Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(22)
Опубликована: Март 16, 2024
Abstract
Chemical
recycling
of
polymers
to
monomers
presents
a
promising
solution
the
escalating
crisis
associated
with
plastic
waste.
Despite
considerable
progress
made
in
this
field,
primary
efforts
have
been
focused
on
redesigning
new
produce
readily
recyclable
polymers.
In
contrast,
limited
research
into
potential
seemingly
“non‐polymerizable”
has
conducted.
Herein,
we
propose
paradigm
that
leverages
“chaperone”‐assisted
strategy
establish
closed‐loop
circularity
for
α,
β‐conjugated
lactone,
5,6‐dihydro‐2H‐pyran‐2‐one
(DPO).
The
resulting
PDPO,
structural
analogue
poly(δ‐valerolactone)
(PVL),
exhibits
enhanced
thermal
properties
melting
point
(
T
m
)
114
°C
and
decomposition
temperature
d,5%
305
°C.
Notably,
owing
similarity
between
DPO
δ‐VL,
copolymerization
generates
semi‐crystalline
P(DPO‐
co
‐VL)s
irrespective
incorporation
ratio.
Intriguingly,
inherent
C=C
bonds
enable
their
convenient
post‐functionalization
via
Michael‐addition
reaction.
Lastly,
PDPO
was
demonstrated
be
chemically
ring‐closing
metathesis
(RCM),
representing
significant
step
towards
pursuit
enabling
lactones
without
altering
ultimate
polymer
structure.
Green Chemistry,
Год журнала:
2022,
Номер
24(6), С. 2321 - 2346
Опубликована: Янв. 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.
ACS Nano,
Год журнала:
2023,
Номер
17(23), С. 23223 - 23261
Опубликована: Дек. 2, 2023
Stimuli-responsive
polymers
can
respond
to
internal
stimuli,
such
as
reactive
oxygen
species
(ROS),
glutathione
(GSH),
and
pH,
biological
enzymes,
external
lasers
ultrasound,
etc.,
by
changing
their
hydrophobicity/hydrophilicity,
degradability,
ionizability,
thus
have
been
widely
used
in
biomedical
applications.
Due
the
characteristics
of
tumor
microenvironment
(TME),
stimuli-responsive
that
cater
specifically
TME
extensively
prepare
smart
nanovehicles
for
targeted
delivery
therapeutic
diagnostic
agents
tissues.
Compared
conventional
drug
nanosystems,
TME-responsive
nanosystems
many
advantages,
high
sensitivity,
broad
applicability
among
different
tumors,
functional
versatility,
improved
biosafety.
In
recent
years,
a
great
deal
research
has
devoted
engineering
efficient
polymeric
significant
improvement
made
both
cancer
diagnosis
therapy.
this
review,
we
summarize
some
advances
involving
use
polymer
nanocarriers
delivery,
imaging,
therapy,
theranostics.
Various
chemical
stimuli
will
be
described
context
nanosystems.
Accordingly,
groups
responsible
responsiveness
strategies
incorporate
these
into
discussed
detail.
With
on
topic
expending
at
fast
pace,
innovative
concepts,
sequential
cascade
release,
NIR-II
multifunctional
formulations,
emerged
popular
enhanced
performance,
which
also
included
here
with
up-to-date
illustrations.
We
hope
review
offer
valuable
insights
selection
optimization
help
accelerate
future
applications
treatment.
Science,
Год журнала:
2023,
Номер
380(6640), С. 64 - 69
Опубликована: Апрель 6, 2023
Polyhydroxyalkanoates
(PHAs)
have
attracted
increasing
interest
as
sustainable
plastics
because
of
their
biorenewability
and
biodegradability
in
the
ambient
environment.
However,
current
semicrystalline
PHAs
face
three
long-standing
challenges
to
broad
commercial
implementation
application:
lack
melt
processability,
mechanical
brittleness,
unrealized
recyclability,
last
which
is
essential
for
achieving
a
circular
economy.
Here
we
report
synthetic
PHA
platform
that
addresses
origin
thermal
instability
by
eliminating
α-hydrogens
repeat
units
thus
precluding
facile
cis-elimination
during
degradation.
This
simple
α,α-disubstitution
enhances
stability
so
substantially
become
melt-processable.
