Surface and chemical properties of surface-modified UHMWPE powder and mechanical and thermal properties of it impregnated PMMA bone cement, III: effect of various ratios of initiator/inhibitor on the surface modification of UHMWPE powder

Polymerization and Applications of Poly(methyl methacrylate)-Graphene Oxide Nanocomposites: A Review

Graphene oxide (GO)-incorporated poly(methyl methacrylate) (PMMA) nanocomposites (PMMA-GO) have demonstrated a wide range of outstanding mechanical, electrical, and physical characteristics. It is of interest to review the synthesis of PMMA-GO nanocomposites and their applications as multifunctional structural materials. The attention of this review is to focus on the radical polymerization techniques, mainly bulk and emulsion polymerization, to prepare PMMA-GO polymeric nanocomposite materials. This review also discusses the effect of solvent polarity on the polymerization process and the types of surfactants (anionic, cationic, nonionic) and initiator used in the polymerization. PMMA-GO nanocomposite synthesis using radical polymerization-based techniques is an active topic of study with several prospects for considerable future improvement and a variety of possible emerging applications. The concentration and dispersity of GO used in the polymerization play critical roles to ensure the functionality and performance of the PMMA-GO nanocomposites.

Optimization of Mechanical and Setting Properties in Acrylic Bone Cements Added with Graphene Oxide

The extended use of acrylic bone cements (ABC) in orthopedics presents some disadvantages related to the generation of high temperatures during methyl methacrylate polymerization, thermal tissue necrosis, and low mechanical properties. Both weaknesses cause an increase in costs for the health system and a decrease in the patient’s quality of life due to the prosthesis’s loosening. Materials such as graphene oxide (GO) have a reinforcing effect on ABC’s mechanical and setting properties. This article shows for the first time the interactions present between the factors sonication time and GO percentage in the liquid phase, together with the percentage of benzoyl peroxide (BPO) in the solid phase, on the mechanical and setting properties established for cements in the ISO 5833-02 standard. Optimization of the factors using a completely randomized experimental design with a factorial structure resulted in selecting nine combinations that presented an increase in compression, flexion, and the setting time and decreased the maximum temperature reached during the polymerization. All of these characteristics are desirable for improving the clinical performance of cement. Those containing 0.3 wt.% of GO were highlighted from the selected formulations because all the possible combinations of the studied factors generate desirable properties for the ABC.

Surface and chemical properties of surface-modified UHMWPE powder and mechanical and thermal properties of its impregnated PMMA bone cement, IV: effect of MMA/accelerator on the surface modification of UHMWPE powder

In our previous study, we manufactured a reinforced poly(methylmethacrylate) (PMMA) bone cement with 3 wt% of the surface-modified ultra high molecular weight polyethylene (UHMWPE) powder to improve its poor mechanical and thermal properties resulting from unreacted methylmethacrylate (MMA), the generation of bubble and shrinkage, and high curing temperature. In the present study, the effect of ratios of MMA and N,N'-dimethyl-p-toluidine (DMPT) solutions in redox polymerization system was investigated for the surface modification of UHMWPE powder. We characterized physical and chemical properties of surface-modified UHMWPE powder and reinforced bone cements by a scanning electron microscope, ultimate tensile strength (UTS) and curing temperature (Tmax). It was found that UTSs (41.3-51.3 MPa) of the reinforced PMMA bone cements were similar to those (44.5 MPa) of conventional PMMA bone cement (control), as well as significantly higher (P < 0.05) than those (33.8 MPa) of 3 wt% unmodified UHMWPE powder-impregnated bone cement. In particular, the UTS of redox polymerization system using MMA/DMPT solution was better than that of radical system using MMA/xylene solution. Also, Tmax of the reinforced PMMA bone cements decreased from 103 to 72-84 degrees C. From these results, we confirmed that the surface-modified UHMWPE powder can be used as reinforcing agent to improve the mechanical and thermal properties of conventional PMMA bone cement.