Properties Research of Secondary Polymeric Materials on the Basis of Polypropylene and Polyethylene Terephthalate Got Under the Influence of Ultrasonic Oscillations on Polymeric Melt - Progress in Organic and Physical Chemistry: Structures and Mechanisms - page 149

The breakdown voltage of PP processed with ultrasound is gradually increasing
in two times from the ¿ rst to the second cycles and it does no change on the fourth
cycle. Breakdown voltage of PP processed without ultrasonic vibro attachment does
not change practically. Percent elongation with rupture of PP received with ultra-
sound and without it does not change practically form the ¿ rst to the fourth process-
ing's cycles.
We can see from the results that breakdown voltage of PET received with ultrason-
ic vibro attachment and without it increases in the second cycle. After ¿ rst decreases
on the third and on the fourth processing's cycles. We should note that the meanings
of PET's physico-mechanical properties processed with ultrasonic inÀ uence are higher
than for PET processed without it. Percent elongation with rupture of PET processed
with ultrasonic vibro attachment is gradually decreasing from the second processing's
cycle. Percent elongation with rupture of PET received without ultrasonic oscillations
does not change practically on the ¿ rst and on the second cycles, then it decreases
abruptly.
The rating of rheological properties was melt's À aw index. In the Figure 1 and 2
there are a dependence of received samples melt's À aw index on the amount of pro-
cessing's cycles.

FIGURE 1 Dependence of PPs melt's flaw index on the amount of processing cycles.

Conducted researches showed that melt's À aw index of PP (Figure 1) received
with ultrasonic oscillations does not change practically from cycle to processing's
cycle. Whereas melt's À aw index at samples received without ultrasonic oscillations
increases in two times on the second processing's cycle.