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·428· 精细化工 FINE CHEMICALS 第 36 卷
拉伸、打结、扭转等一系列的变形。考虑到离子键 MA。对于 AAc 和 IA 体系,当—COO 含量为 25%,
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的动态特点,研究了水凝胶的自愈合特性,结果如 并且 n(Fe )∶n(—COO )=8∶1 时,水凝胶拉伸强度
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图 8d~g 所示。将制备好的 DN 水凝胶用手术刀切成 达到最大值,当 n(Fe )∶n(—COO )<8∶1 时水凝胶
两部分(图 8d),对接用保鲜膜裹住防止水分流失。 交联网络结构不完善,高于 8∶1 时交联过于致密。
放置 16 h 后可以看到虽然凝胶样条被宏观破坏,但
参考文献:
是界面之间的接触将使水凝胶自发愈合(图 8e)。
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这表明凝胶体系中游离的 Fe 可以运动和迁移,从 [1] Vlierberghe S, Dubruel P, Schacht E. Biopolymer-based hydrogels as
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合行为 。从图 8e 可以看出,愈合后的水凝胶可以 [2] Lin C, Metters A. Hydrogels in controlled release formulations:
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络水凝胶网络结构不均一,因此强度较低;而 Ca 、 [14] Tobolsky A, Carlson D, Indictor N. Rubber elasticity and chain
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Fe 、Cu 与—COO 双齿鳌合,网络结构均一性提 [15] Gao Tingting (高婷婷), Li Zhiying (李志英), Gao Ge (高歌), et al.
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高,网络尺寸减小,强度有所提高;Fe 与—COO Mechanical strength and swelling behavior of fatty alcohol
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(3)Fe 与羧基形成离子键存在依时性,随着 203-212.
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其有效交联密度 v 0 较大,因此水凝胶力学性能优于 86-87.