Synergistically,
this
structural
modification
also
endows
with
toughness,
intrinsic
crystallinity,
closed-loop
chemical
recyclability.
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(3), С. 1877 - 1885
Опубликована: Янв. 3, 2023
The
current
scale
of
plastics
production
and
the
attendant
waste
disposal
issues
represent
an
underexplored
opportunity
for
chemically
recyclable
polymers.
Typical
polymers
are
subject
to
trade-off
between
monomer's
polymerizability
polymer's
depolymerizability
as
well
insufficient
performance
practical
applications.
Herein,
we
demonstrate
that
a
single
atom
oxygen-by-sulfur
substitution
relatively
highly
strained
dilactone
is
effective
robust
strategy
converting
"non-recyclable"
polyester
into
polymer
by
lowering
ring
strain
energy
in
monomer
(from
16.0
kcal
mol-1
9.1
monothiodilactone).
These
monothio-modification
monomers
enable
both
high/selective
recyclability,
otherwise
conflicting
features
typical
monomer,
evidenced
regioselective
ring-opening,
minimal
transthioesterifications,
quantitative
recovery
pristine
monomer.
Computational
experimental
studies
n→π*
interaction
adjacent
ester
thioester
backbone
has
been
implicated
high
selectivity
propagation
over
transthioesterification.
resulting
demonstrates
with
its
mechanical
properties
being
comparable
some
commodity
polyolefins.
Thio-modification
powerful
enabling
conversion
six-membered
dilactones
tough
thermoplastics
exhibit
promise
next-generation
sustainable
Chemical Reviews,
Год журнала:
2024,
Номер
124(5), С. 2617 - 2650
Опубликована: Фев. 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.
Macromolecules,
Год журнала:
2023,
Номер
56(3), С. 731 - 750
Опубликована: Фев. 6, 2023
A
crucial
modern
dilemma
relates
to
the
ecological
crisis
created
by
excess
plastic
waste
production.
An
emerging
technology
for
reducing
is
production
of
"chemically
recyclable"
polymers.
These
polymers
can
be
efficiently
synthesized
through
ring-opening
polymerization
(ROP/ROMP)
and
later
recycled
pristine
monomer
ring-closing
depolymerization,
in
an
efficient
circular-type
system.
This
Perspective
aims
explore
chemistry
involved
preparation
these
monomer/polymer
systems,
while
also
providing
overview
challenges
involved,
including
future
directions.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(11)
Опубликована: Янв. 5, 2023
Poly(1,2-dithiolane)s
are
a
family
of
intrinsically
recyclable
polymers
due
to
their
dynamic
covalent
disulfide
linkages.
Despite
the
common
use
thiolate-initiated
anionic
ring-opening
polymerization
(ROP)
under
basic
condition,
cationic
ROP
is
still
not
exploited.
Here
we
report
that
bond
can
act
as
proton
acceptor,
being
protonated
by
acids
form
sulfonium
cations,
which
efficiently
initiate
1,2-dithiolanes
and
result
in
high-molecular-weight
(over
1000
kDa)
poly(disulfide)s.
The
reaction
be
triggered
adding
catalytic
amounts
non-coordinating
anion
salts,
completed
few
minutes
at
room
temperature.
acidic
conditions
allow
applicability
for
monomers.
Importantly,
condition
open
air
without
inert
protection,
enabling
nearly
quantitative
chemical
recycling
from
bulk
materials
original
Advanced Energy Materials,
Год журнала:
2023,
Номер
13(41)
Опубликована: Сен. 24, 2023
The
huge
amount
of
plastic
wastes
has
become
a
pressing
global
environmental
problem,
leading
to
severe
pollution
and
resource
depletion
through
conventional
downcycling
technologies
like
incineration
landfilling.
In
contrast,
selective
upcycling
various
plastics
offers
promising
solution
for
converting
waste
into
valuable
products.
This
review
provides
comprehensive
overview
the
recent
advancements
in
innovative
catalytic
technologies,
including
thermocatalysis,
electrocatalysis,
photocatalysis.
Special
emphasis
is
placed
on
elucidating
reaction
mechanisms,
activating
designated
chemical
bonds
high
selectivity,
elaborating
above
techniques
terms
conditions
Finally,
application
prospects
future
development
trends
catalysis
are
discussed,
providing
insights
realizing
sustainable
circular
economy.
