Computer-Aided Design of Copolymers with Controlled Comonomer Distributions

The sequence distribution of comonomer
units in copolymers
drastically
affects the properties of the polymeric materials; the prediction
and control of the sequence distribution are challenging when there
is a significant reactivity difference among the comonomers. In this
study, we established a computer-aided design (CAD) framework to rationally
design and synthesize copolymers with the desired comonomer distributions
by using the scheduled comonomer addition strategy. We developed a
simulation method that predicted the living copolymerization process
with the scheduled addition of comonomers into the reaction mixture.
The simulation quantitatively reproduced the real-world copolymerization
results. The comonomer addition schedule was designed for a given
target comonomer distribution with the aid of simulation; this process
was then used to experimentally produce the copolymer. With this method,
we successfully synthesized random copolymers via the ring-opening
metathesis copolymerization of two norbornene derivatives with an
approximately 25-fold difference in their propagation rate constant;
this was impossible with a simple batch addition strategy. Copolymers
with much more complicated comonomer distributions could also be designed.
Our CAD framework will promote the development of a vast diversity
of polymers with various properties, even from a limited set of monomers.