Macromolecules,
Год журнала:
2024,
Номер
57(21), С. 10041 - 10052
Опубликована: Окт. 30, 2024
Poly(cyclopentenyl
carbonate)
(PCPC)
is
a
recyclable
polymer
with
great
potential
applications.
However,
the
selective
preparation
of
PCPC
from
cyclopentene
oxide
(CPO)
and
CO2
copolymerization
chemical
recycling
back
to
original
monomer
CPO
are
challenge.
In
this
work,
it
was
found
that
heterometallic
rare-earth
metal(III)/Zn(II)
complexes
(RE(III)-Zn(II)
complexes)
supported
by
phenylenediamine-bridged
triphenols
could
serve
as
highly
active
catalysts
for
give
pure
PCPC.
Remarkably,
same
alone
also
promote
depolymerization
only
simply
raising
reaction
temperature
up
ca.
160
°C.
The
mechanisms
were
proposed.
Chemical Society Reviews,
Год журнала:
2024,
Номер
53(19), С. 9609 - 9651
Опубликована: Янв. 1, 2024
We
present
the
state-of-the-art
of
circular
polymers
based
on
monomer
and
polymer
design
reversible
ring-opening
addition
polymerization
reactions
without
involvement
other
reactants.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 26, 2025
Polyesters,
with
potential
for
degradability
and
sustainability,
are
some
of
the
most
versatile
polymer
materials.
However,
limitation
molecular
weight
(MW)
presents
a
barrier
to
their
applications.
The
synthesis
polyesters
high
MW
by
ring-opening
copolymerization
(ROCOP)
epoxides
cyclic
anhydrides
is
promising
but
rare
challenging.
Herein,
we
report
series
air-stable,
hydrogen-bond-functionalized
imidazole
catalysts
copolymerization.
These
can
produce
(4
examples)
using
cyclohexane
oxide
(CHO),
propylene
(PO),
phenyl
glycidyl
ether
(PGE),
4-vinyl-1-cyclohexene
1,2-epoxide
(VCHO),
phthalic
anhydride
(PA)
record-high
MW:
Mn
=
171.2
kDa
poly(CHO-alt-PA),
518.5
poly(PO-alt-PA),
100.5
poly(PGE-alt-PA),
236.4
poly(VCHO-alt-PA).
Furthermore,
it
achieve
an
unprecedented
efficiency
15.6
kg
polyester/g
catalyst
at
molar
ratio
catalyst/PA/PO
1:40000:60000.
achieved
be
attributed
unique
anionic-cationic
coexisting
ROCOP
mechanism,
which
reduce
transesterification,
chain
transfer,
annulation
side
reactions.
All
showed
excellent
thermal
stability,
tensile
strength,
Young's
modulus
comparable
commodity
thermoplastics
like
polystyrene
polylactic
acid.
Macromolecules,
Год журнала:
2024,
Номер
57(9), С. 4199 - 4207
Опубликована: Апрель 24, 2024
Using
CO2
polycarbonates
as
engineering
thermoplastics
has
been
limited
by
their
mechanical
performances,
particularly
brittleness.
Poly(cyclohexene
carbonate)
(PCHC)
a
high
tensile
strength
(40
MPa)
but
is
very
brittle
(elongation
at
break
<3%),
which
limits
both
its
processing
and
applications.
Here,
well-defined,
molar
mass
terpolymers
are
prepared
from
cyclohexene
oxide
(CHO),
cyclopentene
(CPO),
using
Zn(II)Mg(II)
catalyst.
In
the
catalysis,
CHO
CPO
show
reactivity
ratios
of
1.53
0.08
with
CO2,
respectively;
such,
have
gradient
structures.
The
poly(cyclohexene
carbonate)-grad-poly(cyclopentene
(PCHC-grad-PCPC)
masses
(86
<
Mn
164
kg
mol–1,
ĐM
1.22)
good
thermal
stability
(Td
>
250
°C).
All
polymers
amorphous
single,
glass
transition
temperature
(96
Tg
108
polymer
entanglement
masses,
determined
dynamic
analyses,
range
4
Me
23
mol–1
depending
on
composition
(PCHC:PCPC).
These
superior
performance
to
PCHC;
specifically
lead
material
(PCHC0.28-grad-PCPC0.72)
shows
25%
greater
160%
higher
toughness.
new
plastics
recycled,
cycles
reprocessing
compression
molding
(150
°C,
1.2
ton
m–2,
60
min),
four
times
without
any
loss
in
properties.
