Preparation and characterization of poly(ethylene terephthalate‐co‐aliphatic amide) copolymer fibers with excellent hygroscopicity and softness

Abstract

AbstractThe aliphatic amide with hydrophilic groups and flexible segments are ideal monomers to modify poly(ethylene terephthalate) (PET) fibers. In this paper, two amide monomers, the adipate pentamethylenediamine salts (APs) and its end‐capping substances (APA), were used as the modified monomers to prepare copolymers (PET/APs, PET/APA) by copolymerization with PTA and EG. Their chemical structures and compositions were confirmed by 1H‐NMR and 13C‐NMR. Copolymers exhibited excellent melt fluidity and a lower glass transition temperature than PET due to the incorporation of flexible segments, and the properties of copolymer PET/APA was more evident than PET/APs. The copolymer fibers were prepared by melt spinning, exhibiting excellent hygroscopicity, softness, and antistatic properties. The moisture regain of PET/APs fibers increased by 39% ~ 200%, and the initial modulus decreased by 32% ~ 68% than PET fibers; the moisture regain of PET/APA fibers increased by 53% ~ 213%, and the initial modulus decreased by 50% ~ 72% than PET fibers. Which was proportional to the content of modified monomers, and the soft handle was closed to wool fibers. Moreover, PET/APA fibers exhibited better hygroscopicity and softness properties than PET/APs fibers, and the excellent yellow index (b value) by adopting end‐capping technology, which broaden the application prospects of PET fibers.