Page 66 - Kutnar, Andreja, et al., eds., 2015. Proceedings of the 1st COST Action FP1307 International Conference - Life Cycle Assessment, EPDs, and modified wood. University of Primorska Press, Koper.

ucture
evaluation
of
the
modified
wood
through
different
spectral

techniques

Maria-­‐Cristina
Popescu1,
Carmen-­‐Mihaela
Popescu1

1
PetruPoni
Institute
of
Macromolecular
Chemistry
of
Romanian
Academy,
Iasi,
Romania,

cpopescu@icmpp.ro,
mihapop@icmpp.ro

Keywords:
infrared
spectroscopy,
near
infrared
spectroscopy,
chemometrics,
2D
COS,
X-­‐ray

diffraction

Wood
is
an
important
natural
resource,
which
has
many
technical
advantages,
such
as:
high

specific
stiffness
and
strength,
low
processing
energy,
high
toughness,
renewability,
aesthetic

properties,
etc.
Due
to
its
various
properties,
wood
has
many
applications
from
engineering
to

artworks.
However,
in
addition
to
its
biodegradability
and
dimensional
instability
in
environments

with
changing
moisture
levels,
wood
is
very
susceptible
to
weathering
(especially
degradation
by

UV
light).
Furthermore,
photo-­‐oxidation
occurs
when
oxygen
reacts
with
wood,
causing

discoloration
and
deterioration.

In
order
to
reduce
or
to
stop
wood
degradation
different
modification
techniques
have
been

applied.
Chemical
modification
(where
chemical
moieties
are
covalently
bonded
to
the
wood
cell

wall
polymers)
is
one
method
to
improve
the
dimensional
stability,
decay
resistance,
and
water

sorption
of
wood.
At
the
same
time,
thermal
treatment
is
often
used
to
improve
the
physical

characteristics
of
wood
for
particular
purposes,
including
the
dimensional
stability
and
durability

of
the
wood
if
it
is
to
be
exposed
to
chemicals
or
biological
agents
such
as
fungi
and
bacteria,
or

to
frequent
use
under
natural
environmental
conditions.

The
structural
modifications
induced
by
these
treatments
can
be
easily
evidenced
by
infrared
and

near
infrared
spectroscopy,
as
well
as
by
solid
state
13C
CP/MAS
NMR
spectroscopy.
These

techniques
can
provide
detailed
information
on
the
modifications
at
a
molecular
level
of
the
cell

wall
components
induced
by
the
applied
treatment.
Moreover,
2D
IR
correlation
spectroscopy

(2D-­‐COS)
is
a
powerful
tool
used
to
evaluate
the
differences
appearing
during
an
external

perturbation.
Usually,
this
method
enhances
the
spectral
resolution
giving
new
information,

which
cannot
be
established
through
conventional
infrared
and
its
derivative
spectra.
On
the

other
hand,
X-­‐ray
diffraction
technique
evaluates
the
modification
of
the
crystallinity
degree

according
to
the
applied
modification
technique.

All
these
spectral
techniques
can
be
used
successfully
to
evaluate
and
quantify
of
the
structural

modification
of
wood
samples
after
application
of
different
chemical
or
thermal
treatments.

54