Dyeing Behavior and Multi-Functionalities of Polylactide/Poly (Ethylene Terephthalate) Conjugate Fibers Produced by High-Speed Melt-Spinning

• Published in: Journal of macromolecular science. Physics Vol. 60; no. 1; pp. 63 - 75
• Main Authors: Kawahara, Yutaka, Takarada, Wataru, Takeda, Koji, Ikeda, Yoshimitsu, Onda, Kouki, Kikutani, Takeshi
• Format: Journal Article
• Language: English
• Published: New York Taylor & Francis 16.09.2020; Marcel Dekker, Inc
• Subjects: bacteriostatic activity; Biofilms; conjugate fibers; Conjugates; Crystallization; Dyes; Fibers; Fibrils; Glass transition temperature; High speed; high-speed melt-spinning; Melt spinning; multi-functionalities; Nonwoven fabrics; poly(ethylene terephthalate); Polyethylene; Polyethylene terephthalate; Polylactic acid; polylactide; Pressurized water; Sheaths; Sliding friction; Transition temperatures; Water baths
• ISSN: 0022-2348; 1525-609X
• DOI: 10.1080/00222348.2020.1819665

Various types of conjugate fibers comprised of polylactide (PLA) and polyethylene terephthalate (PET), with their blend in the sheath, PET as the core, were produced by high-speed melt-spinning. Due to the higher glass transition temperature of PET, the orientation-induced crystallization only occurred in the PET core. The crystalline and continuous PET core of the conjugate fibers effectively suppressed the shrinkage during dyeing, even in a pressurized water bath at 130 °C comparable to the commercial level, to less than 5% while achieving a color strength higher than 15. Post-annealing in the restrained mode could effectively cause the fine PET fibrils embedded in the sheath to rise out from the surface of the fibers during dyeing by the sliding friction force between the fibers. The PET fibrils rising out from the sheath were strong enough and showed an entangling behavior which would be useful to fabricate non-woven fabrics. The amorphous PLA domains exposed on the fiber surface showed the bacteriostatic activity valuable for the inhibition of the formation of biofilms.