Synthesis and characterization of adipic acid/polyethylene glycol/poly(ethylene terephthalate) copolyester fiber

Abstract

A series of aliphatic/aromatic copolyesters that contained different amounts of aliphatic segments, constructed from adipic acid (AA, 0∼0.117 mole ratios), were synthesized. The structure of each copolymer was confirmed by 1H nuclear magnetic resonance. The molecular weight was determined directly by gel permeation chromatography and indirectly by the intrinsic viscosity. The results of thermal tests revealed that both melting temperature ( T m) and crystallization temperature ( T c) decreased as the aliphatic segment content increased. The glass transition temperatures ( T g) that were determined by dynamic mechanical analysis followed the same trend as did T m. Moreover, the thermal stability, determined from thermogravimetric analysis, declined as polyethylene glycol (PEG) and AA were incorporated into the poly(ethylene terephthalate) (PET) main chains. All of the polymers that were synthesized herein were spun into fibers and then physically characterized. The tenacity of the fibers decreased as the soft-segment content increased. The crystalline structures, revealed by wide-angle X-ray scattering, indicated that the crystallinity decreased with increasing AA content because of the reduction of regularity of the PET chains. Most importantly, the tests that were carried out on the knitted fabric demonstrated that the moisture regain and cool feeling ( qmax) of the copolymer fabrics were better than those of fabrics that comprised neat PET chains, owing to the incorporation of soft PEG segments. Finally, the copolymer fabric exhibited better hydrolysis and enzymatic degradation than did neat PET fabric.