聚乳酸/氧化锌柱撑皂石纳米复合材料制备与性能及结构表征

通过微波水解法制备了ZnO柱撑皂石,并以其为加工助剂制备了聚乳酸(PLA)/ZnO柱撑皂石纳米复合材料.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、对ZnO柱撑皂石及PLA/ZnO柱撑皂石纳米复合材料的结构进行了表征,并对其力学性能和热稳定性能进行了测试.微观结构分析表明,ZnO柱撑皂石呈现剥离状,并均匀分散在PLA基质中.力学性能研究表明0.3%ZnO柱撑皂石的加入有助于改善PLA复合材料的断裂伸长率.SEM分析表明PLA复合材料的断面发生明显改变,表现良好韧性;DSC结果显示纳米ZnO柱撑皂石可以降低复合材料的玻璃化转变温度、结晶温度,有助于提高PLA复合材料的结晶度,与XRD分析相吻合;热重分析表明ZnO柱撑皂石可以提高PLA复合材料的热稳定性.测试结果表明,ZnO柱撑皂石在PLA基质中起到了异相成核的作用,促进了PLA基质的结晶.

REPARATION AND CHARACTERIZATION OF POLY LACTIC ACID/ZINC OXIDE PILLARED SAPONITE NANOCOMPOSITES

Poly lactic acid(PLA)/zinc oxide(ZnO) pillared saponite nanocomposites were prepared with ZnO pillared saponite synthesized via microwave hydrolysis method.The structure of ZnO pillared saponite and PLA/ZnO pillared saponite nanocomposites were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM) and transmission electron microscope(TEM).Moreover,the mechanical properties and thermostability of PLA/ZnO pillared saponite nanocomposites were studied.The microstructure showed that the ZnO pillared saponite appeared as exfoliated or partially intercalated nanometer layers,and the TEM showed that the ZnO pillared saponites were evenly dispersed in the PLA matrix in the form of exfoliated layers.The mechanical properties showed that the elongation at break of PLA nanoncomposites was improved when the loading content of ZnO pillared saponite was 0.3 wt%.SEM analysis demonstrated that a visible transformation took place in the section morphology which manifested the toughness of PLA nanocomposites;DSC results displayed that the ZnO pillared saponite decreased the glass transition temperature and cold crystallization temperature,and obviously promoted the crystallinity,which was in accordance with XRD analysis.TG-DTA analysis showed that the thermostability of PLA/ZnO pillared saponite nanocomposites was improved.In a word,a hererogeneous nucleation effect of ZnO pillared saponite on the PLA matrix was testified and all the results showed that the ZnO pillared saponite played an active role in accelerating the crystallization process of PLA matrix.