STABILIZATION AND MODIFICATION OF CELLULOSE DIACETATE - Photochemical Reactions in Heterochain Polymers - page 92

It is very important to note that indan - sulphonamides absorb light in the same field as
CDA. The last fact allows to make a conclusion about “shielding” mechanism of the action of
this set of compounds.
Comparison of data on light stabilizing activity of indan - sulphonamides with results,
obtained for sulphonamides on the basis of carbazole, shows that substitution of indan
fragment for carbazole cycle leads to the increase of conjugation effect and, as a result, to the
increase of light protective effect by 15-26%(Table 22).
Light-protective effect changes noticeably depending on substituent both in aromatic
cycle and in amine component. So, carbazol-sulphonamides, obtained on the basis of aliphatic
amines, display much lower activity than arylamine derivates. Quick increase of light
stabilizing activity is observed during introduction of electronoacceptor substituents (R a ) into
phenylene rings and, on the contrary, electrono-donor substituents slightly reduce protective
action of stabilizer.
Table 22. The comparative characteristics of stabilizing effect of sulphuryl amide
derivatives of carbazole and indan

Compound Structural formula Viscosity, %

indan derivatives (Х) 36,6

carbazole
derivatives (XXVI)

72,4

indan derivatives
(ХII)

32,2

carbazole
derivatives (XXX)

83,1

indan derivatives
(XVI)

40,7

carbazole
derivatives (XXVII)

62,1