PHASE-TRANSITION OF AQUEOUS-SOLUTIONS OF POLY(N-ALKOXYALKYLACRYLAMIDE) DERIVATIVES - EFFECTS OF SIDE-CHAIN STRUCTURE

A series of polyacrylamide derivatives having different hydroxyalkyl groups and alkoxyalkyl groups in their side chain structure was prepared via free radical polymerization of the monomer which had been synthesized from corresponding acryloyl chlorides and amines. The solubility of poly (N-hydroxyalkylacrylamide) in water varies depending on the side chain length of alkyl groups: one is soluble in water irrespective of temperature, and one is insoluble in water at any temperature. The solubility of poly(N-alkoxyalkylacrylamide) in water varies depending on the side chain length of alkyl groups: one is soluble in water irrespective of temperature, one is soluble in cold water but insoluble in hot water, and one is insoluble in water at any temperature. Polymers having an alkoxyalkyl group such as N-2-ethoxyethyl, N-3-methoxypropyl, N-3-ethoxypropyl, N-3-isopropoxypropyl, N-3-(2-methoxyethoxy)propyl, N-tetrahydrofurfuryl, N-1-methyl-2-methoxy ethyl, N-1-methoxymethylpropyl,N-(2,2-dimethoxyethyl)-N-methyl, N-(1,3-dioxolan-2-ylmethyl)-N-methyl, N-1,4-dioxa-8-aza-spiro [4.5]decane, N-2-methoxyethyl-N-ethyl, N-2-methoxyethyl-N-isopropyl, N-2-methoxy-ethyl-N-n-propyl, and N-di(2-methoxyethyl) are soluble in cold water but insoluble in hot water. A change of the optical transmittance of 1 wt% aqueous solution of these polymers shows that a sharp phase transition takes place on heating the solution at some temperature between 9°C and 85°C. This transition temperature depends mainly on the primary structure of the polymers. The transition is quite sensitive, reversible, and reproducible under thermal stimulation. © 1990, The Society of Polymer Science, Japan. All rights reserved.