Advanced Functional Materials,
Journal Year:
2024,
Volume and Issue:
34(46)
Published: July 18, 2024
Abstract
Ion‐conductive
elastomers
capable
of
damping
can
significantly
mitigate
the
interference
caused
by
mechanical
noise
during
data
acquisition
in
wearable
and
biomedical
devices.
However,
currently
available
often
lack
robust
properties
have
a
narrow
temperature
range
for
effective
damping.
Here,
precise
modulation
weak
to
strong
ion‐dipole
interactions
plays
crucial
role
bolstering
network
stability
tuning
relaxation
behavior
supramolecular
ion‐conductive
(SICEs).
The
SICEs
exhibit
impressive
properties,
including
modulus
13.2
MPa,
toughness
65.6
MJ
m
−3
,
fracture
energy
74.9
kJ
−2
.
Additionally,
they
demonstrate
remarkable
capabilities,
with
capacity
91.2%
peak
tan
δ
1.11.
Furthermore,
entropy‐driven
rearrangement
ensures
SICE
remain
stable
even
at
elevated
temperatures
(18–200
°C,
>
0.3),
making
it
most
thermally
resistant
elastomer
reported
date.
Moreover,
proves
filtering
out
various
noises
physiological
signal
detection
strain
sensing,
highlighting
its
vast
potential
flexible
electronics.
Macromolecules,
Journal Year:
2024,
Volume and Issue:
57(7), P. 3242 - 3257
Published: March 28, 2024
We
formulate
a
statistical
mechanical
theory
for
how
dynamic
bond
exchange
influences
the
activated
hopping-driven
relaxation
of
Kuhn
segments
in
dynamically
cross-linked
networks
or
vitrimers
over
wide
range
temperatures
and
cross-link
densities.
The
key
new
methodological
aspect
is
to
address
self-consistent
manner
consequences
on
segmental
alpha
relaxation,
vice
versa.
predicted
temperature
dependence
time
at
high
remains
same
as
that
permanent
networks,
but
lower
temperatures,
significant
acceleration
occurs
due
exchanges.
From
mechanistic
perspective,
vitrimer
local
cage
barrier
very
weakly
affected
by
exchange,
while
collective
elastic
contribution
decreases
significantly
deeply
supercooled
regime.
glass
transition
grow
linearly
with
square
root
density,
previously
found
networks.
Material-specific
chemical
effects
such
cross-linker
size
relative
normal
segment
special
attraction
polymers
are
crudely
considered
based
model
calculations.
quantitatively
applied
recent
experiments
dry
ethylene
vitrimers.
Good
agreements
including
follows
an
Arrhenius
law
enough
upward
non-Arrhenius
deviations
emerge
regime,
collapsed
master
curve
exists
densities
temperatures.
Possible
extensions
treat
heterogeneity
penetrant
transport
briefly
discussed.
Chemical Science,
Journal Year:
2024,
Volume and Issue:
15(19), P. 7061 - 7071
Published: Jan. 1, 2024
Acid-base
catalysis
is
a
common
strategy
to
induce
covalent
bond
exchanges
in
dynamic
polymer
networks.
Strong
acids
or
strong
bases
can
promote
rapid
network
rearrangements,
and
are
simultaneously
preferred
catalysts
for
chemical
reactions
where
maximum
efficiency
at
the
lowest
possible
temperature
aimed
for.
However,
within
context
of
networks,
incorporation
highly
active
negatively
affect
longer
term
application
potential.
Network
dynamicity
diminish
through
catalyst
ageing
quenching
may
prematurely
activate
exchanges,
leading
dimensional
instability
thus
low
creep
resistance
Herein,
we
present
several
examples
explicitly
explored
weak
(carboxylic
acids)
as
using
vinylogous
urethanes
(VU)
well-understood
protic
acid
catalysed
vitrimer
chemistry.
Surprisingly,
have
found
that
sought-after
long-term
stability
offered
by
does
not
necessarily
bring
lower
activity
high
temperature.
In
fact,
show
remarkable
thermoswitchable
catalytic
behaviour,
going
from
an
inactive
hydrogen
bonded
state
matrix
protonated,
with
profound
impact
on
reactivity
rheology.
Carboxylic
different
electronic
steric
environments
clear
trends
their
fine-tuning
resulted
most
thermally
responsive
VU
vitrimers
studied
date.
Our
findings
point
out
choice
design
only
poorly
informed
performance
more
traditional
(in
solvent),
tailored
holds
great
promise
field
vitrimers.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(46), P. 25450 - 25462
Published: Nov. 9, 2023
Finding
new
chemistry
platforms
for
easily
recyclable
polymers
has
become
a
key
challenge
to
face
environmental
concerns
and
the
growing
plastics
demand.
Here,
we
report
dynamic
between
CO2-sourced
alkylidene
oxazolidones
thiols,
delivering
circular
non-isocyanate
polyurethane
networks
embedding
N,S-acetal
bonds.
