ACS Engineering Au,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 31, 2024
Polyurethane
foams
(PUF)
are
essential
materials
known
for
their
exceptional
chemical
and
mechanical
properties,
making
them
ubiquitous
in
a
wide
range
of
applications.
Conventionally,
PUF
produced
through
polyaddition
reactions
between
polyols
polyisocyanates
at
room
temperature,
where
water
plays
critical
role
this
process
by
hydrolyzing
the
isocyanates,
leading
to
release
carbon
dioxide
(CO2)
as
blowing
agent.
In
recent
years,
isocyanates
have
raised
significant
concerns
industries
consumers
due
high
toxicity.
Therefore,
driving
need
explore
alternative
synthesis
routes
that
do
not
involve
use
isocyanates.
Nonisocyanate
polyurethane
(NIPUF)
derived
from
aminolysis
cyclic
carbonates
emerged
most
promising
solution
replace
conventional
method
producing
PUF.
Despite
this,
challenging
aspect
lies
identifying
suitable
foaming
strategy
NIPUF
can
satisfy
both
sustainability
performance
requirements.
view
first
part
review
focuses
on
background,
chemistry,
challenges
second
part,
chemistry
various
strategies
used
prepare
discussed
analyzed.
Finally,
outlook
future
research
focus
areas
outlined.
Polymers,
Journal Year:
2025,
Volume and Issue:
17(5), P. 602 - 602
Published: Feb. 24, 2025
The
determination
of
the
surface
charge
density
distribution
and
transcapacitance
capacitive
one-side-access
circular
sensors
with
three
electrodes
on
active
remains
problematic
both
theoretically
experimentally.
To
provide
an
input,
a
novel
experimental
study
was
carried
out
partial
permittivity
rigid
PU
foams
by
means
OSA
sensor
surface.
An
original
effective
method
elaborated
in
order
to
determine
model
functions
obtained
data
permittivity.
A
numerical
estimation
for
rate
change
made
highest
determined.
It
identified
that
takes
place
at
inter-electrode
zone
depends
true
nonlinear
mode,
approximated
second-order
polynomials.
overall
character
dependence
radius
covered
area
found
be
comparable
curve,
estimated
two-electrode
sensor.
results
can
useful
performance
evaluation
design
optimal
proportions
sensors,
as
well
verification
corresponding
mathematical
models.
Plants,
Journal Year:
2025,
Volume and Issue:
14(5), P. 775 - 775
Published: March 3, 2025
The
key
challenge
in
polymer
science
is
developing
sustainable
synthesis
methods
using
renewable
feedstocks.
This
study
explores
plant-derived
diarylheptanoids
with
various
structures
as
the
building
blocks
for
polyurethane
(PU)
materials.
Diarylheptanoid
glucosides
isolated
from
black
alder
(Alnus
glutinosa)
bark
were
hydrolyzed
and
fractionated
to
remove
sugar
moieties.
resulting
diarylheptanoids,
along
unhydrolyzed
analogues
curcumin,
used
biomass-based
polyols
synthesize
model
PU
films.
Incorporating
enhanced
mechanical
strength
reduced
flexibility
of
due
increased
crosslinking,
effects
proportional
OH
functionality
polyols.
Weight
loss,
FTIR,
Py-GC-MS/FID
analyses
revealed
that
catechol
moieties
glucosidic
bonds
are
biodegradable
structural
subunits
incorporated
into
Rigid
foams
(PURs)
incorporating
high-OH-functionality
diarylheptanoid
such
oregonin
demonstrated
significantly
higher
compression
less
weight
loss
during
non-isothermal
thermal
analysis
air
compared
those
commercial
polyol-based
foams.
A
cone
calorimeter
test
showed
PUR
foam
derivatives
had
a
lower
degradation
rate,
longer
flame-burning
time,
30%
heat
emission,
25%
smoke,
indicating
improved
flame
retardancy.
Adding
1–2%
oregonin-enriched
extracts
Elastopir
1132/509/0
its
resistance
oxidative
aging,
outperforming
antioxidant
Irganox.
