简介:以2,2,6,6-四甲基-4-羟基哌啶、烯丙基氯和氢氧化钠为原料催化合成4-烯丙氧基-2,2,6,6-四甲基哌啶,分别研究了反应时间、原料配比、溶剂用量和催化剂用量等条件对合成4-烯丙氧基-2,2,6,6-四甲基哌啶反应的影响,确定的最佳操作条件为:反应温度为45~54℃,反应时间5h,反应物摩尔比为:n(烯丙基氯)∶n(2,2,6,6-四甲基-4-羟基哌啶)∶n(氢氧化钠)为0.45∶0.1∶0.4,溶剂用量为10g,催化剂的用量为0.2g(2,2,6,6-四甲基-4-羟基哌啶为0.1mol),收率可达到95.43%以上,纯度为99.5%。
简介:SlagcorrosionresistanceofMgOZrO2refractorieswasinvestigatedinthiswork.Theresultsindicatethatinanon-orientedelectricsteelslagsystemwithahighratioofcalciatosilica,theslagresistanceofMgOZrO2refractoriescanbedescribedasfollows:ZrO2reactswithCaOformingcalciumzirconatecompoundwhichstrengthensthematerialandblocksthechanneloftheslaginfiltration;however,inanorientedelectricsteelslagsystemwithahighconcentrationofsilicaandthelowratioofcalciatosilica,theslagcorrosionresistanceofMgOZrO2refractoriesisdifferent;ZrO2reactswithCaOformingthecalciumzirconateandsimultaneouslyonemoreproductC2Saswell;C2Scanimprovecorrosionresistancebyblindingporeandenhancingslagviscosity;therefore,itisexpectedtobethemajorreasonfortheenhancedcorrosionresistanceobservedforMgOZrO2refractories.
简介:Al2O3-MgOcastableshavebeenwidelyusedforworkingliningsofsteelladleduetotheirsuperiorhotstrengthandcorrosionresistance.Inthiswork,effectsofmicrosilica,ultrafinealuminaandMgOfinesadditionsontherheologicalbehaviorofthecastableswereinvestigatedbymeansofIBBrheometerV1.0tomeasuretorque(shearstress)undervaryingshearrates.Theresultsshowthatrheologicalpropertiesofcastablesatvaryingshearratesaresignificantlyimprovedwithincreaseofmicrosilicaadditions(from1mass%to5mass%)andcorrespondingdecreaseinwateraddition;thereisonlylittlechangeinrheologicalbehaviorwithvariationofultrafinealuminaandMgOfinesadditions.Optimumultrafinealuminaandmicrosilicaadditionsarerecommendedforcastableswithgoodrheologicalbehavior.
简介:Cr2O3canbesinteredwellat1500℃incarbon-embeddedconditionorH2atmosphere.Butthehighchromebearingrefractoriescannotreachdensificationwhensinteredat1700℃for10hinweakreducingatmosphereformedbythecombustionoffuel,anditsapparentporosityisabout18%.Thehighchromebearingrefractoriesaremainlyusedincoalgasifiers.Thetemperatureinthefurnaceisabout1500℃andtheproductsareH2andCO,whicharejustthesinteringconditionsofthedensechromerefractorieswithapparentporositylessthan10%.Thehighchromebearingrefractoriesusedincoalgasifiersmaybesinteredagainandthenshrink,destroyingthegasifierlining.Thethermodynamiccalculationshowsthatitissafeaboutthehighchromebearingrefractoriesusedingasifiers.Itisalsoexplainedthatthehighchromebearingrefractoriescan’tbesintereddenselyinweakreducingatmosphereformedbythecombustionoffuel.Thenewsinteringtechnologiescanbeusedtoimprovethebulkdensityofthehighchromebearingrefractories.
简介:日本科学技术振兴机构近日发表新闻公报说,大阪府一家化工企业受该机构委托,开发出一种新技术,有助于今后大批量生产对环境友好的磷系阻燃剂。磷系阻燃剂这些年作为卤系阻燃剂的替代品备受瞩目.但是这类阻燃剂多为液态.添加后会导致塑料耐久性和耐水性下降。在本项研究中.片山化学工业公司的研究人员摒弃了以往物理混合的方法,改为将磷元素直接导入高分子树脂的骨架.实现了阻燃剂性能的稳定。添加了这种阻燃剂的塑料机械特性、耐水性等都未出现下降,同时耐燃性得到了很大提高。公报说.在本项研究中,研究人员使用的阳离子镍氢络合催化剂是以廉价的氯化镍为原料开发出的,可以高效催化合成阻燃剂,这将有助于今后大批量生产对环境友好的磷系阻燃剂。
简介:人才培养模式是专业发展的关键性问题之一。宁波工程学院外国语学院经过充分调研和理性思考,最终确立了WITT英语专业人才培养模式。本文拟从WITT人才培养模式的理论基础一交际能力理论和建构主义学习理论入手,探讨WITT人才培养模式独特的内涵与特色。同时,结合具体的人才培养实践以及成果,进一步验证WITT人才培养模式的有效性。
简介:综述了三(2-羟乙基)异氰尿酸酯合成研究进展,及其在含氯聚合物的锌基复合稳定剂和有机基复合稳定剂中的应用研究进展。