Preparation And Properties Of Functional Surface Polysulfide Polymer Brush

Functional modification of the surface of the material plays a vital role in broadening the application field of the material and improving the performance of the material.Reducing the friction coefficient of the material surface can reduce the friction and wear of the material,reduce the energy dissipated due to friction,and extend the service life of instruments and devices.It plays a vital role in industrial production.Building a polymer brush on the surface of the material can make the surface have special properties such as anti-fouling,anti-fog,anti-bacterial,anti-corrosion,super-lubricating and so on.The silver nanoparticles Ag NPs can kill bacteria and viruses effectively.Thioether Group has good chelating ability with Ag NPs.And sulfide has oxidation sensitivity,low-valent sulfide exhibits hydrophobicity,in the presence of oxidant,it can be oxidized into higher valence sulfoxide or sulfone.In this paper,polymer brushes were prepared with thioether-containing monomers to achieve the loading of silver nanoparticles on the surface,and the friction properties of the material surface were changed by adjusting the oxidation degree of the thioether groups.Firstly,a kind of thioether monomer was synthesized,and then the thioether polymer brush [3-(methylthio)propyl methacrylate] polympe was successfully prepared by surface initiated atom transfer radical polymerization(SI-ATRP).We used different oxidants to oxidize the thioether groups to different degrees,and we systematically characterized the surface element composition,morphology and structure of sulfide,sulfoxide and sulfone brushes.We tested the friction performance of three polymer brushes when using water as a lubricant.The results show that as the thickness of the polymer brush increases,the friction factor increases.After the hydrophobic sulfide polymer brush is oxidized to hydrophilic sulfoxide and sulfone,the conformation of the polymer chain is extended,and the friction factor of the surface of the polymer brush is significantly reduced.So we can adjust the hydrophilic and hydrophobic properties of the polymer brush by redox reaction.Then,we investigated the ability of thioether polymer brushes to load Ag NPs.In order to make the polymer brush load Ag NPs better,we prepared poly MPE-b-PMMA brushs by SI-ATRP.And we systematically characterized the element composition,morphology and structure of poly MPE-b-PMMA brushes.We characterized the abilityof poly MPE brushes and poly MPE-b-PMMA polymer brushes to load Ag NPs,and tested the effect of Ag NPs loading on the frictional properties of the surface.The results show that poly MPE and poly MPE-b-PMMA have a strong loading capacity for Ag NPs,after adding the upper layer of PMMA,the Ag NPs adsorbed by the poly MPE layer are locked and the loading capacity is stronger.When the polymer brush is loaded with silver nanoparticles,the friction performance is also greatly affected.Since the hard silver nanoparticles are adsorbed in the polymer brush,the surface becomes rough,and the friction factor increases greatly.