物理化学学报 >> 2005, Vol. 21 >> Issue (06): 591-595.doi: 10.3866/PKU.WHXB20050603

研究论文 上一篇    下一篇

PDEA和P(DEA-co-NHMAA)稀水溶液相分离行为研究

陈勇; 柳明珠; 金淑萍 陈世兰   

  1. 兰州大学化学化工学院, 兰州 730000
  • 收稿日期:2004-10-08 修回日期:2004-12-01 发布日期:2005-06-15
  • 通讯作者: 柳明珠 E-mail:m-zliu@163.com

Study on the Phase Separation Behavior of Poly(N,N-diethylacrylamide) and P(N,N-diethylacrylamide-co-N-hydroxymethylacrylamide) Dilute Aqueous Solutions

CHEN Yong; LIU Ming-zhu; JIN Shu-ping; CHEN Shi-lan   

  1. College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000
  • Received:2004-10-08 Revised:2004-12-01 Published:2005-06-15
  • Contact: LIU Ming-zhu E-mail:m-zliu@163.com

摘要: 运用紫外-可见分光光度法分别考察了聚N,N-二乙基丙烯酰胺(PDEA)和N-羟甲基丙烯酰胺(NHMAA)与DEA的共聚物P(DEA-co-NHMAA)稀水溶液相分离行为. 结果发现,当P(DEA-co-NHMAA)中NHMAA的质量分数小于5.25%时, 随着NHMAA含量的增加, 其最低临界溶解温度(TLCS)下降;当NHMAA的含量大于5.25%时,随着NHMAA含量的增加,其TLCS上升;与PDEA相比P(DEA-co-NHMAA)相分离行为的浓度依赖性减弱;PDEA和P(DEA-co-NHMAA)从无规线团(coil)到蜷曲球(globular)的突然转变与从globular到coil的逐渐转变机理不同. 据此提出了P(DEA-co-NHMAA)在稀水溶液中相变的分子机理.

关键词: PDEA, P(DEA-co-NHMAA), 温敏性, 稀水溶液, 相分离

Abstract: The phase transition behaviors of poly(N,N-diethylacrylamide)(PDEA) and P(N,N-diethylacrylamideco-N-hydroxymethylacrylamide) (P(DEA-co-NHMAA)) aqueous solutions were studied by UV-Vis spectrophotometer. The results suggest that when the mass fraction of NHMAA is below 5.25%, the lower critical solution temperature (TLCS) decreases with the increasing of mass fraction of NHMAA. In contrast, TLCS increases with the increasing of mass fraction of NHMAA when it is higher than 5.25%. Due to the stronger hydrogen bonds between side chains of the copolymer and water, as well as between two side chains of the copolymer in aqueous solution, the phase transition of P(DEA-co-NHMAA) aqueous solution, compared with the phase transition of PDEA aqueous solution, shows less dependence on the concentration. For PDEA and P(DEA-co-NHMAA) aqueous solutions, the abrupt transition from coil to globular and the gradual transition from globular to coil may involve different mechanisms. A model has been proposed for the structure of P(DEA-co-NHMAA) formed in dilute aqueous solution.

Key words: PDEA, P(DEA-co-NHMAA), Thermosensitivity, Dilute aqueous solution, Phase transition