20多個分子中的任意一個。在這種情況下，一般是分子量本身而不是聚合度被用來描述這個分子。當(dāng)知道了特定的氨基酸分子的實際含量，它們的序列正是生物化學(xué)家和分子生物學(xué)家特別感興趣的地方。1題目：Anotherstriking...答案：.thatquantitylowsaturationbottommuchabsb2.乙烯分子帶有一個雙鍵，為一種烯烴，它可以通過連鎖聚合大量地制造聚乙烯，目前，聚乙烯已經(jīng)廣泛應(yīng)用于許多技術(shù)領(lǐng)域和人們

5、的日常生活中，成為一種不可缺少的材料。EthylenemoleculewithadoublebondasakindofolefinsitcanmakechainpolymerizationpolyethyleneatpresentpolyethylenehasbeenwidelyusedinmanyfieldsoftechnologyPeoplesDailylifebecomeakindofindispensablematerials.

6、Unit31Thepolymerizationratemaybeexperimentallyfollowedbymeasuringthechangesinanyofseveralpropertiesofthesystemsuchasdensityrefractiveindexviscositylightabsption.Densitymeasurementsareamongthemostaccuratesensitiveofthetec

7、hniques.Thedensityincreasesby2025percentonpolymerizationfmanymonomers.Inactualpracticethevolumeofthepolymerizingsystemismeasuredbycarryingoutthereactioninadilatometer.Thisisspeciallyconstructedvesselwithacapillarytubewhi

8、challowsahighlyaccuratemeasurementofsmallvolumechanges.Itisnotuncommontobeabletodetectafewhundredthsofapercentpolymerizationbythedilatometertechnique.聚合速率在實驗上可以通過測定體系的任一性質(zhì)的變化而確定，如密度、折射率、黏度、或者吸光性能。密度的測量是這些技術(shù)中最準(zhǔn)確最敏感的。對許多單體

9、的聚合來說，密度增加了20%25%。在實際操作中，聚合體系的體積是通過在膨脹計中進行反應(yīng)測定的。它被專門設(shè)計構(gòu)造了毛細導(dǎo)管，在里面可以對微小體積變化進行高精確度測量。通過膨脹計技術(shù)探測聚合過程中萬分之幾的變化是很常見的。Unti42合成聚合物在各個領(lǐng)域中起著與日俱增的重要作用，聚合物通常是由單體通過加成聚合與縮合聚合制成的。就世界上的消耗量而論，聚烯烴和乙烯基聚合物居領(lǐng)先地位，聚乙烯、聚丙烯等屬聚烯烴，而聚氯乙烯、聚苯乙烯等則為乙烯基聚

10、合物。聚合物可廣泛地用作塑料、橡膠、纖維、涂料、粘合劑等Thesyntheticpolymersplayanincreasinglyimptantroleonarangeofdomainswhicharesynthesizedbymonomersthroughadditionpolymerizationcondensationpolymerization.Polyolefinvinylpolymerhavetakentheleadint

11、ermsofthewldconsumption.PEPPetc.belongtothepolyolefinwhilePSPVCetc.belongtothevinylpolymer.Polymerscanbewidelyappliedinplasticsrubbersfiberscoatingsgluessoon.Unit7Ringopeningpolymerizationsproceedonlybyionicmechanismsthe

12、polymerizationofcyclicethersmainlybycationicmechanismsthepolymerizationoflactoneslactonesbyeitheracationicanionicmechanism.Imptantinitiatsfcyclicetherslactonepolymerizationarethosederivedfromaluminumalkylzincalkylwatersy

13、stems.Itshouldbepointedoutthatsubstitutionnearthereactivegroupofthemonomerisessentialftheindividualmechanismthatoperateseffectivelyinspecificcasesf(2)WhichkindsofmonomerscancarryoutstepgrowthpolymerizationprocessThereare

14、twokindsofmonomerscouldcarryoutstepgrowthpolymerizationprocess.Oneispolyfunctionalmonomerstheotherisasinglemonomercontainingbothtypesoffunctionalgroups.(3)WhatpropertiesofpolymerscanbebasedonfmeasuringthemolecularweightT

15、hemolecularweightofpolymercouldbemeasuredbasedoncolligativepropertieslightscatteringviscosityultracentrifugationsedimentation.3.Pleasewriteoutatleast10kindsofpolymersbothinEnglishinChinesePolyester聚酯polystyrene聚苯乙烯polyae

16、聚酰胺polypropylene聚丙稀polyethylene聚乙烯polyurethane聚氨酯polyvinylalcohol聚乙烯醇Polyvinylchlide聚氯乙烯polybutene聚丁烯polyether聚醚4.Pleasewriteoutatleast10kindsofmonomersbothinEnglishinChinesethecrespongingchemicalstructureClFFFFCNCOOH丁丁丁

17、丁丁丁丁1丁丁丁丁丁14丁丁丁丁丁丁丁丁丁丁丁丁丁丁丁丁ethylenevinylchlidepropylene1buteneacrylonitrile14butadienetetrafluoethylenestyreneisobuteneacrylicacid5Ingeneral，headtotailadditionisconsideredtobethepredominantmodeofpropagationinallpolymeri

18、zations。However，whenthesubstitutesonthemonomeraresmall(donotofferappreciablesterichindrancetotheapproachingradical)donothavealargeresonancestabilizingeffect，asinthecaseoffluineatoms，sizableamountsofheadtoheadpropagationm

19、ayoccur.Theeffectofincreasingpolymerizationtemperatureistoincreasetheamountofheadtoheadplacement。Increasedtemperatureleadstolessive(merom)propagationbuttheeffectisnotlarge.Thus，theheadtoheadcontentinpoly(vinylacetate)onl

20、yincreasesfrom1.30to1.98percentwhenthepolymerizationtemperatureinincreasedfrom30to90℃.通常在所有聚合物的鏈增長中，頭尾加成是主要方式。然而，當(dāng)單體中的取代基很?。▽咏淖杂苫鶝]有空間阻礙）或沒有較大的共振穩(wěn)定作用，如氟原子，則有相當(dāng)量的頭頭增長發(fā)生。提高聚合溫度的影響是提高頭頭排列的量。溫度的提高導(dǎo)致較少的選擇（更多的無規(guī)）增長，但影響不大。因而，在

21、聚乙酸乙烯酯中，當(dāng)聚合溫度由30C提高到90C，頭頭含量僅由1.3%提高到1.98%。2WriteoutanabstractinEnglishfthetextinthisunitPolymerswithdifferentstructurespresentvariousproperties.Usuallypolymersaredividedintothreecategiesi.e.plasticelastomerfiberwithdiff