The effects of high‐speed melt spinning and spin drawing on the structure and resulting properties of bacterial generated poly(3‐hydroxybutyrate) (PHB) fibers were investigated. The fibers were characterized by their degree of crystallinity by differential scanning calorimetry (DSC) and wide‐angle X‐ray scattering (WAXS), their orientation by WAXS, and the textile physical properties. The WAXS studies revealed that the fibers spun at high speeds and high draw ratios possessed orthorhombic (α modification) and hexagonal (β modification) crystals, the latter as a result of stress‐induced crystallization. The fiber structures formed during these processes were fibril‐like as the atomic force microscopy images demonstrated. The maximum physical break stress, the modulus, and the elongation at break observed in the fibril‐like spin drawn fibers were about 330 MPa, 7.7 GPa, and 37%, respectively. The fibers obtained by a low draw ratio of 4.0 had spherulitic structures and poor textile physical properties. The PHB pellets were analyzed by their degradation during the processes of drying and spinning and by their thermal and rheological properties. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2841–2850, 2000

This paper reports on an attempt to use CD and CD/PHB ICs as nucleation agents for PHB in a high-speed melt spinning process. At first rheological and thermal properties of the nucleated melts are determined in order to assess the influence of the nucleating agents. Then spinning tests are carried out. Thermal and textile properties of the spun PHB fibers are also determined. An estimation of the improvement of inhibition of the secondary crystallization from use of the described blood compatible nucleating agents is given.

Five kinds of polylactides (PLAs), with different d-lactide contents and tacticities, were subjected to high-speed melt-spinning experiments. In addition to stereochemical purity, the PLA types differed in molecular mass and molecular mass distribution. The properties of the different PLA materials were characterized by thermogravimetry, differential scanning calorimetry, dynamic mechanical analysis, size exclusion chromatography, and 1 H-NMR and 13 C-NMR spectroscopy. The material was spun with a highspeed spinning process within the range 2000 -5000 m/min. The physical and tensile properties of the fibers were determined. The maximum tensile properties of the fibers were a 300 MPa tenacity at an elongation at break of 30% and a tensile modulus of 6.8 GPa.

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A polylactide (PLA type LA 0200 K) was spun in high-speed melt spinning and spin drawing processes. The fibers were characterized with regard to the degree of crystallinity, the orientation, and the textile physical properties. The polymer was produced by a reactive extrusion polymerization process, and its hydrolytic degradation during the processes of drying and spinning and its thermal and rheological properties were characterized.