版權(quán)說明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請(qǐng)進(jìn)行舉報(bào)或認(rèn)領(lǐng)
文檔簡介
高分子材料與工程專業(yè)部分翻譯Crosslinkedspeciesarefoundinallthreecategoriesandtheprocessofcrosslinkingmaychangethecitedcharacteristicsofthecategories.Cite,vt,引用,引證,舉例;citation,n,引用,引文交聯(lián)的種類在所有三種類型(塑料,橡膠,纖維)中找到,而交聯(lián)過程可以改變分類的引用特征。Thus,plasticsareknowntopossess[p?zes]amarkedrangeofdeformabilityintheorderof100to200%;theydonotexhibitthispropertywhencrosslinked,however.Deformability,形變能力,變形性intheorderof。。。,大約。。。因此,我們熟知塑料具有的形變能力大約在100-200%范圍內(nèi),然而當(dāng)交聯(lián)發(fā)生時(shí)塑料不能展示這個(gè)性能。Rubber,onvulcanization,changesitspropertiesfromlowmodulus,lowtensilestrength,lowhardness,andhighelongationtohighmodulus,hightensilestrength,highhardness,andlowelongation.Vulcanization[vΛlk?nai’zeiS?n],硫化對(duì)橡膠而言,硫化可以改變其性質(zhì),從低模量,低拉伸強(qiáng)度,低硬度及高拉伸率到高模量,高拉伸強(qiáng)度,高硬度及低拉伸率。Thus,polymersmaybeclassifiedasnoncrosslinkedandcrosslinked,andthisdefinitionagreesgenerallywiththesubclassificationinthermoplasticandthermosetpolymers.這樣,聚合物可以分為非交聯(lián)和交聯(lián)的,這個(gè)定義與把聚合物細(xì)分為熱塑性和熱固性聚合物相一致。Fromthemechanisticpointofview,however,polymersareproperlydividedintoadditionpolymersandcondensationpolymers.Bothofthesespeciesarefoundinrubbers,plastics,andfibers.Fromthemechanisticpointofview,從反應(yīng)機(jī)理的觀點(diǎn)看,然而,從反應(yīng)機(jī)理的觀點(diǎn)看,聚合物可以分成加聚物和縮聚物。這些種類聚合物在塑料,橡膠和纖維中都可以找得到。Inmanycasespolymersareconsideredfromthemechanisticpointofview.Also,thepolymerwillbenamedaccordingtoitssourcewheneveritisderivedfromaspecifichypotheticalmonomer,orwhenitisderivedfromtwoormorecomponentswhicharebuiltrandomlyintothepolymer.Bederivefrom…由。。。產(chǎn)生而來,來自于。。。hypotheticalmonomer,假想單體在許多情況下,聚合物可以從反應(yīng)機(jī)理的角度考慮分類。每當(dāng)聚合物來自于一個(gè)假象單體,或來自于兩個(gè)或兩個(gè)以上組成物無規(guī)則構(gòu)建聚合物時(shí),也可以根據(jù)聚合物的來源來命名。Thisclassificationagreeswellwiththepresentlyusedgeneralpractice.這種分類方法與目前實(shí)際情況相符合。Agreewellwith….與。。。相符合。Whentherepeatingunitiscomposedofseveralmonomericcomponentsfollowingeachotherinaregularfashion,thepolymeriscommonlynamedaccordingtoitsstructure.inaregularfashion,規(guī)則地當(dāng)重復(fù)單元由幾個(gè)單體組成物規(guī)則排布,聚合物通常根據(jù)它的結(jié)構(gòu)來命名。Itmustbeborneinmindthat,withtheadventofZiegler-Nattamechanismsandnewtechniquestoimproveandextendcrystallinity,andtheclosenessofpackingofchains,manyolderdatagivenshouldbecriticallyconsideredinrelationtothestereoregularandcrystallinestructure.Bearinmind,牢記,記住Withadventof…,隨著。。。的出現(xiàn)inrelationto,關(guān)于。。。,與。。。有關(guān)theclosenessofpackingofchains,鏈堆砌密度必須記住,隨著Ziegler-Natta機(jī)理的出現(xiàn),以及隨著提高結(jié)晶度和提高鏈的堆砌密度的新方法的出現(xiàn),對(duì)許多過去已經(jīng)得到的關(guān)于空間結(jié)構(gòu)和晶體結(jié)構(gòu)舊的資料,應(yīng)當(dāng)批判地接受。必須記住,隨著Ziegler-Natta機(jī)理,以及提高結(jié)晶度和鏈堆砌緊密度新技術(shù)的出現(xiàn),許多與立構(gòu)規(guī)整與結(jié)晶結(jié)構(gòu)相關(guān)的舊數(shù)據(jù)應(yīng)當(dāng)批評(píng)地接受。