简介:Asubstitutedglycolide,3-benzyloxymethyl-1,4-dioxane-2,5-dione,wassynthesized.Itisasuitableprecursorforthepreparationofanewhydrophilicbiodegradablepoly(a-hydroxyacid).ThepolymerizationswerecarriedoutinbulkinthepresenceofSn(Oct)2at120-140℃.TheresultingpolymersweresubjectedtohydrogenolysiswithaPd/Ccatalystinamixedsolventtoremovetheprotectingbenzylgroups.Anovelpoly(a-hydroxyacid)withpendanthydroxygroupswasobtained.Thehydrophilicityoftheresultingpolymerwasevaluatedpreliminarily.``
简介:Aseriesofsulfonatedpolyimides(SPIs)containingpyridinegroupswerepreparedbydirectpolycondensationfrom1,4,5,8-naphthalenetetracarboxylicdianhydride(NTDA),4,4'-diaminodiphenylether-2,2'-disulfonicacid(ODADS)and4-(4-methoxy)phenyl-2,6-bis(4-aminophenyl)pyridine(DAM).Theresultingcopolymersdisplayedgoodsolubilityincommonorganicsolvents.Flexible,transparent,toughmembraneswereobtainedviasolutioncasting.Allthefilmsshowedhighthermalstabilitywithdesulfonationtemperatureover300℃.TheyexhibitedprominentmechanicalpropertieswithYoung'smodulusaround2.0GPa.Highprotonconductivity(0.23S/cmat100%RH)wasalsoobserved.Moreimportantly,thenewmaterialsexhibitedlowwateruptake(30wt%-75wt%at80℃)andimprovedwaterstability,whichwereattributedtotheacid-baseinteractionbetweensulfonicacidandpyridinefunctionalgroups.
简介:TwokindsofSt/DVBcopolymerbeedscontaining(1-pyrenyl)formyland(1-pyrenyl)methylgroupsrespectivelyhavebeensynthesizedbybothfunctionalizationandcopolymerization.Thefluorescencespectraoftheswollenpolymerssynthesizedaresimilarinshapetothoseofthecorrespondingmodelcompounds,whiletheintensityratioofexcimertomonomershowscleardependenceonthecontentsofthepyrenegroups.
简介:Thisreviewfocusedontherecentreportsrelatedtothefunction,characterizationandmodificationofoxygen-containingsurfacegroupsofactivatedcarbon(AC).TheOxygen-containingsurfacegroupswerebrieflydescribed,andthemostfrequentlyusedtechniquesforcharacterizationoftheoxygen-containingsurfacegroupsonACswerealsobrieflystated.Adetaileddiscussionoftheeffectsoftheoxygen-containingsurfacegroupsontheadsorptivecapacityofACwasgiven.Therecentprogressesinmodificationoftheoxygen-containingsurfacegroupsofACwerealsoreviewed.
简介:Fourpolymerscontainingfive-memberedringsinthemainchain,withorwithoutconjugationstructurealongthebackboneandwithorwithoutconjugatedpendentgroups,weredesignedandsynthesizedbymetathesiscyclopolymerizationoffunctionalizedα,ω-diynes,andcyclopolymerizationoffunctionalizedα,ω-dienescatalyzedbytheα-diiminepalladium-basedcatalyst,respectively.Hightomoderatemonomerconversionswereachieved.Chainstructure,molecularweight,andmolecularweightdistribution(MWD)ofthecyclopolymerizationproductswerecharacterizedby1H-,13C-NMR,FTIR,andGPC.Thepolymersshowedregularmainchainstructures,moderatelyhighmolecularweight,andnarrowMWD.Thermalpropertiesandchainstackingbehaviorsofthepolymerswereinvestigatedbydifferentialscanningcalorimetry(DSC)andX-raydiffraction(XRD)aswellasatomicforcemicroscopy(AFM).ThepolymerwithconjugationsysteminboththebackboneandthependentgroupsexhibitedUV-Visabsorptionatamuchlongerwavelengththanthosewiththeconjugationonlyinthebackboneoronlyinthesidegroups.Thepolymerswithconjugatedbackboneneedmorespaceforchainstacking,andtheconjugatedbackbonecausesenhancedsizeofpolymerparticlesassembledfromsolution.Theresultsshowedthatprimarymicrostructuresofthepolymerexertedsignificantinfluencesonthephysicalproperties.
