• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Polymers and the Environment >PLA and Organoclays Nanocomposites: Degradation Process and Evaluation of ecotoxicity Using Allium cepa as Test Organism
【24h】

PLA and Organoclays Nanocomposites: Degradation Process and Evaluation of ecotoxicity Using Allium cepa as Test Organism

机译：PLA和有机粘土纳米复合材料：降解过程和以洋葱为原料的生态毒性评估

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In this study, nanocomposites of PLA and organoclays Cloisite 20A and Cloisite 30B were prepared by the melt intercalation method and the obtained samples were characterized by transmission electron microscopy (TEM). Since composting is an important proposal to the final disposal of biopolymers, the influence of clays on the hydrolytic degradation process of PLA was evaluated by visual analysis and monitoring of molecular weight after periods of 15 and 30 days of degradation in compost. After degradation of the materials in composting environment, the evaluation of cytotoxic, genotoxic and mutagenic effects of compost aqueous extract was carried out using a bioassay with Allium cepa as test organism. The TEM micrographs permitted the observation of different levels of dispersion, including exfoliated regions. In the evaluation of hydrolytic degradation it was noted that the presence of organoclays can decrease the rate of degradation possibly due to the barrier effect of clay layers and/or the higher degree of crystallinity in the nanocomposite samples. Nevertheless, even in the case of nanocomposites, the molecular weight reduction was significant, indicating that the composting process is favorable to the chain scission of PLA in studied materials. In the analysis performed by the bioassay using A. cepa as test organism, it was found that after degradation of the PLA and its nanocomposites the aqueous extract of compost samples induced a decreasing in the mitotic index and an increasing in the induction of chromosomal abnormalities. These results were statistically significant in relation to the negative control (distilled water). By comparing the results obtained for the nanocomposites in relative to pure polymer, there were no statistically significant differences. The types of the observed chromosomal aberrations indicated a possible genotoxic effect of the materials, which may be related to an aneugenic action of PLA degradation products.
机译：本研究采用熔融插层法制备了PLA与有机粘土Cloisite 20A和Cloisite 30B的纳米复合材料，并对所得样品进行了透射电子显微镜（TEM）表征。由于堆肥是最终处置生物聚合物的重要建议，因此通过目视分析和监测堆肥降解15天和30天后的分子量，可以评估粘土对PLA水解降解过程的影响。在堆肥环境中降解材料后，使用以洋葱洋葱为试验生物的生物测定法对堆肥水性提取物的细胞毒性，遗传毒性和诱变作用进行了评估。 TEM显微照片可观察到不同水平的分散液，包括脱落的区域。在水解降解的评估中，注意到有机粘土的存在可以降低降解速率，这可能归因于粘土层的阻挡作用和/或纳米复合材料样品中较高的结晶度。然而，即使在纳米复合材料的情况下，分子量的降低也是显着的，这表明堆肥过程有利于研究材料中PLA的断链。在通过以洋葱曲霉为测试生物的生物测定进行的分析中，发现PLA和其纳米复合材料降解后，堆肥样品的水提物诱导了有丝分裂指数的降低和染色体异常诱导的增加。与阴性对照（蒸馏水）相比，这些结果具有统计学意义。通过比较相对于纯聚合物获得的纳米复合材料的结果，没有统计学上的显着差异。观察到的染色体畸变的类型表明了该材料可能的遗传毒性作用，这可能与PLA降解产物的气生成作用有关。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号