Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao, 266042, China.
Analysis and Testing Center, Soochow University, Renai Road 199, 215123, Suzhou, China.
Carbohydr Polym. 2018 Oct 1;197:204-214. doi: 10.1016/j.carbpol.2018.05.087. Epub 2018 Jun 4.
In this study, lactic acid monomer or dimer is grafted onto CNC by a simple esterification reaction. The quantitative solid-state C NMR spectrum suggests that more than 87% of all the available OH groups on the surface of CNC are substituted by lactic acid. Such modified CNC (CNC-g-LA) exhibits excellent thermostability and nano-sized dispersion in chloroform. Benefit from this character, fully biobased PLLA/CNC-g-LA nanocomposite could be prepared simply by a solution-casting method. The crystallization behavior of obtained nanocomposites has been systematically investigated by differential scanning calorimetry (DSC). The results show that the crystallization rate of PLLA is distinctly enhanced. Moreover, the mechanical properties of nanocomposites are also improved remarkably by the addition of CNC-g-LA because of its excellent dispersion and compatibility with PLLA matrix. This study provides a green and facile way to modify CNC for fabricating bio-nanocomposites with fast crystallization rate and improved mechanical properties.
在这项研究中，乳酸单体或二聚体通过简单的酯化反应接枝到 CNC 上。定量固态 C NMR 谱表明， CNC 表面上超过 87%的所有可用羟基被乳酸取代。这种改性的 CNC（CNC-g-LA）在氯仿中表现出优异的热稳定性和纳米级分散性。得益于这一特性，通过溶液浇铸法可以简单地制备出完全基于生物的 PLLA/CNC-g-LA 纳米复合材料。通过差示扫描量热法（DSC）系统地研究了所得纳米复合材料的结晶行为。结果表明，PLLA 的结晶速率明显提高。此外，由于 CNC-g-LA 具有优异的分散性和与 PLLA 基体的相容性，纳米复合材料的力学性能也得到了显著提高。本研究为制备具有快速结晶速率和改善力学性能的生物纳米复合材料提供了一种绿色、简便的改性 CNC 的方法。
