High-strength poly(L-lactide) fibers by a dry-spinning/hot-drawing process. I. Influence of the ambient temperature on the dry-spinning process

Variation of the ambient temperature of the spinline during dry spinning of PLLA solutions induced variation of the extrudate swell of the spinline, affected by the rate of solidification of the PLLA. By way of phase separation, porous filaments were achieved in which the morphology depended on the applied ambient temperature. Hot drawing of these filaments led to tensile strengths varying between 1.1 and 2.2 GPa. An optimal tensile strength of 2.2 GPa was achieved by hot drawing of a filament which was spun into a surrounding of 25 o C