二氧化硅对热塑性木薯淀粉力学性能及加工行为的影响

Effect of Silica on Mechanical Properties and Processing Behavior of Thermoplastic Cassava Starch

通过熔融密炼法制备热塑性木薯淀粉(TPS)/二氧化硅(SiO2)复合材料,研究SiO2用量、粒径、表面改性对TPS力学性能和加工行为的影响。研究结果表明,随着SiO2用量的增加,TPS拉伸强度和冲击强度先上升后下降,当SiO2用量为2phr时,拉伸强度和冲击强度最高,分别达到18.24 MPa,23.38kJ/m2。添加纳米SiO2的TPS比微米SiO2的TPS拉伸强度高。经过硅烷偶联剂KH550表面处理后SiO2能更有效提高TPS的拉伸强度和断裂强度,且改性后SiO2在TPS中分散均匀。随着SiO2用量的增加,TPS的塑化时间缩短,塑化峰和平衡转矩增大。TPS/纳米SiO2复合材料的塑化转矩和平衡转矩低于TPS/微米SiO2复合材料,经过表面处理的SiO2能缩短TPS塑化时间、降低塑化转矩。

The thermoplastic cassava starch（TPS）/silica（SiO2）composites were prepared through melt mixing method.The effect of SiO2 content,particle size,surface modification on the properties and processing behavior of TPS was investigated.The results indicate that the tensile and impact strength of TPS first increase and then decrease with the increasing content of SiO2.The tensile and impact strength of TPS reach the maximum value of 18.24 MPa and 23.38kJ/m2,respectively,when the SiO2 content is 2phr.Furthermore,the tensile strength of TPS filled with nano-SiO2 is higher than that with micron-SiO2.The SiO2 of which the surface is treated with KH550 could improve the tensile strength and breaking strength of TPS,and the dispersion of treated SiO2 in TPS is better than that of untreated SiO2.With increase of the SiO2 content,the plasticizing time of TPS reduces,however,the plasticizing peak and equilibrium torque increase.The plasticizing torque and balance torque of TPS/nano-SiO2 composite are lower than those of TPS/micro-SiO2 composite,and the treated SiO2 could reduce the plasticizing time and torque of TPS.