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,
mainly
C‒C,
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
development.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Март 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.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(9), С. 6217 - 6224
Опубликована: Фев. 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
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(19)
Опубликована: Март 11, 2024
Abstract
Photocatalytic
upcycling
and
depolymerization
of
vinyl
polymers
have
emerged
as
promising
strategies
to
combat
plastic
pollution
promote
a
circular
economy.
This
mini
review
critically
summarizes
current
developments
in
the
degradation
including
polystyrene
poly(meth)acrylates.
Of
these
material
classes,
polymethacrylates
possess
unique
possibility
undergo
photocatalytic
back
monomer
under
thermodynamically
favourable
conditions,
thus
presenting
significant
advantages
over
traditional
thermal
strategies.
Our
perspective
on
formidable
challenges
potential
future
directions
are
also
discussed.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(13), С. 9142 - 9154
Опубликована: Март 25, 2024
The
development
of
cleavable
comonomers
(CCs)
with
suitable
copolymerization
reactivity
paves
the
way
for
introduction
backbone
deconstructability
into
polymers.
Recent
advancements
in
thionolactone-based
CCs,
exemplified
by
dibenzo[c,e]-oxepine-5(7H)-thione
(DOT),
have
opened
promising
avenues
selective
deconstruction
multiple
classes
vinyl
polymers,
including
polyacrylates,
polyacrylamides,
and
polystyrenics.
To
date,
however,
no
thionolactone
CC
has
been
shown
to
copolymerize
methacrylates
an
appreciable
extent
enable
polymer
deconstruction.
Here,
we
overcome
this
challenge
through
design
a
new
class
benzyl-functionalized
thionolactones
(bDOTs).
Guided
detailed
mechanistic
analyses,
find
that
radical-stabilizing
substituents
bDOTs
enables
markedly
increased
tunable
methyl
methacrylate
(MMA).
Through
iterative
optimizations
molecular
structure,
specific
bDOT,
F-p-CF3PhDOT,
is
discovered
efficiently
MMA.
High
molar
mass
deconstructable
PMMA-based
copolymers
(dPMMA,
Mn
>
120
kDa)
low
percentages
F-p-CF3PhDOT
(1.8
3.8
mol%)
are
prepared
using
industrially
relevant
bulk
free
radical
conditions.
thermomechanical
properties
dPMMA
similar
PMMA;
former
degrade
fragments
(<6.5
under
mild
aminolysis
This
work
presents
first
example
ring-opening
capable
nearly
random
MMA
without
possibility
cross-linking
provides
workflow
mechanism-guided
future.
Science,
Год журнала:
2025,
Номер
387(6736), С. 874 - 880
Опубликована: Фев. 20, 2025
The
reversion
of
vinyl
polymers
with
carbon-carbon
backbones
to
their
monomers
represents
an
ideal
path
alleviate
the
growing
plastic
waste
stream.
However,
depolymerizing
such
stable
materials
remains
a
challenge,
state-of-the-art
methods
relying
on
"designer"
that
are
neither
commercially
produced
nor
suitable
for
real-world
applications.
In
this
work,
we
report
main
chain-initiated,
visible
light-triggered
depolymerization
directly
applicable
commercial
containing
undisclosed
impurities
(e.g.,
comonomers,
additives,
or
dyes).
By
in
situ
generation
chlorine
radicals
from
solvent,
near-quantitative
(>98%)
polymethacrylates
could
be
achieved
regardless
synthetic
route
radical
ionic
polymerization),
end
group,
and
molecular
weight
(up
1.6
million
daltons).
possibility
perform
multigram-scale
depolymerizations
confer
temporal
control
renders
methodology
versatile
general
recycling.
Macromolecules,
Год журнала:
2025,
Номер
58(5), С. 2210 - 2223
Опубликована: Фев. 18, 2025
Polymeric
materials
have
become
indispensable
due
to
their
versatility
and
low
cost,
yet
environmental
impact
presents
a
significant
global
challenge.
Traditional
chemical
recycling
methods
typically
rely
on
heat
as
stimulus;
for
instance,
pyrolysis
is
popular
methodology
which
faces
limitations
high
energy
consumption,
product
selectivity,
the
generation
of
undesirable
byproducts.
In
response,
recent
advances
in
promotion
depolymerization
degradation
through
alternative
stimuli
such
light,
electrochemistry,
mechanical
force,
shown
promising
potential
more
efficient
selective
polymer
breakdown,
yielding
either
starting
monomers
or
valuable
small
molecules.
This
perspective
explores
key
examples
these
emerging
strategies,
highlighting
improve
upon
current
protocols
offer
pathways
under
milder
conditions,
while
identifying
challenges
that
future
research
must
address
translate
chemistry
into
viable
broadly
applicable
strategies.
Journal of Polymer Science,
Год журнала:
2024,
Номер
62(17), С. 3920 - 3928
Опубликована: Май 22, 2024
Abstract
The
ability
to
revert
polymers
their
original
monomers
represents
a
crucial
chemical
recycling
technique,
promoting
sustainability
and
offering
the
chance
convert
used
materials
into
valuable
products.
In
recent
years,
numerous
studies
have
explored
use
of
synthesized
via
reversible
deactivation
radical
polymerization
(RDRP)
techniques
facilitate
efficient
depolymerization
reactions.
Herein,
we
report
photocatalyst,
zinc
tetraphenylporphyrin
(ZnTPP),
along
with
light
irradiation
accelerate
prepared
by
addition‐fragmentation
chain
transfer
(RAFT)
polymerization.
We
explore
various
parameters
affecting
efficiency,
including
solvents,
reaction
temperature
(80,
100,
120°C),
presence
photocatalysts
(ZnTPP
Eosin
Y),
type
RAFT
end‐groups,
namely
trithiocarbonate,
dithiobenzoate,
1
H
‐pyrazole‐1‐carbodithioate.
For
instance,
when
PMMA
was
diluted
25
mM
in
1,4‐dioxane
heated
120°C
under
green
ZnTPP
(200
ppm),
rapid
exceeding
70%
occurred
within
h.
Without
ZnTPP,
similar
conditions,
required
over
8
h
achieve
slightly
lower
yield.
Furthermore,
this
method
confers
moderate
oxygen
tolerance
system,
enabling
proceed
without
need
deoxygenation,
albeit
at
rate
consequently
lesser
monomer
recovery
(31%).
