Hydraulic Permeability-Temperature Hysteresis for the Hydrophilic Membrane Prepared from the Block Copolymer Consisting of Polyamide and Polyoxyethylene Segments
Hydraulic Permeability-Temperature Hysteresis for the Hydrophilic Membrane Prepared from the Block Copolymer Consisting of Polyamide and Polyoxyethylene Segments
复制标题
聚酰胺和聚氧乙烯嵌段共聚物亲水膜的水力渗透率-温度滞后
DOI：
10.1295/polymj.19.249
复制
发表时间：
1987
期刊：
影响因子：
2.8
通讯作者：
Hiroo Yamamori
中科院分区：
文献类型：
--
作者：
K. Hashimoto;H. Sumitomo;Hiroo Yamamori
以双环草内酰胺8-氧杂-6-氮杂双环[3.2.1]辛烷-7-酮经阴离子开环聚合制备了以聚酰胺为外链段、聚氧乙烯为内链段的嵌段共聚物，并用两端具有异氰酸酯基团的不同分子量的聚氧乙烯活化。将它们浇铸成亲水膜，其水合程度和水渗透率（Kw）取决于共聚物中聚氧乙烯链段的长度。在 50°C 水中预热的膜在 25 至 45°C 的温度范围内的 Kw 值低于原始膜的 Kw 值。然而，通过在室温水中老化一周，渗透性完全恢复。根据热分析对膜中水分子行为的研究，可以推测这种特殊的滞后现象来自于加热时某些结构转变的快速响应和冷却时的缓慢松弛。
Block copolymers composed of polyamide as the outer segment and polyoxyethylene as an inner segment were prepared by the anionic ring-opening polymerization of a bicyclic oxalactam, 8-oxa-6-azabicyclo[3.2.1]octan-7-one, activated with polyoxyethylene of different molecular weight having isocyanate groups at both chain ends. They were cast to the hydrophilic membranes, of which degree of hydration and hydraulic permeability (Kw) depended upon the length of the polyoxyethylene segment in the copolymers. The value of Kw for the membrane preheated in water at 50°C was lower than that for the original membrane in the temperature range from 25 to 45°C. However the permeability was completely restored by aging in water at room temperature for a week. From an investigation on the behavior of water molecules in the membrane in terms of the thermal analyses, such a peculiar hysteresis can be presumed to come from the quick response of some structural transformation on heating and its slow relaxation on cooling.