超临界二氧化碳/纳米无机粒子对聚乳酸不相容共混体系的协同增容及性能研究

项目名称： 超临界二氧化碳/纳米无机粒子对聚乳酸不相容共混体系的协同增容及性能研究

项目编号： No.51263007

项目类型： 地区科学基金项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 徐鼐

作者单位： 海南大学

项目金额： 50万元

中文摘要： 聚乳酸是一种应用前景广阔的环境友好材料。但是其脆性大的缺点限制了它的应用。用常规增韧手段往往在增韧的同时使材料的强度大大降低。本课题应用超临界CO2辅助挤出技术制备无机纳米粒子/有机增韧相/聚乳酸三元共混材料，研究超临界CO2与纳米粒子选择性分散对聚乳酸共混体系的协同增容效应。该协同增容过程可表述为：熔融共混时，利用超临界CO2对聚合物熔体及纳米无机粒子的渗透性和溶胀性，结合无机纳米粒子分布选择性使较高含量的纳米粒子选择性分散在聚乳酸基体中，并形成逾渗网络；同时，由于超临界CO2的降粘作用，熔体内增韧相尺寸被显著细化，部分纳米粒子在相界面处吸附，改善了界面相容性，起到稳定细化相尺寸的作用，材料强度和韧性同时提高。重点研究超临界条件下，纳米粒子选择性分布对聚乳酸-增韧相界面性质、相形态、以及纳米粒子分散性的影响。通过超临界流体和纳米粒子的协同增容作用，最终得到强韧性聚乳酸材料。

中文关键词： 聚乳酸；超临界二氧化碳；蒙脱土；增韧；增容

英文摘要： Poly(lactic acid)(PLA) is an aliphatic biodegradable polymer which can be produced from annually renewable resources. PLA has good strength, thermal plasticity, and biocompatibility, thus being a promising polymer for various end-use applications. However, its drawback of brittleness is limiting the application of PLA. In this research, nano inorganic particle/toughing phase/PLA blends will be prepared using supercritical CO2(SC-CO2) assisted blending technology. The synergistic compatibilization of Sc-CO2 and nano inorganic particles in the incompatible PLA blends will be researched in detail. The possible mechanism is followed as: when molten-blending, most of nano particles locate in PLA matrix and lead to form a percolation structure, due to co-effect of the selective localization of nano particles, and the permeability and swelling effect of SC-CO2. Synchronously, because of the presence of SC-CO2, the size of toughening phase is refined largely. And then, a few of nano particles are absorbed in the phase interface. As a result, the formed phase morphology is stabilized. The co-effect of SC-CO2 conditions and selective localization of nano particles on the properties of phase interface, phase morphology, and dispersion of nano-particles should be study carefully. The toughened and strengthened PLA blends sh

英文关键词： PLA；Supercritical carbon dioxide；Montmorillonite；Toughness；Compatibilization