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指導教授：王振乾 教授 學 生：蕭詠方

指導教授：王振乾 教授 學 生：蕭詠方. Introduction. PLLA 與 PES 均為生物可降解半結晶聚酯，其結構式分別為 -[CH(CH 3 )COO] n - 及 -[OCH 2 CH 2 O 2 CC 2 H 4 CO] n - PLLA 的機械性質差 ( 硬、脆 ) 、結晶速率慢，因此限制了其應用； PES 具良好的機械性質，特別是斷裂延伸率。因此，期盼混摻 PES 後能改善 PLLA 的機械性質及結晶速率。. Experimental. PLLA. PES. (Mw=177,000). (Mw=213,000). 溶於氯仿.

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指導教授：王振乾 教授 學 生：蕭詠方

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  1. 指導教授：王振乾 教授 學 生：蕭詠方

  2. Introduction • PLLA與PES均為生物可降解半結晶聚酯，其結構式分別為-[CH(CH3)COO]n- 及 -[OCH2CH2O2CC2H4CO]n- • PLLA的機械性質差(硬、脆)、結晶速率慢，因此限制了其應用；PES具良好的機械性質，特別是斷裂延伸率。因此，期盼混摻PES後能改善PLLA的機械性質及結晶速率。

  3. Experimental PLLA PES (Mw=177,000) (Mw=213,000) 溶於氯仿 溶於氯仿 PLLAsolution PESsolution PLLA/PES 100/0 80/20 60/40 40/60 20/80 0/100 置入培養皿 室溫下(一天)蒸發掉溶劑 真空烘箱50 ℃(三天)溶劑完全移除

  4. Results and discussion 熔至190 ℃ 急速冷卻至-70 ℃ 無定型態 20 ℃/min 升溫 Tg Tch Tm PLLA PES Tch Tg 混摻PES後可提升PLLA的結晶度 PLLA與PES為不可溶混 Tm Fig. 1. DSC traces of PLLA/PES blends at 20 ℃ /min after quenching from the melt at 100 ℃ /min.

  5. Results and discussion 20 ℃ /min 升溫 PLLA會抑制PES結晶 PLLA Tm PES Tm Fig. 2. Melting behavior of PLLA/PES blends at 20 ℃ /min for the as castsamples.

  6. Results and discussion Fig. 3. Spherulitic morphology of neat PLLA (same magnification, bar =100 mm) at different crystallization temperatures: (a) 110, (b) 115, (c) 120, and(d) 125 ℃.

  7. Results and discussion Maltese cross Fig. 4. Spherulitic morphology of neat PES (same magnification, bar =100 mm) at different crystallization temperatures: (a) 55, (b) 60, (c) 65, and (d) 70 ℃.

  8. Results and discussion 2.27 μ m/min PES球晶成長速率較PLLA快 線性成長 接觸到其它球晶 接觸到其它球晶 0.973 μ m/min Fig. 5. Temperature dependence of spherulitic growth rates of neat PLLA and neat PES.

  9. Results and discussion 5 ℃ /min 降溫 混摻20%的PES ，會抑制PLLA的結晶；混摻40%以上的PES ，PLLA結晶峰消失。 62.9 ℃ PLLA/PES混摻，些微抑制PES的結晶，但仍保有PES相的結晶。 57.5 ℃ PES含量太少 94.2 ℃ 99.8 ℃ (Tc) Fig. 6. DSC traces of PLLA/PES blends cooled from the melt at 5 ℃ /min.

  10. Results and discussion Isothermalcrystallization PLLA/PES混摻，發現PLLA結晶速率較純PLLA快 Fig. 7. (a) Plots of relative crystallinity of PLLA crystallized at 100 ℃ versuscrystallization time for PLLA/PES blends

  11. Results and discussion Avrami equation n：成核機制 k：結晶速率常數 Fig. 7.(b) the Avrami plots of PLLA/PES blends crystallized at 100 ℃.

  12. Results and discussion isothermal crystallization of PLLA from the melt at 100 ℃ and the isothermal crystallization of the PES at 67.5 ℃ from the liquid phase in the presence of previously crystallized PLLA. 混摻PES後，不改變PLLA的結晶機制 混摻PES後，提升PLLA的結晶速率 相分離區域提供了有利的結晶成核點 PES的結晶型態不受混摻PLLA後影響 隨PLLA含量增加，PES結晶速率變慢 相分離區域存在PLLA的結晶

  13. Results and discussion PLLA與PES混摻後會各自結晶，不會改變晶體結構。 16.31 ° (PLLA) 18.55 ° (PLLA) 20.8 ° (PES) 23.23 ° (PES) Fig. 8. WAXD patterns of PLLA/PES blends.

  14. Results and discussion 混摻PES進而改善PLLA的脆性 高模數、脆性材料 Fig. 9. Tensile testing results of PLLA/PES blends.

  15. Results and discussion (a) 純PLLA– 表面光滑 (脆性斷裂) (b) PLLA/PES (80/20) –(不可溶混)PES均勻分散於PLLA基材中 (c)(d)(e) 增加PES含量 兩連續相 有效提升PLLA的機械性質 (脆 延展性) (f) 純PES– 表面粗糙 (韌性) Fig. 10. SEM images of the fracture surfaces of PLLA/PES blends after tensile testing: (a) 100/0, (b) 80/20, (c) 60/40, (d) 40/60, (e) 20/80, and (f) 0/100.

  16. Conclusions • PLLA/PES混摻分別顯示其各自熔點 (Tm) ，表示為不可溶混系統。 • 熔融淬火樣品，混摻PES可提升PLLA的結晶度，而PES結晶度變化不大。 • 恆溫結晶結果發現，混摻後，PLLA與PES兩者的結晶機制不改變；隨PES含量增加，PLLA的結晶速率加快，而PES結晶速率變慢。

  17. Conclusions • 由拉伸測試發現，混摻PES 能有效提升PLLA的斷裂延伸率且仍保有相當的模數。 • SEM顯示，PLLA/PES混摻，由脆性斷裂轉變為韌性斷裂。

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