Alkaline Hydrolysis of Solution-Grown Poly(L-lactic acid)Single Crystals (バイオ材料特集号)
Alkaline Hydrolysis of Solution-Grown Poly(L-lactic acid)Single Crystals (バイオ材料特集号)
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溶液生长聚（L-乳酸）单晶的碱性水解（生物材料特刊）
DOI：
10.2115/fiber.57.172
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Y. Doi
中科院分区：
文献类型：
--
作者：
T. Iwata;Y. Doi
采用透射电镜、原子力显微镜和凝胶渗透色谱等方法研究了溶液生长的聚L-乳酸（PLLA）单晶在不同浓度NaOH水溶液中的形态和结晶状态的变化。六方和菱形PLLA单晶在水解初期从晶体侧面开始降解，形成缺口形貌。随着水解的进行，降解的PLLA晶体的分子量对应于等于从原子力显微镜测量的片层厚度计算的值，这表明晶体表面上的PLLA分子的紧链折叠区域被碱水解降解。结果表明，NaOH溶液的碱解反应首先发生在晶体边缘的松散链堆积区，然后从晶体边缘和紧密链堆积区逐渐进行，并在晶体表面发生链折叠。
The changes in morphology and crystalline state of solution-grown single crystals of poly(L-lactic acid)(PLLA) in aqueous NaOH solution of various strengths were investigated by means of transmission electron microscopy, atomic force microscopy and gel permeation chromatography. The degradations of hexagonal and lozenge shaped PLLA single crystals started from the lateral side of the crystal to generate the notched morphology at initial stage of hydrolysis. As hydrolysis proceeded, the molecular weight of degraded PLLA crystals corresponded to equal the value calculated from lamellar thickness measured by atomic force microscopy, suggesting that the tight chain-folding region of PLLA molecules on crystal surface was degraded by alkaline hydrolysis. Based on the results, alkaline hydrolysis with NaOH solution firstly occurs at the loosely chain-packing region on crystal edges, and then gradually progresses from both crystal edges and tight chain-packing region with chain-folding on the crystal surface.