简介：Thereactionofcrosseddiperoxidationbetweenthecyclicketonesandthealkylketoneswasinvestigated.Thereactionisacompetingindifferentketones.Itisslightlyfavorabletoresultingincrossedketonediperoxideandtoresultingincrossedcycloketonediperoxidewhenthecycloketonereactswiththealiphaticketone.

简介：Inthispaper,wehavestudiedtheadsorptionpropertiesofgoldbyα-alkylsubstitutedpyridineresin(BPR)inalkalinesolution.ThesingleanddualcomponentkineticmasstransferprocessofAu(I),Ag(I)andothermetalcyanideionswerealsoinvestigated.Theresultsobtainedshowthatthemasstransferratesofthecyanideionsintheresinphasearecloselyrelatedtothemolarratioandtheconfigurationofmetalcyanideions.TheelutionkineticsofAu(I)andothercyanideionsbyNH4SCNhasbeeninvestigatedsystematically.TheintraparticlediffusioncoefficientandactivationenergyofAu(I),Ag(I),Ni(I)Fe(Ⅲ）cyanideanionsweredeterminedinCI,NO3,OH-typeBPRresinatdifferenttemperatures.ItisfoundfromtheexperimentalresultsthatthemechanismforextractingAu(I),Ag(I)andothermetalcyanideanionsbyBPRresinbelongstoionexchangeprocess.Thedifferenceofactivationentropyofsomemetalcyanideanions(ΔS-ΔS^-)wasevaluated.

简介：Microwaveirradiationofaromaticaldehydeand2,4-thiazolidinedioneprovidesafastandhigh-yieldaccessto5-benzylidene-2,4-thiazolidinedione.Seven3-alkyl-5-benzylidene-2,4-thiazolidinedionecompoundswereproducedwithhighyieldbyreacting5-benzylidene-2,4-thiazolidinedionewithdifferentalkylatingagentsundermicrowaveirradiation.

简介：Twoalkylsubstitutedpolythiophenederivatives:poly(3-hexylthiophene)(P3HT)andpoly(3-decylthiophene)(P3DT),havesynthesizedbyoxidationcouplingpolymerizationof3-alkylthiopheneusingiron(III)chlorideascatalystinchloroform.Whilebothpolymersinpurechloroformsolutionhavemaximumabsorptionatapproximatelysamewavelengthof440nm,theybehavedifferentlywithrespecttochangesobservedontheirUV-visibleandphotoluminescencespectrawhenthequalityofthepoorsolventischangedingoodsolvent(chloroform)/poorsolvent(methanol)mixtures.Withincreasingvolumefractionofmethanolinmixtures,theabsorptionspectraofP3HTandP3DTred-shift,peakingatmaximumwavelengthof495nm(P3HT)and510nm(P3DT).Furthermore,theabsorptionspectraofthetwopolymersinchloroformblue-shiftasthetemperaturerises.P3HTshows4.73nmblue-shiftsat50℃incontrasttothecaseat20℃,whileP3DTblue-shiftsabout5.04nm.Thephotoluminescencespectraofthetwopolymersinmixedsolutionarealsoinvestigated,whichshowthattheluminescencespectrashifttolongerwavelengthwithanaccompanyingdropinthePLintensityasmethanolisincreased.Theabsorptionandemissionspectraofthetwopolymersinapoorsolventandathinfilmaresimilar,whichindicatethatasimilarlongerconjugationlengthinthetwocases.Itcouldconcludethatthepolymersexistalmostthesameconformationsandaggregationsinbothapoorsolventandathinfilm.P3DTexhibitsmoresensitivespectraproperties(bigred-shiftsinbothabsorptionandluminescencespectrainpoorsolventsandlargeblue-shiftsathightemperature)withcontrasttoP3HT,whichimplythatlongsidealkylmayimprovethechromicpropertiesofthepolymer.

简介：Aseriesof'hairy-rod'polyimides,BBPA(n),withmultiplealkylsidechainswaspreparedfrom3,3′,4,4′biphenyltetracarboxylicdianhydride(BPDA)and4,4′-biphenyldiaminesubstitutedinthe2,2′-positionswithbenzoate,whichwassubstitutedinthe3,4,5-positionswithethersidechainsofvaryinglengths.Thenumberofthemethyleneunits,n,inthesealkylsidechainswereinevennumbersrangingfrom8to18.Combiningtechniquesofone-dimensional(1D)and2Dwideanglex-raydiffraction,1DsmallangleX-rayscattering,differentialscanningcalorimetryexperiments,itwasfoundthatthisseriesof'hairy-rod'polyimidespossessamicro-phaseseparationbetweenthebackbonesandsidechains.Thisledtotheformationoforderedstructuresintwodifferentlengthscales,ofwhichbotharehexagonalpacking:oneisattributedtothealkylsidechainsonthesub-nanometerscale,andanotherisforthewholepolymerchainsonthenanometerscale.Thedevelopmentofthehexagonalstructureonthesub-nanometerscalewascriticallydependentuponthelengthsofthealkylsidechains.Threerelaxationprocesseswerecapturedbydynamicmechanicalanalysis,i.e.,segmentalmotionofthebackbones,α,themeltingofthesidechaincrystals,β1,whichexitsonlyforthematerialswithlongersidechains(n=18,16);andthesubglassrelaxationofsidechains,β2.Thepeakrelaxationtemperatureoftheαprocessdecreasedwithincreasingthelengthofsidechains,whiletheoneoftheβ2processincreased.Theactivationenergyoftheαrelaxationwasrelativelyindependentonthelengthofsidechain,whereas,β2processshowedtheincreasingofactivationenergywithincreasingthelengthofsidechains.

简介：Fivechiralstationaryphases(CSPs)wereusedtoseparatetheenantiomersofaseriesofO,O-diethyl(p-methyl-benzenesulfonamindo)-aryl(alkyl)-methylphosphonates.Achiralrecognitionmechanismwaspresentedtoexplaintheresolutionofthesecompounds.ResultsshowthatCSPwithstrongπ-acceptor3,5-dinitrobenzoylgroupandhighsterichindrancehasthebestresolutionabilityinchiralseparationofO,O-diethyi(p-methyl-benzenesulfonamindo)-aryl(alkyl)-methylphosphonates.WhenaCSPhasjustastrongπ-acceptor3,5-dinitrobenzoylorhighsterichindranceitdoesnothavegoodchiralresolutionability.ThechiralrecognitionismoredifficultwhentheCSPhasmorethanoneasymmetriccenter.

简介：产品概述CarbopolETD2020是一种"容易分散"的聚丙烯酸交联共聚物,在毒性优选的共溶剂系统中制造,提供优良的增稠效能及悬浮能力、长流变性及凝胶体系中的晶莹透明度。虽然CarbopolETD2020具有与Carbopol1342和1382相似的性能,但它是设计成在水中分散时不易结块,而且