Failure of elastic-plastic core-shell microcapsules under compression
Failure of elastic-plastic core-shell microcapsules under compression
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DOI：
10.1002/aic.12804
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发表时间：
2012-09-01
期刊：
影响因子：
3.7
通讯作者：
Goodwin, Ted E.
中科院分区：
文献类型：
--
作者：
Mercade-Prieto, Ruben;Allen, Rachael;Goodwin, Ted E.
表征微胶囊的失效行为对于控制其核心活性物质通过机械力的释放是极其重要的。利用有限元模型和微操作压缩实验，确定了弹塑性未膨胀核壳微胶囊在失效（破裂或爆裂）时的应变和应力。聚合物微胶囊在高变形下的延性破坏被认为是当壳中的最大应变超过临界应变时发生的，导致其破裂。有限元法已被用来确定胶囊壁中存在的最大应变在不同的变形为三种类型的外壳材料：弹性，elasticperfectly plastic和elasticperfectly plastic与应变硬化在大应变。所得结果用于确定三聚氰胺-甲醛微胶囊的破坏应变和应力，平均群体值分别类似于0.48和类似于350 MPa。因此，已经确定了所测试的芯壳微胶囊的弹塑性应力-应变关系。(c)2011美国化学工程师学会AIChE J，2012
Characterization of the failure behavior of microcapsules is extremely important to control the release of their core actives by mechanical forces. The strain and stress of elastic-plastic uninflated coreshell microcapsules at failure (rupture or bursting) has been determined using finite element modeling (FEM) and micromanipulation compression experiments. The ductile failure of polymeric microcapsules at high deformations is considered to occur when the maximum strain in the shell exceeds a critical strain, resulting in their rupture. FEM has been used to determine the maximum strains present in the capsule wall at different deformations for three types of shell material: elastic, elasticperfectly plastic and elasticperfectly plastic with strain hardening at large strains. The results obtained were used to determine the failure strain and stress of melamine-formaldehyde microcapsules, with average population values of similar to 0.48 and similar to 350 MPa, respectively. Thus, the elastic-plastic stressstrain relationship has been determined for the coreshell microcapsules tested. (c) 2011 American Institute of Chemical Engineers AIChE J, 2012