Polyester fibres with improved dye uptake

Abstract

AbstractPoly(ethylene terephthalate) (PET) having ether segments have been prepared by melt condensation by taking dimethyl terephthalate (DMT) and different quantities of ethylene glycol (EG) and polyethyl'ene glycol (PEG) in the initial monomer feed.The polymers were characterized by intrinsic viscosity measurements. The relative thermal stability of the polymers was evaluated by dynamic thermogravimetry in air. The melting point was found to decrease from 258–244°C with increase of polyethylene oxide segments in the polymer backbone.These polymers were spun into fibres by using melt spinning technique. The fibres were drawn to different draw ratios and then heat‐set. With the increase of the mole percentage of polyether segments in the copolymers, a decrease in tensile strength and initial modulus of the fibres was observed while percentage elongation increased. An optimum tenacity was obtained with BL 3 fibres, and further increase of PEG (BL 4) did not affect the tenacity of initial modulus. The dye uptake and moisture regain in copolyesters was greatly enhanced compared to PET. The crystallinity and orientation of fibres was studied by X‐ray diffraction pattern. In the drawn and heat set fibres, the density decreased on increasing the PEG content except in BL 4 where the density was higher than in PET.