Thepropertiesofpolymersarelargelydependentonthetypeandextentofbothstereoregularityandcrystallinity.Asanexample,thedensitiesandmeltingpointsofatacticandisotacticspeciesarepresentedinTable8.1.Stereoregularity,立體規(guī)整性,立體規(guī)整度Atactic,a,無規(guī)立構(gòu)的,Isotactic,a,等規(guī)立構(gòu)的,全同立構(gòu)的聚合物的性質(zhì)主要依靠立體規(guī)整性和結(jié)晶度的類型和程度。如,無規(guī)立構(gòu)和全同立構(gòu)物質(zhì)的密度和熔點(diǎn)展示在表8.1中。UNIT9StructureandPropertiesofPolymers聚合物的結(jié)構(gòu)和性質(zhì)UNIT11FunctionalPolymersFunctionalpolymersaremacromoleculestowhichchemicallyfunctionalgroupsareattached;theyhavethepotentialadvantagesofsmallmoleculeswiththesamefunctionalgroups.功能聚合物是具有化學(xué)功能基團(tuán)的大分子,這些聚合物與具有相同功能基團(tuán)的小分子一樣具有潛在的優(yōu)點(diǎn)。Theirusefulnessisrelatedbothtothefunctionalgroupsandtothenatureofthepolymerswhosecharacteristicpropertiesdependmainlyontheextraordinarilylargesizeofthemolecules.它們的實(shí)用性不僅與功能基團(tuán)有關(guān),而且與巨大分子尺寸帶來的聚合物特性有關(guān)。Theattachmentoffunctionalgroupstoapolymerisfrequentlythefirststeptowardsthepreparationofafunctionalpolymerforaspecificuse.把功能基團(tuán)連接到聚合物上常常是制備特殊用途功能高分子的第一步。UNIT11FunctionalPolymersHowever,theproperchoiceofthepolymerisanimportantfactorforsuccessfulapplication.然而,對(duì)成功應(yīng)用而言,選擇適當(dāng)?shù)木酆衔锸堑囊粋€(gè)重要因素。Inadditiontothesyntheticaliphaticandaromaticpolymers,awiderangeofnaturalpolymershavealsobeenfunctionalizedandusedasreactivematerials.Aliphatic,脂肪組的Aromatic,芳香組的Inadditionto。。。,除了。。。之外,除了合成的脂肪組和芳香組聚合物之外,許多天然高分子也被功能化,被用做反應(yīng)性材料。Inorganicpolymershavealsobeenmodifiedwithreactivefunctionalgroupsandusedinprocessesrequiringsevere[si’vi?]serviceconditions.無機(jī)聚合物也已經(jīng)用反應(yīng)功能基團(tuán)改性,被用于要求耐用條件的場(chǎng)合。UNIT11FunctionalPolymersInprinciple,theactivegroupsmaybepartofthepolymerbackboneorlinkedtoasidechainasapendantgroupeitherdirectlyorvia[vai?]aspacer[s’peis?]group.理論上講,活性基團(tuán)可以是聚合物主鏈上的一部分,或者直接連接到側(cè)鏈或通過一個(gè)中間基團(tuán)的側(cè)基。pendantgroup側(cè)基;spacergroup,隔離基團(tuán),中間基團(tuán)。Arequiredactivefunctionalgroupcanbeintroducedontoapolymericsupportchain(1)byincorporationduringthesynthesisofthesupportitselfthroughpolymerizationorcopolymerizationofmonomerscontainingthedesiredfunctionalgroups,(2)bychemicalmodificationofanon-functionalizedperformedsupportmatrixand(3)byacombinationof(1)and(2).所需的活性功能基團(tuán)可以通過幾種方法引入到聚合物主鏈上,(1)在主鏈的合成過程中,通過聚合或共聚合含有理想功能基團(tuán)的單體來獲得,(2)通過對(duì)已有的非功能化主鏈進(jìn)行化學(xué)改性的方法,(3)通過結(jié)合(1)和(2)來獲得。UNIT11FunctionalPolymersEachofthetwoapproacheshasitsownadvantagesanddisadvantages,andoneapproachmaybepreferredforthepreparationofaparticularfunctionalpolymerwhentheotherwouldbetotallyimpractical.兩種途徑中的每一種都有自身的優(yōu)點(diǎn)和缺點(diǎn),對(duì)特殊功能聚合物的制備而言,當(dāng)其他方法都無法實(shí)現(xiàn)時(shí),所選的方法或許是更合適的。Thechoicebetweenthetwowaystothesynthesisoffunctionalizedpolymersdependsmainlyontherequiredchemicalandphysicalpropertiesofthesupportforaspecificapplication.功能聚合物合成的兩種方法中,如何選擇主要取決于特殊應(yīng)用要求的主鏈聚合物的化學(xué)和物理性質(zhì)。Usuallytherequirementsoftheindividualsystemmustbethoroughlyexaminedinordertotakefulladvantageofeachofthepreparativetechniques.takefulladvantageof。。。