Polymers,
Год журнала:
2024,
Номер
16(24), С. 3542 - 3542
Опубликована: Дек. 19, 2024
The
present
work
focuses
on
the
synthesis
and
characterization
of
biobased
lignin-poly(lactic)
acid
(PLA)
composites.
Organosolv
lignin,
extracted
from
beechwood,
was
used
as
a
filler
at
0.5,
1.0,
2.5
wt%
loadings,
with
ultrasonication
reducing
lignin
particle
size
to
~700
nm.
PLA–lignin
composites
were
prepared
via
in
situ
ring-opening
polymerization
(ROP)
L-lactide
presence
lignin.
This
method
ensured
uniform
dispersion
PLA
matrix
due
grafting
chains
onto
particles,
preventing
aggregation.
Strong
polymer–filler
interactions
confirmed
through
spectroscopic
analysis
(FTIR
XPS)
their
effects
static
dynamic
glass
transitions
(DSC).
These
enhanced
mechanical
properties,
including
two-fold
increase
tensile
strength
elongation
1
Crystallization
suppressed
shorter
chains,
15%
drop
dynamical
fragility
observed
Broadband
Dielectric
Spectroscopy
(BDS).
Antioxidant
activity
improved
significantly,
PLA–2.5%
ultrasonicated
organosolv
DPPH•
content
7%
after
8
h,
while
UV-blocking
capability
increased
content.
Polymers,
Год журнала:
2023,
Номер
15(13), С. 2807 - 2807
Опубликована: Июнь 25, 2023
With
the
gradual
depletion
of
petroleum
resources
and
increasing
global
awareness
environmental
protection,
biodegradable
plastics
are
receiving
more
attention
as
a
green
substitute
for
traditional
petroleum-based
plastics.
Poly
(lactic
acid)
is
considered
to
be
most
promising
material
because
its
excellent
biodegradability,
biocompatibility,
good
processability.
However,
brittleness
high
cost
limit
application
in
fields.
Lignin,
second
largest
renewable
biopolymer
nature
after
cellulose,
not
only
rich
reserves
low
cost,
but
it
also
has
an
UV
barrier,
antioxidant
activity,
rigidity.
The
molecular
structure
lignin
contains
large
number
functional
groups,
which
easy
endow
with
new
functions
by
chemical
modification.
Currently,
mostly
treated
waste
industry,
value-added
utilization
insufficient.
combination
poly
can
on
one
hand
solve
problems
PLA
less
efficient
lignin;
other
hand,
lignocellulosic
biomass
compounding
synthetic
polymers
expected
afford
high-performance
wholly
polymer
composites.
This
mini-review
summarizes
latest
research
achievements
acid)/lignin
Emphasis
was
put
influence
mechanical
properties
composite
acid),
well
compatibility
two
components.
Future
these
composites
prospected.
Polymers,
Год журнала:
2023,
Номер
15(10), С. 2386 - 2386
Опубликована: Май 19, 2023
Poly(lactic
acid)
(PLA)
composites
with
0.5
wt%
lignin
or
nanolignin
were
prepared
two
different
techniques:
(a)
conventional
melt-mixing
and
(b)
in
situ
Ring
Opening
Polymerization
(ROP)
by
reactive
processing.
The
ROP
process
was
monitored
measuring
the
torque.
synthesized
rapidly
using
processing
that
took
under
20
min.
When
catalyst
amount
doubled,
reaction
time
reduced
to
15
dispersion,
thermal
transitions,
mechanical
properties,
antioxidant
activity,
optical
properties
of
resulting
PLA-based
evaluated
SEM,
DSC,
nanoindentation,
DPPH
assay,
DRS
spectroscopy.
All
processing-prepared
characterized
means
GPC,
NMR
assess
their
morphology,
molecular
weight,
free
lactide
content.
benefits
size
reduction
use
demonstrated,
as
processing-produced
nanolignin-containing
had
superior
crystallization,
mechanical,
properties.
