열처리 조건이 PLLA SDY 섬유의 열적 특성 및 물성에 미치는 영향

초록

Poly(L-lactic acid) (PLLA) filament fibers were prepared by one-step melt spinning process with spin drawing and the effects of the annealing at 100 ℃ and 120 ℃ on their thermal and mechanical properties were investigated by using a differential scanning calorimeter (DSC), dynamic mechanical analyzer (DMA), and universal testing machine (UTM). The glass transition temperature (Tg) of the PLLA spin draw yarn (SDY) fibers increased with increasing annealing time while the melting temperature (Tm) remained unaffected. The birefringence increased with increasing time at both 100 ℃ and 120 ℃, indicating the enhanced orientation of the polymers in the fiber. The tenacity of the fibers increased to almost double, while the elongation at break decreased to almost half by 5 minutes annealing at both 100 ℃ and 120 ℃. However, annealing time of more than 5 minutes did not affect the tenacity and elongation at break. The boiling water shrinkage (BWS) decreased continuously with increasing time, the increment was larger for the annealing at 120 ℃ than that at 100 ℃. A BWS of less than 3% was obtained by annealing at 120 ℃ for 30 minutes.

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