雙向延伸聚(L-乳酸)薄膜於不同熱處理過程後的 氣體滲透性能。

Gas Permeation Properties of Biaxial Orientated Poly(L-lactic acid) Films

林靖淵(Jing-Yuan Lin)

指導教授 ： 孫一明

元智大學/工程學院/化學工程與材料科學學系/碩士(2011年)

https://doi.org/10.6838/YZU.2011.00144

摘要

本研究探討雙向延伸聚(L-乳酸)（BOPLLA）薄膜於不同熱處理
過程後的晶體結構、自由體積與氣體滲透性能。利用雙向延伸(逐步
與同步)處理主要目的為了使高分子鏈的排列具有方向性，在利用不
同熱處理的特性，改變薄膜的結晶結構與自由體積特性。研究中使用
廣角度X光散射（WAXD）與小角X光散射（SAXS）鑑定晶體結構分
析與型態、利用正子消散時間光譜儀（PALS）技術測試薄膜內自由
體積的變化與利用固定體積變壓之氣體滲透量測設備與時間滯留法
決定氣體於薄膜內的輸送性質（滲透、擴散與溶解度）。
結果顯示雙向延伸聚乳酸（BOPLLA）薄膜在退火溫度超過
130℃時，結晶結構會有α′- and α-form 結晶的改變。增加熱處理溫度
增加 BOPLLA 結晶度與規則區尺寸大小卻降低自由體積，但氣體是
無法穿過結晶區，是利用非結晶區裡面的自由體積通過，使氣體滲透
性下降。

關鍵字

雙向延伸聚(L-乳酸)（BOPLLA），滲透性，正子消散時間光

並列摘要

The relationships among chain orientation, crystalline structure, crystallinity, free
volume properties, and gas permeation properties of biaxial oriented poly(L-lactic
acid) (BOPLLA) films were discussed in this study. The BOPLLA films were
obtained from various treatments such as simultaneous and sequential biaxial
stretching and then annealing with different lengths of time at 100, 130, or 160 oC,
respectively.
The crystal structure, lamellar behavior, and free volume properties of BOPLLA
films were determined by wide angle X-ray diffraction (WAXD), small-angle X-ray
scattering (SAXS), and Positron Annihilation Lifetime Spectroscopy (PALS),
respectively. The oxygen gas permeability, diffusivity, and solubility were determined
with a constant-volume variable-pressure permeation apparatus and the time-lag
method. The results of WAXD indicated that increasing the annealing temperature and
time will result in the increasing of crystallinity of BOPLLA. However, the in situ
SAXS results from NSRRC revealed that the lamellar thickness of PLLA was
maintained about the same as the annealing temperature increased from 100 to 130oC,
and a rapid increased from 130 to 160oC possibly due to the α’- to α-form transition in
the crystalline lattices. The α’- to α-form transition behavior can be also observed in
the WAXD results of various films.
IV
In addition, the gas barrier property of the sequentially BOPLLA films is better
than that of the simultaneously ones due to the orientated crystalline structure and
higher crystallinity. The free volume properties obtained by PALS can generally
explain the trend of oxygen diffusion coefficient of BOPLLA films prepared with
various processing conditions.

並列關鍵字

Biaxial oriented poly(L-lactic acid) (BOPLLA) ； permeation properties

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