,充分利用。。。為了充分利用每種制備方法,必須全面地考察獨(dú)立體系的要求。UNIT11FunctionalPolymersRapidprogressintheutilizationoffunctionalizedpolymericmaterialshasbeennotedintherecentpast.近年來,功能化聚合物材料的使用方面有了飛速的發(fā)展。Interestinthefieldisbeingenhancedduetothepossibilityofcreatingsystemsthatcombinetheuniquepropertiesofconventionalactivemoietiesandthoseofhighmolecularweightpolymers.Interestin,。。。的(重大)意義,對(duì)。。。關(guān)注由于能夠制造出來兼有活性官能團(tuán)特性和高分子量聚合物性能的功能聚合物,所以,人們對(duì)功能聚合物這個(gè)領(lǐng)域的興趣與日俱增。Thesuccessfulutilizationofthesepolymersarebasedonthephysicalform,solutionbehavior,porosity,chemicalreactivityandstabilityofthepolymers.這些聚合物的成功利用,基于功能聚合物的物理形態(tài),溶液行為,空隙率,化學(xué)活性及穩(wěn)定性。UNIT11FunctionalPolymersThevarioustypesoffunctionalizedpolymerscoverabroadrangeofchemicalapplications,includingthepolymericreactants,catalysts,carriers,surfactants,stabilizers,ion-exchangeresins,etc.各種功能化聚合物類型覆蓋化學(xué)應(yīng)用的寬廣領(lǐng)域,包括聚合物試劑,催化劑,載體,表面活性劑,穩(wěn)定劑,離子交換樹脂等。Inavarietyofbiologicalandbiomedicalfields,suchasthepharmaceutical,agriculture,foodindustryandthelike,theyhavebecomeindispensablematerials,especiallyincontrolledreleaseformulationofdrugsandagrochemicals.Pharmaceutical[fa:m?’sju:tik?l],藥品,藥物andthelike,等等,以及諸如此類。Indispensable,不可缺少的;controlledrelease,控制釋放agrochemicals,農(nóng)藥,化肥在生物學(xué)及生物醫(yī)學(xué)領(lǐng)域中,如藥物,農(nóng)業(yè),食品工業(yè)等,功能聚合物是不可缺少的材料,尤其在藥物和農(nóng)藥的控制釋放配方上。UNIT11FunctionalPolymersBesides,thesepolymersareextensivelyusedastheantioxidants,flameretardants,corrosioninhibitors,flocculatingagents,antistaticagentsandtheothertechnologicalapplications.Anti-,抗,反,對(duì),解,阻,減。antioxidants,抗氧化劑flameretardants,阻燃劑corrosioninhibitors,緩蝕劑flocculating[‘flokju:leiti?]agents,絮凝劑,floccule,n,絮狀物,絮狀沉淀。Flocculent,adj,羊毛狀的,絮凝的,antistaticagents,抗靜電劑此外,這些聚合物被廣泛地用做抗氧化劑,阻燃劑,緩蝕劑,絮凝劑,抗靜電劑及其他技術(shù)應(yīng)用。UNIT11FunctionalPolymersInaddition,thefunctionalpolymerspossess[p?’zes]broadapplicationprospectsinthehightechnologyareaasconductivematerials,photosensitizers,nucleartrackdetectors,liquidcrystals,theworkingsubstancesforstorageandconversionofsolarenergy,etc.possess[p?’zes],支配,控制,擁有,具有,掌握,克制,迷住。Prospects,展望,視野,景色,境界,[復(fù)數(shù)]前景,前程,前途conductivematerials,photosensitizers,光敏劑nucleartrackdetectors,核徑跡探測(cè)器另外,功能化聚合物在高科技領(lǐng)域具有廣闊的應(yīng)用前景。如導(dǎo)電材料,光敏劑,核徑跡探測(cè)器,液晶,用于太陽能等的轉(zhuǎn)化與儲(chǔ)存的工作物質(zhì)。Unit12PreparationsofAminoResinsinLaoratoryFormalin[‘fo:m?lin],福爾馬林(40%的甲醛水溶液)NaOH,sodiumhydroxide(hydrate),氫氧化鈉,potassiumhydrate(hydroxide),氫氧化鉀;calciumhydroxide,氫氧化鈣。HCl,chlorhydricacid,鹽酸。/glacialaceticacid,冰醋酸furfuryalcohol,糖醇triethanolamine[traieθ?’nol?min],三乙醇胺/woodflour,木粉/calciumphosphate,磷酸鈣ammoniumchloride,氯化銨/H2SO4,sulfuricacid,硫酸。Na2SO3,亞硫酸鈉,sodiumsulfite,Na2SO4,硫酸鈉,sodiumsulfate/Na2S2O8,過硫酸鈉,sodiumpersulfate.Thymolphthalein[‘θaimolfθ?’lin],百里酚酞/Glycerol[‘gliserol],甘油Monomethylolurea,methylol=hydromethyl,羥甲基,單羥甲基尿素UNIT14BulkPolymerization
