The super-fine down powder was modified by 3-mercaptopropyl trimethoxysilane(KH590), phenyl isocyanate(PI) and octadecyl isocyanate(ODI), respectively. The modified super-fine down powder was characterized by Fourier transform infrared (FTIR) spectrum, Thermogravimetry (TG), water contact angle, moisture absorption. The results showed that PI and ODI are chemically bonded to the surface of down powder. The down powder modified by PI and ODI has good hydrophobic property and excellent moisture absorption capacity. The initial temperature of thermal degradation for the modified down powder increases by about 4~7 ℃. However, the modification of KH590 has no evident influence on the down powder. The modification of PI and ODI could improve the surface property of down powder and the non-polar matrix (e.g. polypropylene, et al) and increase the moisture absorption of non-polar fiber. This modification could also favor the thermal process of the relevant composites.
