Lookingatthesehorrificdisplaysofplasticspollutingtheenvironment, whetherthatwasinouroceansoronlandandinlandfills, anditwasprettyclearthatplasticsneeded a redointermsofhowwedesignthem, specificallyaddressingtheeventualitythattheirendoflifeneededtoberevisited a littlebit.
The "endlife" iswhyplasticproductshavetobeseparatedintodifferentstreamstoberecycledindifferentways.
Thatheterogeneityessentiallymakesitvery, very, verydifficulttothinkaboutwhattodowiththeplasticoutsideofgrindingitupintolittlepiecesandtryingtopelletizeitwith a bunchofotherdifferentplasticsthatallhavetheirownadditives.
TheteamatLawrenceBerkeleyNationalLabhasturnedto a newkindofplasticcalledpoly (diketoenamine) orPDKforshort.
PDKsareaninterestingtypeofplasticthatdifferfromconventionalplasticsinthatwecompletelyreplacedthestaticcovalentbondsthattypicallycomprise... thatmakeupthepolymerbackboneandwereplacedthemwithdynamiccovalentbondsthatallowyoutodo a numberofnewthings.
Picturethebondsof a polymerin a traditionalplasticlike a metalchain.
Tobreakdowntheplastic, youhavetobreakthelinksofthechainandthenspendtimeandenergytryingtore-formthem, withtheadditionof a lotofglueandmaybeevensomenewmetal.
With a materiallikePDK, thelinksbetweenatomsinthepolymerchainareactuallyreversible.
Becausetheyusedynamicbondsbetweenmonomerscalleddiketoenamines, whichis a triketoneandaminestucktogether.
Around 13 millionmetrictonnesofplasticendupintheoceaneachyear.
Sounlesswewanttoloseouroceansandbeburiedundermountainsoftrash à laWall-E, something's gottagive.
Thisnewmaterialholdsgreatpromiseformodernizingourrecyclingworldandmakingitmoreefficient, hopefullypushingtoward a worldwhereplasticproductsarenotonlymuchmorerecyclable, butdon't endupin a landfillorouroceansatall.