Viscometric and Morphological Properties of Novel Magnesium Electrolyte–Polyacrylamide Composite Polymers in Aqueous Solution Khai Ern Lee • Imran Khan • Norhashimah Morad • Tjoon Tow Teng • Beng Teik Poh Received: 7 November 2011 / Accepted: 21 March 2012 / Published online: 15 January 2013 Ó Springer Science+Business Media New York 2013 Abstract The viscometric properties of novel magnesium electrolyte–polyacrylamide composite polymers in aqueous solutions were investigated using response surface methodology. Independent factors such as concentration of the magnesium electrolyte (magnesium chloride and magnesium hydroxide), concentration of polyacrylamide, and the solution temperature were taken into account for viscometric modeling. Experiments were carried out according to central composite design, which includes factorial, central and axial points of the factors. Solution viscosity was taken as the response variable. A polynomial model for the viscometric properties was developed using ANOVA and non- linear regression analysis, and the R 2 values are 0.9995 and 0.9996 for aqueous solutions of magnesium chloride–polyacrylamide (MCPAM) and magnesium hydroxide–polyacryl- amide (MHPAM) composite polymers, respectively. Two diagnostic plots have been constructed to validate the developed models for the natural logarithm of viscosity of aqueous solutions of the MCPAM and MHPAM composite polymers. The least-squares values show that the developed models are adequate for predictive purposes. TEM was used to investigate the morphological properties of MCPAM and MHPAM composite polymers. Magnesium chloride was impregnated into the polyacrylamide chain while magnesium hydroxide was just adsorbed on the surface of the polyacrylamide chain. Keywords Viscosity  Morphology  Magnesium chloride  Magnesium hydroxide  Polyacrylamide  Composite polymer Electronic supplementary material The online version of this article (doi:10.1007/s10953-012-9952-y) contains supplementary material, which is available to authorized users. K. E. Lee  I. Khan  N. Morad (&)  T. T. Teng  B. T. Poh School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang, Malaysia e-mail: nhashima@usm.my 123 J Solution Chem (2013) 42:27–43 DOI 10.1007/s10953-012-9952-y