本體聚合Bulkpolymerizationtraditionallyhasbeendefinedastheformationofpolymerfrompure,undilutedmonomers.Undiluted,adj,未沖淡的,未摻水,純粹的,dilute,v,沖淡,稀釋傳統(tǒng)上本體聚合定義為聚合物從純的、未稀釋的單體中形成。Incidentalamountsofsolventsandsmallamountsofcatalysts,promoters,andchain-transferagentsmayalsobepresentaccordingtotheclassicaldefinition.Incidental,adj,附帶的,非主要的Promoter,促進(jìn)劑,助劑chain-transferagents,鏈轉(zhuǎn)移劑根據(jù)傳統(tǒng)定義,很少量的溶劑和少量的催化劑,促進(jìn)劑,以及鏈轉(zhuǎn)移劑也可以存在。UNIT14BulkPolymerization
Thisdefinition,however,serveslittlepracticalpurpose.Itincludesawidevarietyofpolymersandpolymerizationschemesthathavelittleincommon,particularlyfromtheviewpointofreactordesign.Serve,vt.適合[用,宜]于,(合)用,起...作用,適合;達(dá)到然而,這個(gè)定義適用于少量的實(shí)踐用途。它包括了許多聚合物種類和聚合方案。從反應(yīng)其設(shè)計(jì)角度看,這些聚合方案(工藝)很少有共性的地方。Themoderngas-phaseprocessforpolyethylenesatisfiestheclassicaldefinition,yetisafarcryfromthemethylmethacrylateandstyrenepolymerizationwhichremainsingle-phasethroughoutthepolymerizationandaremoretypicallythoughtofasbeingbulk.Satisfy,vt.使?jié)M足;使?jié)M意;符合[達(dá)到](標(biāo)準(zhǔn)),【化】使飽和afarcry,n.遙遠(yuǎn)的距離,大不相同的東西;afarcryfrom,與…截然不同根據(jù)傳統(tǒng)的定義,現(xiàn)代的氣相聚乙烯聚合工藝屬于本體聚合過程,但與通常認(rèn)為的甲基丙烯酸甲酯和苯乙烯的典型的本體聚合過程截然不同,后者在整個(gè)聚合反應(yīng)過程中始終保持單相體系。UNIT14BulkPolymerization
本體聚合Acommonfeatureofmostbulkpolymerizationandotherprocessnottraditionallyclassifiedassuchistheneedtoprocessfluidsofveryhighviscosity.assuch,adv,同樣地,同量地,本身,照此,象這樣,就這一點(diǎn)而論;以那個(gè)資格[身分]classifyas,分為…類多數(shù)本體聚合以及不是按傳統(tǒng)分類為本體聚合的其他聚合過程有一個(gè)共同特征,就是需要處理非常高粘性的流體。Thehighviscosityresultsfromthepresenceofdissolvedpolymerinacontinuousliquidphase.高粘性是溶解在液相連續(xù)相的高分子的存在造成的。Significantconcentrationsofahighmolecular-weightpolymertypicallyincreasefluidviscositiesby10ormorecomparedtotheuncreatedmonomers.Uncreated,adj,自存的,未創(chuàng)造的,尚未產(chǎn)生的高分子量聚合物的高濃度顯著提高流體的粘度,達(dá)到單體自身粘度的10倍以上。UNIT14BulkPolymerization
本體聚合Thissuggestsclassifyingapolymerizationasbulkwheneverasubstantialconcentrationofpolymeroccursinthecontinuousphase.只要聚合物真實(shí)濃度存在連續(xù)相中(只要聚合物真正溶解在連續(xù)相中),就可以歸類為本體聚合。Althoughthisdefinitionencompassesawidevarietyofpolymerizationmechanisms,itleadstounifyingconceptsinreactordesign.Encompasses,v,包含或包括某事物,包圍,環(huán)繞Unifying,vt,統(tǒng)一,使成一體,使一致盡管這種定義包含多種聚合機(jī)理,在反應(yīng)器設(shè)計(jì)中還是導(dǎo)致了統(tǒng)一的概念。UNIT14BulkPolymerization
本體聚合Thedesignengineermustconfrontthepolymerinitsmostintractableform,i.e.,asahighviscositysolutionorpolymermelt.Confront,vt,使面臨,對(duì)抗Intractable,adj,難處理,難加工的,難治療的,難對(duì)付的,難駕御的,倔強(qiáng)的設(shè)計(jì)工程師必須面對(duì)聚合物以最難處理的形式存在,如高粘性溶液或聚合物熔體。Thereviseddefinitionmakesnosharpdistinctionbetweenbulkandsolutionpolymerizationsandthusreflectsindustrialpractice.Sharp,adj.明顯的,強(qiáng)烈的,刺耳的,急劇的,精明的,敏捷的修改的定義使本體聚合和溶液聚合沒有明顯的區(qū)別,但反映了產(chǎn)業(yè)實(shí)際情況。UNIT14BulkPolymerization
