Absorptive and expansive behaviors of poly(methyl methacrylate-co-acrylic acid) bone cement

Some additives had provided the expansion capacity to the polymethylmethacrylate (PMMA) bone cement and also reduced its maximum reaction temperature. However, the corresponding modified bone cement displayed inferior simulated body fluid (SBF) absorption capacity and expansion behavior, the mechanism of SBF absorption and the trend of expansion stress were ignored additionally. In this study, a homogeneous distribution of poly (methyl methacrylate-co-acrylic acid) [P(MMA-AA)] microspheres led to the formation of microchannels that favored the delivery of SBF to the interior, causing an increased absorption capacity and enhanced expansion behavior before solidification of the bone cement, with the maximum equilibrium absorption ratio and the expansion ratio reaching 27.3 % and 26.3 %, respectively, at an AA content of 50 %. In addition, the expansion stress induced by the expansion behavior experienced a gradual increase from the 0 s to 2590s, followed by a sharp climbed in a short period ranging from 2590s to 2900s, finally reaching maximum stress of 82.1 MPa. Furthermore, the expansion stress within the maximum value could be obtained by controlling the AA content in the P(MMA-AA) bone cement. With the above characteristics, the prepared P(MMA-AA) bone cement has potential applications as a filling and adhesive material in arthroplasties, vertebroplasties, joint replacements, bone screws, and dentistry.