Accelerated hydrolytic degradation of Poly(L-lactide)/Poly(D-lactide) stereocomplex up to late stage
Accelerated hydrolytic degradation of Poly(L-lactide)/Poly(D-lactide) stereocomplex up to late stage
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DOI：
10.1016/j.polymdegradstab.2010.01.008
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发表时间：
2010-04-01
影响因子：
5.9
通讯作者：
Tsuruno, Tomonori
中科院分区：
文献类型：
--
作者：
Tsuji, Hideto;Tsuruno, Tomonori
以乙腈为溶剂，通过溶液结晶法制备了仅含立体配合物的聚l -丙交酯(PLLA)/聚d -丙交酯（PDLA）共混样品以及纯PLLA和纯PDLA样品。在磷酸盐缓冲溶液中，在70-97℃的高温下进行加速水解降解，直至后期。在水解降解过程中，首先用凝胶渗透色谱法对立体角络合物晶体残基进行了追踪。与纯PLLA和PDLA样品的水解降解相似，立体络合PLLA/PDLA共混样品的水解降解在后期减慢，此时大部分非晶态链被去除，晶位形成并降解。预估的立体角络合物晶体残基水解降解活化能（97.3 kJ mol(-1)）明显高于α形式PLLA晶体残基的75.2 kJ mol（-1）。这表明立体络合物晶体残基比α型PLLA晶体残基具有更高的抗水解能力。(C) 2010 Elsevier Ltd.版权所有。
Poly(L-lactide) (PLLA)/poly(D-lactide) (PDLA) blend specimens containing only stereocomplex as crystalline species, together with those of pure PLLA and PDLA specimens, were prepared by solution crystallization using acetonitrile as the solvent. Their accelerated hydrolytic degradation was carried out in phosphate-buffered solution at elevated temperatures of 70-97 degrees C Up to the late stage. During hydrolytic degradation, the stereocornplex crystalline residues were first traced by gel permeation chromatography. Similar to the hydrolytic degradation of pure PLLA and PDLA specimens, the hydrolytic degradation of stereocomplexed PLLA/PDLA blend specimens slowed down at the late stage when most of the amorphous chains were removed and crystalline resides were formed and degraded. The estimated activation energy for hydrolytic degradation of stereocornplex crystalline residues (97.3 kJ mol(-1)) is significantly higher than 75.2 kJ mol(-1) reported for alpha-form of PLLA crystalline residues. This indicates that the stereocomplex Crystalline residues showed the higher hydrolysis resistance compared to that of alpha-form of PLLA crystalline residues. (C) 2010 Elsevier Ltd. All rights reserved.