Chemistry Reference
In-Depth Information
metric analysis (TGA), electron microscopy (SEM), differential scanning
calorimetry (DSC) and dynamic thermal analysis of mechanical properties
(DMTA).
The samples were heated in the ambient temperature in temperature
range of 30-490 °C with speed of 5 deg/min. The test was conducted with
thermo balance TGA manufactured by “Perkin Elmer.” Turning points
were made after freezing the samples in the liquid nitrogen for about
3 min. The surfaces of the turning points were concocted with gold with
vacuum powdering. The scanning electron microscope JSM 6100 manu-
factured by JEOL was used to conduct the tests. The photographs have
been made in magnification of 2000x.
8.3
RESULTS OF THE TESTING
Influence of the content of elastomer Engage I on physical properties of
TPE with PP and EOE modified (grafting/cross-linking) with a silane/
peroxide cross-linking system has been shown in Fig. 8.3 and Table 8.2.
The content of comonomer had significant influence on such properties
of the elastomer as elasticity, modulus, density and hardness. Values of
two last parameters decreased with the increase of content of
n
-octene in
elastomer. It has been stated that properties of the dynamically vulcanized
blends could be adjusted with content of the elastomer phase. With the
increase of content of EOE in range 15-45% tensile strength increased
(18-30 MPa), and, in the same time, relative elongation increased with
tear off (300-700%). With elastomer content over 50% a visible decrease
of both properties occurred, which came to 15 MPa and 600%, respec-
tively. Whereas hardness expressed in Sh degrees or in MPa) systemati-
cally decreased with the increase of the content of EOE in the blend. The
optimum content of EOE introduced to PP was 45% and therefore in most
subsequent tests a blend was used, in which iPP/EOE ratio was 55/45%.
Such contents had also the blends listed in Table 8.3, made of three types
of EOE and two types of silane, with constant content of the cross-linking
system (silane A-174/dicumyl peroxide 3.0/0.01%, irganox 1010-0.2%.
The blends containing elastomers Engage I and Engage II, with difference
of content of octene by 2% Shore hardness A (66 and 75, respectively)
and with very similar Mooney viscosities, showed comparable resistance
and rheological characteristic. The blends containing elastomer Engage
