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Unit12PreparationsofAminoResinsinLaboratorySchoolofMaterialScienceandEngineering,WuhanInstituteofTechnology•Aminoresinsarereactionproductsofaminoderivativeswithaldehydesunderacidicorbasicconditions.Themostimportantrepresentativesofthisclassaretheurea-formaldehyde(UF)andmelamine-formaldehyderesins.氨基树脂是由氨基衍生物和醛在酸性或碱性条件下反应生产得到的其中最重要最具代表性的物质是脲醛树脂和蜜胺树脂。•Chemicals:Urea,formalin(37%),ethanol,2NNaOHsolution,1NstandardNaOHsolution,1NstandardHCl（hydrogenchloride）solution,glacialaceticacid,furfurylalcohol（糠醛）,triethanolamine（三乙醇胺）,woodflour（木屑）,calciumphosphate（磷酸钙）,ammoniumchloride（氯化铵）,0.5NH2SO4（sulfuricacid）solution,Na2SO3(sodiumsulphite),1%ethanolicthymolphthalein（百里酚酞）indicatorsolution,melamine(三聚氰胺),glycerolandmonomethylolurea(单羟甲基脲).药品：尿素，福尔马林（37%），乙醇，2NNaOH,0.1NNaOH溶液，1N标准NaOH溶液，1N标准HCl溶液，冰醋酸，糠醇，三乙醇胺，木粉，磷酸钙，氯化铵，0.5NH2SO4溶液，Na2SO3，1%乙醇百里酚酞指示剂溶液，三聚氰胺，甘油和单羟甲基脲。•Apparatus.Flasksandbeakers,500-mLthree-neckresinkettle,heatingmantle,mechanicalstirrer,condenser,Dean-Starktrap,oven,universalindicatorpaper,testtubes,250-mLvolumetricflask,icebath,10-mlpipette,burette,oilbath,screwcapandjar.装置：烧瓶和烧杯，500ml的三口烧瓶，加热套，机械搅拌器，冷凝器，迪安—斯达克塔分水器，烘箱，广泛试纸，试管，250mL的容量烧瓶，冰浴，10ml的移液管，滴管，油浴和广口瓶。•PreparationofaUFresinunderacidicconditions.酸性条件下制备脲醛树脂•Inordertodemonstratetherapidityofthereactionofureawithformaldehydeunderacidiccondition,mix5gofureawith6mLofformalininatesttube,andshakethetubeuntiltheureahasdissolved.为了证明尿素和甲醛在酸性条件下的迅速反应，将5g尿素和6mL福尔马林在试管中混合，振荡试管直到尿素全部溶解。•AdjustthepHofthesolutionto4bytheadditionof4dropof0.5NH2SO4,andobservethetimerequiredforprecipitationtooccur.Removepartoftheprecipitateandcompareitssolubilityinwaterwiththesampleofmonomethylolurea.滴加4滴0.5NH2SO4以调节溶液pH到4，观察析出沉淀所需要的时间，取出部分沉淀并比较此沉淀以及单羟甲基脲样品在水中的溶解性。•Preparationofaurea-formaldehydeadhesive.制备脲醛树脂粘合剂•60grams(1mole)ofureaand137g(1.7mole)offormalin(37%)arechargedintoa500-mLreactionkettleequippedwithamechanicalstirrerandarefluxcondenser.将600g(1mole)尿素和137g(1.7mole)福尔马林放入500ml三口烧瓶中，并安装好机械搅拌器和回流冷凝器，•ThepHofthemixtureisadjustedwith2NNaOHsolutiontobetween7and8asdeterminedbyuniversalindicatorpaper,andthemixtureisrefluxedfor2hr.通过用广泛试纸测定用2NNaOH溶液把混合物PH值调至7~~8，然后将混合物回流2小时，•Ateachsubsequent0.5-hrintervaluntilthewaterhasbeenremoved，determinethefree-formaldehydecontentofthemixturebytheprocedureindicatedbelow.每隔半小时用下面的方法测定一次混合物中的自由甲醛含量，直到水完全脱除为止。•Afterthemixturehasrefluxedfor2hrs,aDean-Starktrapisintroducedbetweentheflaskandtherefluxcondenser.当混合物回流2小时后，将迪安—斯达克塔分水器安装在烧瓶和回流冷凝器之间，。