Pathways for degradation of plastic polymers floating in the marine environment

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1、EnvironmentalScienceProcesses&ImpactsViewArticleOnlineCRITICALREVIEWViewJournal

2、ViewIssuePathwaysfordegradationofplasticpolymersfloatinginthemarineenvironmentCitethis:Environ.Sci.:ProcessesImpacts,2015,17,1513BeritGewert,MerleM.PlassmannandMatthewMacLeod*Eachyearvasta

3、mountsofplasticareproducedworldwide.Whenreleasedtotheenvironment,plasticsaccumulate,andplasticdebrisintheworld'soceansisofparticularenvironmentalconcern.Morethan60%ofallfloatingdebrisintheoceansisplasticandamountsareincreasingeachyear.Plasticpolymersinthemarineenviron

4、mentareexposedtosunlight,oxidantsandphysicalstress,andovertimetheyweatheranddegrade.Thedegradationprocessesandproductsmustbeunderstoodtodetectandevaluatepotentialenvironmentalhazards.Someattentionhasbeendrawntoadditivesandpersistentorganicpollutantsthatsorbtotheplast

5、icsurface,butsofarthechemicalsgeneratedbydegradationoftheplasticpolymersthemselveshavenotbeenwellstudiedfromanenvironmentalperspective.Inthispaperwereviewavailableinformationaboutthedegradationpathwaysandchemicalsthatareformedbydegradationofthesixplastictypesthatarem

6、ostwidelyusedinEurope.WeextrapolatethatinformationCreativeCommonsAttribution3.0UnportedLicence.tolikelypathwaysandpossibledegradationproductsunderenvironmentalconditionsfoundontheoceans'surface.Thepotentialdegradationpathwaysandproductsdependonthepolymertype.UV-radia

7、tionandoxygenarethemostimportantfactorsthatinitiatedegradationofpolymerswithacarbon–carbonbackbone,leadingtochainscission.SmallerpolymerfragmentsformedbychainscissionaremoresusceptibletobiodegradationandthereforeabioticdegradationisexpectedtoReceived30thApril2015prec

8、edebiodegradation.Whenheteroatomsarepresentinthemainchainofapolymer,degradationAccepted3rdJuly2015proceedsbyphoto-oxidation,hydrolysis,andbiodegradation.DegradationofplasticpolymerscanleadDOI:10.1039/c5em00207atolowmolecularweightpolymerfragments,likemonomersandoligo

9、mers,andformationofnewendThisarticleislicensedunderarsc.li/process-impactsgroups,especiallycarboxylicacids.EnvironmentalImpactOpenA