A pH-sensitive porous chitosan membrane prepared via surface grafting copolymerization in supercritical carbon dioxide

作者：Cao Liqin^*; Wang Xiaohu; Wang Gang; Wang Jide

来源：Polymer International, 2015, 64(3): 383-388.

DOI：10.1002/pi.4798

• Graft co polymerizations
• Grafting copolymerization
• Initiator concentration
• Monomer concentration
• pH sensitive
• Polymerization temperature
• Reaction temperature
• Supercritical carbon dioxides

The morphology and properties of a porous chitosan membrane can be modified in supercritical CO2. The graft yield of the porous chitosan membrane under optimum conditions was 23%. We report the successful grafting copolymerization of acrylic acid (AA) on a crosslinked porous chitosan membrane in supercritical carbon dioxide at pressures ranging from 13 to 25MPa with the use of benzyl peroxide (BPO) as the reduction-oxidation free radical initiator. The effects of reaction pressure, initiator concentration, monomer concentration, reaction temperature and reaction time on grafting yield (GY) were investigated. GY initially increases and then decreases with increasing polymerization temperature and AA and BPO concentrations. The optimum grafting conditions to obtain maximum GY are as follows: 8h reaction time, 80°C reaction temperature, 3.05×10-2gmL-1 AA concentration, 3×10-3gmL-1 BPO concentration and 16MPa reaction pressure. The water flux of the grafted chitosan membranes decreases with pH from 2 to 7, even at considerably low GY (0.95wt%). A novel and green modification method has been developed for the preparation of biopolymer-based membranes.

• 出版日期2015