本體聚合Severalso-calledbulkprocessesforpolystyreneandABSuse5%-15%solventasaprocessingaidandchain-transferagent.個(gè)別的所謂本體聚合工藝的聚苯乙烯和ABS聚合使用5%-15%的溶劑作為工藝助劑和鏈轉(zhuǎn)移劑。Fewsuccessfulprocesseshaveusedtheverylargeamountsofsolventneededtoavoidhighviscositiesinthecontinuousphase,althoughthisapproachissometimesusedforlaboratorypreparations.少量成功的工藝使用大量的溶劑以避免連續(xù)相的高粘度,盡管這與實(shí)驗(yàn)室制備有時(shí)使用的方法接近。Bulkpolymerizationsoftenexhibitasecond,discontinuousphase.本體聚合常常出現(xiàn)第2個(gè)非連續(xù)相。UNIT14BulkPolymerization
本體聚合Theyfrequentlyexhibithighexothermicity,butthisismorecharacteristicofthereactionmechanismthanofbulkpolymerizationassuch.Exothermicity,放熱性本體聚合常常表現(xiàn)出高的放熱性,但是這是反應(yīng)機(jī)理的特征明顯要比本體聚合本身的特征更加明顯。Bulkpolymerizationsofthefree-radicalvarietyaremostcommon,althoughseveralcommerciallyimportantcondensationprocessessatisfythereviseddefinitionofabulkpolymerization.自由基類型本體聚合是最普通的,盡管一些重要的工業(yè)濃縮過程符合修正的本體聚合定義。Inallbulkpolymerizations,highlyviscouspolymersolutionsandmeltsarehandled.在所有的本體聚合中,高粘性聚合物溶液和熔體是可以控制的。UNIT14BulkPolymerization
本體聚合Thisfacttendstogoverntheprocessdesignandtoalesserextent,theprocesseconomics.這個(gè)事實(shí)支配聚合過程的設(shè)計(jì),使過程經(jīng)濟(jì)效益下降。Suitablyrobustequipmenthasbeendevelopedforthevariousprocessingsteps,includingstirred-tankandtubularreactors,flashdevolatilizers,extruderreactors,andextruderdevolatilizers.Robust,adj.強(qiáng)[健]壯的;雄壯的;費(fèi)力的(運(yùn)動(dòng)等);直爽的;健全的;堅(jiān)定的,粗魯[野]的;濃的,堅(jiān)固的,耐用的flashdevolatilizers,閃蒸釜extruder,擠出機(jī),singlescrewextruder,單螺桿擠出機(jī),twinscrewextruder,雙螺桿擠出機(jī);針對(duì)各種工藝步驟,適宜的耐用設(shè)備已經(jīng)得到發(fā)展,包括攪拌釜和管式反應(yīng)器,閃蒸釜,擠出反應(yīng)器,以及擠出脫揮器。
UNIT14BulkPolymerization
本體聚合Equipmentcostsarehighbasedonworkingvolume,butthevolumetricefficiencyofbulkpolymerizationsisalsohigh.volumetriccoefficient,容積系數(shù)設(shè)備成本很高基于工作體積(處理量),但是本體聚合的容積系數(shù)仍然是高的。Ifapolymercanbemadeinbulk,manufacturingeconomicswillmostlikelyfavorthisapproach.inbulk,散裝;松散;大批,大量:數(shù)量、數(shù)目或體積很大如果一種聚合物可以本體聚合方式制備,這種工藝因生產(chǎn)的經(jīng)濟(jì)性而受到歡迎。Itistemptingtosuggestthatpolymerprocesseswillgraduallyevolvetowardbulk.Evolve,vt.使發(fā)展,(使)進(jìn)化,演化,引伸出,推理,引出,放出,放射出;釋出,【化】離析聚合工藝將逐步向本體聚合發(fā)展是非常有吸引力的。UNIT14BulkPolymerization
本體聚合Recently,thesuspensionprocessforimpactpolystyrenehasbeensupplantedbythebulkprocess,andtheemulsionprocessforABSmaysimilarlybereplaced.Supplant,vt.代替,取代;(以不正當(dāng)?shù)氖侄?排擠;取而代之;最近,抗沖擊聚苯乙烯懸浮聚合工藝已經(jīng)被本體聚合所替代,而且ABS的乳液聚合工藝可能同樣被替代。However,themoderngas-phaseprocessforpolyethyleneappearstorepresentanoppositetrend.然而,聚乙烯的現(xiàn)代氣相聚合工藝則表現(xiàn)出相反的趨勢(shì)。Itseemsthatpolymerizationtechnologytendstoeliminatesolventsandsuspendingfluidsotherthanthemonomersthemselves.otherthan,adv.不同于,除了去除溶劑和不同于單體的懸浮流體似乎是聚合技術(shù)傾向。UNIT14BulkPolymerization
