Bicomponent Spinning of Biodegradable Polymers: Melt-Spun PHBV Micro Fibers

Biodegradable polymers have gained lots of interest and publicity. Polyhydroxyalkanoates (PHAs) are a member of biodegradable thermoplastic polyesters, biologically derived by bacterial fermentation. These biodegradable, compostable and biocompatible polymers are of great interest in the production of medical textiles, disposable materials and packaging. However, slow crystallization rate and low thermal stability of PHAs limits the melt spinning of fibers and results in inadequate mechanical properties. In this study, two biodegradable polymers were coaxially combined in a spinneret for bicomponent fiber production with islands-in-the-sea geometry. The co-extrusion of a poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate) (PHBV) as the island polymer and a polyvinyl alcohol (PVA) as the sea polymer having a higher thermal stability and faster crystallization enabled the stable winding of filaments. Following the filament production, the filaments were soaked in distilled water to remove the PVA sea polymer and PHBV micro fibers were obtained. Thermal analysis revealed that the complete removal of PVA was possible. Microscopic analysis showed that PHBV microfilaments (single filament diameter < 7 mu m) have been successfully melt-spun.