Chemistry Reference
In-Depth Information
samples, respectively. The 3D plots show
that the blend without the interfacial agent
decomposes faster at higher temperatures
and at any given conversion degree than the
PA6/LLDPE/SEBS-g-DEM blend. Degra-
dation rates are lower in the blend with the
interfacial agent, evidencing that its inclu-
sion enhances the thermal stability of the
blend.
The most probable function is then
ch
osen by the average minimum value of
S
j
defined by the relationship,
p
X
v
¼
p
1
S
j
¼
S
jv
(A2)
v¼
1
where
is the number of heating rates used.
The probability associated with each value
f
j
(
p
a
) can be calculated by defining the ratio,
S
j
S
2
m
in
F
j
¼
(A3)
Conclusions
where
S
2
min
is the average minimum of
residual dispersion. This ratio obeys the
The thermogravimetric analysis carried out
in these samples showed that when the
SEBS-g-DEM is added to the PA6/LLDPE
there is an actual enhancement of the
thermal stability due to the increase in the
interfacial area within the blend. The IKP
method proved to be a qualitative techni-
que evidencing the type of degradation
mechanisms taking place in the material
vicinity. Nucleation and phase boundary
reactions are the kinetic models on the
thermal decomposition more likely of
occurring. Statistical calculations along
with the Molau test evidenced that the
inclusion of SEBS-g-DEM in the PA6/
LLDPE increases the thermal stability.
F
distribution,
F
ðv=
2
Þ
1
j
F
j
Þ¼
G
ð
v
Þ
q
ð
(A4)
v
2
ð
1
þ
F
j
Þ
ðv=
2
Þ
G
where
is the number of degrees of freedom
equal for every dispersion and
G
is the
gamma function. It is interesting to note
that the average of the residual dispersion,
and not simply the residual dispersion, was
chosen t
o
define the ratio
n
F
j
because the
average
S
j
is a good non-biased estimate of
all
S
jv
values and gives a better statistic
representation of the process.
The probabilities of the
th function
are computed on the assumption that the
experimental data with
j
kinetic functions
are described by a complete and indepen-
dent system of events:
L
Appendix
[15]
The degradation is modeled by computing
the probabilities associated with the 18
degradation functions showed in Table 2.
Degradation of a polymer material often
cannot be represented with a single degra-
dation function. The kinetic functions f
j
(
a
)
may then be discriminated using the log A
inv
and
X
j
¼
L
P
j
¼
1
(A5)
j
¼
1
Therefore we obtain:
qðF
j
Þ
P
P
j
¼
(A6)
j
¼
L
E
inv
values obtained. Having
n
of the
qðF
j
Þ
th
of the experimental values of (d
a
/dT)
iv
,
the residual sum of squares for each
i
j
¼
1
f
j
(
a
)
and for each heating rate
b
v
may be
[1] C. Albano, J. Trujillo, A. Caballero, O. Brito,
Polymer
Bulletin 2001, 45(6), 531.
[2] C. J. R. Verbeek, Material Letters 2002, 52, 453.
[3] S. Bhadrakumari, P. Predeep,
computed as:
Sj
jv
¼
X
Supercond. Sci. Tech-
ð
n
1
Þ
nol. 2006, 19, 808.
[4] J. Reyes, C. Albano, M. Claro, D. Moronta,
iv
f
j
a
i
ðÞ
i
¼
n
2
da
dT
A
inv
b
v
E
inv
RT
iv
Radiation
exp
Physics and Chemistry
, 435.
[5] C. Rosales, H. Rojas, R. Perera, A. S´nchez,
J.M.S.-Pure and Applied Chemistry 2000, A37(10), 1227.
2003,
63
i
¼
1
(A1)
