PBT/纳米SiO_2非等温结晶动力学研究

Study of the Nonisothermal Crystallization Kinetics of PBT/Nano-SiO_2 Composites

熔融制备了 PBT/纳米 SiO_2复合材料,用 DSC 分别研究了 SiO_2在低含量(0.3%,质量分数,下同)和高含量(3%)时的非等温结晶行为;并分析了 PBT/纳米 SiO_2复合材料的结晶动力学。结果表明,纳米 SiO_2对 PBT 有异相成核作用,加入纳米 SiO_2后,显著提高了 PBT 结晶温度,加快了其结晶速率。结晶动力学表明,莫志深法很好地吻合了 PBT/纳米 SiO_2复合材料体系,而 Ozawa 方法并不太适合。通过结晶活化能的计算,表明在低含量(0.3%)时有更好的结晶能力。

Poly（butylenes terephthalate）/nano-SiO2 nanocomposites were prepared by melt blending using a twin screw extruder. The nonisothermal crystallization kinetics of the nanocomposites was studied with differential scanning calorimetry （DSC） and the effect of SiO2 was explored. It showed that crystallization peak temperature for the nanocomposites was much higher than that of neat PBT. Nano-SiO2 accelerated the crystallization rate, indicating an obvious heterogeneous nucleation. Crystallization kinetics data was analyzed by Ozawa, Mo, and Kissinger methods. The results confirmed the applicability of Mo, and Kissinger models, and the inadequacy of the Ozawa approach. In addition, a lower activation energy was observed at a low content of nano-SiO2（0.3wt% ） than that at a high content （3.0wt% ）.