Study On Tribological Properties Between Silicone Rubber And Ice Surface

Tribology is a discipline that studies the surface-to-surface interaction of relative motion.As a branch of tribology,ice tribology is widely used in daily life and production.In the north of China in winter,the road surface after snowy days will bring many potential traffic hazards,so it is necessary to take various anti-icing and anti-slip measures.In addition,many reservoirs and rivers will freeze.When ice and snow melt,reservoir dams and river embankments will face a series of squeeze damage and friction damage.Therefore,it is very necessary to understand the mechanism of ice friction and explore the relevant factors affecting the friction coefficient of ice surface.Researchers have suggested that the "self-lubrication" effect is the main cause of such a small friction coefficient.The polydimethylsiloxane(PDMS)as a hydrophobic polymer soft material,has been widely used in various fields such as coatings,microfabrication,biomedical and bionic substitution.In addition,PDMS has the advantages of short preparation process,mild reaction conditions,easy access to reaction products.At the same time,PDMS can perform good surface modification.Therefore,the study of the friction properties of PDMS on the ice surface provides a feasible way to put forward the ice friction mechanism,and can deduce and summarize the friction mechanism of many polymer soft materials on the ice surface.In this thesis,the friction between PDMS and ice surface was studied under different friction conditions and different physical and chemical properties of PDMS.Consequently,the general mechanism of ice tribology was summed up.Meanwhile,effects of water-soluble polymer film and lubricating oil film on the friction properties of ice surface was explored,and the general regulation of friction and lubrication on ice surface was proposed.The main contents and conclusions are as follows:(1)Tribological behavior of silicone rubber on ice surface: Friction experiments were carried out on ice surface using soft polymer PDMS prepared by mixing liquid main agent and curing agent.The results of friction test show that the friction coefficient decreases gradually with the increase of load when other conditions remain unchanged.As the sliding speed increases,the corresponding friction coefficient also shows a decreasing trend,and with the increase of ice surface temperature,the friction coefficient of PDMS on the ice surface decreases gradually.When the solid-liquid ratio of PDMS is changed,the corresponding tensile strength is gradually reduced,resulting in a decrease in the friction coefficient.(2)Effect of physicochemical properties of PDMS surface on tribological properties of PDMS and ice surface: The surface of PDMS was treated by oxygen plasma and fluoride reagent respectively,so that the surface wettability of PDMS was different.Friction tests show that the friction coefficient of PDMS on ice surface decreases gradually when the wettability of PDMS surface changes from hydrophilic to hydrophobic.In addition,two different treatment methods are used to change the surface roughness of PDMS.By comparing and testing the friction coefficient under different roughness,it is found that the friction coefficient decreases first when the surface roughness increases,but with the continuous increase of the surface roughness,the corresponding friction coefficient will increase rapidly,and the overall trend of decline first and then rise.Finally,the friction mechanism of PDMS silicone rubber on ice surface is roughly divided into three stages: the first stage of dry friction,the second stage of water film formation and the last stage of hydrodynamic friction under water lubrication.(3)Study on tribological properties regulation of PDMS and ice surface: The lubricating effect on friction was investigated by constructing a water-soluble polymer lubricating film layer and a lubricating oil film layer between PDMS and the ice surface.It is found that the molecular weight and viscosity of water-soluble polymers have a great influence on their lubrication effect.When the molecular weight and viscosity increase,the low temperature fluidity of water-soluble polymers is poor,which results in the relative weakening of the lubrication effect of water-soluble polymers on ice friction.Similarly,the lubricating effect of a lubricating oil whose properties are easily changed under low temperature conditions will also change,while some lubricants or greases with good low-temperature fluidity can maintain excellent and stable lubricating effects at high viscosities.Meanwhile,when lubricating oil is used as a means of regulating ice friction,the change of friction conditions such as load does not affect its result on friction lubrication.In the field where ice lubrication adjustment is required,water-soluble polymers or lubricants with low molecular weight and good fluidity at low temperature can be used to reduce friction and wear.Through the study on the tribological behavior of silicone rubber on ice surface,the tribological law between polymer soft matters and ice surface can be grasped more clearly.Meanwhile,the general tribological mechanism can be discovered.Consequently,the theoretical ground can be provided for preparing,tribological properties regulation,and application of ice friction materials.On the other hand,the technical support can be offered for ice prevention and anti-slip measures.