High-Speed Melt Spinning of New Biodegradable Polymers
Gerhilt Schmack, Bernhard Tändler, Roland Vogel
Institute for Polymer Research Dresden (IPF Dresden)
Germany
Keywords: high speed melt spinning, biodegradable , fibers
Biodegradable polymers were pushed into public interest, as the rapidly expanding production and the use of plastic materials created massive problems in the area of waste disposal. Hence comprehensive waste management concepts were recognized as chance for a stronger commercial exploitation of biodegradable polymers and with it for materials, which are biodegradable under composting and landfilling conditions in a reasonable short period of time. The present study was undertaken to investigate the spinnability of new biodegradable polymers by a high-speed spinning process, because the fiber-forming process is of general importance in many potential textile technological applications, especially also for nonwoven materials. Different kinds of polylactides (PLA), synthesized on the basis of renewable resources, biotechnologically generated poly(3-hydroxybutyrate) (PHB) and synthetically generated polymers (PEA, PTAT) were subjected to melt spinning experiments within the range of 2,000 - 6,000 m/min. The PLA types differed in addition to the different D lactide contents and different tacticity, in molecular mass and molecular mass distribution. As biodegradable synthetic polymers a polyesteramid (PEA) based on adipic acid, 1,4 butanediol, 1,6 hexanediamine, and diethoxyether and a copolyester (PTAT) on the basis of polybutylenadipat-co-terephthalat were used. The polymers were characterized with regard to their thermal, rheological, and molecular properties by the methods of thermogravimetry (TG), differential scanning calorimetry (DSC), and dynamic rheological measurements (DMA) to derive suitable parameters for the high-speed melt spinning process. Effects of different polymers and melt spinning conditions on the development of a structural hierarchy of the fibers, on the orientation and crystallinity in the filaments were determined and the physical properties of the fibers: degree of crystallinity, birefringence, E-modulus, elongation at break, and tenacity were characterized. The fibers are biodegradable in accordance with DIN 54 900.