Chemical Engineering May 2014 - 18

A new class of polymers that utilize CO2
ChementatoR
A
new plastic made from CO2 and
butadiene has been synthesized
by Kyoko Nozaki and her research
group at the University of Tokyo
(Tokyo, Japan; www.chembio.t.utokyo.ac.jp/labs/nozaki).
Although
butadiene is already produced on
a large scale for making synthetic
rubber, it has previously been impossible
to copolymerize CO2 and
butadiene in a single-step reaction,
because the propagation step with
CO2 is highly endothermic.
To " make the impossible possible, "
the researchers avoided the thermodynamic
and kinetic barriers by using
a meta-stable lactone intermediate,
3-ethylidene-6-vinyltetrahydro-2Hpyran-2-one,
which is formed by the
palladium-catalyzed condensation of
CO2 and 1,3-butadiene. Subsequent
free-radical polymerization of the
lactone intermediate produces generated
copolymers of high molecular
weight with a CO2 content of 33
mol% (29 wt.%). No poisonous gases
are released upon ignition. The new
polymer maintains its integrity at
high temperature (maximum decomposition
temperature of 340°C), making
it suitable for melt molding, products
such as housings, films and other
general-purpose applications.
covered lagoons
(Continued from p. 14)
ing system. The first and largest zone
receives most of the incoming wastewater.
This is where the anaerobic digestion
takes place. The second zone
serves as a post-digestion and presettling
zone where a partial clarification
of the effluent wastewater
takes place. Settled sludge collected
here is pumped back to the lagoon's
inlet. The remaining effluent flows by
The process was also successfully
applied for the one-pot terpolymerization
of CO2, butadiene and a
second 1,3-diene. This copolymerization
technique opens the door to
a new class of polymeric materials
that utilize CO2 as a feedstock. (For
more on CO2 utilization, see Chem.
Eng. July 2013, pp. 16-19.)
gravity toward complementary technology,
such as GWE's SuperSep-CFS
separation technology.
Each anaerobic lagoon is covered
by a special floating membrane to
retain the methane produced. A typical
feature of the system is that it
operates at zero biogas pressure. A
membrane level measuring system
controls the speed of a biogas extraction
fan, bringing the gas at 20 mbar
to go to the flare.
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18 ChemiCal engineering www.Che.Com may 2014
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Chemical Engineering May 2014

Table of Contents for the Digital Edition of Chemical Engineering May 2014
