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Plas%csAddi%vesandGreenChemistry

EvanBeach

14thAnnualGreenChemistry&EngineeringConference

Addi%ves

1tonne=1000kg

106 ton

nes/yrprodu

ced

About5%(wt.)ofallplas%cisaddi%ves

Plas%cizersaccountfor>50%ofaddi%ves

Flameretardantsaccountforabout25%

Consequences

persistence,bioaccumula1on,toxicity

DOTP(akaDEHP)

PBDEs

Solu%onsandstrategies• Small‐molecule,drop‐inreplacementsforDOTP,PBDEsetc.

• Higher‐MWaddi%vesforreducedmigra%on

• Designingpolymerswithinherentlydesirableproper%es

&

greendesignprinciples

Solu%onsandstrategies• Small‐molecule,drop‐inreplacementsforDOTP,PBDEsetc.

• Higher‐MWaddi%vesforreducedmigra%on

• Designingpolymerswithinherentlydesirableproper%es

&

greendesignprinciples

ImpactsofPVC

PVCaccountsfor80%ofplas%cizeruse;theplas%cizermarketis75‐85%phthalates

0%plas%cizer 85%plas%cizer

PVCconsump1onisnotexpectedtodecreaseintheshortterm

PVCisonlypartofthechallenge

Biopolymersbasedoncellulose,starch,andwheatglutenwillconsumeplas%cizers

Poly(lac%cacid)(Tg=55°C)isbri_lelikePVC(Tg=82°C)andrequiresaddi%vesifitistobeusedasaflexibleplas%c

Smallmoleculealterna%vestoDOTPTheliteratureaboundswithexamples.Manyalterna%vesbelongtothephthalateclass(e.g.DINP).Manyarealsoproblema%c(e.g.mellitateesters).

Certainbio‐basedfeedstocksmightbeexpectedtoresultinlesshazardousproducts.

sorbitolderivedfromglucose tuneproper%esvia

choiceoffa_yacid

C8diestershowsDOTP‐likeperformance

TerVeld,M.G.R.etal.Agric.FoodChem.2006,54,4407‐4416.vanHaveren,J.etal.inFeedstocksfortheFuture.AmericanChemicalSociety:Washington,DC,2006.

Isosorbideestersofalkanoicacidsarefullybiodegradableandpassedtestsforacutetoxicity,sensi%za%on,mutagenicity,&estrogenicity

FlameretardancyisawidespreadneedDemandisexpectedtoincrease5%/yr

M.Chanda,S.K.Roy.IndustrialPolymers,SpecialtyPolymers,andTheirApplica1ons

Limi'ngOxygenIndices(LOI)ofcommonpolymers

Non‐self‐ex%nguishingpolymer

LOI Self‐ex%nguishingpolymer

LOI

polyoxymethylene 16 polycarbonate 27

polyethylene 17 polyarylate 34

polypropylene 18 polyethersulfone 38

polystyrene 18 PEEK 40

PMMA 18 PVC 42

naturalrubber 18 polyamide‐imide 43

ABS 18 poly(phenylenesulfide) 44

Nylon‐6,6 24 polyether‐imide 47

PETE 25 poly(vinylidenechloride) 60

polychloroprene 26 PTFE 95

TheLOIforself‐ex%nguishingisusuallytakenas27,not21(thevolume%ofO2inair)tocorrectforlackofconvec%vehea%nginthetestmethod.

Flameretardants

Source:SRIConsul%ng/h_p://www.flameretardants‐online.com

Goal:compa%blewithplas%cs,effec%veatreasonablelevels,non‐leaching,non‐toxic

Non‐halogenatedflameretardants

• 2007AddConconference:nopapersonhalogenatedchemicals,althoughflameretardantsmadeuponeofthelargestgroupofsubmissions

• Governmentandindustrygroupshaveconductedextensivereviews,e.g.h_p://www.nonhalogenated‐flameretardants.com

• Fewerexamplesfrombio‐organicfeedstocks

• Solu%onsareolenbasedonmechanismsspecifictoapolymer

MolecularHeatEater®• Powderorgelbasedoncarbonateandphosphatesaltsandbenignorganic

acids– citric

– glutaric

– succinic

– oxalic

– formic

– ace%c

– stearic

Someareagriculturalwasteproducts

Sub‐micronpar1clesrequireastrongendothermicreac1ontodecompose

MHEinac%onuntreated treated

Solu%onsandstrategies• Small‐molecule,drop‐inreplacementsforDOTP,PBDEsetc.

