聚己内酯/纳米Si_3N_4复合材料的非等温结晶研究

Study on the nonisothermal cold crystallization behaviors of poly(ε-caprolactone)/Si_3N_4 nanocomposites

采用溶液成膜法制备纳米Si3N4/聚己内酯(PCL)复合材料,并通过DSC、偏光显微镜及透射电镜等研究手段分析了纳米Si3N4颗粒对PCL的非等温结晶行为和微观形态的影响。结果表明:改性后的纳米Si3N4粒子在PCL基质中的分散性好于未改性纳米Si3N4;纳米Si3N4具有明显的成核效应,加快了PCL的前期结晶速率,对由成核控制的聚合物结晶前期阶段具有积极作用,而对晶体的生长则具有限制作用,导致聚合物结晶后期速率缓慢,晶体尺寸变小,结晶度下降;当纳米Si3N4的含量为5%时,聚合物结晶温度出现最大值;加快降温速率与添加纳米粒子对聚合物结晶行为的影响具有相似的效果。

Nano-SiaN4/poly（ε-caprolactone） （PCL） composites were synthesized by the method of solution for film , and the effect of nano- Si3 N4 on the microstructure and nonisothermal crystallization behavior of PCL were investigated by DSC,polarizing microscope equipped with a hot-stage and transmission electron microscopy. Our results manifested that modified Si3 N4 nanoparticles dispersed in the PCL matrix was better than the unmodified nano- Si3 N4. And nano-Si3 N4 par- ticles had a prominent ability of nucleation agent effect,which can speed up the crystallization rate and had a positive effect on the earlier stage controlled by nucleation. Meanwhile, the addition of nano-Si3 N4 particles can also restrict the growth of spherulites,which results in the lower crystallization rate later period, small dimension of crystal and low crystallinity. When the content of Sia N4 particles was 5%, the crystal temperature of PCL reached the maximum. There were similar re- sults between speeding up the cooling rate and adding nanoparticles into polymers for the influence on crystallization behav- ior.