In this laboratory experiment, students work in pairs to
synthesize a simple aliphatic polycarbonate via ring-opening polymerization
of trimethylene carbonate using 1,8-diazabicyclo[5.4.0]undec-7-
ene and thiourea as organocatalysts. Following polymer isolation,
students cool the material in a dry ice/acetone bath to observe its glasstransition
behavior. This experiment is convenient to perform under
teaching laboratory conditions and reinforces key concepts learned in
second-year undergraduate organic chemistry, for example, nucleophilic
acyl substitution, transesterification reactions, and Lewis acidity−basicity. Additionally, the experiment introduces students
to polymer chemistry, heterocycles, materials science, and green chemistry. It also covers interesting concepts that are less
frequently encountered at the undergraduate level such as biomimetic chemistry, bifunctional catalysis, and polymer−glass
transitions.