The Applied Basic Reseach Of Epoxidized Natural Rubber In Tread Compound And Ply Compound Of Tires

Epoxidized natural rubber (ENR) with epoxide groups was a kind of polar rubber and could react with silica. ENR had excellent wet skid resistance and could improve the adhesiveness of fibers. Hence, two aspects about ENR were studied in this subject.(1) The application of ENR in tread compound of tires was studied, including the mechanism of reactions among ENR, silica and silane coupling agent KH792and performance characteristics of KH792/silica/ENR composites as tread compound.(2) The application of ENR in ply compound of tires was studied, including effects of ENR and correlative factors on the adhesive property between aramid cord and rubber and the mechanism of adhesive reaction.Firstly, when it came to the application of ENR in tread compound, the synergistic effect of two kinds of silane coupling agent (KH792, Si69) modifying silica was studied. Compared with Si69/silica/ENR composites, KH792/silica/ENR composites had better cutting resistance and higher heat build-up.Secondly, when it came to the synergistic effect of ENR and KH792modifying silica, the reactions among ENR, KH792and silica were studied by FTIR and effects of different dosages of silica and KH792on properties of KH792/silica/ENR composites were studied. The results showed that ENR could react with KH792and KH792could react with silica. Heat treatment could lead to pre-crosslinking, so that it influenced the processability. So KH792/silica/ENR composites didn’t need heat treatment. With the increase of silica, the mechanical properties and cutting resistance of vulcanizates were enhanced and heat build-up and rolling resistance were raised. With the increase of KH792, the percent of bound rubber rose. KH792/silica/ENR composites had excellent cutting resistance and abrasive resistance and low heat build-up.Thirdly, when it came to the application of ENR in ply compound, with H pull-out force used to character the adhesive property between aramid cord and rubber, the synergistic effect of ENR and silica to adhesive systems and effects of curing systems and adhesive systems on the adhesive property between aramid cord and rubber were studied. The results showed that ENR, silica, curing time, RF99or HMT-80had some influence on the adhesive property between aramid cord and rubber and the best dosage existed. The accelerator NS (curing rate) had almost no influence on the adhesive property between aramid cord and rubber. The dosage of sulfur (crosslink density) was nearly linear with the adhesive property. Compared with the referenced recipe, the optimized recipe not only had better adhesive property, but also had better aging resistance.Lastly, when it came to the mechanism of adhesive reaction, the reacting condition, mechanism and reacting rate between RF99and HMT-80were studied by DSC, FTIR and TGA. The results showed that RF99could react with HMT-80and ENR could promote rhe reaction between RF99and HMT-80at151℃, improving the reacting rate and degree. HMT-80reacted by75%-85%after60minutes.