本體聚合Whenthemonomerisasolventforthepolymer,bulkprocessesasdescribedinthisarticlearechosen.當(dāng)單體是該聚合物的溶劑時(shí),就可以選擇這篇文章所描述的本體聚合工藝。Whenthemonomerisnotasolvent,suspensionandslurryprocesseslikethoseforpolyethyleneandpolypropyleneareemployed.當(dāng)單體不是該聚合物的溶劑時(shí),如聚乙烯和聚丙烯,懸浮聚合及泥漿聚合工藝,Hence,itisworthwhileavoidingahighlyviscouscontinuousphase,butnotatthepriceofintroducingextraneousmaterial.因此,避免高粘連續(xù)相,而不讓其他物料進(jìn)入是值得做的。因此,我們應(yīng)該做到避免高粘連續(xù)相,而不讓其他物料進(jìn)入。UNIT15GeneralDescriptionoftheVCSuspensionPolymerizationProcess(氯乙烯懸浮聚合過程概述)ByfarmajorityofPVCisproducedviathesuspensionroute.①絕大多數(shù)聚氯乙烯是采用懸浮聚合工藝生產(chǎn)的。Inthisprocessthevinylchloridemonomerissuspended,asliquiddroplets,inacontinuouswaterphasebyacombinationofvigorousagitationandthepresenceofaprotectivecolloid(dispersantorsuspendingagent).Droplet,小滴protectivecolloid,保護(hù)膠體vigorous,adj,精力旺盛的,有力的,健壯的,強(qiáng)勁的agitation,n,攪拌;stir,n,vt,攪動(dòng),攪拌這個(gè)工藝中,在強(qiáng)力攪拌和保護(hù)單體存在的聯(lián)合作用下,氯乙烯單體以液滴形式懸浮在水連續(xù)相中。UNIT15GeneralDescriptionoftheVCSuspensionPolymerizationProcess(氯乙烯懸浮聚合過程概述)Amonomersolublefreeradicalinitiatorisusedsuchthathasbeenshowntobeequivalenttothatfoundinbulkpolymerization.beequivalentto,相等[當(dāng)]于...,等(同)于,與...等效溶解自由基引發(fā)劑的單體(液滴)表現(xiàn)出與在本體聚合等同的行為。Commercialplantsarebasedonbatchreactors,thesizeofwhichhaveincreasedprogressivelyovertheyears.theoriginalplantsbuiltduringthe1940susuallyconsistedof1000gallonreactors.Progressively,adv.日益增多地商用設(shè)備是基于間歇式反應(yīng)器,與19世紀(jì)40年代建造的1000加侖反應(yīng)器相比,反應(yīng)器的尺寸逐年增加。Duringthe1950sand1960sthisincreasedto3000-5000gallonandsubsequently,duringtheearly1970s,29000gallonreactorsystemsweredevelopedbyShinEstu②andupto44000gallon(200m)bytheGermancompanyHuls.1950-1960期間尺寸增大到3000-5000加侖,后來在19世紀(jì)70年代初期,由信月公司開發(fā)了29000加侖反應(yīng)器系統(tǒng),后來德國的Huls公司又增加到44000(200m2)加侖的反應(yīng)器體積。UNIT15GeneralDescriptionoftheVCSuspensionPolymerizationProcess(氯乙烯懸浮聚合過程概述)Atthepresenttimefewnewplantsbeingbuiltconsistofreactoroflessthan15000galloncapacity,havingabatchsizeofabout25tonesofmonomer.目前正建造的新反應(yīng)器很少有小于15000加侖的,約25噸單體所需要的釜尺寸。Smallerreactorswereoftenglasslinedtogiveasmooththatwouldresistthelaydownofdepositsonthewalls.③Largerreactorsareusuallyofpolishedstainlesssteel.④小型的(氯乙烯懸浮聚合)反應(yīng)器內(nèi)壁搪?lián)懿A贡诿婀饣?,以防止聚合物粘壁。而大的反?yīng)器通常是拋光的不銹鋼(內(nèi)壁)。Thepolymerizationofvinylchlorideisaveryexothermicreactionandsotheabilitytoremoveheatisusuallythelimitingfactorinattemptingtominimizereactiontimes.氯乙烯的聚合反應(yīng)是放熱反應(yīng),所以移走熱量的能力常常是使反應(yīng)時(shí)間最小化的限制因素。UNIT15GeneralDescriptionoftheVCSuspensionPolymerizationProcess(氯乙烯懸浮聚合過程概述)Asthesizeofreactorshasincreasedthesurfaceareatovolumeratiohasdecreasedthusaggravatingtheproblem.thesurfaceareatovolumeratio,比表面積隨著反映其尺寸的增加,比表面積減小,從而使(散熱)問題更嚴(yán)重。Internalcoolingcoilsarenotusuallyusedastheywouldattractdepositsandbedifficulttocleanandthushaveanadverseeffectonproductproperties.coolingcoil,冷卻旋管通常不采用內(nèi)部的冷卻旋管(進(jìn)行冷卻),因?yàn)檫@些管路很容易沉積而且很難清洗,對(duì)產(chǎn)品質(zhì)量的影響是負(fù)面的。Theproblemisoftenovercomebytheuseofchilledwaterorthefittingofarefluxcondenserwhich,viathecontinuedrefluxingofvinylchloridemonomer,utilisesitslatentheatofvapourisationforcoolingpurposes.⑤解決問題的方法是采用冷凍水或安裝回流冷凝器,回流冷凝器連續(xù)回流氯乙烯單體,利用單體的蒸發(fā)潛熱冷卻反應(yīng)物料。UNIT15GeneralDescriptionoftheVCSuspensionPolymerizationProcess(氯乙烯懸浮聚合過程概述)Coldwaterisusuallychargedtothereactorfirstalthoughitissometimespreheated.