The Preparation And Properties Of The Composites Of Polymethylmethacrylate And Functionalized Multi-walled Carbon Nanotubes

Objective:To enhance the denture resin base, functionalized multi-walled carbon nanotubes were added into the polymethylmethacrylate as the reinforcement to prepare F-MWCNTs/PMMA composite, in which functionalized multi-walled carbon nanotubes were distributed homogeneously. The fresh fracture surfaces morphology were observed. The mechanical properties of MWCNTs/PMMA composites were compared with the control groups polymethylmethacrylate, so as to provide a reference for clinical application.Methods:1 Preparation of F-MWCNTs/PMMA composite:After further purification, multi-walled carbon nanotubes were functionalized by the oxidition of UV-Fenton reagent. Shocked by ultrasonic vibration, Carbon nanotubes were distributed homogeneously in the methylmethacrylate monomer in cases of adding the surfactant named triton X-305.Then this methylmethacrylate monomer and polymethylmethacrylate powder were prepared in situ polymerization. The standard test specimens of MWCNTs/PMMA composite were prepared by using the energy of microwave radiation. According to the clinical requirements of denture base polymer, standard test specimens of the control group (polymethylmethacrylate without reinforcing agent) were prepared. The surface morphology of the test group and the control group were observed using scanning electron microscopy.2 Mechanical properties test:The mechanical properties including tensile strength, bending strength, hardness were tested in the test group and control group samples. The experimental data were treated by statistical method. The differences of mechanical properties between the two groups were evaluated. Results:1 The further purification and function of the multi-walled carbon nanotubes: After further purification, it can be confirmed by the observation of scanning electron microscope that the purity of multi-walled carbon nanotubes were increased. Infrared spectroscopy showed that a large number of hydroxyl and a small mount of carboxyl were added onto the surfaces of the multi-walled carbon nanotubes by the oxidation of the UV-Fenton reagent.2 Results of the mechanical properties test:Compared to the control group, the tensile strength and bending strength and hardness of F-MWCNTs/PMMA composite; were significantly improved (p<0.05).3 Morphology observation of the scanning electron microscopy:The function-alized multi-walled carbon nanotubes were uniformly dispersed in the polymethyl methacrylate matrix. The functionalized multi-walled carbon nanotubes combined with the polymethylmethacrylate made them composite particles. There were a large number of river-like appearance and dimples on the surfaces of tensile in the composite group under the observation of scanning electron microscope.Conclusions:1 The functional results of the multi-walled carbon nanotubes can be achieved by the UV-Fenton reagent perfectly. It's a mild reaction and requires less strictly conditions. It does less harm to the structures of the multi-walled carbon nanotubes and has a good advantages of high efficiency.2 With the function of ultrasonic and surfactant, it made the multi-walled carbon nanotubes a good dispersion. The Suspension can be kept stable rather a long time. This approach can preserve most of the chemical active site, in which way carbon nanotubes can play a more favorable performance.3 The functionalized multi-walled carbon nanotubes can improve the mechanical properties of polymethylmethacrylate. Strength and hardness and of MWCNTs/ PMMA composite which was prepared by using in situ polymerization can be improved compare with that the polymethylmethacrylate without reinforcing agent.