高性能轮胎用橡胶纳米复合材料的制备与性能

Preparation and properties of rubber nanocomposites applied to high performance tires

"节油、安全"的高性能轮胎已成为世界汽车轮胎的发展趋势.构成轮胎的橡胶复合材料中,胎面胶、钢丝圈垫胶和气密内衬层胶等高性能纳米复合材料是发展节油轮胎的关键材料.胎面胶是轮胎与路面直接接触的部分,要求具有低滚动阻力、高抗湿滑性能和优异的耐磨性;钢丝圈垫胶位于钢丝圈上端,起到填充和加强胎圈的作用;气密内衬层胶贴覆在轮胎内表面,起到保持轮胎气压的作用.本文主要介绍了近年来胎面胶用白炭黑/橡胶纳米复合材料、钢丝圈垫胶用针状硅酸盐/橡胶纳米复合材料、气密内衬层胶用黏土/橡胶纳米复合材料,以及含碳纳米管和石墨烯增强的新型橡胶纳米复合材料的制备方法、性能特点及应用状况,并对将来的发展进行了展望.

The high performance tire with low fuel consumption and high wet skid resistance is the developing trend of tires in the world. Among the varied rubber composites comprising of tires,the rubber composites applied to tire tread,bead filler and inner liner are the keys to develop high performance tires. This review mainly introduces the preparation methods and properties of novel rubber nanocomposites for tires,and the future development trend is also suggested. Tire tread,which directly contacts the road,should meet the demands of low rolling resistance,high wet skid resistance and excellent abrasion resistance. The filler type,filler dispersion level and the filler-rubber interaction are important affecting factors for tire tread rubber composites. Now,silane-silica filled rubber nanocomposites are usually used as tire tread materials for high performance tires. This is due to the facts that silane-silica filled rubber nanocomposites exhibit lower rolling resistance and higher wet skid resistance than carbon black filled rubber nancomposites. The underlying mechanism was also discussed. To ensure the fine silica dispersion,in situ modification dispersion method is often applied during the industrial preparation process,and exact controlling in situ modification temperature is the key. In addition,liquid compounding method has attracted increasing attention. Further,new types of filler,such as carbon nanotube（CNT） and grapheme,can also be used in tire tread rubber nanocomposites,and the latest advances are mentioned. Bead filler,applied on the top of bead bundles,gives filling and reinforcing performance. Rubber nanocomposites used for bead filler should exhibit high modulus,high hardness,and excellent adhesion. Fibrillar silicate（FS） is composed of many fibrillar nanosized single crystals. Similar to silane-silica filled rubber composites,FS filled rubber composites can also be prepared by in-situ modification dispersion method to improve FS dispersion and interfacial interaction. Similar to the conventional short microfiber reinforced rubber,FS/rubber composites also exhibited high modulus,high tear strength,and anisotropy. It is worthy to note that FS filled rubber composites show better flow characteristics than short microfiber reinforced rubber. The potential of FS filled rubber nanocomposites used for bead filler was discussed. Innerliner,placed on the inner surface of tubeless tires,is to maintain the air pressure,and it requires that the rubber nanocomposite should have excellent gas barrier property. Clay,different from CB and silica,is of layered structure,and it can greatly improve the gas barrier property of rubber materials by its nanolayers. Clay can be dispersed on a nanometer level in rubber matrix by latex compounding method（LCM）. LCM combines and fully makes good use of the two facts：（1） Many rubbers have their own latex form and latex can be considered as nanopolymer spheres dispersed in a water medium;（2） layered structural clay can be totally exfoliated by water. Further,for LCM,the organic modifier can also be added into the clay/water suspension to in situ modify the clay layers to improve interaction between clay and rubber matrix. And so,LCM is a low cost and easily controlled process. The clay/rubber nanocomposites prepared by LCM exhibit excellent mechanical and gas barrier properties,and they can be a good alternative for innerliner materials. Industrialized clay/rubber nanocomposites have been applied in tire inner liner,off the road tire tread and etc. For spherical and fibrillar types of filler,such as silica,FS and CNT,the fine dispersion and interfacial interaction can be achieved by in situ modification dispersion method; for layered fillers,such as clay and graphene,LCM is an effective method to obtain the fine dispersion and interfacial interaction. In the future,the applications of CNT and graphene filled rubber nanocomposites will largely depend on their preparation costs.