Angewandte Chemie,
Год журнала:
2024,
Номер
136(45)
Опубликована: Июль 29, 2024
Abstract
Polythioesters
(PTEs)
are
emerging
sustainable
polymers
for
their
degradability
and
recyclability.
However,
low
polymerizability
of
monomers
extensive
side
reactions
often
hampered
the
polymerization
process.
Moreover,
copolymers
containing
both
thioester
other
types
functional
groups
in
backbone
highly
desirable
but
rarely
accomplished
owing
to
several
synthetic
challenges.
Here,
we
report
ring‐opening
cascade
(ROCAP)
N
‐(2‐(acetylthio)ethyl)‐glycine
‐carboxyanhydrides
(TE‐NCA)
afford
recyclable
PTEs
unprecedented
poly(thioester‐co‐peptoid)s
(P(TE‐co‐PP)s)
a
controlled
manner.
By
developing
appropriated
carboxylic
acid‐tertiary
amine
dual
catalysts,
intramolecular
S
‐to‐
acyl
shift
is
coupled
into
ROCAP
process
TE‐NCA
yield
products
with
dispersity
below
1.10,
molecular
weight
(
M
n
)
up
84.5
kDa,
precisely
ratio
peptoids.
Random
copolymerization
sarcosine
NCA
(Sar‐NCA)
gives
thioester‐embedded
polysarcosine
facile
degradation
while
maintaining
water
solubility.
This
work
represents
paradigm
ROP
NCAs,
enriches
realm
polymerizations,
provides
powerful
approach
P(TE‐co‐PP)s
that
otherwise
difficult
or
impossible
make.
Macromolecules,
Год журнала:
2025,
Номер
58(5), С. 2210 - 2223
Опубликована: Фев. 18, 2025
Polymeric
materials
have
become
indispensable
due
to
their
versatility
and
low
cost,
yet
environmental
impact
presents
a
significant
global
challenge.
Traditional
chemical
recycling
methods
typically
rely
on
heat
as
stimulus;
for
instance,
pyrolysis
is
popular
methodology
which
faces
limitations
high
energy
consumption,
product
selectivity,
the
generation
of
undesirable
byproducts.
In
response,
recent
advances
in
promotion
depolymerization
degradation
through
alternative
stimuli
such
light,
electrochemistry,
mechanical
force,
shown
promising
potential
more
efficient
selective
polymer
breakdown,
yielding
either
starting
monomers
or
valuable
small
molecules.
This
perspective
explores
key
examples
these
emerging
strategies,
highlighting
improve
upon
current
protocols
offer
pathways
under
milder
conditions,
while
identifying
challenges
that
future
research
must
address
translate
chemistry
into
viable
broadly
applicable
strategies.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 3, 2025
Thermosets
are
used
in
numerous
industrial
applications
due
to
their
excellent
stabilities
and
mechanical
properties;
however,
covalently
cross-linked
structures
limit
chemical
circularity.
Cleavable
comonomers
(CCs)
offer
a
practical
strategy
impart
new
end-of-life
opportunities,
such
as
deconstructability
or
remoldability,
thermosets
without
altering
critical
properties,
cost,
manufacturing
workflows.
Nevertheless,
CC-enabled
recycling
of
has
so
far
been
limited
one
cycle
with
25%
recycled
content.
Here,
we
introduce
"fragment
reactivation"
strategy,
wherein
the
oligomeric
fragments
obtained
from
thermoset
deconstruction
activated
functional
groups
that
improve
fragment
solubility
reactivity
for
subsequent
rounds
recycling.
Using
polydicyclopentadiene
(pDCPD),
an
hydrocarbon
material,
containing
low
loadings
siloxane-based
CC,
first
demonstrate
two
by
incorporating
40
wt
%
norbornene
silyl
ether-reactivated
derived
prior
generation's
deconstruction.
Then,
show
two-step
sequence
reactivation
can
be
unified
into
single-step
process,
referred
"deconstructive
reactivation."
this
approach,
three
40-45
incorporated
per
while
maintaining
key
material
properties
deconstructability.
These
generations
effectively
extend
lifespan
deconstructable
pDCPD
∼2.6
times.
Combined
CCs,
presents
promising
potentially
generalizable
efficiency
thermosets.
Macromolecules,
Год журнала:
2024,
Номер
57(14), С. 6727 - 6740
Опубликована: Июль 9, 2024
An
understanding
of
monomer
sequence
is
required
to
predict
and
engineer
the
properties
copolymers.
