Advanced Science,
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 18, 2024
Abstract
Plastic
recycling
is
a
critical
step
toward
improving
waste
management
and
achieving
economic
recycling.
Here,
thermoset
crosslinked
by
guanythiourea
structure
(GTUH
network)
reported,
that
addresses
the
issue
of
thermosets
serial
hybridization
thiourea
guanidine
urea.
The
dual
dissociative
dynamic
exchange
reaction
guanamine
urea
thiourea,
combined
with
non‐covalent
hydrogen
bonding
interactions,
endows
network
rapid
relaxation
ability.
GTUH
networks,
in
particular,
can
be
recycled
through
continuous
extrusion
processing
due
to
multiple
reversible
mechanisms,
as
opposed
hot
pressing
alone.
Even
if
reprocessed
pressing,
only
5
min
at
140
°C
10
MPa
are
required.
oxidation
enhancement
mechanism
contributes
maintaining
or
even
mechanical
properties
network.
Moreover,
reactions
allow
for
closed‐loop
chemical
Research
into
recyclable
carbon
fiber‐reinforced
composites
indicates
promising
potential
applications
this
material
circular
economy
resources.
Materials Horizons,
Год журнала:
2024,
Номер
11(8), С. 1867 - 1876
Опубликована: Янв. 1, 2024
A
new
facile
and
scalable
interfacial
locking
engineering
strategy
is
exploited
to
endow
reversible
microcages
with
infinite
chemical
recyclability
starting
monomers,
exceptional
durability,
high
flame-retardant
efficiency,
extensive
applicability
across
diverse
polymers.
Advanced Functional Materials,
Год журнала:
2024,
Номер
unknown
Опубликована: Июнь 29, 2024
Abstract
Epoxy
resins‐based
engineering
plastics
are
indispensable
in
the
global
economy,
but
they
have
created
a
serious
waste
crisis
caused
by
their
chemical
cross‐linked
networks.
To
solve
this
problem,
current
strategies
often
require
assistance
of
catalysts
or
solvents
at
expense
thermal
and
mechanical
performance.
In
work,
high‐performance
epoxy
resin
featuring
dynamic
ester
disulfide
bonds
(TDS)
is
reported,
which
exhibits
higher
properties
than
common
plastics,
i.e.,
tensile
strength
modulus
66.6
MPa
2.63
GPa,
flexural
103.2
3.52
glass
transition
temperature
(
T
g
)
133
°C.
Moreover,
reversible
transformation
between
aromatic
thiyl
radicals
endows
TDS
with
autonomous
visualization
damage
healing.
addition,
harmonious
interplay
bonds‐promoted
tertiary
amine
accelerated
topological
network
rearrangements,
enabling
to
easily
reshape
weld.
Specifically,
can
be
completely
degraded
pure
water
200
°C
without
any
catalyst,
products
directly
re‐polymerized
achieve
green
closed‐loop
recycling.
This
work
proposes
simple
economical
strategy
for
development
resin‐based
cutting‐edge
that
both
functional
sustainable.
Polymer Chemistry,
Год журнала:
2024,
Номер
15(19), С. 1962 - 1974
Опубликована: Янв. 1, 2024
Allyl-containing
bis(oxazolidone)s,
obtained
by
depolymerization
of
polycarbonates,
are
polymerized
with
dithiols
to
deliver
functional
poly(oxazolidone)s,
easily
derived
thioether
oxidation
sulfoxides
or
sulfones,
S
-alkylation.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Июнь 3, 2024
Covalent
adaptable
networks
(CANs),
leveraging
the
dynamic
exchange
of
covalent
bonds,
emerge
as
a
promising
material
to
address
challenge
irreversible
cross-linking
in
thermosetting
polymers.
In
this
work,
we
explore
introduction
catalyst-free
and
associative
C=C/C=N
metathesis
reaction
into
polyurethanes,
creating
CANs
with
superior
stability,
solvent
resistance,
thermal/mechanical
properties.
By
incorporating
reaction,
stress-relaxation
is
significantly
accelerated
compared
imine-bond-only
networks,
rate
adjustable
by
modifying
substituents
ortho
position
double
bonds.
