Effect Of Surface Treatment On Adhesive Properties Of Rubber Materials

The advantages such as convenience,shortcut and comfort make railway carriages and subway vehicles more and more popular.Rubber has been widely concerned and studied,since it has many advantages such as good elasticity,wear resistance,durability,tightness,corrosion resistance and light weight.It has great effect on improving the beauty and comfort of train and the quality and grade of the interior vehicle.However,Ethylene Propylene Diene Monomer(EPDM)and Natural Rubber(NR)widely used in railway train are non-polar in nature,which makes EPDM and NR have poor bonding properties with polyurethane and other polar materials.With the wide application of rubber composites in various fields,the bonding between rubber composites and other materials has become a hot research issue.To improve the bonding properties of EPDM and NR,in this thesis,the surface treatment of EPDM is conducted in sulfuric acid solution and sodium hydroxide solution,respectively.Acetone solution of trichloroisocyanuric acid is used for the surface treatment of natural rubber.By means of scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)and fourier transform infrared spectroscopy(FTIR)and T-peeling strength,the effect of grinding,concentration of treatment solution,tempreture,time and adhesive on the bonding properties of EPDM and NR have been investigated.The results are as follows:When the surface of EPDM is treated by sulfuric acid solution,the suitable processing condition is that EPDM is ground with a file,followed by isopropanol cleaning,and then is treated for 10 minutes in the 5 mol·L-1 sulfuric acid solution at 30?,followed by 5 minutes in dilute 3 wt%ammonia solution at room temperature.At last,EPDM is rinsed with water and dried.The surface polarity and adhesion strength of EPDM are obviously improved after acid treatment.After screening,the better adhesive is Adhesive X,and the T-peeling strength of the EPDM/Adhesive X/EPDM is 2.12 N·mm-1,and the rubber substrate is broken during test.When the surface of EPDM is treated by sodium hydroxide solution,the suitable processing condition is that EPDM is ground using a file,followed by isopropanol cleaning,and then is treated for 15 minutes in the sodium hydroxide solution of 15 wt%at 60?.At last,EPDM is rinsed with water and dried.After alkali treatment,the adhesion strength of EPDM is obviously improved.After screening,the better adhesive is Adhesive X,and the T-peeling strength of the EPDM/Adhesive X/EPDM is 3.09 N·nm-1,and the rubber materials is destroyed.When the surface of NR is treated by TCCA/MEK solution,the suitable processing condition is that NR is ground by a file,followed by isopropanol cleaning,and then is treated for 20 minutes in 3 wt%TCCA/MEK solution at room tempreture.At last,NR is rinsed with water and dried.After the treatment,the surface polarity and adhesion properties of natural rubber are obviously improved.After screening,the better adhesives' are 801 strong adhesive,Sikaflex 265,Tianshan 1956.The T-peeling strength of the NR/801 strong adhesive/NR is 2.85 N·mm-1,and the rubber material is destroyed.The T-peeling strength of the NR/Sikaflex 265/NR is 2.48 N·mm-1,and the rubber material is broken.The T-peeling strength of the NR/Tianshan 1956/NR is 2.53 N·nm-1,and the rubber material is also broken.The results show that grinding and chemical treatment can improve the surface polarity,chemical properties and surface roughness of EPDM and NR,and subsequently improve the adhesive performance of rubber.