Structure and Wear Properties of Nano-Silicon Dioxide Modified Polyacrylate Composites

polyacrylate/nano-silicon dioxide nanocomposites were fabricated through a simple mixing process for resisting scratch and wear as coating. Chemical compatibility between polyacrylate matrix and nano-silicon dioxide (nano-SiO2) was achieved by functionalized nano-SiO2 via three silane coupling agents. Scanning electron microscopy (SEM) was done to characterize surface and wear morphology of the nanocomposites. Differential scanning calorimetry (DSC) was used for representing interfacial properties of the nanocomposites. A MM-200 machine and a Norman Tool RCA abrader were performed for testing friction and wear properties. SEM showed that incorporation of the nano-SiO2 functionalized with silane into the polyacrylate matrix showed a better dispersion than the composite without silane at low nanoparticle content (≤3 wt%). SEM also revealed that adhesive wear mechanism of the polyacrylate matrix was transited to dominated particle wear of the nanocomposites. An increase of glass transition temperature (Tg) was recorded via DSC at low nanoparticle content (1 wt%). Further addition of the nanoparticles to 3 wt% led to a 10°C increase in Tg comparing to neat polyacrylate. Results of friction and wear properties exhibited that friction coefficient and wear loss of the nanocomposites with silane were lower than those of the neat polyacrylate. The wear loss of the neat polyacrylate, the nanocomposite containing 3 wt% nanoparticles with silane KH570, and the nanocomposite with raw nano-particles were 108.6, 65.8, and 110.5mg, respectively. RCA results also showed a significant improvement of the nanocomposites in the presence of the nanoparticles with silane.