Effect of Polymer Infiltration on the Flexural Behavior of β-Tricalcium Phosphate Robocast Scaffolds.
Effect of Polymer Infiltration on the Flexural Behavior of β-Tricalcium Phosphate Robocast Scaffolds.
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DOI：
10.3390/ma7054001
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发表时间：
2014-05-21
期刊：
影响因子：
--
通讯作者：
Miranda P
中科院分区：
文献类型：
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作者：
Martínez-Vázquez FJ;Pajares A;Guiberteau F;Miranda P
分析了聚合物浸润对机器人铸造（直写装配）制备的β-磷酸三钙（β-TCP）支架抗弯强度和韧性的影响。通过在聚合物熔体中浸渍生物可降解聚合物（聚乳酸（PLA）和聚ε-己内酯（PCL）），制备了由互穿棒组成的四边形三维晶格的多孔结构。浸润使这些模型支架的抗弯强度增加了5倍（PCL）或22倍（PLA），这一增强幅度远远大于模拟材料的抗压强度。由于与陶瓷棒表面前驱体缺陷密封相关的强化程度应保持不变，因此在这种恳求下，更有效地将应力传递到聚合物，从而使弯曲强度得到了更大的提高。任何一种聚合物的浸渍也比压缩进一步提高了支架的断裂能（提高了两个数量级以上）。这种增加与浸渍提供的非凡强化和聚合物原纤维产生的裂缝桥接增韧机制有关。
The influence of polymer infiltration on the flexural strength and toughness of β-tricalcium phosphate (β-TCP) scaffolds fabricated by robocasting (direct-write assembly) is analyzed. Porous structures consisting of a tetragonal three-dimensional lattice of interpenetrating rods were impregnated with biodegradable polymers (poly(lactic acid) (PLA) and poly(ε-caprolactone) (PCL)) by immersion of the structure in a polymer melt. Infiltration increased the flexural strength of these model scaffolds by a factor of 5 (PCL) or 22 (PLA), an enhancement considerably greater than that reported for compression strength of analogue materials. The greater strength improvement in bending was attributed to a more effective transfer of stress to the polymer under this solicitation since the degree of strengthening associated to the sealing of precursor flaws in the ceramic rod surfaces should remain unaltered. Impregnation with either polymer also improved further than in compression the fracture energy of the scaffolds (by more than two orders of magnitude). This increase is associated to the extraordinary strengthening provided by impregnation and to a crack bridging toughening mechanism produced by polymer fibrils.