The researches of the designed MPs (Table 6) showed that their coefficient of
thermal linear expansion was lower compared with initial polymer (by 4 – 56% at the
all investigated temperature intervals). It can be because of the decrease in the free
volume due to the chemical interaction of macromolecules of amorphous phenylone
with the active surface of disperse metals. This method is confirmed by the fact that
the temperature of vitrification (T
v
) of MPs is by 8 – 120 K higher than that of the base
polymer (see Table 6).
The thermal expansion of polymers reacts sensitively to the transitions in
polymers. First of all it gives as a chance to determine T
v
by the fracture on curves
“relative extension – temperature”. Vitrification, determined by dilatometric method,
is structural and, as it’s known [25], depends on the test conditions less than the
temperature of mechanical vitrification.
Table 6 Coefficients of thermal linear expansion of MPs containing 15 %
of filler, ·10
-6
К
-1
Temperature range, К
APP
Ni
Ti
Al
Cu
Bronze
298 – 323
13.03
12.47
1.20
1.20
1.20
12.00
298 – 373
35.05
30.56
25.33
26.08
24.53
28.41
298 – 423
44.20
32.51
30.36
33.63
28.29
33.37
298 – 473
40.52
27.37
32.52
36.28
32.81
35.84
298 – 523
38.71
38.07
34.28
37.53
35.01
37.72
Тv, К
457
465
553
571
577
579
T
v
depends on the structure and polarity of polymer. This affects both the
flexibility of the circuit and the energy of the intermolecular interaction. It is proved
[26] that the less flexibility of the circuit you have, the bigger size of the potential
rotation barrier you get.
As it can be seen from Table 6, phenylone is characterized by high enough Tv that
is peculiar for polymers with high rigidity and polarity and for ones with strong
intermolecular interaction. Such features make it difficult to rotate the elements. That’s
why it’s necessary to heat up to higher temperatures for the development of circuit
flexibility.
Fillers create chemical connections with polymer developing at the interface. At
the same time the energy of intermolecular interaction increases. It leads to even bigger
spatial difficulties and, as a consequence, at their presence an increase in the
temperature of vitrification occurs. Obviously, the stronger the interaction at the
interface is, the higher the T
v
is. This is consistent with the data obtained earlier [22].
The effect of various metallic filling materials on the physical-mechanical
and tribological properties of aromatic-polyamide-based composite materials. As
for the physical-mechanical and tribotechnical characteristics of metal – containing
polymers, the correlation between them and the morphology of the structural units
within the polymers is really confirmed (see Table 7). As it can be seen from the table,
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