Carrier effect on structure and properties of heat‐treated poly(ethylene terephthalate) fibers. II. Dyeing behavior

Abstract

SYNOPSISThe changes in the morphology of heat-setted poly (ethylene terephthalate) (PET) fibers (as spun and 2.SX) submitted to benzoic acid action a t different concentrations and times were analyzed by wide-angle x-ray scattering and dynamic and mechanical thermal analysis. Also, dyeings in the presence of two different Disperse dyes were performed. Therefore, the calculated diffusivities as well as the dye absorption percentage a t equilibrium were related to the morphological changes of the fibers, due to the benzoic acid action. The plasticization effect of the benzoic acid over the as-spun fiber occurs in the first 30 min of exposition and in 24 h for the drawn one. This plasticizing action of the benzoic acid seems to be the commanding factor over the dyeing behavior of the fibers, as demonstrated by an increase of the diffusion coefficient with the increase of benzoic acid concentration. However, the morphological changes due to exposition for long periods of time a t increased benzoic acid concentrations are one of the major responsible factors by the observed maxima in the figures of percentage of dye on the fibers a t equilibrium versus benzoic acid concentration. Also, changes in the angular coefficient ( B ) calculated from the free volume theory equation are indicative that factors such as the size of the dye molecules as well as their solubilities in water in addition to the morphological changes may be playing a role in the dyeing behavior.

Structural Investigation of Chemical Treated Polyester Fibers Using Saxs and Other Techniques

“…Chemical treatment of PET with different substances like strong acids and bases (alkaline products) as well as certain solvents brings about change in fine structure, improvement in some important properties like dyeability and wettability of polymers [2]. Change of morphology of PET by acid treatment studied by mechanical and thermal analysis [3][4][5][6] and modification of fiber structure by alkali treatment [7][8][9][10] have been reported; but this study does not reveal much on mechanical responses of polymeric fibers to any chemical treatment. The physical state and morphological characteristics of polyester have a strong influence on its mechanical properties.…”

Solvent‐induced modifications in polyester yarns. II. Structural and thermal behavior

“…Poly (ethylene terephthalate) (PET) has a compact fiber structure with a high degree of crystallinity and high glass transition temperature and without recognized dye sites 1. Because of this, satisfactory dyeing of PET below 130°C is difficult to achieve.…”

Interaction of N‐methylformanilide with high‐performance polyimide fibre and its effect on dyeing

“…This dyeing theory has been proven by the dyeing of polyester fibres. Polyester fibre can be dyed at a lower temperature because swelling agents decrease the T g 18,28 . However, PI fibre has a very high T g ( ca .…”

“…Polyester fibre can be dyed at a lower temperature because swelling agents decrease the T g . 18,28 However, PI fibre has a very high T g (ca. 350-400 C), which it is impossible to lower to the dyeing temperature (ca.…”