综述了近年来国内外关于聚乳酸/无机纳米粒子复合材料的研究和发展状况。研究表明将聚乳酸与无机纳米粒子通过复合改性,能够明显提高复合材料各方面的性能,从而扩展了聚乳酸的应用范围。聚乳酸/无机纳米复合材料分为两类,一类是层状硅酸盐无机纳米复合材料,另一类是无机纳米刚性粒子,主要包括二氧化硅、二氧化钛、氧化镁、氧化锌等氧化物。介绍了两类复合材料的制备方法,包括原位聚合法、共混法和溶胶凝胶法,阐述了无机纳米粒子的添加对聚乳酸力学性能、热稳定性能、结晶性能、降解性能、流变性能和气体阻隔性能的影响。未来的发展方向是希望通过加入具有一定特性的纳米粒子,制备出特定功能的聚乳酸无机纳米粒子复合材料。
The research and the development of poly(lactic acid)(PLA) inorganic particles nanocomposites in recent years are reviewed in this paper. The nanocomposites are classified into two different kinds, i.e., the PLA/layered silicate nanocomposites. Montmorllonite is among the most commonly used layered silicates for the preparation of nanocomposites, with high cation exchange capacities, surface area, and surface reactivity. It is hydrophilic in nature, and its property makes it very difficult to be dispersed into the PLA matrix. The most useful way to overcome the difficulty is to replace the interlayer cations with the quaternary ammonium or phosphonium cations, preferably with long alkyl chains. The other is the inorganic oxide nanoparticles including SiO2, TiO2, MgO and ZnO. They have surface defects and high reactivity because a layer of hydroxyl (-OH) groups from the water dissociation covers the surface of oxide nanopaticles. Moreover, they could be modified by the hydrophobicity organic agent to improve the dispersion. In general, the ways to prepare the two kinds of nanocompositions include the in situ polymerization, the blending method and the Sol-gel method. With only a little inorganic nanoparticles being dispersed into the PLA matrix, the nanocomposite will exhibit significantly improved properties compared with pure PLA, including the mechanical properties, the thermal stability, the crystallization, the biodegradability, the rheological properties and the gas barrier properties.The trend of the PLA inorganic particles nanocomposites is to add the nanoparticles to achieve certain functions.
