Chemical Society Reviews,
Journal Year:
2023,
Volume and Issue:
52(9), P. 3035 - 3097
Published: Jan. 1, 2023
In
this
review,
we
provide
a
brief
history,
progress,
and
applications,
discuss
the
remaining
challenges
of
photocontrolled
reversible
addition-fragmentation
chain
transfer
(RAFT)
polymerization
(i.e.,
photoinduced
electron/energy
transfer-RAFT
(PET-RAFT),
photoiniferter,
photomediated
cationic
RAFT
polymerization).
Among
these,
visible-light-driven
has
attracted
particular
attention
in
recent
years
due
to
its
benefits,
including
low
energy
consumption
safe
reaction
procedure.
Moreover,
incorporation
visible-light
photocatalysis
conferred
attractive
features,
such
as
spatiotemporal
control
oxygen
tolerance;
however,
clear
understanding
mechanism
not
been
completely
provided.
We
also
present
research
efforts
elucidate
mechanisms
with
aid
quantum
chemical
calculations
combined
experimental
evidence.
This
review
offers
an
insight
into
better
design
systems
for
desired
applications
helps
realize
full
potential
both
academic-
industrial-scale
applications.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(18), P. 9898 - 9915
Published: May 1, 2023
Controlled
polymerization
methods
are
well-established
synthetic
protocols
for
the
design
and
preparation
of
polymeric
materials
with
a
high
degree
precision
over
molar
mass
architecture.
Exciting
recent
work
has
shown
that
end-group
fidelity
and/or
functionality
inherent
in
these
techniques
can
enable
new
routes
to
depolymerization
under
relatively
mild
conditions.
Converting
polymers
back
pure
monomers
by
is
potential
solution
environmental
ecological
concerns
associated
ultimate
fate
polymers.
This
perspective
focuses
on
emerging
field
from
synthesized
controlled
polymerizations
including
radical,
ionic,
metathesis
polymerizations.
We
provide
critical
review
current
literature
categorized
according
technique
explore
numerous
concepts
ideas
which
could
be
implemented
further
enhance
lower
temperature
systems,
catalytic
depolymerization,
increasing
polymer
scope,
depolymerization.
ACS Macro Letters,
Journal Year:
2023,
Volume and Issue:
12(8), P. 1173 - 1178
Published: Aug. 2, 2023
Fast
bulk
depolymerization
of
poly(n-butyl
methacrylate)
and
poly(methyl
methacrylate),
prepared
by
atom
transfer
radical
polymerization
(ATRP),
is
reported
in
the
temperature
range
between
150
230
°C.
Depolymerization
Cl-terminated
polymethacrylates
was
catalyzed
a
CuCl2/TPMA
complex
(0.022
or
0.22
equiv
vs
P-Cl)
studied
using
TGA,
also
under
isothermal
conditions.
Relatively
rapid
5-20
min
observed
at
180
The
preparative
scale
reactions
were
carried
out
short-path
distillation
setup
with
up
to
84%
within
15
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(29)
Published: April 13, 2023
Abstract
Shaping
a
sustainable
future
is
closely
tied
to
the
development
of
advanced
plastic
recycling
technologies.
As
global
rates
remain
low,
lion's
share
post‐consumer
plastics
either
incinerated
or
disposed
in
landfills.
This
unbalanced
waste
management
not
only
poses
severe
environmental
risks,
but
also
entails
an
irrevocable
loss
chemical
resources
that
are
embedded
synthetic
polymers.
To
give
new
life,
series
photocatalytic
methods
has
recently
been
reported
convert
polymers
directly
into
value‐added
organic
molecules.
These
approaches
operate
at
ambient
temperature,
show
high
reactivity/selectivity,
and
provide
alternative
reaction
pathways
as
compared
thermal
depolymerizations.
Minireview
highlights
scientific
breakthroughs
upcycling
through
state‐of‐the‐art
photocatalysis
under
environmentally
benign
conditions.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(19), P. 10480 - 10485
Published: May 8, 2023
We
establish
a
synthetically
convenient
method
to
degrade
polyacrylate
homopolymers.
Carboxylic
acids
are
installed
along
the
polymer
backbone
by
partial
hydrolysis
of
ester
side
chains,
and
then,
in
one-pot
sequential
procedure,
carboxylic
converted
into
alkenes
oxidatively
cleaved.
This
process
enables
robustness
properties
polyacrylates
be
maintained
during
their
usable
lifetime.
