Macromolecules,
Год журнала:
2024,
Номер
57(2), С. 682 - 690
Опубликована: Янв. 9, 2024
A
strategy
to
efficiently
synthesize
thermally
reprogrammable
but
mechanically
stable
liquid
crystalline
elastomers
(LCEs)
is
reported
by
investigating
the
catalytic
effects
of
para-substituted
phenols
on
dynamic
aza-Michael
reactions.
The
synthesis
LCEs
was
optimized
based
a
study
catalyzed
small-molecule
reactions,
where
presence
an
electron-withdrawing
substituent
significantly
improved
reactivity
system.
catalysts
were
then
screened
their
exchange
adducts.
Catalysts
with
substituents
efficient
in
inducing
bonds,
thus
influencing
mesogen
alignment
and
actuation.
After
programming
alignment,
catalyst
washed
away
dramatically
reduce
activity
improve
creep
resistance
material
while
preserving
postsynthetic
alignment.
This
approach
represents
straightforward
accessible
methodology
for
obtaining
programmable
as
well
actuators
from
LCEs.
ACS Applied Materials & Interfaces,
Год журнала:
2022,
Номер
14(41), С. 47025 - 47035
Опубликована: Окт. 10, 2022
The
vast
majority
of
traditional
vulcanized
rubber
products
are
insoluble
and
infusible,
which
is
difficult
to
reprocess
biodegrade,
resulting
in
black
pollution.
In
addition,
although
most
materials
based
on
covalent
adaptive
networks
(CANs)
can
achieve
structural
reconstruction,
the
lack
vulcanization
system
leads
a
decline
strength.
this
study,
biobased
vanillin
derivatives
(PV)
were
synthesized
cross-link
commercially
available
1,2-polybutadiene
precursor
construct
imine-based
CANs,
thereby
fabricating
resource-renewable,
recyclable,
degradable
high-performance
material.
Due
rigid
tripod
structure
PV,
tensile
strength
material
as
high
16.24
MPa,
ranking
among
best
field
recyclable
polybutadiene-based
materials.
Benefiting
from
dynamic
imine
unit,
"dynamic
bridge"
be
re-established
repair
damaged
network
endow
with
excellent
weldability.
And,
shape
memory
faculty
was
proved
depicted.
Moreover,
displayed
antibacterial
property
originates
introduced
Schiff-base
structure.
By
mixing
graphene,
application
action
sensors
also
achieved.
ACS Applied Materials & Interfaces,
Год журнала:
2023,
Номер
15(21), С. 25212 - 25223
Опубликована: Март 8, 2023
Thermoset
materials
sacrifice
recyclability
and
reshapeability
for
increased
chemical
mechanical
robustness
because
of
an
immobilized,
cross-linked
polymeric
matrix.
The
robust
material
properties
thermosets
make
them
well-suited
applications
such
as
heat-shielding
(HSMs)
or
ablatives
where
excellent
thermal
stability,
good
strength,
high
charring
ability
are
paramount.
Many
these
characteristic
covalent
adaptable
networks
(CANs),
the
static
connectivity
has
been
replaced
with
dynamic
cross-links.
This
allows
network
mobility
while
retaining
cross-link
to
permit
damage
repair
reshaping
that
traditionally
inaccessible
thermoset
materials.
Herein,
we
report
synthesis
hybrid
inorganic–organic
enaminone
vitrimers
contain
exceptionally
weight
percent
polyhedral
oligomeric
silsesquioxane
(POSS)-derivatives.
Polycondensation
β-ketoester-containing
POSS
various
diamine
cross-linkers
led
facile
tunability,
shapeability,
predictable
glass
transition
temperatures,
residual
char
mass
following
degradation.
Furthermore,
show
notable
retention
their
preordained
shape
decomposition,
suggesting
future
utility
in
design
HSMs
complex
detailing.
Polymer,
Год журнала:
2023,
Номер
287, С. 126426 - 126426
Опубликована: Окт. 25, 2023
Benzoxazines
represent
a
class
of
thermoset
resins
known
for
their
exceptional
thermal,
fire,
and
mechanical
properties.
These
find
wide
applications
in
various
industries,
including
composites
electronic
components.
However,
like
conventional
thermosets,
benzoxazines
have
limitations
terms
end-of-life
options,
typically
being
landfilled
or
incinerated.
To
address
this
concern,
researchers
been
exploring
the
incorporation
dynamic
bonds
into
structure
polybenzoxazines
to
add
functionalities
such
as
reprocessability,
self-healing,
recycling
capabilities,
develop
polybenzoxazine-based
covalent
adaptable
networks
(CANs).
This
mini-review
offers
an
overview
recent
endeavors
focused
on
introduction
within
polybenzoxazine
structures.
It
emphasizes
synergies
between
molecular
exchanges,
transesterification
disulfide
metathesis,
provides
comparative
summary
properties
achieved
by
materials
developed
context.
By
leveraging
strengths
benzoxazine
structures,
aims
foster
exploration
development
innovative
approaches
that
combine
unique
CANs,
enabling
more
sustainable
environmentally
friendly
materials.
Macromolecules,
Год журнала:
2024,
Номер
57(2), С. 682 - 690
Опубликована: Янв. 9, 2024
A
strategy
to
efficiently
synthesize
thermally
reprogrammable
but
mechanically
stable
liquid
crystalline
elastomers
(LCEs)
is
reported
by
investigating
the
catalytic
effects
of
para-substituted
phenols
on
dynamic
aza-Michael
reactions.
The
synthesis
LCEs
was
optimized
based
a
study
catalyzed
small-molecule
reactions,
where
presence
an
electron-withdrawing
substituent
significantly
improved
reactivity
system.
catalysts
were
then
screened
their
exchange
adducts.
Catalysts
with
substituents
efficient
in
inducing
bonds,
thus
influencing
mesogen
alignment
and
actuation.
After
programming
alignment,
catalyst
washed
away
dramatically
reduce
activity
improve
creep
resistance
material
while
preserving
postsynthetic
alignment.
This
approach
represents
straightforward
accessible
methodology
for
obtaining
programmable
as
well
actuators
from
LCEs.
