The
dynamic
covalent
bond
(DCB)
strategy
endows
the
polymer
with
recyclability,
enabling
resourceful
recycling,
energy
conservation,
and
addressing
environmental
pollution
issues,
thereby
garnering
significant
attention
currently
in
field.
Here,
we
achieved
closed-loop
recycling
of
a
series
shape
memory
polymers
(SMPs)
through
nucleophilic
aromatic
substitution
(SNAr)
reaction.
First,
SNAr
reaction
facilitated
high-strength,
high-transition-temperature
cyanate
esters
(SMCEs)
their
composite
(SMCEC)
into
triethoxytriazine
(TETA)
diols.
recycled
monomers
can
then
be
used
to
synthesize
SMPs
tailored
mechanical
properties
broad
range
transition
temperatures,
including
epoxy
resins,
ester
elastomers,
4D
printing
elastomers.
TETA
again
from
elastomers
Furthermore,
devised
two
innovative
strategies
for
materials
produce
actuators
high
resolution.
Notably,
polyacrylate
elastomer,
which
undergoes
situ
cross-linking
after
postheating
reactions,
presents
groundbreaking
method
high-performance
utilizing
DCBs.
This
work
not
only
provides
an
achieving
but
also
introduces
interesting
approach
SMPs.
Advanced Functional Materials,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 24, 2025
Abstract
Efficient
recycling
of
carbon
fiber‐reinforced
polymer
composites
(CFRCs)
into
their
original
monomers
and
fibers
(CFs)
in
a
non‐destructive
manner
remains
significant
challenge.
In
this
study,
high‐performance,
closed‐loop
recyclable
aromatic
polyamide
(APAD)
plastics
are
synthesized
via
polycondensation
amines
aldehydes
through
dynamic
imine
bonds.
Due
to
fully
structure
as
well
interchain
hydrogen
bonds
π–π
interactions,
APAD
exhibit
tensile
strength
≈78.3
MPa,
glass
transition
temperature
(
T
g
)
≈200.4
°C,
excellent
chemical
resistance.
The
can
be
depolymerized
mixture
polar
organic
solvents
acids
at
ambient
temperature,
enabling
high‐purity
recovery
precipitation
selective
solvents.
Water‐resistant
CF/APAD
fabricated
complexation
with
CF
cloths.
These
mechanical
properties
comparable
those
CF/epoxy
thermoset
superior
thermal
stability.
mild
depolymerization
conditions
for
enable
the
efficient
disintegration
composites.
Therefore,
CFs
realized.
recovered
cloths
used
re‐manufacture
This
study
presents
an
effective
method
CFRCs,
offering
environmental
economic
benefits.
ACS Sustainable Chemistry & Engineering,
Journal Year:
2024,
Volume and Issue:
12(7), P. 2668 - 2677
Published: Feb. 5, 2024
Replacing
traditional
petroleum-based
plastics
with
degradable
biobased
has
become
one
of
the
significant
strategies
to
address
energy
shortages
and
environmental
issues.
Nevertheless,
it
still
remains
a
scientific
challenge
develop
ultrastrong
mechanical
strength
superior
recyclability.
Here,
catalytic
conversion
Sapium
sebiferum
oil
(SSO)
9,10-dihydroxy-octadecanoic
acid
(C18-OH)
monomer
is
first
designed.
Simultaneously,
novel
plastic,
namely,
PEA,
fabricated
by
dual
network
through
one-pot
melt-polymerization,
which
exhibits
performance
higher
than
most
commercial
other
reported
PEAs.
Benefiting
from
synergy
dynamic
nature
H-bonds
hydroxy-ester
bonds
as
well
flexibility
long
aliphatic
chain,
PEAs
exhibit
exceptional
repairability
reprocessability.
More
importantly,
can
be
efficiently
degraded
into
original
reagents
cross-linked
materials
reconstructed
recovered
monomers
without
losing
pristine
performance.
Additionally,
abundant
polar
groups
provide
excellent
adhesion
properties
for
high
shear
10.29
±
0.21
MPa.
This
work
unveils
an
elegant
efficient
synthetic
route
fabricate
impressively
robust
chemically
recyclable
promising
alternatives
conventional
plastics.
ACS Applied Materials & Interfaces,
Journal Year:
2024,
Volume and Issue:
16(29), P. 38586 - 38605
Published: July 10, 2024
Novel
reprocessable
thermosetting
adhesives
(RTAs),
which
combine
high
adhesive
strength,
reusability,
disassembly,
and
recyclability
features,
have
attracted
increasing
attention.
