Effect of in vitro hydrolysis on the compressive behavior and strain rates dependence of tricalcium phosphate/poly(L-lactic acid) composites
Effect of in vitro hydrolysis on the compressive behavior and strain rates dependence of tricalcium phosphate/poly(L-lactic acid) composites
复制标题
体外水解对磷酸三钙/聚（L-乳酸）复合材料压缩行为和应变率依赖性的影响
DOI：
10.1080/09243046.2012.760437
复制
发表时间：
2013
影响因子：
2.9
通讯作者：
Satoshi Kobayashi
中科院分区：
文献类型：
--
作者：
Shusaku Yamaji;Satoshi Kobayashi
生物活性陶瓷/生物可吸收塑料复合材料具有比整体式生物可吸收塑料更好的生物相容性，有望成为骨折内固定材料。研究了应变速率对聚L-乳酸（PLLA）和磷酸三钙/聚L-乳酸（TCP/PLLA）复合材料力学性能的影响。TCP/PLLA复合材料含有三种不同的TCP含量（5、10和15重量%），通过注射成型制备。然后将制造的试样浸入模拟的身体环境中，例如磷酸盐缓冲溶液（pH = 7.4），以研究水解对机械性能的影响。为了表征力学性能，在应变速率范围为10 - 3至10 - 1/s的条件下进行了压缩试验。未退火的PLLA和TCP/PLLA复合材料的初始分子量（Mw）为约173，000和154，000。浸泡24周后，Mwof 15 wt.%下降到91000。在这些测试的结果中，TCP/PLLA复合材料表明，它们的杨氏模量没有依赖于应变速率和它们的压缩强度随着应变速率的增加而增加。浸泡16周后，抗压强度为15重量%复合材料在10 - 1/s的应变速率下略有下降。浸泡24周后，5、10和15重量%的抗压强度复合材料下降。
Bioactive ceramics/bioresorbable plastic composites have been expected as materials for the fracture fixations which have more biocompatibility than monolithic bioresorbable plastics. In this study, effects of strain rate on the mechanical properties of poly(L-lactic acid) (PLLA) and tricalcium phosphate/Poly(L-lactic acid) (TCP/PLLA) composites specimens were investigated experimentally. The TCP/PLLA composites containing three different TCP contents (5, 10 and 15 wt.%) were prepared by injection molding. The fabricated specimens were then immersed in the simulated body environment, such as phosphate buffered solution (pH = 7.4), to investigate effects of hydrolysis on the mechanical properties. In order to characterize the mechanical properties, compressive tests were performed at the strain rates ranging from 10−3to 10−1/s. Initial molecular weights (Mw) of non-annealing PLLA and TCP/PLLA composites were approximately 173,000 and 154,000. After 24 weeks immersion,Mwof 15 wt.% decreased to 91,000. In the results of these tests, TCP/PLLA composites showed that their Young’s modulus has no dependence on the strain rate and their compressive strength increased with increasing strain rates. After 16 weeks immersion, compressive strength of 15 wt.% composites decreased slightly at a strain rate of 10−1/s. After 24 weeks immersion, compressive strength of 5, 10, and 15 wt.% composites decreased.