Chemical groups present in the triacetate polymers are the hydroxyl and acetate groups. The hydroxyl groups results in the presence of hydrogen bonds.
These hydrogen bonds are relatively few in number, so less significant in the acetate fiber polymer system. This explains the non-polarity of secondary cellulose acetate polymers.
According to the definition of triacetate, its polymers should have less than 8 per cent of hydroxyl groups.
Such a small number of hydroxyl groups cannot form any significant hydrogen bonds, so triacetate polymer lacks polarity.
It is for the above reasons that both acetate and triacetate fibers depends mostly upon Van der Waals forces for their polymer cohesion.