冷卻水通常先被加入反應(yīng)器中,盡管這樣有時(shí)可能被預(yù)熱。ThepHregulatoristhenaddedfollowedbythedispersant(s)aresprinkledontothesurfaceoftheaqueousphaseimmediatelybeforesealingthereactorwhichisthenevacuatedtoremoveoxygenasthiscanincreasepolymerizationtimeandaffectproductproperties.pHregulator,pH計(jì)seal,n.封鉛,封條,印,圖章,密封;vt.封,密封;n.海豹,海豹毛皮evacuate,v.疏散,撤出,排泄然后安裝pH計(jì),接著立即將分散劑噴灑到液相表面,在密封反應(yīng)器之前,將氧氣排除,因?yàn)檠鯕鈺?huì)增加聚合時(shí)間而且影響產(chǎn)物的性質(zhì)。Whenevacuationiscompletethevinylchlorideischargedandheat-upofthereactorcontentscommenced.⑥當(dāng)氧氣排除結(jié)束后,填充氯乙烯,開始反應(yīng)物料的加熱。UNIT15GeneralDescriptionoftheVCSuspensionPolymerizationProcess(氯乙烯懸浮聚合過程概述)Reactortemperature,whichisthemaincontrollingfactorforproductmolecularweight,iscommonlyintherange50-70℃resultinginreactorpressuresof100-165psig.Psig,abbr.poundspersquareinch,gauge磅/平方英寸(表壓)反應(yīng)器溫度,是控制產(chǎn)物分子量的因素,通常在50-70℃,導(dǎo)致反應(yīng)器壓力為100-165psig。Thetrendistowardstheoperationoflargeclosedreactorswhichareonlyopenedformaintenanceor,possibly,occasionalcleaningoperations.⑦反應(yīng)器的大型化封閉式操作是發(fā)展方向,僅僅在維護(hù)或偶然的清理時(shí)才打開聚合釜Inthiscaseallingredientsarechargedassolutionsordispersionsandtherewouldgenerallybenoneedfortheevacuationstep.在這種場(chǎng)合下,所有的物料以溶液或分散體系的方式被填充,因此不需要排除空氣的步驟。UNIT15GeneralDescriptionoftheVCSuspensionPolymerizationProcess(氯乙烯懸浮聚合過程概述)Whenthedesiredconversionhasbeenreached,usually75%-95%,thereactioncanbechemicallyshort-stoppedifrequiredandthebulkoftheremainingmonomerrecovered.thebulkof…,大半,大部,大多數(shù)recover,vt.恢復(fù),使恢復(fù)原狀,使(身體)復(fù)原;尋找回,重新獲得;挽回,彌補(bǔ)使和解,安撫;使悔改;重新利用;再生當(dāng)達(dá)到理想的轉(zhuǎn)換率,通常為75-95%,如果需要的話,反應(yīng)可以被停下來,而且剩余單體的大部分被補(bǔ)充。Theproductslurryisthenstrippeddowntoverylowresidualvinylchloridelevelsbytreatmentatelevatedtemperatures,eitherinthereactororsimilarvessel,orbycontactwithsteaminacountercurrentmutilatestrippingtower.Countercurrent,n.,逆流,[電]反向電流;adv.相反地strippingtower,汽提塔通過在提高溫度情況下處理,不是在反應(yīng)器中,就是在逆流氣提塔與水蒸氣接觸,淤漿產(chǎn)物被脫出單體到非常低的氯乙烯殘留水平,
Theslurryisthendewateredbycentrifugingandtheresultingwetcakedried,commonlyonamulti-stageflashdrier,althoughawidevarietyofdifferentdriertypesisusedbyvariousmanufactures.flashdrier,急驟干燥機(jī)然后采用離心過濾將淤漿脫水,將產(chǎn)生的濕濾餅用多步急驟干燥機(jī)進(jìn)行干燥,盡管不同的企業(yè)采用不同的干燥器類型。Afterdrying,theproductispassedthroughsomekindofscalpingscreentoremoveextraneouslargeparticlesbeforebaggingorloadingtobulkroadtankers.passthrough,v.經(jīng)過,通過scalpingscreen,篩分設(shè)備干燥以后,產(chǎn)物通過篩份設(shè)備移開無關(guān)的大顆粒,然后包裝,裝填到大的油罐汽車。II.TextComprehension1.在此過程中,通過強(qiáng)烈攪拌并使用保護(hù)性膠體(分散劑或懸浮劑),氯乙烯單體呈液滴狀懸浮在連續(xù)的水相中。所用的自由基引發(fā)劑能溶于單體,故聚合反應(yīng)發(fā)生在懸浮液滴內(nèi)部,且研究表明,液滴內(nèi)的聚合機(jī)理相當(dāng)于本體聚合。2.工廠生產(chǎn)以間歇反應(yīng)器為基礎(chǔ),其規(guī)模逐年增大。3.現(xiàn)在,新建工廠的反應(yīng)器的容積幾乎不會(huì)小于15000加侖,其間歇反應(yīng)的單產(chǎn)能力約為25噸單體。4.氯乙烯聚合反應(yīng)放出的熱量很大,因此,排除反應(yīng)熱的能力通常是縮短反應(yīng)時(shí)間的制約因素。隨著反應(yīng)器體積的增大,反應(yīng)器表面積與其體積之比隨之減小,這又會(huì)加劇上述問題。