They
also
efficiently
chemically
recycled
selectively
yield
two
epoxide
monomers,
CPO,
well
carbon
dioxide,
activity
(TOF
=
270–1653
h–1,
140
120
min).
isolated
monomers
repolymerized
form
thermoplastic
showing
same
findings
highlight
benefits
terpolymer
strategy
deliver
combining
beneficial
low
mass,
temperatures,
strengths;
PCHC
properties
significantly
improved
incorporating
small
quantities
(23
mol
%)
carbonate
linkages.
general
designing
include
chain
segments
may
help
toughen
other
renewably
sourced
plastics.
Controlling
the
reactivity
of
bonds
along
polymer
chains
enables
both
functionalization
and
deconstruction
with
relevance
to
chemical
recycling
circularity.
Because
substrate
is
a
macromolecule,
however,
understanding
effects
chain
conformation
on
emerges
as
important
yet
underexplored.
Here,
we
show
how
oxy-functionalization
chemically
recyclable
condensation
polymers
affects
acidolysis
monomers
through
control
over
distortion
interaction
energies
in
rate-limiting
transition
states.
Oxy-functionalization
polydiketoenamines
at
specific
sites
either
amine
or
triketone
monomer
segments
increased
rates
by
more
than
three
orders
magnitude,
opening
door
efficient
linear
architectures.
These
insights
substantially
broaden
scope
applications
for
circular
manufacturing
economy,
including
adhesives
diverse
range
surfaces.
Angewandte Chemie,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 28, 2025
Abstract
Great
achievements
have
been
made
in
CO
2
/epoxide
copolymerization
and
dialkyl
carbonate/diol
polycondensation;
however,
efficient
preparation
of
high‐molecular‐weight
(>100
kDa)
aliphatic
polycarbonates
with
tunable
properties
recyclability
under
mild
conditions
still
remains
as
a
great
challenge.
Herein,
we
presented
“polycondensation–depolymerization–repolymerization”
strategy
for
structurally
diverse
polycarbonates.
This
involved
step
growth
polycondensation
carbonate
diol
to
low‐molecular‐weight
(0.5−1.9
atmosphere
pressure,
which
are
then
utilized
produce
cyclic
monomers
through
catalytic
depolymerization.
The
ring‐opening
polymerization
led
high
molecular
weight
polymers,
can
be
converted
back
monomer
via
ring‐closing
depolymerization
or
diol/dialkyl
alcoholysis,
enabling
chemical
recycling
dual
closed
loops.
thermal
mechanical
the
widely
adjusted
by
varying
substituent,
polycarbonate
four‐membered
spiro‐cyclic
substituent
shows
recorded
melting
temperature
(217
°C)
strength
within
reported
family.
A(hard)‐B(soft)‐A(hard)
triblock
thermoplastic
elastomers
good
performance
elastic
recovery
were
also
created
sequential
polymerization.
“polycondensation−depolymerization−repolymerization”
provided
powerful
toolbox
developing
high‐performance
Angewandte Chemie International Edition,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 28, 2025
Abstract
Great
achievements
have
been
made
in
CO
2
/epoxide
copolymerization
and
dialkyl
carbonate/diol
polycondensation;
however,
efficient
preparation
of
high‐molecular‐weight
(>100
kDa)
aliphatic
polycarbonates
with
tunable
properties
recyclability
under
mild
conditions
still
remains
as
a
great
challenge.
Herein,
we
presented
“polycondensation–depolymerization–repolymerization”
strategy
for
structurally
diverse
polycarbonates.
This
involved
step
growth
polycondensation
carbonate
diol
to
low‐molecular‐weight
(0.5−1.9
atmosphere
pressure,
which
are
then
utilized
produce
cyclic
monomers
through
catalytic
depolymerization.
The
ring‐opening
polymerization
led
high
molecular
weight
polymers,
can
be
converted
back
monomer
via
ring‐closing
depolymerization
or
diol/dialkyl
alcoholysis,
enabling
chemical
recycling
dual
closed
loops.
thermal
mechanical
the
widely
adjusted
by
varying
substituent,
polycarbonate
four‐membered
spiro‐cyclic
substituent
shows
recorded
melting
temperature
(217
°C)
strength
within
reported
family.
A(hard)‐B(soft)‐A(hard)
triblock
thermoplastic
elastomers
good
performance
elastic
recovery
were
also
created
sequential
polymerization.
“polycondensation−depolymerization−repolymerization”
provided
powerful
toolbox
developing
high‐performance