The
production
of
oxazolidone
monomers
from
CO2
is
facile
scalable
starting
cheap
reagents.
Their
copolymerization
with
polythiol
occurs
under
mild
conditions
in
presence
catalytic
amount
acid
furnish
polymer
networks.
structure
tuned
by
virtue
monomer
design,
translating
into
wide
panel
mechanical
properties
similar
commodity
plastics,
ranging
PDMS-like
elastomers
[with
Young's
modulus
(E)
2.9
MPa
elongation
at
break
(εbreak)
159%]
polystyrene-like
rigid
(with
E
=
2400
MPa,
εbreak
3%).
highly
dissociative
nature
bonds
demonstrated
exploited
offer
three
different
recycling
scenarios
thermosets:
(1)
compression
molding,
extrusion,
or
injection
molding─with
multiple
(at
least
10
times)
without
any
material
property
deterioration,
(2)
chemical
through
depolymerization,
followed
repolymerization,
also
applicable
composites,
(3)
upcycling
two
oxazolidone-based
thermosets
single
one
distinct
properties.
This
work
highlights
platform
designing
containing
elusive
motifs.
versatility
this
shows
great
potential
preparation
materials
(including
composites)
tuneable
structures
properties,
end-of-life
scenarios.
Advanced Science,
Journal Year:
2023,
Volume and Issue:
11(5)
Published: Dec. 7, 2023
Abstract
Vitrimers
are
an
innovative
class
of
polymers
that
boast
a
remarkable
fusion
mechanical
and
dynamic
features,
complemented
by
the
added
benefit
end‐of‐life
recyclability.
This
extraordinary
blend
properties
makes
them
highly
attractive
for
variety
applications,
such
as
automotive
sector,
soft
robotics,
aerospace
industry.
At
their
core,
vitrimer
materials
consist
crosslinked
covalent
networks
have
ability
to
dynamically
reorganize
in
response
external
factors,
including
temperature
changes,
pressure
variations,
or
shifts
pH
levels.
In
this
review,
aim
is
delve
into
latest
advancements
theoretical
understanding
computational
design
vitrimers.
The
review
begins
offering
overview
fundamental
principles
underlie
behavior
these
materials,
encompassing
structures,
behavior,
reaction
mechanisms.
Subsequently,
recent
progress
vitrimers
explored,
with
focus
on
employment
molecular
dynamics
(MD)/Monte
Carlo
(MC)
simulations
density
functional
theory
(DFT)
calculations.
Last,
existing
challenges
prospective
directions
field
critically
analyzed,
emphasizing
necessity
additional
advancements,
coupled
experimental
validation.
ACS Applied Polymer Materials,
Journal Year:
2023,
Volume and Issue:
5(6), P. 3971 - 3978
Published: May 8, 2023
A
mechanically
interlocked
vitrimer
(MIV)
based
on
a
benzoxazine
monomer
and
polyrotaxane
(PR)
has
been
prepared
through
network
(MIN)
dynamic
covalent
bond
chemistry.
The
transacetalation
exchange
the
N,O-acetal-type
polybenzoxazine
(PBz)
structure
was
catalyzed
by
tin
compound.
Compared
to
controlled
PBz
without
MIN,
designed
MIV
shows
enhanced
mechanical
performance
including
ductility
tensile
strength
while
maintaining
relatively
high
Young's
modulus
glass
transition
temperature
(Tg).
can
be
reprocessed
several
times
compromising
thermal
stability.
also
exhibits
faster
lower
activation
energy
compared
due
mobile
intramolecular
motions
of
PR
in
allowing
for
more
readily.
usefulness
present
study
preparation
high-performance
eco-friendly
thermosetting
vitrimers
is
discussed.
Macromolecules,
Journal Year:
2023,
Volume and Issue:
56(17), P. 6978 - 6987
Published: Aug. 27, 2023
Polyurethane
(PU)
thermosets
are
usually
landfilled
at
the
end
of
their
service
lifetimes
and
cannot
be
recycled
through
conventional
means.
Although
dibutyltin
dilaurate
(DBTDL)
is
an
effective
catalyst
for
reprocessing
PU
thermosets,
organotins
immunotoxic
teratogenic,
which
concerning
catalysts
embedded
within
covalent
adaptable
networks
(CANs).
Here,
we
identify
Zr(acac)4
Zr(tmhd)4
as
to
reprocess
CANs
more
sustainably.
Thermoset
foams
containing
Zr-based
exhibit
characteristic
stress
relaxation
times
between
6
200
s,
similar
or
faster
than
DBTDL.
These
capable
a
foam
four
five
cycles.
Dynamic
mechanical
thermal
analysis
indicates
that
zirconium-based
preserve
glass
transition
temperature
crosslink
density
cycles
promising
bulk
thermoset
PUs.
Furthermore,
solvent-free
method
was
developed
by
co-milling
Zr
catalyst.
Ultimately,
these
methods
using
will
impart
greater
sustainability
circularity
plastics.
