Preparation And Properties Of MWCNTs/PMMA Composite

Objective:To enhance the mechanical properties of poly methyl methyacrylate(PMMA), multi-walled carbon nanotubes(MWCNTs) were added into the methyl methacrylate(MMA) to prepare MWCNTs/PMMA composite,in which MWCNTs were distributed homogeneously.The surface morphology was observed.The mechanical properties of MWCNTs/PMMA composite were compared with the control group,poly methyl methyacrylate,and their biology safeties were evaluated.Methods:1.Preparation of MWCNTs/PMMA composite:On the basis of optimizing content of MWCNTs,the ratio of adding 1mg MWCNTs into 15ml MMA monomer was chosen to make MWCNTs/PMMA composite.The MMA monomer with MWCNTs was shocked by ultrasonic vibration for 15 min to make MWCNTs dispersed homogeneously in the monomer.Then this MMA monomer and PMMA powder were polymerized to prepare standard test specimens of MWCNTs/PMMA composite.According to the clinical requirements of denture base polymer,standard test specimens of the control group(PMMA 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 and abradability 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.3.Biological performance test:Referring to technical reports of ISO7406 standards, biology safety tests of the materials were tested in vivo and in vitro,including acute systemic toxicity test,oral mucosa irritation test and cytotoxicity test.Results:1.Material Preparation and surface morphology observation:MWCNTs/PMMA composite was prepared and the surface morphology was observed under scanning electron microscopy.MWCNTs were uniformly dispersed in the PMMA matrix. 2.Results of the mechanical properties test:Compared to the control group,the tensile strength and bending strength of MWCNTs/PMMA composite were significantly improved(p<0.05).Hardness and abradability were higher than the control group(p<0.05).3.Results of the biological properties test:Evaluation of the cytotoxicity test was level 1.No significant cytotoxicity or acute toxicity reaction was observed and no abnormal histological response was found in oral mucosa irritation test.Conclusions:1.MWCNTs can be homogenized in the PMMA by ultrasonic vibration.This method is an effective way,which has a lot advantages such as time,energy and cost saving.2.MWCNTs can improve the mechanical properties of PMMA.Strength, hardness and abradability of MWCNTs/PMMA composite which was prepared by using in situ polymerization can be improved compare with that the PMMA without reinforcing agent.3.The mucosal irritation test,acute systemic toxicity test and cytotoxicity test of MWCNTs/PMMA composite achieved the standard.The composite has good biological performance,safety and non-toxicity.