P(AM/AA/PEGDA)微凝胶的制备及自降解机理研究

Preparation of P(AM/AA/PEGDA)microgels and study of self-degradation mechanism

以聚乙二醇二丙烯酸酯(PEGDA)为交联剂,与丙烯酰胺(AM)、丙烯酸(AA)共聚,制备了一种自降解性微凝胶,考察各因素对微凝胶吸水性能和自降解性能的影响。结果表明,微凝胶合成优化条件为:0.05%PEG600DA,0.5%过硫酸铵,25%AA,75%AM,反应温度65℃,反应时间7 h。微凝胶的吸水倍数随一价离子和二价离子浓度的增大而减小,在50℃纯水中,吸水倍数最高可达近800 g/g。微凝胶在碱性条件下具有良好的自降解性能,并且温度越高,自降解时间越短,在150℃下放置6 h,降解液残渣几乎为0,通过凝胶色谱(GPC)测得数均分子量为Mn=2.9×10^(5)g/mol,表明微凝胶可以完全降解。

A self-degrading microgel was prepared by copolymerizing polyethylene glycol diacrylate(PEGDA)with acrylamide(AM)and acrylic acid(AA)as a cross-linking agent.The effects of various factors on the water absorption properties and self-degrading properties of the microgel were investigated.The results showed that the mass fraction of microgels synthesized was 0.05%PEG600DA,0.5%ammonium persulfate,25%AA and 75%AM,the reaction temperature was 65℃,and the reaction time was 7 h.The water absorption multiplier of microgels decreased with the increase of monovalent and divalent ion concentration,and the highest water absorption multiplier was nearly 800 g/g in pure water at 50℃.Microgels have good self degradation performance under alkaline conditions,the higher temperature,the shorter self degradation time when the microgels are placed at 150℃for 6 h,the residue of degradation liquid is almost 0.The number average molecular weight of Mn=2.9×10^(5)g/mol was measured,which indicated that the microgels could be completely degraded.