Identification and assessment of alternatives to selected phthalates

DEHP
2 Application of DEHP, DBP and
BBP in products and articles
2.1 The phthalates
The term "phthalates" is here (and commonly) used for esters of orthophthalic
acid and are the most commonly used plasticisers in the world.
The general structural formula of phthalates is shown in Figure 2.1. The
functional groups (indicated as R) can either be linear aryl groups or alkyl
groups with an aromatic ring. The properties of the phthalates are determined
by the functional groups.
O
O
O
R
O
R
Figure 2.1
General structural formula of orthophthalates.
R can be linear alkyl groups
or aryl groups with an aromatic ring.
Examples of two of the phthalates are shown below, DEHP with symmetric
linear functional groups and BBP with asymmetric aryl and alkyl functional
groups.
O
O
O
O
CH3
CH3
CH3
CH3
Figure 2.2
Examples of structural formula of phthalates
The softening effects of the phthalates decrease with increasing length of the
functional groups (Hoffmann, 1996): DBP > BBP > DEHP > DINP >
DIDP > DTDP. Consequently higher loading are necessary to obtain a certain
level of softness for the phthalates with longer functional groups.
One property of importance for the application of the phthalates concerned in
this study is the gelling ability of the plasticiser i.e. the ability of the plasticiser
BBP
O
O
O
O
CH3
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