Preparation and Characterization of Hydroxyapatite Impregnated Semi‐interpenetrating Polymer Networks (IPNs) of Polyvinyl Alcohol and Poly(Acrylamide‐co‐acrylic Acid)

Abstract

A semi‐interpenetrating polymer network (IPN) of poly(vinyl alcohol) and poly(acrylamide‐co‐acrylic acid) was prepared, and the formation of calcium hydroxyapatite (HAP) on/in the polymeric network was studied by a novel alternate soaking process. The prepared HAP–IPN matrix was characterized by IR, x‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron micrograph (SEM) analyses, and structural parameters of the IPN such as average molecular weight between crosslinks (M _c), crosslink density (q), and number of elastically effective chains (V _e) were calculated from water uptake measurements. The swelling of the IPN in phosphate and calcium solutions and the amount of HAP formed were investigated as a function of the chemical architecture of the polymeric matrix. The influence of number of reaction cycles and temperature of the swelling medium on the amount of HAP formed within the IPN were also studied.

Keywords:

• Polyvinyl alcohol
• IPN
• Hydroxyapatite
• Characterization
• Swelling

Acknowledgments

The authors gratefully acknowledge the Indian Institute of Technology, Mumbai, India and Central Drug Research Institute, Lucknow, India for carrying out IR, DSC, TGA, XRD, and SEM analyses.