Crystallization, Crystal Structure, and Isothermal Melt Crystallization Kinetics of Novel Polyamide 6/SiO2 Nanocomposites Prepared Using the Sol-Gel Technique
Crystallization, Crystal Structure, and Isothermal Melt Crystallization Kinetics of Novel Polyamide 6/SiO2 Nanocomposites Prepared Using the Sol-Gel Technique
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DOI：
10.1021/jp505046v
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发表时间：
2014-08-07
影响因子：
3.3
通讯作者：
Vasanthan, Nadarajah
中科院分区：
文献类型：
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作者：
Rafique, Fatima Zohra;Vasanthan, Nadarajah
采用新型溶胶凝胶技术制备了不同 SiO2 含量的聚酰胺 6/SiO2 (PA6/SiO2) 纳米复合材料。这些纳米复合材料是使用甲酸和少量水作为 PA6 的溶剂，通过水解和四乙氧基硅烷 (TEOS) 缩合原位形成的。 TGA 观察表明，PA6 纳米复合材料的热稳定性较纯 PA6 显着提高。结合差示扫描量热法 (DSC)、FTIR 光谱、扫描电子显微镜 (SEM) 和 AFM 研究了 PA6/SiO2 纳米复合材料热诱导结晶过程中微观结构的发展。利用 FTIR 光谱测定了这些纳米复合材料的晶型，得出 SiO2 纳米粒子具有 γ 成核效应的结论。与纯 PA6 相比，纳米复合材料的结晶度随着 TEOS 负载量的增加而降低。 SEM 显示纳米级二氧化硅非常精细的分散，而 SEM 和 Zetasizer 证明二氧化硅颗粒尺寸约为 100-200 nm。研究了随着 SiO2 含量的增加这些纳米复合材料的等温结晶动力学，结果表明 SiO2 的量在结晶动力学中起着重要作用。
Polyamide 6/SiO2 (PA6/SiO2) nanocomposites with varying amounts of SiO2 were prepared by using a novel sol gel technique. These nanocomposites were formed in situ by hydrolysis and through the condensation of tetraethoxysilane (TEOS) using formic acid with a small amount of water as the solvent for PA6. Observations of TGA showed that the thermal stability of PA6 nanocomposite was significantly improved compared to that of neat PA6. Microstructure development during the thermally induced crystallization of PA6/SiO2 nanocomposites was investigated with a combination of differential scanning calorimetry (DSC), FTIR spectroscopy, scanning electron microscopy (SEM), and AFM. FTIR spectroscopy was used to determine the crystal form of these nanocomposites, and it was concluded that SiO2 nanopartides have the gamma-nucleating effect. The crystallinity of nanocomposites decreased with increasing TEOS loading as compared to that for neat PA6. SEM showed a very fine dispersion of nanoscale silica whereas SEM and Zetasizer proved the silica particle size was about 100-200 nm. The isothermal crystallization kinetics of these nanocomposites with increasing SiO2 content were investigated, and it was shown that the amount of SiO2 plays a significant role in crystallization kinetics.