Fibers with good flame retardant (FR) and smoke suppression performances are highly desirable for the purpose of eliminating fire hazard. This study developed a novel FR fiber by wet-spinning poly (vinyl alcohol)/β-cyclodextrin (PVA/βCD) composite fiber and crosslinking it with hexamethylene diisocyanate (HDI). βCDs showed good compatibility with PVA matrix, and the resulting PVA/CD/HDI fibers showed mechanical strength at the same level as natural cotton fiber. The PVA/CD/HDI fibers also showed excellent flame retardance (the LOI value of PVA/CD/HDI could reach 41.7%, and their peak of heat release (PHRR) could be reduced by up to 77.7% by neat PVA), and super-smoke suppression (the value of total smoke production (TSP) was only 28.6% compared to PVA). These dramatic reductions of fire hazard were ascribed to the char formation of βCD and crosslinking structure of PVA/CD/HDI, which formed a compact char layer during combustion, thus preventing heat transmission and smoke release.

Poly (vinyl alcohol)/β-cyclodextrin (PVA/CD) composite fibers are prepared by wet spinning followed by hot stretching. XRD results show that β-CDs are in an amorphous state in fiber, and β-CD can help maintain the fibrous crystal that exists in the composite fiber. The DSC results show that the total crystalline ratio of the composite fibers decreased with the increase of β-CD. The as-prepared composite fibers were further crosslinked with glutaraldehyde (GA) to improve their usability. The crosslinked structure, together with amorphous β-CD, contributes to the loading and sustained release of fragrance molecules that were studied. The fragrance retention ratio of PVA/CD/GA is 55.63% and 48.25% for cis-jasmone and citronella, even after 25 days. The inclusion complexes of β-CD and fragrance molecules are confirmed by 2D-FTIR, which is responsible for the sustained release of fragrance. This study may contribute to the mass production of wearable long-term scented fabrics.