简介:Fourpolymer-supportedFe-Cotetrametallicclustershavebeenpreparedbyionexchangeandligandexchange.TheirstructureswerecharacterizedbyIR,UV/visiblediffusereflectancespectraandelementalanalysis,andbyanalogywiththereferenceclusterPhCH2NMe3FeCo3(CO)2.Thefourheterogenousclusterswereefficientcatalystsinthehydroformylationof1-hexene,turnovernumbersamountedto823—924withtheyieldof83.2—92.4%heptylaldehydesandratiosofnormalaldehydetoiso-aldehydeof1.2—1.6,theyarefacilitatedformingthenormalaldehydeincomparisonwiththehomogeneousanalogue.Forthepolymer-supportedclusterspreparedbyionexchange,thepolymer-cationpartshadnoobviouseffectontheactivityoftheclusteranion.Thepolymer-phosphinesubstitutedclusterpreparedbyligandexchangewasmorestablethantheclusterspreparedbyionexchange.
简介:Thisworkdealswiththekineticsofco-condensationpolymerizationofAB2andABmonomers,givingexpressionsofthetwo-dimensionalmolecularweightdistributionfunctionandthenumber/weightaveragemolecularweightsoftheresultingcopolymers.Thetwo-dimensionalmolecularweightdistributiondependsontwoindices,nandl,whicharetherespectivenumbersofAB2andABunitsinacopolymerspecies.Theevolutionofthetwo-dimensionalweightandzdistributionsduringtheco-condensationpolymerizationhasbeenevaluatedsystematically.Finally,thetwo-dimensionaldistributionwastransformedintoaone-dimensionalmolecularweightdistributionwithonlyonevariable(themolecularweightoftheproductsinsteadofthedegreeofpolymerization).Thecalculatedresultsshowthatthehighlybranchedcopolymerhasaverybroadmolecularweightdistributionwhentheco-condensationpolymerizationapproachescompletion.
简介:Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/Organophilicmontmorillonite(PHBV/OMMT)nanocompositeswerepreparedandthebiodegradabilityofthePHBV/OMMTnanocompositeswasstudiedbyacultivationdegradingmethodinsoilsuspension.TherelationshipbetweenstructureandbiodegradabilityofPHBV/OMMTnanocompositeswasinvestigated.TheresultsshowedthatthebiodegradabilityofPHBV/OMMTnanocompositesdecreasedwithincreasingamountofOMMTanditwasrelatedtothenumberofPHBVdegradingmicroorganismsindegradationenvironment,theanti-microbialpropertyofOMMTandthedegreeofcrystallinityofthenanocomposites.
简介:Synthesisofsuperabsorbentofstarch-graft-poly(patassiumacrylate-co-acrylamide)hasbeenstudiedbyinversesuspensionpolymerization.Inthispaper,theeffectsofreactionconditions,suchas,monomericconcentration,theamountofcross-linkingagent,ratioofwatertooil,reactiontemperatureandthebestconditionbeingabletoobtainthesphericalresinwereinvestigated.Experimentsshowthatthewater-absorbingresinisstrongandcapableofresistingpressureofretainwater.Itkeepstheshapeofparticlesafterabsorbingwater.Aftermixingwithsoil,itdoesnotbecomesticky,andthecoosstructurecanbetterretainair.Itjustfitagricultureandforest.Inaddition,thermogravimetricanalysisrevealedthesuperiorthermalstabilityofthegraftedproduct,anditslargesizeparticlesalsoreducesriskofairpollution.
简介:Fromaneconomicalpointofviewboththequalityoftheionexchangeresinsandthetechnologyusedinthefieldofindustrialwatertreatmentareimportantforasuccessfulperformance.Ingeneral,twodifferenttechnologieshavebeenestablishedonthemarket:ThemaindiffernecesbetweentheCO-andcountercurrenttechnologeswillbediscussedanddataconcerningtherequirementofchemicalsforregenerationandthequalityofthedeionizedwaterwillbeopposed.Inadditionseveraldifferentvarietiesofthemoderncountercurrenttechnologies,developedandpatentedbyBayerAG,willbedescribedandtheadvantages,dependingontheapplicationandthedemandonthequalityofthedeionizedwater,pointedout.Inviewofstrongerregulationsconcerningtheconsumptionofregenerationchemicals,andwastewater,andalsobecauseofthesuperiorqualityoftheproducedwater,themarketshareofcountercurrenttechnologieswillcontinuetoincreaseworld-wide.
简介:Metalion-imprintedlycrosslinkedchitosanresin1andresin2werepreparedbytheuseofCu^2+andNi^2+astemplateionsandglutaraldehydeascrosslinkingagent,respectively,ThroughinvestigationontheadsorptioncapactiesandbindingconstantsforCu^2+,Ni^2+andCo^2+ionsonchitosanresins,resin1andresin2exhibittheadsorptionselectivityforthemixturesolutionof1L1Cu^2+andNi^2+ions.Theadsorptionselectivityofmetalion-imprintedresinsfortheirtemplateionsinmuchhigherthanthatofuncrosslinkedchitosanresin.
简介:Blendsofpoly(3-hydroxybutyrate-co-3-hydroxyhexanoate)(PHBHHx)andpoly(butylenesuccinate-adipate)(PBSA),bothbiodegradablesemicrystallinepolyesters,werepreparedwiththeratioofPHBHHx/PBSArangingfrom80/20to20/80bymeltmixingmethod.Differentialscanningcalorimetry(DSC),thermogravimetryanalysis(TGA),dynamicmechanicalthermalanalysis(DMA),polarizingopticalmicroscopy(POM)andwideangleX-raydiffractometer(WAXD)wereusedtostudythemiscibilityandcrystallizationbehaviorofPHBHHx/PBSAblends.ExperimentalresultsindicatethatPHBHHxisimmisciblewithPBSAasshownbythealmostunchangedglasstransitiontemperatureandthebiphasicmelt.