[Effect of nano ZrO2 on flexural strength and surface hardness of polymethylmethacrylate].

Purpose: To study the effect of polymethylmethacrylate(PMMA's) mechanical properties reinforced by nano ZrO(2) particles with different filling amounts.

Methods: The nano ZrO(2) particles were surface-treated by silane coupling agent(Z-6030) in 1.5wt% ratio, the untreated particles were regarded as the control group. The modified nano ZrO(2) particles were mixed with the PMMA powders in proportion of 0.5%,1%,1.5%,2%,2.5%,3% and 3.5%, respectively.Then the nano ZrO(2) /PMMA composites were synthesized. The specimens were examined by Vickers hardness test and three-point bending test, the surface of fracture was observed by SEM.All data were analyzed with ANOVA test by SAS 6.12 software package.

Results: Fourier transform infrared(FTIR) spectroscopy showed that the silane coupling agent linked to the nano ZrO(2) particles' surface after treating,the Vickers hardness was highest when the adding amount of nano ZrO(2) particles was 1.5% and 2%(P<0.05).The flexural strength of nano ZrO(2)/PMMA composites in the proportion of 1.5% was the highest(P<0.05). SEM indicated that the ductile fracture existed on the surface of fracture.

Conclusions: The silane coupling agent can enhance the bonding strength of nano ZrO(2) particles and the PMMA matrix, the PMMA's mechanical properties could be improved by adding the nano ZrO(2) particle in an appropriate proportion. 1.5% and 2% of nano ZrO(2) particles render the nanocomposite the maximal Vickers hardness, while 1.5% ZrO(2) nanoparticles render the nanocomposite the maximal flexural strength.