互穿网络聚乳酸/细菌纤维素生物复合材料的制备与性能

Preparation and Properties of Polylactic Acid/Bacterial Cellulose Bio-Composites with Interpenetrating Networks Structure

以聚乳酸(PLA)为基体,细菌纤维素(BC)为增强体,通过PLA-三氯甲烷溶液与BC-无水乙醇悬浮液的共混扩散制备互穿网络结构的PLA/BC生物复合材料。采用扫描电子显微镜、热失重分析仪、偏光显微镜和电子万能试验机等研究了复合材料的微观形态、分散性、力学性能、热分解温度及球晶形貌。结果表明,采用溶液共混扩散法可得到以BC为骨架、PLA缠绕其表面的互穿网络结构的生物复合材料;BC可作为异相成核剂,显著细化PLA的球晶尺寸,提高复合材料的力学性能和热分解温度。BC的质量比为1.0%时,PLA/BC复合材料的球晶尺寸最小,力学性能和热分解温度最高。其中复合材料的缺口冲击强度和热分解温度分别较纯PLA提高了37.84%和约5℃。

Polylactic acid（ PLA） and bacterial cellulose（ BC） were selected as matrix and reinforcement respectively to prepare PLA / BC biological composites with interpenetrating networks structure via blending diffusion of PLA-chloroform solution and BC-anhydrous ethanol dispersion. The micro-morphology,dispersibility,mechanical properties,thermal decomposition temperature and spherulite morphology of the composites were investigated by scanning electron microscope（ SEM）,thermogravimetry analysis（ TGA）,polarized optical microscopy（ POM） and electronic universal-testing machine. The results show that the blending diffusion method is available for preparation of PLA / BC composites with interpenetrating networks structure of PLA wound on the surface of BC skeleton. As a heterogeneous nucleating agent,proper amount BC can refine the spherulite,and improve mechanical properties and thermal decomposition temperature simultaneously. The minimum spherulites,the optimal mechanical properties and the highest thermal decomposition temperature of PLA / BC composite are obtained at the mass fraction of 1. 0% BC,in which the notched impact strength and thermal decomposition temperature of PLA / BC composite are increased by 37. 84% and about 5 ℃ compared with pure PLA,respectively.