STUDIES ON MORPHOLOGICAL STRUCTURE AND GELLING BEHAVIOR OF PARTIALLY HYDROLYZED POLYACRYLAMIDE-ALUMINIUM CITRATE SYSTEM

The morphological structure and properties of gels prepared from partially hydrolyzed polyacrylamide (HPAM) and aluminum citrate (AlCA) were studied through optical microscopy,scanning electron microsopy and rheological measurement.Experimental results show that the gels prepared from solutions containing HPAM and AlCA appear in three typical states with the increase of HPAM concentration:the dispersed gel,the gel containing both dispersed and continuous network phase and the gel with continuous network structure.The dispersed gel contains particles composed of crosslinked HPAM macromolecules and its increase in viscosity is not evident.For the gel with continuous network structure its complex viscosity and complex modulus are markedly raised and the crosslinked HPAM particles are connected with each other in a network.