乳液共混法制备微纤化纤维素/聚乳酸生物复合材料及性能

为了提高聚乳酸(PLA)的韧性和刚性,扩大应用范围,分别以PLA为基体,微纤化纤维素(MFC)为增强材料,通过乳液共混法制备出MFC/PLA生物复合材料。采用扫描电镜、偏光显微镜和万能电子试验机等研究了复合材料的断面形貌、球晶形态和力学性能等。结果表明,通过乳液共混法可将MFC均匀分散在PLA基体中制备MFC/PLA生物复合材料;适量MFC可显著细化PLA的球晶尺寸,提高PLA的力学性能。当MFC质量分数为0.6%时,复合材料的拉伸强度、弹性模量、弯曲强度和缺口冲击强度分别较纯PLA提高了15.6%、21.1%、30.6%和53.6%。

Preparation of Microfibrillated Cellulose/Polylactic Acid Composites and Their Characteristics via Emulsion Blend Method

In order to improve the toughness and stiffness of polylactic acid (PLA) and enlarge its application scope,PLA and microfibrillated cellulose (MFC) were selected to prepare MFC/PLA bio-composites via emulsion blend method.The fracture morphology,spherulitic morphology and mechanical properties of the composites were characterized by scanning electron microscope (SEM),polarized optical microscopy (POM),electro-mechanical universal testing machines,etc.Results show that MFC can be homodispersed in the PLA matrix to prepare MFC/PLA bio-composites via emulsion blend method.The sphemlite size and mechanical properties of PLA can be significantly refined and improved at the appropriate amount of MFC.Comparing with pure PLA,the tensile strength,elastic modulus,bending strength and notched impact strength of the composites at 0.6 ％ the mass fraction of MFC increase by 15.6％,21.1％,30.6％ and 53.6％ respectively.