The
obtained
plasticity
enables
recycle
without
altering
chemical
structure
or
mechanical
properties,
also
found
be
vital
for
achieving
shape
memory
functions
complex
spatial
structures.
This
new
crosslinker
polymer
has
potential
accelerate
ongoing
exploration
malleable
functional
thermoset
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(28), С. 19177 - 19182
Опубликована: Июль 2, 2024
The
development
of
intrinsically
recyclable
cross-linked
materials
remains
challenged
by
the
inherently
unfavorable
chemical
equilibrium
that
dictates
efficiency
reversible
covalent
bonding/debonding
chemistry.
Rather
than
having
to
(externally)
manipulate
bonding
equilibrium,
we
here
introduce
a
new
chemistry
platform
based
on
monosubstituted
thiomaleimides
can
undergo
complete
and
independent
light-activated
on-demand
thermal
debonding
above
120
°C.
Specifically,
repeated
small-molecule
thiomaleimide
[2
+
2]
photodimer
is
demonstrated
over
five
heat/light
cycles
with
full
conversion
in
both
directions,
thereby
regenerating
its
initial
monothiomaleimide
constituents.
This
motivated
synthesis
multifunctional
reagents
as
precursors
for
design
covalently
networks
display
intrinsic
switching
between
monomeric
polymeric
state.
resulting
are
shown
dissociate
depolymerize
upon
heating
solution
bulk,
thus
transforming
densely
photo-cross-linked
material
back
into
viscous
liquid.
Temperature-regulated
photorheology
evidenced
recyclability
thiomaleimide-based
thermosets
during
multiple
UV
cross-linking
de-cross-linking.
thermally
photodimerization
presents
addition
designer
playground
dynamic
polymer
networks,
providing
interesting
opportunities
reprocessing
closed-loop
recycling
materials.
Macromolecules,
Год журнала:
2024,
Номер
57(21), С. 10311 - 10323
Опубликована: Окт. 19, 2024
This
work
presents
the
synthesis
and
characterization
of
a
highly
transparent
colorless
covalent
adaptable
network
(CAN)
exhibiting
short
relaxation
times
(30
s
at
150
°C)
limited
creep
100
°C.
Based
on
N,S-acetal
functions,
strongly
stabilized
by
trifluoromethyl
group,
this
network,
however,
retains
ability
to
undergo
fast
thiol
exchanges.
The
present
article
describes
detailed
monitoring
cross-linking
via
ATR-FTIR
19F
HRMAS
NMR
(high-resolution
magic
angle
spinning
NMR),
complete
structural
material
13C
NMR,
comprehensive
study
rheological
properties
novel
network.
CAN
shows
hydrolytic
stability
higher
activation
energies
(>90
kJ
mol–1)
than
its
nonfluorinated
counterparts.
Its
reprocessing
occurs
under
relatively
mild
conditions
without
need
for
catalyst,
depolymerization
can
be
achieved
either
with
an
amine
(benzylamine),
acidic
(1
M
HCl)
room
temperature,
or
(1-dodecanethiol)
Advanced Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 2, 2025
Abstract
Additive
manufacturing
(AM)
has
risen
in
popularity
due
to
its
ability
produce
complex
shapes
a
material‐efficient
way.
However,
objects
with
advanced
properties,
multimaterial
strategies
are
often
employed.
This
one‐polymer‐one‐property
paradigm
significantly
slows
down
the
application
of
AM,
and
particular
fused
deposition
modeling
(FDM),
for
functional
objects.
In
this
study
advantage
pluripotency
materials
is
taken,
i.e.,
attain
different
properties
from
single
stock,
afford
mechanically
tunable
3D
printed
dynamic
thermosets
(moduli
2
MPa
–
3
GPa,
1500×
increase,
Stress
at
break
70
MPa,
35×
increase).
To
do
so,
FDM‐compatible
CO
‐derived
dissociative
polymer
networks
designed
that
undergo
reaction‐induced
phase‐separation
(DRIPS).
strategy
enables
control
size
rigid
phase
simple
post‐printing
thermal
treatment,
cascading
spatially
patterned
mechanical
properties.
showcases
new
directions
printing
communities,
deep
implications
soft
robotics
compliant
mechanics.