通常,反應(yīng)器中不采用內(nèi)冷盤管,因?yàn)閮?nèi)冷盤管易引起結(jié)垢、且難以清理而對(duì)產(chǎn)品質(zhì)量有不利的影響。5.一般先注入冷水(盡管有時(shí)冷水需要預(yù)熱),再加入PH值調(diào)節(jié)劑,然后再加入一種或幾種預(yù)先制備成溶液的分散劑。一種或幾種引發(fā)劑在密封反應(yīng)器之前才噴灑在液相表面,隨后反應(yīng)器抽真空除氧,因?yàn)檠鯐?huì)延長聚合反應(yīng)時(shí)間并影響產(chǎn)品質(zhì)量。除氧結(jié)束再加入氯乙烯,并開始加熱反應(yīng)物料。反應(yīng)溫度(是影響產(chǎn)品分子量的主要因素)通??刂圃?0~70℃左右,相應(yīng)的反應(yīng)器表壓為100~165英鎊/英寸2。psig=poundpersquareinchgauge,英磅/英寸2(表壓力)6.在這種情況下,所有的反應(yīng)組分均以溶液或分散液的形式加入,且通常無須真空排氧工序。7.當(dāng)轉(zhuǎn)化率達(dá)到要求(通常為75-95%)時(shí),根據(jù)需要,反應(yīng)可進(jìn)行化學(xué)終止,此后必須將大量的殘留單體分離并回用。在較高的溫度下,在反應(yīng)器中或類似的容器中,或通過在多級(jí)脫揮塔中與蒸汽的逆向接觸,可將反應(yīng)產(chǎn)物淤漿中的殘留氯乙烯含量降到很低的水平。隨后,淤漿進(jìn)行離心脫水,生成的潮濕餅料再行干燥,干燥設(shè)備一般為多級(jí)閃蒸干燥器,當(dāng)然各生產(chǎn)廠家可根據(jù)實(shí)際情況采用各種不同類型的干燥設(shè)備。經(jīng)過干燥以后,在產(chǎn)品包裝或罐裝到大型槽車內(nèi)之前,產(chǎn)品還需通過某種類型的分級(jí)篩以去處其中的大顆粒。Unit24MechanicalPropertiesofPolymers1、聚合物的機(jī)械性能在所有用作結(jié)構(gòu)材料的應(yīng)用中都很重要。聚合物的機(jī)械性能是指材料在外力作用下的形變特性。2、最重要、最有特征性的機(jī)械性能稱為模量,模量是作用的應(yīng)力與相應(yīng)的變形量之比。模量的倒數(shù)稱為柔量。模量的性質(zhì)依賴于形變的性質(zhì)。reciprocala.1)相互的,互惠的,有來有往的;2)相應(yīng)的,互補(bǔ)的;3)相對(duì)的,彼此相反的;4)[數(shù)]倒數(shù)的,反商的n.1)互相關(guān)聯(lián)的事物,互相起作用的事物;2)[數(shù)]倒數(shù),反商3.其他較為重要、略為復(fù)雜的變形是彎曲和扭變,由彎曲變形可求得材料的拉伸模量,而材料的扭矩則是由其剛性所決定的。flexurala.撓性的,彎曲的flexuren.1)屈曲,褶曲,彎曲(部);2)曲線;3)[數(shù)]歪度;4)[物]曲率4.交聯(lián)的彈性體是一種特殊情況。由于交聯(lián),這類聚合物幾乎不能流動(dòng)。橡膠彈性的動(dòng)力學(xué)理論是由Kuhn、Guth、James、Mark、Flory、Gee和Trelaor提出的。對(duì)于較小應(yīng)變下的楊氏模量可推導(dǎo)出下列方程:leadto通向,導(dǎo)致5.上文討論了理想的彈性變形,即假定應(yīng)變是應(yīng)力的非時(shí)間依賴性函數(shù)的形變。而實(shí)際上,材料不可能是理想彈性的,在某些情況下材料具有非彈性的性質(zhì)。6.對(duì)于非
溫馨提示
- 1. 本站所有資源如無特殊說明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請(qǐng)下載最新的WinRAR軟件解壓。
- 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請(qǐng)聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
- 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁內(nèi)容里面會(huì)有圖紙預(yù)覽,若沒有圖紙預(yù)覽就沒有圖紙。
- 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
- 5. 人人文庫網(wǎng)僅提供信息存儲(chǔ)空間,僅對(duì)用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對(duì)用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對(duì)任何下載內(nèi)容負(fù)責(zé)。
- 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請(qǐng)與我們聯(lián)系,我們立即糾正。
- 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對(duì)自己和他人造成任何形式的傷害或損失。
最新文檔
- 員工環(huán)?,F(xiàn)場(chǎng)培訓(xùn)
- 員工法律合規(guī)培訓(xùn)
- 員工心態(tài)培訓(xùn)課件
- 施工機(jī)械保養(yǎng)制度
- 酒店股份合資經(jīng)營協(xié)議
- 員工崗位技能培訓(xùn)
- 教育培訓(xùn)退費(fèi)制度
- 基礎(chǔ)金融知識(shí)
- 扶貧資產(chǎn)公廁管護(hù)制度
- 員工培訓(xùn)課件設(shè)計(jì)
- 2026年商洛市兒童福利院招聘備考題庫(6人)附答案詳解
- 2025年湖北能源集團(tuán)股份有限公司招聘筆試真題
- ARK+Invest+年度旗艦報(bào)告《Big+Ideas+2026》重磅發(fā)布
- 2026山西臨汾市大寧縣招聘第四次全國農(nóng)業(yè)普查辦公室人員8人備考題庫及一套完整答案詳解
- 美國變壓器市場(chǎng)深度報(bào)告
- 建設(shè)工程第三方質(zhì)量安全巡查標(biāo)準(zhǔn)
- 乳化液處理操作規(guī)程
- 飯店轉(zhuǎn)讓協(xié)議合同
- 營建的文明:中國傳統(tǒng)文化與傳統(tǒng)建筑(修訂版)
- 液化天然氣氣化站安全檢查表
- 2023年白銀有色集團(tuán)招聘筆試題庫及答案解析
評(píng)論
0/150
提交評(píng)論