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Polymethylmethacrylate-based (PMMA) bone cements containing functionalized carbon nanotubes (CNTs) were prepared, and the thermal properties of the resultant nanocomposite cements were characterized in accordance with the international standard for acrylic resin cements. The aim of this study was to determine the peak temperatures during the polymerization reaction in PMMA bone cement by thermocouple (temperature sensor). The CNTs were uniformly dispersed in the cement matrix. The setting time of the cement increased and the maximum temperature during exothermic polymerization reaction was effectively reduced by the incorporation of functionalized CNTs. This reduction decreased thermal necrosis of the respective nanocomposite cements, which probably could reduce the hyperthermia experienced in vivo.

Polymethylmethacrylate-based (PMMA) bone cements incorporating multiwalled carbon nanotubes (MWCNTs) as a means of reinforcement were prepared, and their structure and properties were investigated by displacement sensor and chevron-notched test method. The aim of this study was to determine the transverse-direction fracture toughness (KIv) in PMMA bone cement by using the displacement sensor. Three major advantages of the displacement sensor test method are: (1) It is easier to achieve the plane strain requirements; (2) Not required to make the fatigue-precracking; (3) It is considerable easy to produce stable crack propagation before completely fracture. The fracture toughness values of PMMA bone cement and PMMA/MWNCTs bone cement were measured to be 1.235±0.15 MPa m1/2 and 1.725±0.15 MPa m1/2, respectively. Based on the microstructures shown in SEM images, the improved fracture toughness of PMMA bone cement was contributed to the incorporation of surface functionalized MWCNTs.

In this work, an efficient procedure for the functionalization of multiwalled carbon nanotube (MWCNTs) based on nitric acid oxidation was presented. The morphologies of MWCNTs oxidized under various conditions were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The FTIR provided clear evidence for the presence of carboxylic groups (–COOH) attached to the surface of MWCNTs resulting from the acid treatment. The unfunctionalised MWCNTs(p-MWCNTs) and carboxy1 functionalized MWCNTs (f-MWCNTs) were successfully applied into the Polymethyl methacrylate (PMMA) bone cement. The resultant mechanical experiment indicated that the f-MWCNTs were a promising additive to improve the compressive strength and bend strength of the PMMA bone cement. The morphology and degree of dispersion of the MWCNTs in the PMMA matrix at different scales were analyzed by SEM. Improvements in mechanical properties were attributed to the MWCNTs arresting or retarding crack propagation through the cement by providing a bridging effect into the crack, normal to the direction of crack growth.