Effect of water absorption on the izod impact energy of crosslinked poly(methyl methacrylate‐acrylic acid) and their composites

Abstract Crosslinked poly(methyl methacrylate‐acrylic acid) and composites using this crosslinked copolymer as the matrix have been synthesized and evaluated for their potential as bioimplantable materials in design of a new class of bone anchors. The low‐velocity impact energy absorption properties of this slightly hydrophilic class of materials were examined by Izod impact testing. In particular, the influence of swelling (by absorption of water) on the impact resistance of the crosslinked copolymer and composites based on this copolymer was investigated. Also, the influence of fiber type and preform architecture on the impact resistance of the composite, in both the dry and swollen states, was investigated. The fracture surfaces and the modes of failure in these tests were examined using scanning electron microscopy. The results indicated that absorption of water leads to about a threefold increase in the impact resistance of the copolymer. However, the increase in the impact resistance of the composite samples after water absorption varied considerably, depending on the type and form of fibrous reinforcement. These results and our understanding of the role of water absorption on the impact resistance of these novel systems are presented.