Chemical Engineering Journal,
Journal Year:
2024,
Volume and Issue:
482, P. 148861 - 148861
Published: Jan. 21, 2024
As
the
demand
of
polyethylene
terephthalate
(PET)
increases
worldwide
along
with
waste
generated
from
its
use,
it
is
urgent
to
develop
cost-efficient
and
sustainable
recycling
processes,
such
as
depolymerization
that
yields
monomers
virgin-like
qualities.
However,
most
these
processes
require
harsh
conditions
their
true
mechanisms
are
poorly
understood,
leading
marginal
gains
in
energy
efficiency
yield.
In
spite
lack
solubility
PET,
we
demonstrate
swelling
plastification
PET
a
good
solvent
allows
better
mass
transport
ethylene
glycol
catalyst
into
polymer
during
glycolysis.
Based
on
insights,
report
process
which
depolymerized
bis(2-hydroxyethyl)terephthalate
(BHET)
yield
88
%
at
65
°C
within
1
h
presence
1,3-Dioxolane
green
cosolvent
carrier.
The
improved
perform
even
below
Tg
polymer.
Indeed,
by
kinetic
modelling
demonstrated
heterogeneous
could
be
easily
transformed
an
homogeneous
appropriate
selection.
environmental
impact
proposed
process,
including
recovery,
compared
solvent-free
counterpart
results
demonstrates
using
1,3-Dioxolane,
carbon
footprint
newly
developed
glycolysis
can
reduced
up
20
due
increased
efficiency.
This
enables
viable
strategy
repetitive
unit,
contributing
development
competitive
chemical
solutions
reduce
PET-derived
pollution.
Industrial & Engineering Chemistry Research,
Journal Year:
2024,
Volume and Issue:
63(8), P. 3355 - 3399
Published: Feb. 12, 2024
Poly(ethylene
terephthalate)
(PET)
is
the
most
widely
produced
thermoplastic
and
used
in
drink
bottles,
packaging,
textiles.
Chemical
depolymerization
represents
a
way
to
recycle
PET
that
robust
low
purity
quality
of
some
waste
sources.
This
work
investigates
three
primary
routes
depolymerize
into
feedstocks
produce
polymer:
methanolysis,
glycolysis,
hydrolysis.
unique
providing
thorough
review
thermodynamics,
chemistry,
purification
strategies,
design
processes
from
an
industrial
perspective.
provides
detailed
descriptions
different
variants
processes.
We
summarize
available
data
necessary
process
indicate
where
gaps
exist.
demonstrate
importance
separation
sections
process,
which
are
rarely
addressed
academic
literature.
also
designs
strategies
technologies
employ
address
challenges.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: July 25, 2024
Alcoholysis
of
poly(ethylene
terephthalate)
(PET)
waste
to
produce
monomers,
including
methanolysis
yield
dimethyl
terephthalate
(DMT)
and
glycolysis
generate
bis-2-hydroxyethyl
(BHET),
is
a
promising
strategy
in
PET
management.
Here,
we
introduce
an
efficient
PET-alcoholysis
approach
utilizing
oxygen-vacancy
(V
Polymers,
Journal Year:
2024,
Volume and Issue:
16(1), P. 142 - 142
Published: Jan. 2, 2024
This
work
addresses
a
novel
bio-solvolysis
process
for
the
treatment
of
complex
poly(ethylene
terephthalate)
(PET)
waste
using
biobased
monoethylene
glycol
(BioMEG)
as
depolymerization
agent
in
order
to
achieve
more
sustainable
chemical
recycling
process.
Five
difficult-to-recycle
PET
streams,
including
multilayer
trays,
coloured
bottles
and
postconsumer
textiles,
were
selected
study.
After
characterization
conditioning
samples,
an
evaluation
proposed
was
carried
out
by
monitoring
reaction
over
time
determine
degree
conversion
(91.3–97.1%)
bis(2-hydroxyethyl)
terephthalate
(BHET)
monomer
yield
(71.5–76.3%).
A
purification
process,
activated
carbon
(AC),
also
developed
remove
colour
reduce
metal
content
solid.
By
applying
this
strategy,
whiteness
(L*)
BHET
greatly
increased
from
around
60
95
(L*
=
100
pure
white)
Zn
significantly
reduced
200
2
mg/kg.