In
stochastic
polymerizations
involving
more
than
one
monomer,
typically
inferred
or
determined
from
reactivity
ratios,
which
are
measured
through
copolymerization
experiments.
The
accurate
determination
ratios
copolymerizations
where
both
monomers
undergo
reversible
propagation,
however,
has
been
complicated
by
difficulty
in
solving
underlying
population
balance
equations,
presence
myriad
copolymer
equations
literature
derived
under
varying
assumptions
simplifications,
lack
an
easy-to-fit
integrated
model.
Here,
we
rectify
assert
consistency
between
previously
reported
disparate
forms,
introduce
a
new
method
explicitly
solve
perform
simulations
evaluate
ability
these
three
methods
produce
consistent
comonomer
consumption
predictions
fits
simulated
data.
We
find
that
all
given
same
input
parameters,
implies
accuracy
precision
when
modeling
copolymerization,
fitting
experimental
data,
making
sequence.
Considering
this
consistency,
make
recommendation
use
numerical
integration
appropriate
equation
fit
real
data
due
its
ease
implementation.
further
identify
minimum
number
parameters
for
suggest
ways
measure
other
information
ex
situ
expedite
fitting.
Finally,
practical
utility
developed
herein
demonstrated
seven
distinct
sets,
span
wide
range
reactivities.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(44)
Опубликована: Июль 15, 2024
We
describe
a
methodology
of
post-polymerization
functionalization
to
enable
subsequent
bulk
depolymerization
monomer
by
utilizing
mechanochemical
macro-radical
generation.
By
harnessing
ultrasonic
chain-scission
in
the
presence
N-hydroxyphthalimide
methacrylate
(PhthMA),
we
successfully
chain-end
functionalize
polymers
promote
bulk,
achieving
up
82
%
poly(methyl
methacrylate)
(PMMA)
and
poly(α-methylstyrene)
(PAMS)
within
30
min.
This
method
yields
high-purity
that
can
be
repolymerized.
Moreover,
as
compared
most
common
methods
depolymerization,
this
work
is
efficient
with
ultra-high
molecular
weight
(UHMW)
polymers,
establishing
potential
address
highly
persistent,
non-degradable
all-carbon
backbone
plastic
materials.
Lastly,
demonstrate
expansion
commercial
cell
cast
PMMA,
high
degrees
from
post-consumer
waste.
first
demonstration
applying
PhthMA-promoted
strategies
homopolymer
PMMA
PAMS
prepared
conventional
polymerization
methods.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(44), С. 30662 - 30667
Опубликована: Окт. 28, 2024
A
robust
method
is
described
to
synthesize
degradable
copolymers
under
aqueous
miniemulsion
conditions
using
α-lipoic
acid
as
a
cheap
and
scalable
building
block.
Simple
formulations
of
(up
10
mol
%),
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(45)
Опубликована: Июль 29, 2024
Polythioesters
(PTEs)
are
emerging
sustainable
polymers
for
their
degradability
and
recyclability.
However,
low
polymerizability
of
monomers
extensive
side
reactions
often
hampered
the
polymerization
process.
Moreover,
copolymers
containing
both
thioester
other
types
functional
groups
in
backbone
highly
desirable
but
rarely
accomplished
owing
to
several
synthetic
challenges.
Here,
we
report
ring-opening
cascade
(ROCAP)
N-(2-(acetylthio)ethyl)-glycine
N-carboxyanhydrides
(TE-NCA)
afford
recyclable
PTEs
unprecedented
poly(thioester-co-peptoid)s
(P(TE-co-PP)s)
a
controlled
manner.
By
developing
appropriated
carboxylic
acid-tertiary
amine
dual
catalysts,
intramolecular
S-to-N
acyl
shift
is
coupled
into
ROCAP
process
TE-NCA
yield
products
with
dispersity
below
1.10,
molecular
weight
(M
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 23, 2024
Herein
we
address
the
question
of
whether
a
supramolecular
finite
metal-organic
structure
such
as
cage
or
polyhedron
(MOP)
can
be
synthesized
via
controlled
cleavage
three-dimensional
(3D)
structure.
To
demonstrate
this,
report
synthesis
Cu(II)-based
cuboctahedral
MOP
through
orthogonal
olefinic
bond
cavities
3D,
Cu(II)-based,
framework
(MOF).
Additionally,
that
controlling
ozonolysis
conditions
used
for
enables
Clip-off
Chemistry
two
MOPs
differ
by
their
external
functionalization:
one
in
which
all
24
groups
represent
mixture
aldehydes,
carboxylic
acids,
acetals
and
esters,
are
aldehydes.
