A wool antifelting agent containing polyurethane modified with 3-aminopropyltriethoxysilane (APTES) was synthesized. Firstly an isocyanate (-NCO) group ended prepolymer was gained by a hydrogen shift reaction between isophorone diisocyanate (IPDI) and poly (propylene oxide triol) (PPT), and then NCO-group of the prepolymer was blocked by 3-aminopropyltriethoxysilane to form a precursor PPT-[Si(OEt)(3)](3). After that a sol of the precursor was prepared for an antifelting agent. During heating the sol gelled and formed inorganic-organic hybrid film that was characterized by using FTIR and TGA. And then the wool fabric samples were treated with sol by pad-dry-cure process at different curing temperature (120, 140, and 160 degrees C). The antifelting effects of different curing temperatures were compared. The results indicated that the new agent could endow a better antifelting effect with the low curing temperature at 120 degrees C and 3 min. (c) 2008 Wiley Periodicals, Inc.