聚氯乙烯钙-锌-钛纳米复合物的热解动力学

聚氯乙烯钙-锌-钛纳米复合物的热解动力学摘要：

本研究采用差热分析-热重分析法（DTG-TG）研究了聚氯乙烯钙/锌/钛（PVC/Ca/Zn/Ti）纳米复合物的热解动力学。通过对不同升温速率下的样品热重分析数据进行分析，确定了热解过程的主要失重转化和反应温度。结果表明，PVC/Ca/Zn/Ti纳米复合物的热解过程包括三个阶段，分别是PVC的分解、钙、锌和钛的反应以及残炭生成。根据热解过程的主要失重转化和反应温度，利用Kissinger公式和Flynn-Wall-Ozawa方法计算了热解过程的反应活化能和指前因子。结果表明，PVC/Ca/Zn/Ti纳米复合物热解反应活化能随失重转化率增加而增加。该研究揭示了PVC/Ca/Zn/Ti纳米复合物的热解过程机理，为进一步研究该材料的热稳定性提供了参考依据。

关键词：聚氯乙烯；钙/锌/钛纳米复合物；热解动力学；Kissinger公式；Flynn-Wall-Ozawa方法

Abstract:

Thethermaldecompositionkineticsofpolyvinylchloride/calcium/zinc/titanium(PVC/Ca/Zn/Ti)nanocompositeswerestudiedbydifferentialthermalanalysis-thermogravimetry(DTG-TG).Themainweightlossconversionsandreactiontemperaturesofthethermaldecompositionprocessweredeterminedbyanalyzingthethermalgravimetricdataofthesamplesatdifferentheatingrates.TheresultsshowedthatthethermaldecompositionprocessofPVC/Ca/Zn/Tinanocompositesconsistsofthreestages,includingthedecompositionofPVC,reactionsofcalcium,zincandtitanium,andtheformationofresidualchar.Thereactionactivationenergyandpre-exponentialfactorofthethermaldecompositionprocesswerecalculatedusingtheKissingerformulaandtheFlynn-Wall-Ozawamethodbasedonthemainweightlossconversionsandreactiontemperatures.TheresultsshowedthatthereactionactivationenergyofPVC/Ca/Zn/Tinanocompositesincreasedwiththeincreaseofweightlossconversion.ThisstudyrevealsthemechanismofthermaldecompositionofPVC/Ca/Zn/Tinanocompositesandprovidesareferenceforfurtherresearchonthethermalstabilityofthismaterial.

Keywords:Polyvinylchloride;Calcium/zinc/titaniumnanocomposites;Thermaldecompositionkinetics;Kissingerformula;Flynn-Wall-OzawamethodPolyvinylchloride(PVC)isawidelyusedplasticmaterialduetoitsexcellentmechanicalpropertiesandlowcost.However,itsthermalstabilityisrelativelypoor,whichlimitsitsapplicationinhigh-temperatureenvironments.Therefore,addingthermalstabilizerstoPVCisnecessarytoimproveitsperformance.Calcium,zinc,andtitaniumarecommonlyusedthermalstabilizersforPVC,andtheircombinationcanfurtherenhancethethermalstabilityofPVC.

Inthisstudy,PVC/Ca/Zn/Tinanocompositeswerepreparedbymeltblending,andtheirthermaldecompositionkineticswereinvestigated.TheKissingerformulaandFlynn-Wall-Ozawamethodwereusedtocalculatethereactionactivationenergyandpre-exponentialfactor.Theresultsshowedthattheactivationenergyincreasedwithincreasingweightlossconversion,indicatingthatthedecompositionprocessbecamemoredifficultathighertemperatures.Thepre-exponentialfactoralsoincreasedwithincreasingweightlossconversion,whichsuggeststhatthedecompositionrateofPVC/Ca/Zn/Tinanocompositesacceleratedasthetemperatureincreased.

ThemechanismofthermaldecompositionofPVC/Ca/Zn/Tinanocompositescanbeexplainedasfollows.Atlowtemperatures,thethermaldecompositionofPVC/Ca/Zn/Tinanocompositesprimarilyoccursviathedehydrochlorinationreaction,whichleadstotheformationofcrosslinkedstructures.Asthetemperatureincreases,thedecompositionofPVC/Ca/Zn/Tinanocompositesbecomesmorecomplicatedduetotheformationofintermediatesandthecompetitionbetweendifferentreactions.Ultimately,thedecompositionproductsarereleasedasgases,leavingbehindaresiduecontainingCa,Zn,andTicompoundsthatcanenhancethematerial'sthermalstability.

Insummary,thisstudyprovidesabetterunderstandingofthethermaldecompositionkineticsofPVC/Ca/Zn/Tinanocomposites.TheresultsindicatethatthecombineduseofCa,Zn,andTicaneffectivelyimprovethethermalstabilityofPVC.ThesefindingscanhelpguidethedevelopmentofnewthermalstabilizersforPVCandotherpolymermaterialsAdditionally,itisimportanttonotethatthethermalstabilityisnottheonlyfactortoconsiderwhendesigningPVCmaterials.Otherpropertiessuchasmechanicalstrength,flexibility,andtransparencymayalsobeofsignificancedependingontheapplication.Therefore,furtherresearchisneededtoinvestigatetheeffectofCa,Zn,andTiontheseproperties.

Furthermore,theuseofnanocompositesintheindustryisbecomingincreasinglypopularduetotheiruniquepropertiesandpotentialapplications.Nanocompositesarematerialscomposedofapolymermatrixandnanoscalefillers,suchasnanoparticlesornanotubes,whichcanimprovemechanical,thermal,andelectricalproperties,amongothers.

FuturestudiescouldexplorethecompatibilityofCa,Zn,andTiwithothernanoparticlestodevelopnovelnanocompositesforPVC.Inaddition,theeffectofvaryingtheconcentrationsoftheseelementsontheperformanceofPVCcouldalsobeinvestigated.

Inconclusion,thisstudyprovidesimportantinsightsintothethermaldecompositionkineticsofPVC/Ca/Zn/TinanocompositesandhighlightsthepotentialofusingtheseelementstoenhancethethermalstabilityofPVC.Thefindingsofthisstudycouldpavethewayforthedevelopmentofnew,advancedmaterialswithimprovedpropertiesandperformanceforvariousapplicationsinindustry,medicine,andtechnologyFurthermore,futureresearchcouldexploretheeffectsofothernanoparticles,suchassilicaorgraphene,onthethermalstabilityofPVC.ThesematerialshaveshownpromiseinenhancingthepropertiesofvariouspolymernanocompositesandcouldsimilarlyimprovetheperformanceofPVC.Additionally,furtherinvestigationsintothemechanicalandthermalpropertiesofPVC/Ca/Zn/Tinanocompositescouldhelptodeterminetheirsuitabilityforvariousapplications.

Moreover,thestudyhighlightstheimportanceofaccuratelycharacterizingthethermalpropertiesofpolymericmaterialstooptimizetheirperformanceandensuretheirsafeuse.Understandingthekineticsofthermaldecompositioncanaidinthedevelopmentofpolymernanocompositeswithimprovedthermalstability,whichcouldhavesignificantimplicationsforindustriessuchastheconstructionandelectronicindustries.

Overall,thestudyofPVC/Ca/Zn/Tinanocompositesprovidesvaluableinsightsintothepotentialofusingnanoparticlestoenhancethethermalstabilityandperformanceofpolymericmaterials.Futureinvestigationsintotheeffectsofothernanoparticles,aswellasthemechanicalandth