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Mixed donor-acceptor monomers
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
FAIR
MAIR
-ethylfumaroyl-
2,3-
O
-isopropylidene-d-ribo furanoside
Allyl-5-
O
-ethylfumaroyl-
2,3-
O
-isopropylidene-d-ribo furanoside
Allyl-5-
O
Multifunctional donor monomers
O
O
O
O
O
TAX
Allyl-2,3,5-tri-
O
-allyl-d-xylopyranoside
Scheme 10 Multifunctional monomers derived from carbohydrates.
Table 6 Kinetic data for the photopolymerization of monofunctional and multifunctional
sugar-based monomers (C
PI
=
1 wt-% of TPO; P
=
150 W).
Initial rate
(mmol
kg
1
s
1
)
Molar ratio
Final conversion (%)
Polymer
blends
f
D
a
(R
p
)
0
(R
p
)
0
p
A
N
p
D
N
f
A
AIR-DEF
0.5
0.5
2.9
2.3
77
73
FAIR
0
1
1.6
1.2
63
52
MAIR
0
1
0.3
0.3
62
62
FAIR-DEF
0.5
0.5
0.8
0.4
67
67
0
b
0.7
c
0
b
89
c
FAIR-DEM 0.5
0.5
0.5
60
62
c
23
MAIR-DEM 0.5 0.5 0.3 0.4 24 46
a
Molar ratio of donor monofunctional monomer (AIR) or of mixed donor-acceptor mono-
mers (FAIR or MAIR).
b
0
b
0.2
c
0
b
MAIR-DEF
0.5
0.5
0.1
For maleate unsaturation at 810 cm
1
.
c
For fumarate unsaturation at 775 cm
1
.
allyl ether unsaturations. The resulting data enabled the determination
of the two characteristic quantities: the absolute rate of consumption of
each monomer function, (R
p
)
0
, and the ultimate degree of conversion,
p
N
. The initial rates of polymerization measured with FAIR for donor
and acceptor unsaturations were close ((R
p
)
0
A
=
1.6mmol
kg
1
s
1
vs.
(R
p
)
0
D
=
1.2mmol
kg
1
s
1
) and, as observed for monofunctional
allylether monomers (see entry AIR-DEF in Table 6), the butenedioate
unsaturation disappeared faster than donor one. Moreover, both donor
and acceptor final conversions did not reach high values (p
N
A
=
63% and
p
N
D
=
52%) because of the premature vitrification of reactive films, a
major physical change that does not occur during the course of the
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