ACS Sustainable Chemistry & Engineering,
Год журнала:
2023,
Номер
11(22), С. 8294 - 8307
Опубликована: Май 19, 2023
Reversible
crosslinking
offers
an
attractive
strategy
to
modify
and
improve
the
properties
of
polymer
materials
while
concurrently
enabling
a
pathway
for
chemical
recycling.
This
can,
example,
be
achieved
by
incorporating
ketone
functionality
into
structure
enable
post-polymerization
with
dihydrazides.
The
resulting
covalent
adaptable
network
contains
acylhydrazone
bonds
cleavable
under
acidic
conditions,
thereby
providing
reversibility.
In
present
work,
we
regioselectively
prepare
novel
isosorbide
monomethacrylate
pendant
levulinoyl
group
via
two-step
biocatalytic
synthesis.
Subsequently,
series
copolymers
different
contents
levulinic
monomer
methyl
methacrylate
are
prepared
radical
polymerization.
Using
dihydrazides,
these
linear
then
crosslinked
reaction
groups
in
side
chains.
Compared
prepolymers,
networks
exhibit
enhanced
glass
transition
temperatures
thermal
stability,
up
170
286
°C,
respectively.
Moreover,
dynamic
efficiently
selectively
cleaved
conditions
retrieve
polymethacrylates.
We
next
show
that
recovered
polymers
can
again
adipic
dihydrazide,
thus
demonstrating
circularity
materials.
Consequently,
envision
isosorbide-based
polymethacrylate
have
great
potential
field
recyclable
reusable
biobased
thermoset
polymers.
Covalent
adaptable
networks
(CANs)
combine
the
uniqueness
of
thermoplastics
and
thermosets
to
allow
for
reprocessability
while
being
covalently
crosslinked.
However,
it
is
highly
desirable
but
rarely
achieved
CANs
simultaneously
demonstrate
reversibility
mechanical
robustness.
Herein,
we
report
a
feasible
strategy
develop
novel
epoxy
vitrimer
(EV)
composed
phosphate
(APNs),
by
which
EVs
exhibit
promising
properties
(tensile
strength
62.5
~
87.8
MPa
tensile
modulus
1360.1
2975.3
MPa)
under
ambient
conditions.
At
elevated
temperatures,
topology
rearrangement
occurs
relied
on
transesterification,
contributes
shape
memory
performance,
self-healing,
reprocessing,
welding
behaviors.
Moreover,
incorporation
APNs
allows
improvements
in
anti-ignition
also
inhibition
both
heat
release
smoke
generation
avoid
empyrosis,
asphyxiation,
toxication
during
burning,
showing
expected
intrinsic
fire
safety.
Thermal,
properties,
flame
retardancy
reprocessed
after
hot
pressing
are
very
close
those
original
EVs,
attributed
sufficient
APNs.
Accordingly,
combining
aforementioned
features,
manufactured
as
flame-triggered
switches
alarms,
symbolizes
innovative
development
high-performance
covalent
polymeric
materials.
Macromolecular Materials and Engineering,
Год журнала:
2022,
Номер
308(4)
Опубликована: Окт. 26, 2022
Abstract
Polybenzoxazines
are
high‐performance
materials
capable
of
replacing
conventional
thermosets
such
as
phenolics,
epoxies,
and
bismaleimides
in
composites
manufacturing
due
to
their
excellent
thermomechanical
chemical
behavior.
Their
versatility
compatibility
with
biobased
precursors
make
them
an
attractive
option
composite
matrices.
Like
other
thermosets,
polybenzoxazines
not
recyclable
cannot
be
reprocessed.
Incorporating
dynamic
bonds
benzoxazine
monomers
can
produce
vitrimeric
polybenzoxazines,
which
potentially
overcome
this
limitation
tuned
exhibit
smart
functionalities
self‐healing
shape
memory.
