Biobased, catalyst-free non-isocyanate polythiourethane foams: Highly dynamic nature affords fast reprocessability, extrudability and refoamability
Chemical Engineering Journal,
Год журнала:
2024,
Номер
496, С. 154035 - 154035
Опубликована: Июль 21, 2024
Язык: Английский
Rapidly Self‐Healable and Melt‐Extrudable Polyethylene Reprocessable Network Enabled with Dialkylamino Disulfide Dynamic Chemistry
Macromolecular Rapid Communications,
Год журнала:
2024,
Номер
45(22)
Опубликована: Июль 24, 2024
Abstract
Catalyst‐free,
radical‐based
reactive
processing
is
used
to
transform
low‐density
polyethylene
(LDPE)
into
covalent
adaptable
networks
(PE
CANs)
using
a
dialkylamino
disulfide
crosslinker,
BiTEMPS
methacrylate
(BTMA).
Two
versions
of
BTMA
are
used,
BTMA‐S
2
,
with
nearly
exclusively
bridges,
and
n
mixture
oligosulfide
produce
S
PE
CAN
CAN,
respectively.
The
two
CANs
exhibit
identical
crosslink
densities,
but
the
manifests
faster
stress
relaxation,
average
relaxation
times
∼4.5
shorter
than
those
over
130
160
°C
temperature
range.
more
rapid
dynamics
translate
compression‐molding
reprocessing
time
at
only
5
min
(vs
30
for
CAN)
achieve
full
recovery
density.
Both
melt‐extrudable
within
experimental
uncertainty
density
after
extrusion.
self‐healable,
crack
fully
repaired
original
tensile
properties
restored
or
60
slightly
above
LDPE
melting
point
without
assistance
external
forces.
Язык: Английский
Extrudable and Highly Creep-Resistant Covalent Adaptable Networks Made from Polyethylene and Ethylene/1-Octene Copolymers by Reactive Processing with Aromatic Disulfide Cross-Links
ACS Applied Polymer Materials,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 3, 2024
Polyolefins
like
polyethylene
(PE)
and
ethylene-based
copolymers
are
widely
used
in
consumer
industrial
applications
due
to
their
versatility,
the
diversity
tunability
of
properties,
theoretical
recyclability
at
elevated
temperatures.
However,
recycling
rates
markedly
low,
and,
though
cross-linking
PE
enhances
its
properties
through
creation
a
networked
architecture,
resulting
thermoset
known
as
PEX
is
rendered
completely
unrecyclable.
Incorporating
associative
or
dissociative
dynamic
covalent
bonds
cross-links
into
plastics
promising
route
both
make
use
spent
(via
"upcycling"
them)
generate
recyclable
alternatives
unrecyclable
thermosets
PEX.
Such
materials
adaptable
networks
CANs
(also
called
vitrimers
if
exclusively
associative).
Here,
we
present
method
for
imbuing
polymers
with
aromatic
disulfide
cross-links,
robust,
reprocessable
CANs.
Radical-based
reactive
processing
ethylene/1-octene-based
1
wt
%
dicumyl
peroxide
5
bis(4-methacryloyloxyphenyl)
(BiPheS
methacrylate
BPMA)
successfully
resulted
which
fully
recovered
cross-link
densities
associated
thermomechanical
after
multiple
reprocessing
cycles.
These
demonstrate
remarkable
elevated-temperature
creep
resistance
high-temperature
thermal
stability
high
temperatures
required
exchanges
BiPheS-based
cross-links.
copolymer
also
enable
(re)processability
via
extrusion
temperatures,
property
recovery
demonstrated
260
°C,
thereby
indicating
feasibility
extending
our
approach
scales
processes
well
other
rigorous
applications.
Язык: Английский
Development of Mechanically Tunable Polythiourethane Elastomers for Recyclable Energetic Material
ACS Applied Polymer Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 20, 2025
Язык: Английский
Next-generation vitrimer composites for future mobility: Balancing sustainability and functionality – A perspective
European Polymer Journal,
Год журнала:
2025,
Номер
unknown, С. 113967 - 113967
Опубликована: Май 1, 2025
Язык: Английский
Covalent Adaptable Networks with Associative Siloxane Exchange Enabled by Amide‐Based Internal Catalysis: Designing for Reprocessability and Extrudability by Increasing the Cross‐Link Density
Advanced Functional Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 9, 2025
Abstract
Replacing
non‐recyclable
thermosets
with
covalent
adaptable
networks
(CANs)
that
recover
cross‐link
density
after
reprocessing
will
reduce
waste
and
contribute
to
a
circular
polymer
economy.
Many
CANs
undergoing
associative
dynamic
exchange
require
catalysis.
External
catalysis
often
leads
harmful
effects,
e.g.,
increased
creep,
accelerated
material
aging,
catalyst
leaching.
Herein,
internally
catalyzed
siloxane
chemistry
is
demonstrated
resulting
from
amides
covalently
linked
through
alkyl
chains
siloxanes.
Small‐molecule
studies
show
the
formation
of
products
reaction
two
amide‐containing
molecules.
From
rubbery
plateau
modulus,
each
siloxane‐exchange‐based
CAN
exhibits
temperature‐invariant,
or
nearly
so,
characteristic
CANs.
The
length
in
siloxane‐containing
monomer
tunes
network
density.
Cross‐link
recovery
achieved,
required
time
temperature
decreasing
increasing
Stress
relaxation
also
faster
dynamics
reprocessability
arise
because
second
order
(i.e.,
cross‐linker)
concentration.
Capitalizing
on
this,
melt
extrusion
highest
demonstrated,
achieving
same
extruded
compression‐molded
Using
identical
conditions,
next‐highest
not
extrudable.
Язык: Английский