采用熔融共混法制备了聚ε 己内酯(PCL)/二氧化硅(SiO2)纳米复合材料,研究了SiO2含量对复合材料微观形貌、流变行为、静态和动态力学性能以及生物降解性能的影响,并分析了其作用机理.结果表明,随着SiO2含量的增加,PCL/SiO2纳米复合材料中细小的第二相粒子的含量逐渐增多,且当SiO2含量超过3%(质量分数,下同)时,第二相粒子的团聚现象较为显著;随着复合材料中SiO2含量的增加和温度的升高,PCL/SiO2纳米复合材料基体的线性黏弹区有所减小;PCL/SiO2纳米复合材料的流变逾渗阈值在7%~9%之间;SiO2含量从0增加至9%时,复合材料的拉伸强度和弹性模量均呈现先增加后降低的趋势,当SiO2含量为3%时复合材料的拉伸强度达到最大值,当SiO2含量为7%时弹性模量达到最大值;随着SiO2含量的增加,PCL/SiO2纳米复合材料的降解速率呈逐渐升高的趋势,且降解均通过表面逐层浸蚀的方式进行.%Polycaprolactone (PCL )-based nanocomposites with different contents of SiO2 nanoparticles were prepared by a melt-blending method, and effects of SiO2 content on morphology,rheological behavior,static and dynamic mechanical properties,and biodegradability of PCL/SiO2 nanocomposites were investigated.The results indicated that the fraction of small particles as the second phase tended to increase gradually with an increase of SiO2 content. However,the second phase particles presented a serious aggregation when the SiO2 content exceeded 3 wt %.As the SiO2 content and temperature increased,the PCL/SiO2 nanocomposites showed a decrease in their linear viscoelastic region. The nanocomposites also exhibited a rheological percolation in the range of 7 wt %~9 wt %.When the SiO2 content varied from 0 to 9 wt %,the tensile strength and Young's modulus of the nanocomposites presented an increasing trend at first and then decreased.The nanocomposites achieved the maximum tensile strength and Young's modulus at the SiO2 contents of 3 wt%and 7 wt%,respectively.The degradation rate of the nanocomposites was improved gradually with increasing the SiO2 content,and the degradation occurred from the specimen surface in a layer-etching mode.
展开▼