简介:生一个anthraquinoneimide(AQI)组的基于胆固醇的organogelator被综合并且描绘。它进chiral自我装配在在低集中的acetonitrile的胶化,它显示了electrochromic和chiroptical性质的联合。在在700mV的电气化学的减小之上,胶化在相应于的约820nm展出了新吸收乐队**(SOMOLUMO)在一样AQI和强壮的否定棉花效果的激进的阴离子转移光谱区域。与在1000mV的进一步的减小,有在到800nm的从500nm的范围的否定棉花效果的一个新CD乐队出现了有吸收光谱的变化的伴随物。因此,与是的electrochromicAQI色基的使用一个开关应答的单位和复合的N-的稳定的胶化[3-cholest-5-en-3-ylN-(2-aminoethyl)氨基甲酸酯]是的anthraquinone-2,3-dicarboxylicimidechiral脚手架,在可见、在红外线附近的区域操作的一个被触发氧化还原作用的chiroptical开关被认识到。
简介:稀土元素aryloxides由各种各样的烷基组代替了[行(浆)3]例如甲基,isopropyl和tertbutyl,被用作单个部件催化剂影响L减水乳酸(LLA)的戒指洞聚合。催化活动,聚合特征,聚合动力学和机制被学习。稀土元素aryloxides的催化活动被结构和烷基组的数字在苯基戒指上影响,这被发现。越强壮烷基组的电子捐赠能力,催化活动将是越多higher。代用品组的数字的增加将导致一项更高催化的活动。镧tris(2,4,6-tri-tert-butylphenolate)[La(OTTBP)3]在所有镧aryloxides之中展出最高的活动。根据1H-NMR数据,LLA聚合经由包含减水乳酸的酰氧债券的劈开的协作插入机制继续了,这被建议。关键词戒指洞聚合-L减水乳酸-稀土元素aryloxides这个工作被山西省(号码2006011069)的自然科学基础和山西省(号码2009011059-7)的关键实验室的开的基础支持。
简介:Anewdi-functionadsorbent(JN-3)waspreparedbysulfhydrylmodified.ComparingwithAmberliteXAD-4andNDA-150,theequilibriumadsorptionforphenolontheJN-3fromaqueoussolutionswastested,perfectadsorptioncapacitywasshown.Pb2+canbealsoremovedbyJN-3becauseofthechelateinteractionbetweensulfhydrylgroupsandmetalions.Thisadsorbentcouldbeusedinremovalofcombinepollutantssuchasphenoliccompoundsandheavymetalionsfromwastestreams.
简介:Theadsorptionbehaviorofionicgoldontochelatingfibercontainingamidoximegroupswasinvestigated.ThechelatingfiberpresentshighadsorptioncapacityforionicgoldAu^3+(upto626mg/g,whenthecontentofamidoximegroupreaches7.59mmol/g),andpossessestheabilitytoreducetheAu^3+intometallicgold,Intheredoxprocess,theamidoximegroupisoxidizedintocarboxylgroup.
简介:Networkcrownetherpolymerwithpendantsulfidesidechaininthenetworkstructureunitshasbeensynthesizedviaring-openingcopolymerizationofβ-ethylthioethylglycidyletheranddiethyleneglycolbisglycidylether.Akindofactivecatalystsuitableforthisreactionwassuggested.Thetitlepolymerwasfoundtobeagoodligandforplatinouschloride,andtheplatinouscomplexcouldcatalyzethehydrosilylationofolefinswithtriethoxysilaneefficiently.