However,
developing
RTAs
with
a
rapidly
rate
while
ensuring
strength
self-healing
ability
is
still
significant
challenge.
Here,
we
prepared
novel
vitrimer
called
DAx-DTSAy,
can
be
used
as
an
RTA.
First,
by
adjusting
the
ratio
of
rigid
flexible
segments,
maximum
tensile
reached
35.92
MPa.
Second,
combined
effect
dynamic
hydroxyl
ester
bonds
disulfide
resulted
in
rapid
stress
relaxation
behavior,
complete
time
13.6
times
shorter
than
only
cross-linked
hydroxy
bonds.
This
feature
endowed
its
good
reprocessing
capabilities.
After
at
180
°C,
healing
mechanical
properties
was
91.8%.
three
reprocesses,
recovery
120.2%.
Furthermore,
combination
segments
synergistic
dual
covalent
made
DAx-DTSAy
capable
use
high-performance
The
lap
shear
film
on
stainless
steel
18.18
MPa
after
15
min,
91.9%
5
rebonding
cycles.
Additionally,
disassembled
chemical
agents
exhibited
better
insulation
compared
to
traditional
epoxy
resins.
employed
applications
such
electronic
devices
transportation,
contributing
development
toward
sustainability.
Small,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 11, 2024
Abstract
Reversible
and
recyclable
thermosets
have
garnered
increasing
attention
for
their
smart
functionality
sustainability.
However,
they
still
face
challenges
in
balancing
comprehensive
performance
dynamic
features.
Herein,
silicon
(Si)─oxygen
(O)
imidazole
units
covalent
bonds
are
coupled
to
generate
a
new
class
of
bio‐polyimines
(Bio‐Si‐PABZs),
endow
them
with
high
excellent
reprocessing
capability
acid‐degradability.
By
tailoring
the
molar
content
diamines,
this
Bio‐Si‐PABZs
displayed
both
markedly
glass
transition
temperature
(162
°C)
char
yield
at
800
°C
an
oxygen
atmosphere
(73.1%).
These
favorable
properties
outperformed
various
previously
reported
polyimines
competed
effectively
commercial
fossil‐based
polycarbonate.
Moreover,
scratch
(≈10
µ
m)
on
surface
samples
can
be
self‐healing
within
only
2
min,
effective
“
Bird
Nest
”‐to‐“
Torch
”
recycling
also
achieved
through
free
amines
solution.
Most
importantly,
bio‐based
siloxane
adhesive
derived
from
intermediate
Bio‐Si‐PABZ‐1
by
acidic
degradation
demonstrated
broad
robust
adhesion
substrates,
values
reaching
up
≈3.5
MPa.
For
first
time,
study
lays
scientific
groundwork
designing
polyimine
Si─O
units,
as
well
converting
plastic
wastes
into
thermal‐reversibility
renewable
adhesives.
ACS Applied Polymer Materials,
Journal Year:
2024,
Volume and Issue:
6(15), P. 9008 - 9016
Published: July 31, 2024
Covalent
adaptable
networks
(CANs)
are
supposed
to
address
the
reprocessing
and
recycling
issues
of
epoxy
resins
via
their
reversible
cross-linking
structures.
However,
development
CANs
simultaneously
exhibiting
high
mechanical
strength
fast-reprocessing
ability
is
still
a
huge
challenge.
Herein,
with
fabricated
by
modifying
linear
polymers
nitrogen-coordinated
boronic
ester
imine
bonds.
Owing
densities
rigid
network
structures,
obtained
show
breaking
∼76.0
MPa,
yield
stress
∼81.5
Young's
modulus
∼1.67
GPa,
respectively.
Because
fast
exchange
reaction
bonds,
as-prepared
can
be
easily
processed
into
desirable
shapes
within
only
1
min
at
150
°C
under
pressure
10
MPa.
Moreover,
owing
this
unique
feature,
quickly
reprocessed
least
three
times
without
losing
original
properties.
Finally,
prepared
exhibit
shape
fixed
ratio
recovery
more
than
∼90%
when
used
as
shape-memory
polymers.
This
study
provides
feasible
solution
for
constructing
mechanically
strong
thermosets
ability,
which
will
contribute
next-generation
sustainable
resins.
