简介:Thestarch/D,L-lactidegraftcopolymersweresynthesizedbyreactingD,L-lactidewithcornstarchinN,N-dimethylacetamide(DMAM)inthepresenceoftriethylamine(NEt3)andanhydrouslithiumchloride.TheeffectofreactiontimeandthemolarratioofD,L-lactidetoglucosestructuralunitofstarchonmonomerconversion(C%),graft(G%)andgraftefficiency(GE%)werestudied,TheC%,G%andGE%couldapproach37.3%179.7%and68.0%,respectivelywhenthemolarratioofD,L-lactidetoglucosestructuralunitofstarchis10:1andthegraftcopolymerizationwascarriedoutat80-85℃for4hrundernitrogenatmosphere.TheFouriertransformsinfra-red(FTIR)spectroscopy.differentialscanningcalorimetry(DSC)andX_raydiffraction(XRD)spectroscopywereusedinordertocharacterizethegraftcopolymers.FTIRspectrashowthatabsorptionbandat1740cm^-1confirmedtheformationofesterbond,indicatingthestarch/D,L-lactidegraftcopolymerswereproduced,theDSCcharacteristicresultsshowthemeltingtemperatureofthegraftcopolymerwereelevatedslightlyasthemolarratioofD,L-lactidetoglucosestructuralunitsofstarchincreasedandtheX-raydiffractionspectrashowthesynthesizedgraftcopolymerswereamorphous.Thedegradabilityofgraftcopolymerwastestedwiththeaidofacid,alkaliandmicrobesuchasbacillussubtilisandstaphylococcusaureus.Theresultsofwaterrsistanceshowthegraftcopolymerproducedcanbeusedasacomponentofimpermeablecoatingforcardboard.
简介:摘要:国有企业职工家属区供水、供电、供热(供气)及物业管理(统称“三供一业”)分离移交,是深化国有企业改革的一项重要任务,是剥离企业办社会职能,减轻国有企业历史负担、精干主业发展,整合资源改造提升基础设施、改善民生的重要举措。本文介绍了DL公司在供热分离移交工作中的主要做法及三点工作体会,以供参考。
简介:Anewbiodegrablehydrogelbasedonα,β-poly-aspartamidewassynthesizedbypolycondensationofDL-asparticacidand85%phosphoricacidinvacuityat180°C,andthenbyring-openingwith3-aminopropanoltogetherwithcross-linkingreactionwithethanediamimo.
简介:摘要:DL166H扁钢,在线预硬后下坑缓冷,辊底炉回火后精整检查发现侧面纵裂。裂纹断续,未延伸至端面,裂纹取料分析,有裂纹源,裂纹源有脱碳。