摘要
Chitosan （CS） was successfully modified in supercritical carbon dioxide （ scCOz ） by grafting method to enhance its water solubility. In this work, a three.arm star-like fluorinated polymer was synthesized by atom transfer radical polymerization （ ATRP ） method and applied as a surfactant in supereriticul carbon dioxide （scCO2 ）. Then 2-acrylamido-2-methyl propane sulfonie acid （AMPS） was grafted onto CS （CS-g-PAMPS） in H2O/scCO2 inverse emulsion. The effects of mass ratio of water and surfactants （Rw/s ） and pressure of scCO2 on the grafting reaction were investigated. The grafting rate, partide size, and dispersity in water of CS-g-PAMPS varied greatly as Rw/s and pressure of scCO2 changed. It could be found that the value of Rw/s at 12 and the pressure of scCO2 at 30 MPa were the optimum conditions for the grafting reaction. CS-g-PAMPS prepared in this reaction system has higher grafting rate, smaller particle sizes, and better dispersity in water than those prepared via conventional methods.
Chitosan(CS)was successfully modified in supercritical carbon dioxide(scCO2)by grafting method to enhance its water solubility.In this work,a three-arm star-like fluorinated polymer was synthesized by atom transfer radical polymerization(ATRP)method and applied as a surfactant in supercritical carbon dioxide(scCO2).Then 2-acrylamido-2-methyl propane sulfonic acid(AMPS)was grafted onto CS(CS-g-PAMPS)in H2O/scCO2inverse emulsion.The effects of mass ratio of water and surfactants(R w/s)and pressure of scCO2on the grafting reaction were investigated.The grafting rate,particle size,and dispersity in water of CS-g-PAMPS varied greatly as R w/s and pressure of scCO2changed.It could be found that the value of R w/s at 12 and the pressure of scCO2at 30 MPa were the optimum conditions for the grafting reaction.CS-g-PAMPS prepared in this reaction system has higher grafting rate,smaller particle sizes,and better dispersity in water than those prepared via conventional methods.
基金
National Natural Science Foundation of China(No.20674017)
Shanghai Key Laboratory Project of China(No.08DZ2230500)