These
improvements
attributed
participation
a
macroinitiator,
PLA-grafted
particles
improved
its
dispersion.
Molecules,
Год журнала:
2022,
Номер
27(23), С. 8143 - 8143
Опубликована: Ноя. 23, 2022
Lignin,
being
one
of
the
main
structural
components
lignocellulosic
biomass,
is
considered
most
abundant
natural
source
phenolics
and
aromatics.
Efforts
for
its
valorisation
were
recently
explored
as
it
mostly
treated
waste
from
heat/energy
production
via
combustion.
Among
them,
polymer-based
lignin
composites
are
a
promising
approach
to
both
valorise
fine
tune
properties
polymers.
In
this
work,
organosolv
lignin,
beech
wood,
was
used
fillers
in
poly
(lactic
acid)
(PLA)
matrix.
The
PLA/lignin
prepared
using
melt
mixing
masterbatches
with
neat
PLA
three
different
contents:
0.5,
1.0
2.5
wt%.
Lignin
as-isolated,
biomass
pretreatment/fractionation
process
after
8
h
ball
milling.
characterised
Scanning
Electron
Microscopy
(SEM),
Fourier
Transform
Infrared
Spectroscopy
(FTIR)
spectroscopy,
X-ray
Diffraction
(XRD),
Differential
Calorimetry
(DSC).
Additionally,
their
antioxidant
activity
assessed
2,2-Diphenyil-1-picrylhydrazyl
(DPPH)
method,
colour
measured
colorimeter
mechanical
evaluated
tensile
testing.
Ball
milling,
at
least
under
conditions
applied
study,
did
not
induce
further
substantial
decrease
already
relatively
small
primary
particles
~1
μm.
All
produced
had
uniform
dispersion
lignin.
Compression-moulded
films
successfully
prepared,
they
coloured
brown,
ball-milled
giving
slightly
lighter
comparison
as-received
Hydrogen
bonding
detected
between
composites,
crystallization
suppressed
by
suppression
less
pronounced
showed
significantly
improved
activity,
maintained
filler
content
1
ACS Applied Polymer Materials,
Год журнала:
2023,
Номер
5(9), С. 7308 - 7317
Опубликована: Авг. 22, 2023
Due
to
the
exhaustion
of
fossil
resources
and
degradation
environment,
there
is
an
increasing
utilization
eco-friendly
materials
as
substitutes
for
petroleum-derived
materials.
In
this
work,
a
series
poly(ε-caprolactone-co-lactic
acid)
diols
were
synthesized
via
one-pot
ring-opening
polymerization
with
different
lactic
acid
(LA)/ε-caprolactone
(CL)
feed
ratios.
Subsequently,
mixed
polyether
diol,
4,4′-diphenylmethane
diisocyanate
(MDI),
other
additives
produce
polyurethane
reactive
hot-melt
adhesives
(PURHAs).
The
enhancement
LA/CL
ratios
correspondingly
led
increase
in
glass
transition
temperature
(Tg)
polyester
diols.
differential
scanning
calorimetry
(DSC)
data
demonstrated
that
PCL-diol
had
highest
crystallinity,
polarizing
optical
microscopy
(POM)
observations
revealed
smallest
spherulite
size
PCLA28-diol.
Thermogravimetric
analysis
(TGA)
results
indicated
5
wt
%
loss
(T5)
PURHAs
surpassed
265
°C.
Tensile
testing
showed
elongation
at
break
containing
PCL
segments
increased
by
least
eight
times
compared
PURHA
without
segments.
Lap-shear
illustrated
higher
ratio
exhibits
green
strength.
addition,
PUHRA-PCLA28
derived
from
PCLA28-diol
PUHRA-PCL
possessed
better
tensile
lap-shear
strengths.
Notably,
strengths
on
PC
substrate
reached
impressive
values
8.85
8.05
MPa,
respectively.
These
bio-based
show
potential
applications
electronic
appliances,
automotive
industry,
construction
