Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(4)
Published: Nov. 28, 2022
Nylon-6
is
selectively
depolymerized
to
the
parent
monomer
ϵ-caprolactam
by
readily
accessible
and
commercially
available
lanthanide
trisamido
catalysts
Ln(N(TMS)2
)3
(Ln=lanthanide).
The
depolymerization
process
solvent-free,
near
quantitative,
highly
selective,
operates
at
lowest
temperature
reported
date.
catalytic
activity
of
different
trisamides
scales
with
Ln3+
ionic
radius,
this
effective
post-consumer
as
well
Nylon-6+polyethylene,
polypropylene
or
polyethylene
terephthalate
mixtures.
Experimental
kinetic
data
theoretical
(DFT)
mechanistic
analyses
suggest
initial
deprotonation
a
Nylon
terminal
amido
N-H
bond,
which
covalently
binds
catalyst
polymer,
followed
chain-end
back-biting
in
units
are
sequentially
extruded
from
chain
end.
Chemical Reviews,
Journal Year:
2021,
Volume and Issue:
122(1), P. 385 - 441
Published: Nov. 2, 2021
As
the
world
pledges
to
significantly
cut
carbon
emissions,
demand
for
sustainable
and
clean
energy
has
now
become
more
important
than
ever.
This
includes
both
production
storage
of
carriers,
a
majority
which
involve
catalytic
reactions.
article
reviews
recent
developments
homogeneous
catalysts
in
emerging
applications
energy.
The
most
focus
been
on
hydrogen
as
several
efficient
have
reported
recently
(de)hydrogenative
transformations
promising
economy.
Another
direction
that
extensively
covered
this
review
is
methanol
Homogeneous
investigated
from
CO
Science,
Journal Year:
2021,
Volume and Issue:
373(6556), P. 783 - 789
Published: Aug. 12, 2021
Identifying
plastics
capable
of
chemical
recycling
to
monomer
(CRM)
is
the
foremost
challenge
in
creating
a
sustainable
circular
plastic
economy.
Polyacetals
are
promising
candidates
for
CRM
but
lack
useful
tensile
strengths
owing
low
molecular
weights
produced
using
current
uncontrolled
cationic
ring-opening
polymerization
(CROP)
methods.
Here,
we
present
reversible-deactivation
CROP
cyclic
acetals
commercial
halomethyl
ether
initiator
and
an
indium(III)
bromide
catalyst.
Using
this
method,
synthesize
poly(1,3-dioxolane)
(PDXL),
which
demonstrates
strength
comparable
some
commodity
polyolefins.
Depolymerization
PDXL
strong
acid
catalysts
returns
near-quantitative
yield
even
proceeds
from
waste
mixture.
Our
efficient
method
affords
tough
thermoplastic
that
can
undergo
selective
depolymerization
monomer.
Chemical Reviews,
Journal Year:
2023,
Volume and Issue:
123(9), P. 5612 - 5701
Published: March 14, 2023
Plastics
are
everywhere
in
our
modern
way
of
living,
and
their
production
keeps
increasing
every
year,
causing
major
environmental
concerns.
Nowadays,
the
end-of-life
management
involves
accumulation
landfills,
incineration,
recycling
to
a
lower
extent.
This
ecological
threat
environment
is
inspiring
alternative
bio-based
solutions
for
plastic
waste
treatment
toward
circular
economy.
Over
past
decade,
considerable
efforts
have
been
made
degrade
commodity
plastics
using
biocatalytic
approaches.
Here,
we
provide
comprehensive
review
on
recent
advances
enzyme-based
biocatalysis
design
related
processes
recycle
or
upcycle
plastics,
including
polyesters,
polyamides,
polyurethanes,
polyolefins.
We
also
discuss
scope
limitations,
challenges,
opportunities
this
field
research.
An
important
message
from
that
polymer-assimilating
enzymes
very
likely
part
solution
reaching
Cell Reports Physical Science,
Journal Year:
2021,
Volume and Issue:
2(8), P. 100514 - 100514
Published: July 22, 2021
Various
recycling
technologies
have
been
developed
to
deal
with
plastic
problems,
but
they
face
considerable
economic
and
technological
challenges
in
practice.
An
attractive
alternative
is
upcycling,
which
aims
dig
out
the
embedded
value
incentivize
large-scale
valorization
of
wastes.
The
degradation
nonrecoverable
wastes
another
necessity
treat
omnipresent
pollution.
This
review
presents
an
overview
on
conversion
toward
value-added
products
catalytic
Based
examination
traditional
products,
we
summarize
state-of-the-art
design
development
high-value
high-performance
fuels,
chemicals,
materials.
Subsequently,
highlight
advances
plastics
environmentally
benign
or
degradable
mineralization
into
carbon
dioxide
water.
We
conclude
our
perspective
ongoing
challenge
opportunities.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(12), P. 5366 - 5376
Published: March 15, 2022
Aliphatic
polyamides,
or
nylons,
are
typically
highly
crystalline
and
thermally
robust
polymers
used
in
high-performance
applications.
Nylon
6,
a
high-ceiling-temperature
(HCT)
polyamide
from
ε-caprolactam,
lacks
expedient
chemical
recyclability,
while
low-ceiling
temperature
(LCT)
nylon
4
pyrrolidone
exhibits
complete
but
it
is
unstable
not
melt-processable.
Here,
we
introduce
hybrid
nylon,
4/6,
based
on
bicyclic
lactam
composed
of
both
HCT
ε-caprolactam
LCT
motifs
hybridized
offspring
structure.
Hybrid
4/6
overcomes
trade-offs
(de)polymerizability
performance
properties
the
parent
exhibiting
excellent
polymerization
facile
depolymerization
characteristics.
This
stereoregular
forms
nanocrystalline
domains,
allowing
optical
clarity
high
thermal
stability,
however,
without
displaying
melting
transition
before
decomposition.
Of
series
statistical
copolymers
comprising
4,
50/50
copolymer
achieves
greatest
synergy
reactivity
polymer
each
homopolymer,
offering
an
amorphous
with
favorable
properties,
including
clarity,
glass
temperature,
melt
processability,
full
recyclability.