Dynamic
bond
exchange
mechanisms
for
vitrimer
development
transesterification,
imine
bond,
disulfide
exchange,
transamination,
transcarbamoylation,
transalkylation,
olefin
metathesis,
transcarbonation,
siloxane‐silanol
boronic
ester,
silyl
ether
dioxaborolane
metathesis
applicable
chemistry,
transesterification
having
successfully
vitrimerized
benzoxazines
topological
transitions
at
−8.5
88
°C,
respectively.
Benzoxazine
vitrimers
featuring
glass
193,
224,
222–236
°C
now
known.
These
place
the
forefront
reprocessable
thermosetting
polymers
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.
ACS Applied Polymer Materials,
Год журнала:
2023,
Номер
5(6), С. 3971 - 3978
Опубликована: Май 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.
ACS Applied Polymer Materials,
Год журнала:
2024,
Номер
6(7), С. 3985 - 3995
Опубликована: Апрель 2, 2024
Polybenzoxazines
are
a
type
of
thermosetting
resin
with
good
thermal
resistance.
A
flame-retardant
and
degradable
polybenzoxazine
(ERY-a)
was
synthesized
by
special
bisphenol
containing
bridging
diacetal
structure
(ERY)
aniline.
systematic
comparative
study
conducted
between
ERY-a
A/aniline-type
benzoxazine
(BA-a).
Their
chemical
structures
were
confirmed
Fourier
transform
infrared
(FTIR)
spectra
nuclear
magnetic
resonance
(NMR)
spectra.
The
curing
behaviors
polymerization
reactions
analyzed
differential
scanning
calorimetry
(DSC)
FTIR
Dynamic
mechanical
analysis
(DMA)
thermogravimetric
(TGA)
used
to
investigate
their
properties,
the
results
showed
that
cured
ERY-a,
referred
as
P(ERY-a),
exhibited
notable
glass
transition
temperature
Tg
297
°C
char
yield
51%
under
N2
at
800
°C,
both
which
significantly
higher
than
those
BA-a.
Furthermore,
flame
retardancy
P(ERY-a)
ERY-a-based
composites
assessed
through
microcalorimetry
(MCC)
vertical
combustion
testing.
findings
highlighted
superior
low
heat
release
capacity
(HRC)
due
presence
structure.
More
importantly,
cross-linked
can
be
degraded
in
solvent
via
cleavage
structure,
optimal
degradation
conditions
systematically
studied.
Moreover,
carbon
fiber
from
composite
easily
recycled
ERY-a.
International Polymer Processing,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 20, 2025
Abstract
Concerns
about
the
effect
on
environment
and
non-renewable
nature
of
plastics
have
sparked
a
substantial
field
study
towards
creation
recyclable
polymers.
Vitrimers
are
potential
class
reusable
polymers
that
recently
attracted
lot
interest.
Like
conventional
thermosets
in
strength,
durability,
chemical
resistance,
these
materials
offer
added
benefit
being
at
end
their
useful
life.
Their
structure,
which
includes
dynamic
covalent
crosslinks
to
provide
stability
while
enabling
reprocessing,
is
credited
with
this
special
characteristic.
We
lay
out
an
overview
recent
developments
applications
epoxy
based
vitrimeric
by
using
different
types
adaptable
networks
(CANs)
–
single,
dual
triple
paper
attention
design
tactics
make
it
easier
create
circular
future.
Covalent
Adaptable
Networks
(CAN),
novel
polymer
family
can
bridge
gap
between
thermoplastics,
emerged
years
uses
chemistry
crosslinked
networks.
The
was
enhanced
2011
Leibler
colleagues
when
they
introduced
notion
vitrimers,
retain
integrity
network
even
after
heating
allow
connections
be
reallocated
within
them
associative
exchange
reactions.
This
review
also
demonstrates
how
vitrimer
community
paying
need
for
sustainable
material
development
demonstrating
use
biobased
building
blocks
synthesis
high-performing
vitrimers.
Having
outlined
primary
characteristics
commercialization
vitrimers
emphasized
portray
benefits
self-healing,
malleability,
orthogonal
processability,
various
shape
memories
along
solutions
synthetic
materials.
