Environmental Engineering Reference
In-Depth Information
O
O
O
O
O
O
O
O
O
O
O
Dimethyl phthalate (DMP)
O
Dimethyl isophthalate (DMIP)
Dimethyl terephthalate (DMTP)
O
O
O
O
O
O
O
O
O
O
O
O
Diethyl phthalate (DEP)
Dibutyl phthalate (DBP)
Di (2-ethylhexyl) phthalate (DEHP)
FIGURE 15.1
Chemical. structures. of. several. common. phthalate. esters,. including. phthalate. ester. isomers.
(DMP,.DMIP,.and.DMTP),.diethyl.phthalate.(DEP),.dibutyl.phthalate.(DBP),.and.di(2-ethylhexyl).
phthalate.(DEHP).
at. the.
ortho
,.
meta
,. or.
para
. position.. Meanwhile,. the. esteriication. forms. not.
only.diesters.but.also.monoesters..Various.reactions.yield.a.large.and.diverse.
group. of. products. of. PAEs,. with. distinctive. position. and. the. length. of. the.
alkyl.side.chains.
Different.chemical.structures.can.have.distinctive.physicochemical.proper-
ties.for.PAEs..The.physical.properties.of.selective.PAEs.are.listed.in.Table.15.1..
What.should.be.noticed.is.the.hydrophilic.ability.of.PAEs,.because.hydrophilic.
ability.affects.the.occurrence,.distribution,.and.biotoxicity.of.a.chemical.in.the.
environment..The.existence.of.aromatic.ring.and.ester.groups.on.the.ring.gen-
erally. results. in. low. solubility. of. PAEs. in. water,. with. a. pattern. of. decrease.
following.the.increase.of.the.alkyl.chain.length..For.example,.with.an.increase.
of. alkyl. chain:. DMP.<.diethyl. phthalate. (DEP).<.diallyl. phthalate. (DAP),.
the. solubility. of. PAEs. in. water. generally. follows:. DMP. (4200.mg/L).>.DEP.
(1100.mg/L).>.DAP.(182.mg/L).(Staples.et.al..1997)..However,.there.are.excep-
tional. cases. for. high-molecular-weight. PAEs.. As. mentioned. by. Howard.
et.al..(1985),.the.diisononyl.phthalate.(DINP).has.water.solubility.of.0.20.mg/L,.
whereas.the.solubility.of.diisooctyl.phthalate.(DIOP).is.0.09.mg/L..There.is.a.
large.variation.among.the.water.solubility.values,.especially.when.measure-
ment.is.obtained.based.on.different.methods..For.example,.in.the.case.of.di-
n
-octyl. phthalate. (DnOP),. it. can. be. 0.02.mg/L. by. conventional. shake-lask/
centrifugation.method.(Holliield.1979)..Staples.et.al..(1997),.however,.recom-
mended.the.value.of.0.0005.mg/L.for.the.solubility.of.DnOP.based.on.the.data.
available..These.results.suggest.that.even.though.the.data.were.published.as.a.
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