•About40mLofwaterisdistilledintothetrapandisdiscarded.Thesolutionisacidifiedwith5dropsofglacialaceticacid;44goffurfurylalcoholand0.55goftriethanolamineareintroducedintothereactionmixture,andthesolutionisheatedat90℃for15min.大约有40ml水被蒸馏，用5滴冰醋酸将溶液酸化；将44g糠醇和0.55g的三乙醇胺加入到反应混合液中，加热此溶液到90℃并恒温15分钟。。•Themixtureiscooledtoroomtemperature.A15gsampleoftheresinisremovedandismixedwithahardenercomposedof1gofwoodflour,0.5gofcalciumphosphate,and0.2gofammoniumchloride.将混合物冷却到室温。取出15g的树脂样品和由1g木粉，0.05g磷酸钙和0.2g氯化铵组成的硬化剂混合，。•Themixtureissetasidetohardenatroomtemperature.Theremainingresintowhichthehardenerhasnotbeenaddedisplacedinascrewcapjarandissubmittedtothelaboratoryinstructor.将混合物进行室温固化，将剩下的没有加工硬化剂的树脂放入广口瓶中并提交给实验导师。。•Determinnationofthefreeformaldehydecontent自由甲醛含量的测定：•Prepare250mLofa1MNa2SO3solution,andneutralizethesolutionsoitproducesfaintbluecolorwiththymolphthaleinindicatorsolution.自由甲醛含量的测定：准备250mL1NNa2SO3溶液，并中和该溶液，从而使其产生淡蓝色的百里酚酞指示剂溶液。。•Addaweighed2to3gsampleofresininto100mLofwaterina250-mLErlenmeyerflask（锥形瓶）,andswirlthecontentsoftheflaskuntiltheyaredissolvedcompletely.在250ml锥形瓶中加入重为2到3克的树脂样品到100mL的水中，摇晃锥形瓶使锥形瓶内的溶液充分溶解。。•Iftheresinwillnotdissolve,ethanolmaybeaddedtoaidthesolutionprocess.如果树脂不能溶解，加入乙醇可以帮助溶解。•Coolthesolutionto4℃inanicebath.Place25mLofthe1MNa2SO3solutionina100mLbeaker,andpipette10.00mLofastandardized1NHClsolutionintothebeaker.Coolthesolutionto4℃.在冰浴中使溶液的温度下降到4℃，加25mL的1MNa2SO3溶液在100mL的烧瓶中，用移液管移取10ml标准的1NHCl溶液到烧瓶中，降温至4℃。。•Add10to15dropsofthymolphthaleinindicatorsolutiontotheflaskcontainingthesample,andadjustthecolorofthesolutiontoafaintbluewith0.1NNaOH.加10-15滴百里酚酞指示剂溶剂到样品烧瓶中，调整溶液的颜色至淡蓝色，。•Immediately,transfertheacid-sulfitesolutiontotheflaskcontainingthesample,completingthetransferwithcoldwater.Titratethesolutiontothethymolphthaleinendpointwithstandard1NNaOHsolution.•CH2O+Na2SO3+H2O→CH2OHSO3-Na++NaOH用冷水冷却以后迅速地转移酸式亚硫酸盐溶液到样品烧瓶中。滴定溶液到百里酚酞的终点（标准1NNaOH溶液）。•Determinethe%freeformaldehydefromthequantityofHCLrequiredtoneutralizetheresinsolution.通过中和树脂溶液的HCl溶液的量来测定自由甲醛的百分含量。。•Preparationofamelamine-formaldehyderesin.三聚氰胺甲醛树脂的制备。•Toa500-mlreactionkettleequippedwithamechanicalstirrerandacondenserisadded63g(0.5mole)ofmelamineand122g(1.5mole)offormalin(37%).Themixtureisrefluxedfor40min.在一个500ml的配置有机械搅拌器和一个冷凝器的反应器中加入63g(0.5ml)的三聚氰胺和122g(1.5ml)的福尔马林（37%）。混合物回流40分钟。。•the%offreeformaldehydeshouldbedeterminedbutat10-mininterval.Theprocedureforthefree-formaldehydedeterminationisgivenabove.%自由甲醛需要每隔十分钟测定一次。自由甲醛的测定步骤如上所述。。•After20-minheatingofthesample,aDean-Starktrapisinsertedbetweentheflaskandthecondenser,and10mlofwaterisdis