Abstract:

Abstract:Objective  To investigate the influence of low temperature argon plasma in the shear strength  polyetheretherketone (PEEK) and PEEK composites, and to clarify the bonding mechanism of PEEK and PEEK composites.Methods The specimens were divided into control group (PEEK) and experiment group (PEEK composites).The surfaces of the specimens were treated with low temperature  argon plasma for 0,5,15,and 25 min　(plasma 0,5,15,and 25 min groups).The surface microstructure of the specimens after  treated with plasma was measured by scanning electronic microscope (SEM).Then the  RelyXTM Unicem was bonded onto the specimens.After 24 h at 37°C distilled water storage,the shear strength of the specimens was measured;the  failure modes were assessed by stereomicroscope.Results The grooves,cracks,and deposits appeared on the surfaces of the specimens in plasma 5,15,and 25 min groups after treated with low temperature  argon plasma.The shear strength of the specimens in control group was significantly increased in plasma  5 min group compared with plasma  0 and 15 min groups (P<0.01).The shear  strength of the specimens in plasma  25 min group had no significant differences compared with plasma  5 min group (P>0.05).In experiment group,the shear  strength of the specimens in plasma 5 min group was decreased compared with plasma 15 and 25 min groups (P<0.05).The shear  strength of the specimens had no significant difference between plasma 15 and 25 min groups (P>0.05).The shear  strength of the specimens in  control group was statistically lower than that in  experiment group at 15 min (P<0.05).There were no significant differences of shear strength among the other groups (P>0.05).The main failure mode of the specimens was the interface damage in all groups.Conclusion Low temperature argon plasma treatment can enhance the bond strength of PEEK and PEEK composites.The shear strength of the specimens  is increased with the increasing of treatment time.The different hardness of the specimen surfaces results in the inconsistencies of the shear  strength between PEEK and PEEK composites.

Key words: plasma, polyetheretherketone, surface treatment, bonding, microstructure