• Higher‐MWaddi%vesforreducedmigra%on

• Designingpolymerswithinherentlydesirableproper%es

&

greendesignprinciples

HighMWplas%cizers

• Limitmobilityinpolymermatrix

• Preventtransportacrossbiologicalmembranes

• Degrada%onproductsmustbeconsidered

1,3‐propanediolfromglucoseviaglycerol(engineeredE.coli)

Adipicacidfromglucose(engineeredmicrobes)

MW1500‐2500Da

isabe_erplas%cizerforPLAthan:

MW371

Mar%no,V.P.;Jimenez,A.;Ruseckaite,R.A.J.Appl.Polym.Sci.2009,112,2010‐2018.

Strategiesforhigh‐MWflameretardants• Copolymeriza%onwithspecialmonomers,gralingreac%veaddi%vestobackbone

– Flameretardancyis“permanent”

– Lessdisrup%onofpolymerproper%es

– Effec%veatlowerloadingsthanlow‐MWaddi%ves

Lu,S.‐Y.;Hamerton,I.Prog.Polym.Sci.2002,27,1661‐1712.

Mul%‐wallcarbonnanotubes

max.heatreleaserate~800kW/m2

max.heatreleaserate~500kW/m2

2%nanotubes

• Effec%veinpolycarbonate,polyamide,polyethylene,polypropylene,polystyrene

• Cannotstandalone–butpromising

• Nohalogens,metals,orphosphorus

Schartel,B.etal.Polym.Eng.andSci.2008,48,149‐158.

Solu%onsandstrategies• Small‐molecule,drop‐inreplacementsforDOTP,PBDEsetc.

• Higher‐MWaddi%vesforreducedmigra%on

• Designingpolymerswithinherentlydesirableproper%es

&

greendesignprinciples

Plas%citywithoutaddi%ves:thermoplas%celastomers(TPEs)

• Metallocene‐catalyzedpolyolefins:“thethreattoflexiblePVC”– 1millionlbpolymer/1lbcatalyst/1hr

– JournalofVinylandAddi1veTechnology,1998:poten%altocapture50%oftheflexiblePVCmarket(30‐40%plas%cized)

Wilson,R.B.,Jr.J.VinylAddit.Technol.1998,4,84‐86.

TPEsfromBiobasedMaterials

• Polyethers

• Polyamidesbasedoncanola,castoroil

• Polyurethanesfromvegetableoil

Mizuno’s2009runningshoemodelscontainPebax®Rnew,abio‐basedTPE(upto94%renewablecarbon)

Markarian,J.Plas1csAddi1ves&Compounding2008,10,38‐43.

InherentlyFireRetardantPolymers

Self‐ex'nguishingpolymer

LOI

polycarbonate 27

polyarylate 34

polyethersulfone 38

PEEK 40

PVC 42

polyamide‐imide 43

poly(phenylenesulfide) 44

polyether‐imide 47

poly(vinylidenechloride) 60

PTFE 95

Zhang,H.U.S.DepartmentofTransporta%on,FederalAvia%onAdministra%on,OfficeofAvia%onResearch,2004.

poly(hydroxyamide) poly(benzoxazole)

Challenges• Cost,mechanicalperformance,processingdifficul%es

• Mechanis%cunderstanding– Heteroatoms(N,O,P,S,halogens)

– Aroma%crings

– Heteroatomicrings

– Pro‐crosslinkingorpro‐cycliza%onchemicalgroups

Kevlar®(paralinkages)

Nomex®(metalinkages)

Whysuchasignificantdifferenceinheatrelease?

Zhang,H.U.S.DepartmentofTransporta%on,FederalAvia%onAdministra%on,OfficeofAvia%onResearch,2004.

Inspira%onfromnature:woolWoolfoamsratherthanburns.Igni%ontemperatureis570‐600°C(higherthanrayon,nylon,polyester)

Aneffectofmicrostructure?Chemicalcomposi%on?Both?

Be_erunderstandingofnaturallyflameretardantmaterialswillleadtoinnova%oninfire‐safe,bio‐basedplas%cs

CSIRO,FlameResistanceofWool

Solu%onsandstrategies• Small‐molecule,drop‐inreplacementsforDOTP,PBDEsetc.

• Higher‐MWaddi%vesforreducedmigra%on

• Designingpolymerswithinherentlydesirableproper%es

&

greendesignprinciples

Reducinghazard(atalllifecyclestages)

Useofrenewableresourcesistobeencouraged,butitcannotbetheonlymetric

Conclusions

• Func%onalalterna%vestoDEHPandPBDEsareabundant

• Bio‐basedchemicalplaxormsare(andwillbe)asourceofinnova%on

• Allgreenprinciplesshouldbemetbynewmaterials,toavoidtheproblemsofthepast