The
ability
tune
degree
degradation
was
demonstrated
varying
acid
content
polymers.
is
compatible
with
wide
range
polymers
prepared
from
vinyl
monomers
through
copolymerization
acrylic
different
including
acrylates,
acrylamides,
styrenics.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(39), P. 21146 - 21151
Published: Sept. 22, 2023
A
photocatalytic
ATRP
depolymerization
is
introduced
that
significantly
suppresses
the
reaction
temperature
from
170
to
100
°C
while
enabling
temporal
regulation.
In
presence
of
low-toxicity
iron-based
catalysts
and
under
visible
light
irradiation,
near-quantitative
monomer
recovery
could
be
achieved
(up
90%),
albeit
with
minimal
control.
By
employing
ppm
concentrations
either
FeCl2
or
FeCl3,
during
dark
periods
completely
eliminated,
thus
control
possibility
modulate
rate
by
simply
turning
"on"
"off".
Notably,
our
approach
allowed
preservation
end-group
fidelity
throughout
reaction,
carried
out
at
high
polymer
loadings
2M),
was
compatible
various
polymers
sources.
This
methodology
provides
a
facile,
environmentally
friendly,
temporally
regulated
route
chemically
recycle
ATRP-synthesized
polymers,
opening
door
for
further
opportunities.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(38)
Published: July 31, 2023
Although
controlled
radical
polymerization
is
an
excellent
tool
to
make
precision
polymeric
materials,
reversal
of
the
process
retrieve
starting
monomer
far
less
explored
despite
significance
chemical
recycling.
Here,
we
investigate
bulk
depolymerization
RAFT
and
ATRP-synthesized
polymers
under
identical
conditions.
RAFT-synthesized
undergo
a
relatively
low-temperature
solvent-free
back
thanks
partial
in
situ
transformation
end-group
macromonomer.
Instead,
can
only
depolymerize
at
significantly
higher
temperatures
(>350
°C)
through
random
backbone
scission.
To
aid
more
complete
even
lower
temperatures,
performed
facile
quantitative
modification
strategy
which
both
ATRP
end-groups
were
successfully
converted
macromonomers.
The
macromonomers
triggered
temperature
with
onset
150
°C
yielding
up
90
%
regeneration.
versatility
methodology
was
demonstrated
by
scalable
(≈10
g
polymer)
retrieving
84
intact
could
be
subsequently
used
for
further
polymerization.
This
work
presents
new
low-energy
approach
depolymerizing
creates
many
future
opportunities
as
high-yielding,
methods
are
sought.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(9), P. 6217 - 6224
Published: Feb. 21, 2024
In
this
study,
we
present
an
efficient
approach
for
the
depolymerization
of
poly(methyl
methacrylate)
(PMMA)
copolymers
synthesized
via
conventional
radical
polymerization.
By
incorporating
low
mol
%
phthalimide
ester-containing
monomers
during
polymerization
process,
colorless
and
transparent
polymers
closely
resembling
unfunctionalized
PMMA
are
obtained,
which
can
achieve
>95%
reversion
to
methyl
methacrylate
(MMA).
Notably,
our
catalyst-free
bulk
method
exhibits
exceptional
efficiency,
even
high-molecular-weight
polymers,
including
ultrahigh-molecular-weight
(10
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: March 20, 2024
Abstract
Only
a
small
proportion
of
global
plastic
waste
is
recycled,
which
most
mechanically
recycled
into
lower
quality
materials.
The
alternative,
chemical
recycling,
enables
renewed
production
pristine
materials,
but
generally
comes
at
high
energy
cost,
particularly
for
processes
like
pyrolysis.
This
review
focuses
on
light-driven
approaches
chemically
recycling
and
upcycling
waste,
with
emphasis
reduced
consumption
selective
transformations
not
achievable
heat-driven
methods.
We
focus
challenging
to
recycle
backbone
structures
composed
mainly
C‒C
bonds,
lack
functional
groups
i.e.,
esters
or
amides,
that
facilitate
e.g.,
by
solvolysis.
discuss
the
use
light,
either
in
conjunction
heat
drive
depolymerization
monomers
via
photocatalysis
transform
polymers
valuable
molecules.
structural
prerequisites
these
are
outlined,
highlighting
their
advantages
as
well
limitations.
conclude
an
outlook,
addressing
key
challenges,
opportunities,
provide
guidelines
future
photocatalyst
(PC)
development.
