STABILIZATION AND MODIFICATION OF POLYETHYLENETEREPHTHALATE - Photochemical Reactions in Heterochain Polymers - page 132

Obtained samples of PETP - fibres being investigated were completely solved in solvents
without formation of precipitates (possible products of hexaazocyclanes and PETP
interaction), that shows attaining required inertness of components regarding each other
according to technology.
Thus, all compounds being tested are solved and combined with PETP melt quite well,
stable in polymer melt, do not have negative effect on polymer, facilitates polymer
crystallization and fibre strengthening and do not require change of factory technological
regulations.

3.5. T HERMO - AND T HERMOOXIDATIVE D ESTRUCTION OF
M ODIFIED PETP - F IBRE

Data on complex thermogravimetric analysis at aerodynamic heating are given in
Table29.

Table 29. Thermal characteristics of PETP - fibres dyed by hexaazocyclenes

T of melting, ºC T of initial

oxidation, ºC

T of mass loss, ºC

Fibre sample

5% 10% 25%

PETP - initial 269 320 360 415 428

PETP + additive HC-1 250 335 441 444 447

PETP + additive HC-2 245 385 480 526 576

PETP + additive HC-3 260 265 345 360 370

PETP + additive HC-4 250 290 360 368 375

PETP + additive HC-5 260 340 400 480 505

PETP + additive HC-6 263 340 420 445 453

PETP + additive HC-7 250 365 415 440 503

DTA curves of modified and unmodified PETP - fibres taken in air at the rate of
temperature rise 5 ºC/min are given in Figure 3.11 - 3.13.
Curve of differential - thermal analysis (DTA) of unmodified PETP on which there given
physical transitions and chemical transformations, accompanied by exothermanl and
endothermic effects, which correspond to separate bend of a curve is shown in Figure 3.11
(curve 1).
Exothermic processes are crystallization, oxidation and decay (sections B, Г, Д in Figure
3.11), while vitrification and melting are endothermic transformations (sections А, Б in
Figure 3.11).