Synthesis and characterization of optically active polyurethane/CdS-SiO2 nanocompsites

• 作 者: CHENJing;ZHOUYuming;YEXiaoyun;SUNYanqing;WANGZhiqiang;
• 机 构: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189
• 出 处: 2007两岸三地博士生NBIC学术论坛
• 发表日期: 2007年期

　　In this study,optically active polyurethanes (PU) were prepared from chiral 1,1-binaphthyl (BINOL) and 2,4-toluene diisocyanate (TDI) by the simple hydrogen transfer addition reaction and the high-intensity ultrasonic was applied to the preparation of polyurethane/CdS-SiO2 nanocomposites.The (R)-BPU and (S)-BPU were analyzed by 1H NMR,FT-IR spectroscopy,thermogravimetric analysis (TGA),UV-Vis spectroscopy and circular dichroism (CD) spectra.The results indicated that the polymers exhibited stronger CD signals with positive and negative Cotton effect in their CD spectra.Meanwhile,the nanocomposites were characterized by IR,powder X-ray diffraction,TEM and SEM.The results manifested the improvement of heat stability of the nanocomposites with the presence of CdS-SiO2 nanoparticles.The infrared emissivity (8~ 14μm) study revealed that the nanocomposites possessed much lower infrared values compared with those of the neat polymers and nanoparticles,respectively.