阴离子型高吸水性树脂凝胶的响应性能

以CMCTS-g-PAA和CMCTS-g-(PAANa-co-PVP)两类羧甲基壳聚糖改性阴离子型高吸水性树脂凝胶为研究对象,对其所吸收液体性能变化的响应性进行了研究。研究发现,阴离子型高吸水性树脂随乙醇/水混合溶剂中乙醇体积分数(φ)的增大发生体积相转变;随树脂结构中链段极性的增大,凝胶相变点相应的(φ)值降低;并随所吸收液体中低极性乙醇含量的增大,-COO-之间的相互排斥作用减弱,树脂的吸水速率降低。当研究溶液离子强度对树脂溶胀性能的影响时发现,1/S值较大时,离子强度与Q5/3成正比;但离子浓度较大时,Q5/3与1/S的线性关系消失。此外所吸收溶液的pH值对树脂的吸收率也有很大的影响。

Response Characteristics of the Ionic Superabsorbent Hydrogel

Influence of properties of the solution on the swelling ratios of the CMCTS-gPAA and CMCTS-g-(PAANa-co-PVP) ionic superabsorbent hydrogels,which were prepared through modification of carboxymethyl chitosan,was studied.The phase transition of the hydrogel can be observed if the volume fraction of alcohol(φ) in the alcohol/water mixture is increased.The volume phase transition points of the hydrogels are decreased as increasing of the polarity of the segments in the structure of the hydrogel.The exclusion between the-COO-is decreased as increasing of the content of the alcohol,with which the polarity is low,and the swelling of the polymer is slow-down.Response of the hydrogels to the ion strength was also studied.The 1/S value is found to be directly proportional to Q5/3 at high 1/S value.On the contrary,the linear correlation between the Q5/3 and 1/S is disappeared if the ion concentration was high.The swelling ratio of the hydrogel is also influenced greatly by the pH value of the absorbed solution.The maximum swelling ratio can be reached around the pH value between 6 and 7.