Chen Yongchun, Zhou Shuxue, Yang Haihua, Gu Guangxin, Wu Limin
Department of Materials Science, The Advanced Coatings Research Center of China Educational Ministry, Fudan University, Shanghai 200433, People's Republic of China.
J Colloid Interface Sci. 2004 Nov 15;279(2):370-8. doi: 10.1016/j.jcis.2004.06.074.
Polyurethane/nanosilica composites were prepared using polyester polyol/nanosilica composite resins obtained from in situ polymerization or blending methods and investigated by Fourier transform infrared spectra (FTIR), dynamical mechanical analysis (DMA), transmittance electron microscopy (TEM), contact angle measurement, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM), respectively. It was found that more polyester segments had chemically bonded with silica particles during in situ polymerization than during blending, introducing nanosilica increased the Tgs of polyurethanes, and different preparation methods and different particle sizes caused various impact on Tg. Contact angle measurement and XPS analyses indicated that nanosilica tended to move towards the surfaces and interfaces of polyurethane coats, decreasing the free energies of the surfaces and interfaces, but the nanosilica particles were just observed at interfaces not surfaces by AFM.
采用通过原位聚合或共混方法制得的聚酯多元醇/纳米二氧化硅复合树脂制备了聚氨酯/纳米二氧化硅复合材料，并分别通过傅里叶变换红外光谱（FTIR）、动态力学分析（DMA）、透射电子显微镜（TEM）、接触角测量、X射线光电子能谱（XPS）和原子力显微镜（AFM）对其进行了研究。结果发现，与共混过程相比，原位聚合过程中有更多的聚酯链段与二氧化硅颗粒发生了化学键合，引入纳米二氧化硅提高了聚氨酯的玻璃化转变温度（Tg），且不同的制备方法和不同的粒径对Tg产生了不同的影响。接触角测量和XPS分析表明，纳米二氧化硅倾向于向聚氨酯涂层的表面和界面移动，降低了表面和界面的自由能，但通过AFM仅在界面而非表面观察到纳米二氧化硅颗粒。
