Macromolecules,
Год журнала:
2024,
Номер
57(4), С. 1546 - 1555
Опубликована: Фев. 11, 2024
A
series
of
biobased
alipharomatic
polyesters
using
vanillin-derived
bifunctional
hydroxy-aldehyde
monomers
(M1)s
as
the
starting
materials
are
synthesized
through
direct
dehydrogenative
polycondensation
with
commercially
available
Milstein
catalyst.
The
thermal
properties
resulting
P(M1)s
can
be
precisely
tuned
by
altering
alkylene
length
monomers,
a
maximum
Tg
value
reaching
37.9
°C.
Compared
to
reported
vanillic
acid-based
polyesters,
synthesis
M1
is
less
labor-intensive,
and
polymerization
conditions
milder
than
those
conventional
polycondensation.
Additionally,
experimental
results
mechanism
elucidations
revealed
four
different
types
ester
linkages
in
P(M1)
chain.
ruthenium
dihydride
complex
has
been
identified
true
active
species
required
for
promoting
into
polyesters.
Moreover,
this
catalytic
system
also
exhibits
depolymerization
capability
toward
polyester
back
diol
(M2),
which
then
repolymerized
P(M2)
an
identical
structure
that
P(M1),
thus
demonstrating
rare
example
where
two
yield
same
polymer
product.
This
study
presents
green
economical
approach
preparation
recycling
widely
used
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(24)
Опубликована: Апрель 8, 2024
Abstract
Polyesters,
a
highly
promising
class
of
circular
polymers
for
achieving
closed‐loop
sustainable
plastic
economy,
inherently
exhibit
material
stability
defects,
especially
in
thermal
and
hydrolytic
instability.
Here,
we
introduce
polyesters,
P(4
R
‐BL)
(R=Ph,
Bu),
featuring
conformationally
rigid
1,3
‐
cyclobutane
rings
the
backbone.
These
polyesters
not
only
superior
thermostability
(
T
d,5%
=376–380
°C)
but
also
demonstrate
exceptional
resistance
with
good
integrity
even
after
1
year
basic
acidic
aqueous
solutions,
distinguishing
themselves
from
typical
counterparts.
Tailoring
flexibility
side
group
enables
controlled
mechanical
performance
Ph
Bu
to
rival
durable
syndiotactic
polystyrene
(SPS)
low‐density
polyethylene
(LDPE),
respectively.
Significantly,
despite
their
high
stability,
both
can
be
effectively
depolymerized
into
pristine
monomers,
establishing
life
cycle.
Polymer Chemistry,
Год журнала:
2023,
Номер
14(28), С. 3270 - 3276
Опубликована: Янв. 1, 2023
The
study
investigates
the
potential
in
solvent
triggered
chemical
recycling
and
how
power
of
effect
is
influenced
by
monomer
structure.
Catalyst
selectivity
utilized
to
demonstrate
mixed
polymer
waste.
Polymer Chemistry,
Год журнала:
2024,
Номер
15(11), С. 1070 - 1076
Опубликована: Янв. 1, 2024
A
seven-membered
cyclic
carbonate
bearing
a
cis
-fused
cyclohexane
structure
enabled
the
chemical
recycling
of
polycarbonate
to
high-ring-strain
monomer.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(44)
Опубликована: Сен. 15, 2023
To
synthesize
high
molecular
weight
poly(phenolic
ester)
via
a
living
ring-opening
polymerization
(ROP)
of
cyclic
phenolic
ester
monomers
remains
critical
challenge
due
to
serious
transesterification
and
back-biting
reactions.
Both
bonds
in
monomer
polymer
chains
are
highly
active,
it
is
difficult
so
far
distinguish
them.
In
this
work,
an
unprecedented
selectively
bifunctional
catalytic
system
tetra-n-butylammonium
chloride
(TBACl)
was
discovered
mediate
the
syntheses
salicylic
acid-based
copolyesters
ROP
salicylate
esters
(for
poly(salicylic
methyl
glycolide)
(PSMG),
Mn
=361.8
kg/mol,
Ð<1.30).
Compared
previous
catalysis
systems,
side
reactions
were
suppressed
remarkably
because
bond
can
be
cleaved
over
that
during
progress.
Mechanistic
studies
reveal
halide
anion
alkyl-quaternaryammonium
cation
work
synergistically,
where
moiety
interacts
with
carbonyl
group
substrates
non-classical
hydrogen
bonding.
Moreover,
these
recycled
dimeric
under
solution
condition,
original
monomeric
without
catalyst
sublimation
condition.
Journal of Polymer Science,
Год журнала:
2024,
Номер
62(21), С. 4921 - 4927
Опубликована: Апрель 25, 2024
Abstract
Low‐strain
cyclic
olefin
monomers,
including
five‐membered,
six‐membered,
eight‐membered,
and
macrocyclic
rings,
have
been
recently
exploited
for
the
synthesis
of
depolymerizable
polyolefins
via
ring‐opening
metathesis
polymerization
(ROMP).
Such
can
undergo
ring‐closing
depolymerization
(RCMD)
to
regenerate
their
original
monomers.
Nevertheless,
behavior
prepared
by
ROMP
seven‐membered
olefins,
an
important
class
low‐strain
still
remains
unexplored.
In
this
study,
we
demonstrate
chemical
recycling
polyheptenamers
cycloheptene
under
standard
RCMD
conditions.
Highly
efficient
polyheptenamer
was
enabled
Grubbs'
second‐generation
catalyst
in
toluene.
It
observed
that
monomer
yields
increased
when
temperature
starting
polymer
concentration
reduced.
A
near‐quantitative
regeneration
(>96%)
achieved
within
1
h
dilute
conditions
(20
mM
olefins)
at
60°C.
Moreover,
exhibited
a
decomposition
above
430°C,
highlighting
its
potential
as
new
thermally
stable
chemically
recyclable
materials.
Organic & Biomolecular Chemistry,
Год журнала:
2024,
Номер
22(20), С. 4135 - 4144
Опубликована: Янв. 1, 2024
This
is
the
first
contribution
reported
to
date
in
literature
which
natural
precursors
such
as
amino
acids
(AAs)
have
been
effectively
employed
bio-organocatalysts
for
preparation
of
biobased
polyesters.
Fundamental Research,
Год журнала:
2024,
Номер
unknown
Опубликована: Июнь 1, 2024
The
development
of
modern
society
is
closely
related
to
polymer
materials.
However,
the
improper
disposal
wastes
not
only
squanders
resources
but
also
intensifies
environmental
issues,
despite
that
energy
recovery,
physical
recycling
and
chemical
pathways
have
been
developed
tackle
recycle
reuse
polymers.
Among
them,
considered
as
most
pivotal
solution,
it
can
depolymerize
back
monomers,
which
then
repolymerize
into
Recently,
remarkable
progress
has
made
in
chemically
recyclable
polymers
through
monomer
design
shift
"polymerization-depolymerization"
equilibrium
realize
selective
depolymerization
achieve
closed-loop.
This
article
reviews
closed-loop
such
polyesters,
polycarbonates,
sulfur-containing
polymers,
vinyl
monomer-based
well
other
types
Moreover,
challenges
prospects
this
field
are
discussed.
