Chemical Reviews,
Journal Year:
2024,
Volume and Issue:
124(5), P. 2617 - 2650
Published: Feb. 22, 2024
The
societal
importance
of
plastics
contrasts
with
the
carelessness
which
they
are
disposed.
Their
superlative
properties
lead
to
economic
and
environmental
efficiency,
but
linearity
puts
climate,
human
health,
global
ecosystems
at
risk.
Recycling
is
fundamental
transitioning
this
linear
model
into
a
more
sustainable,
circular
economy.
Among
recycling
technologies,
chemical
depolymerization
offers
route
virgin
quality
recycled
plastics,
especially
when
valorizing
complex
waste
streams
poorly
served
by
mechanical
methods.
However,
exists
in
interlinked
system
end-of-life
fates,
complementarity
each
approach
key
environmental,
economic,
sustainability.
This
review
explores
recent
progress
made
five
commercial
polymers:
poly(ethylene
terephthalate),
polycarbonates,
polyamides,
aliphatic
polyesters,
polyurethanes.
Attention
paid
not
only
catalytic
technologies
used
enhance
efficiencies
also
interrelationship
other
systemic
constraints
imposed
Novel
polymers,
designed
for
depolymerization,
concisely
reviewed
terms
their
underlying
chemistry
potential
integration
current
plastic
systems.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(13), P. 5745 - 5749
Published: March 23, 2022
Chemical
upcycling
of
polystyrene
into
targeted
small
molecules
is
desirable
to
reduce
plastic
pollution.
Herein,
we
report
the
benzoyl
products,
primarily
benzoic
acid,
using
a
catalyst-controlled
photooxidative
degradation
method.
FeCl3
undergoes
homolytic
cleavage
upon
irradiation
with
white
light
generate
chlorine
radical,
abstracting
an
electron-rich
hydrogen
atom
on
polymer
backbone.
Under
oxygen-rich
environment,
high
MW
(>90
kg/mol)
degrades
down
<1
kg/mol
and
produces
up
23
mol
%
products.
A
series
mechanistic
studies
showed
that
radicals
promoted
via
hydrogen-atom
abstraction.
Commercial
efficiently
in
our
method,
showing
compatibility
system
fillers.
Finally,
demonstrated
potential
scaling
approach
photoflow
process
convert
gram
quantities
PS
acid.
Green Chemistry,
Journal Year:
2022,
Volume and Issue:
24(6), P. 2321 - 2346
Published: Jan. 1, 2022
The
design
and
synthesis
of
chemically
recyclable
polymers,
which
can
be
reutilized
as
their
starting
monomers
or
new
value-added
chemicals,
has
provided
a
practical
approach
to
address
the
end-of-use
problem
polymer
materials
possible
closed-loop
method
for
material
usage.
More
more
attention
been
paid
exhibit
an
increasing
prominent
role
in
sustainable
development.
Nowadays,
polymers
including
polyesters,
polythioesters,
polycarbonates,
polyacetals,
polyamides,
so
on
have
made
significant
achievements.
Consequently,
this
minireview
summarizes
examples
achieving
polymerization–depolymerization
cycle
access
are
categorized
into
seven
parts
based
monomers.
Science,
Journal Year:
2023,
Volume and Issue:
381(6658), P. 666 - 671
Published: Aug. 10, 2023
Conversion
of
plastic
wastes
to
fatty
acids
is
an
attractive
means
supplement
the
sourcing
these
high-value,
high-volume
chemicals.
We
report
a
method
for
transforming
polyethylene
(PE)
and
polypropylene
(PP)
at
~80%
conversion
with
number-average
molar
masses
up
~700
670
daltons,
respectively.
The
process
applicable
municipal
PE
PP
their
mixtures.
Temperature-gradient
thermolysis
key
controllably
degrading
into
waxes
inhibiting
production
small
molecules.
are
upcycled
by
oxidation
over
manganese
stearate
subsequent
processing.
ꞵ-scission
produces
more
olefin
wax
yields
higher
acid-number
than
does
ꞵ-scission.
further
convert
large-market-volume
surfactants.
Industrial-scale
technoeconomic
analysis
suggests
economic
viability
without
need
subsidies.
Journal of the American Chemical Society,
Journal Year:
2021,
Volume and Issue:
143(49), P. 20591 - 20597
Published: Nov. 29, 2021
The
development
of
high-performance
recyclable
polymers
represents
a
circular
plastics
economy
to
address
the
urgent
issues
plastic
sustainability.
Herein,
we
design
series
biobased
seven-membered-ring
esters
containing
aromatic
and
aliphatic
moieties.
Ring-opening
polymerization
studies
showed
that
they
readily
polymerize
with
excellent
activity
(TOF
up
2.1
×
105
h–1)
at
room
temperature
produce
high
molecular
weight
(Mn
438
kg/mol).
variety
functionalities
allows
us
investigate
substitution
effect
on
polymerizability/recyclability
monomers
properties
(such
as
Tgs
from
−1
79
°C).
Remarkably,
stereocomplexed
P(M2)
exhibited
significantly
increased
Tm
crystallization
rate.
More
importantly,
product
P(M)s
were
capable
depolymerizing
into
their
in
solution
or
bulk
efficiency,
thus
establishing
life
cycle.
Advanced Materials,
Journal Year:
2022,
Volume and Issue:
35(7)
Published: Nov. 11, 2022
Development
of
closed-loop
chemically
recyclable
plastics
(CCRPs)
that
can
be
widely
used
in
daily
life
a
fundamental
solution
to
the
global
plastic
waste
crisis.
Hence,
it
is
great
significance
develop
easy-to-recycle
CCRPs
possess
superior
or
comparable
material
properties
commodity
plastics.
Here,
novel
dual
crosslinked
CCRP,
namely,
supramolecular
covalent
adaptable
networks
(supra-CANs),
reported,
which
not
only
displays
mechanical
higher
than
strong
and
tough
polycarbonate,
but
also
exhibits
excellent
solvent
resistance
as
thermosets.
The
supra-CANs
are
constructed
by
introducing
reversible
noncovalent
crosslinks
into
dynamic
polymer
networks,
resulting
highly
stiff
thermosets
exhibit
thermoplastic-like
ductile
behaviors
well
reprocessability
rehealability.
In
contrast,
analogs
do
have
(CANs)
show
elastomeric
with
significantly
decreased
strength.
Importantly,
developed
CANs
converted
back
initial
monomers
high
yields
purity
at
room
temperature,
even
additives,
enables
sustainable
polymer-monomer-polymer
circulation.
This
work
provides
new
design
principles
for
high-performance
polymers
substitutes
conventional