The
structure
purified
monomers
analyzed
via
infrared
spectroscopy
(FTIR)
differential
scanning
calorimetry
(DSC),
composition
samples
measured
proton
nuclear
magnetic
resonance
(1H-NMR),
proving
high
purity
with
up
99.5%
mol.
Materials,
Journal Year:
2024,
Volume and Issue:
17(12), P. 2991 - 2991
Published: June 18, 2024
Plastic
pollution
has
escalated
into
a
critical
global
issue,
with
production
soaring
from
2
million
metric
tons
in
1950
to
400.3
2022.
The
packaging
industry
alone
accounts
for
nearly
44%
of
this
production,
predominantly
utilizing
polyethylene
terephthalate
(PET).
Alarmingly,
over
90%
the
approximately
1
PET
bottles
sold
every
minute
end
up
landfills
or
oceans,
where
they
can
persist
centuries.
This
highlights
urgent
need
sustainable
management
and
recycling
solutions
mitigate
environmental
impact
waste.
To
better
understand
PET's
behavior
promote
its
within
circular
economy,
we
examined
chemical
physical
properties,
current
strategies
most
effective
methods
available
today.
Advancing
economy
framework
by
closing
industrial
loops
demonstrated
benefits
such
as
reduced
landfill
waste,
minimized
energy
consumption,
conserved
raw
resources.
end,
identified
various
based
on
R-imperatives
(ranging
3R
10R),
focusing
latest
approaches
aimed
at
significantly
reducing
waste
2040.
Additionally,
comparison
(including
primary,
secondary,
tertiary,
quaternary
recycling,
along
concepts
"zero-order"
biological
techniques)
was
envisaged.
Particular
attention
paid
heterogeneous
catalytic
glycolysis,
which
stands
out
rapid
reaction
time
(20-60
min),
high
monomer
yields
(>90%),
ease
catalyst
recovery
reuse,
lower
costs,
enhanced
durability.
Accordingly,
use
highly
efficient
oxide-based
catalysts
glycolytic
degradation
is
underscored
promising
solution
large-scale
applications.
Polymer Chemistry,
Journal Year:
2024,
Volume and Issue:
15(7), P. 585 - 608
Published: Jan. 1, 2024
This
review
discusses
the
physical-,
chemical
recycling
and
biodegradation
processes
mechanisms
of
PET,
proposing
effecting
compromise
between
its
overall
properties
conferred
intrinsic
biodegradability
by
modified
monomer
polymerisation.
Chemical Engineering Journal,
Journal Year:
2024,
Volume and Issue:
485, P. 149832 - 149832
Published: Feb. 19, 2024
In
the
pursuit
of
circular
economies
aimed
at
eliminating
waste
and
pollution,
chemical
recycling
emerges
as
a
promising
avenue
for
transforming
plastics
into
monomers.
This
study
addresses
need
economically
viable
mild
depolymerisation
methods,
focusing
on
poly(bisphenol
A
carbonate)
(BPA-PC),
an
engineering
plastic
with
monomer
bisphenol
(BPA),
known
xenoestrogen.
Improving
BPA-PC
is
crucial
to
prevent
release
BPA
environment.
Our
investigation
centres
three
commercially
available
organocatalyst-modified
silica
gels
in
polycarbonate
(PC)
methanolysis,
alongside
one
functionalised
1,5,7-triazabicyclo-[4.4.0]-dec-5-ene
(TBD),
previously
reported
polyethylene
terephthalate
(PET)
glycolysis.
The
latter
Si-TBD,
among
these
catalysts,
exhibits
superior
catalytic
activity
PC
methanolysis.
methanolysis
process
was
optimised
by
experimental
design.
Under
optimal
reaction
conditions
(PC:
2.00
g,
methanol
(n(MeOH):n(PC)
=
13:1),
Si-TBD:
5
mol%,
65
°C,
2
h),
96
%
non-isolated
yield
obtained.
kinetics
reveals
that
Si-TBD-catalysed
pseudo-first-order
exceptionally
low
activation
energy
44.19
kJ
mol−1,
lowest
date.
Si-TBD
recycled
ten
cycles
after
regeneration,
even
though
regenerated
catalyst
has
slightly
lower
than
native
catalyst,
good
yields
(72
±
4
%)
were
achieved
consistently.
Investigations
necessity
inert
atmosphere
during
indicate
it
not
required.
Impressively,
demonstrates
ability
depolymerise
room
temperature,
without
stirring,
days,
excellent
(94
%).
Notably,
this
offers
similar
performance
temperature
others
literature
