STABILIZATION AND MODIFICATION OF POLYETHYLENETEREPHTHALATE - Photochemical Reactions in Heterochain Polymers - page 131

Figure 3.10. Microphotographs of PETP - fibre (a) and its cross-section (b), modified by HC-6.
Authors of these works consider that hexaazocyclanes influence the rate of formation of
crystallization nuclei at the expense of surface energy of crystallites that leads to greater
regularity of structure and decrease of critical sizes of crystallites.
Comparison of microphotoes of modified and unmodified PETP - fibres shows that
introduction of hexaazocyclones increases the degree of PETP crystallinity that well agrees
with above-mentioned literature data.
Amount of amorphous part in modified fibre decreases; this will increase fibre strength
and improve its mechanical characteristics, since amorphous region is the most weak for
mechanical loads action and stress as it contains regions of the least degree of order in
macromolecules package and in the region of defects concentration.
High degree of crystallinity causes high fibre density, resistance to the action of chemical
reagents and physico-chemical properties of polymer. Fibrillar structure of the fibre is seen in
microphotoes of modified fibres, moreover introduction of hexaazocyclanes into PETP
facilitates increase of regularity and density of polymer structure. All this proves that
introduction of hexaazocyclanes additives increases PETP ability to crystallization.