MODIFICATION OF SILK FIBER via EMULSION GRAFT COPOLYMERIZATION WITH FLUOROACRYLATE

2,2,3,3,4,4,5,5-Octafluoropentyl acrylate was grafted onto silk fiber in a two-step heterogeneous system through the vinyl bonds of acryloyloxyethyl isocyanate modified on the silk.The grafted copolylner was analyzed by FTIR and WAXD,and the results revealed that the fluoroacrylate was successfully grafted onto silk fiber and the crystalline structure of silk fibroin withβ-sheet structure was not changed after graft copolymerization.The FT-IR corrected method was used to simulate the grafting yield onto silk compared with the weight increasing method.The results obtained from these two methods were roughly consistent.The influence of the initiator concentration,monomer concentration,react time and temperature on the graft yield was also investigated.The experimental data of thermogravimetry (TG) and differential thermal analysis (DTA) showed that the thermal stability of the modified silk fibers was improved due to the introduction of fluoroacrylate.In comparison with the untreated silk fibers,the water repellence of the modified silk fibers was also improved.