Development of Circularly Recyclable Low Melting Temperature Bicomponent Fibers toward a Sustainable Nonwoven Application

Abstract

Sustainable low melting temperature bicomponent polyester fibers that can be circularly recycled were developed. The potentially biobased poly(hexamethylene terephthalate) (PHT), acting as the low melting temperature sheath material in the designed bicomponent fibers, was synthesized in a pilot scale. The obtained PHT with an intrinsic viscosity of 0.47 dL/g showed suitable processability when it was processed together with a poly(butylene terephthalate) (PBT) core in a melt-spinning process of bicomponent fibers. Compared with the commercial low melting temperature terephthalate−isophthalate copolyester LMP-160, PHT showed superior mechanical properties according to DMA analysis. The low melting temperature bicomponent fibers with a ratio of the PBT core and PHT sheath at 70:30 were produced smoothly at 290 °C in a pilot melt-spinning line. Preliminary chemical recycling investigations by methanolysis revealed that PHT/PBT bicomponent fibers were completely depolymerized within 2 h at 200 °C, yielding pure terephthalate, which could be conveniently separated and recycled. This indicated the feasibility of circular recycling, which will greatly improve the sustainability of nonwovens thermally bonded by these new bicomponent fibers.

Biocompatible non-leachable antimicrobial polymers with a nonionic hyperbranched backbone and phenolic terminal units

“…Poly(hexamethylene terephthalate) (PHT, M n ∼ 13 kDa, M w ∼ 21 kDa) was selected as the matrix for leaching investigations, which is softer than PET and suitable for various applications, 84–86 particularly bicomponent fibres in nonwoven textiles. 87 Another potential advantage of PHT is that it is synthesized using 1,6-hexanediol, which could be readily produced from various bio-resources. 88,89 In this work, PHT powder was synthesized according our previously reported procedure.…”

Upcycling Waste Polycarbonate to Poly(carbonate imine) Vitrimers with High Thermal Properties and Unprecedented Hydrolytic Stability

“…Recycling of waste polymers has been extensively reported for sustainability. − Also, the use of biobased monomers − in the synthesis of high-performance thermoplastics, − thermosets, − vitrimers, − and other polymers , has been extensively reported and reviewed by Zeng et al and Rana et al Among several biobased monomers, vanillin is readily accessible because it holds two active functional groups (hydroxyl and aldehyde) at the para position of phenylene. Thermosets, due to their highly cross-linked structures, are not easy to recycle as they cannot be melted and reprocessed.…”

A Rapid Quantitative Analysis of Bicomponent Fibers Based on Cross-Sectional In-Situ Observation

“…Bicomponent fibers are widely used in functional protective textiles, filter materials, and biomedical materials owing to their unique elastic, fluffy, multifunctional features and super-clean properties [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. In addition, many scientists have focused on various fiber-based flexible devices.…”