UFPR粒子提高胎面胶复合材料抗滑性能的基础研究

Generally, the tan δ value of tread compound in the range from -20 to 20 ℃ is an important parameter to evaluate the performance of the wet skid resistance, the higher the tan δ value, the higher the wet skid resistance of the tread compound, which has been widely used in rubber researches for many years. The ultrafine fully-vulcanized powder rubber (UFPR) is a novel irradiation vulcanized rubber particle prepared using the industrial technologies of irradiating rubber latex and spray drying. It is worth noting that the sizes of the UFPR particles are close to nanometer scale, and the glass transition temperature (Tg) of the UFPR particles are in the temperature range from -20 to 20 ℃. Our research results shows that the ultrafine fully-vulcanized powder nitrile butadiene rubber (UFPNBR) increases the wet skid resistance of tread compound while the ultrafine fully-vulcanized powder styrene butadiene rubber (UFPSBR) increasing the dry skid resistance of the tread compound in the case of rolling resistance not increasing. In this proposal, we will optimize the UFPR particles to modify the tread compound. On one hand, the ideal tanδ-temperature curves will be designed for the UFPR particles modified tread compound with high wet skid resistance. On the other hand, the effects of UFPR particles on the wet skid resistance and the dry skid resistance of the tread compound will be studied in three areas, the adhesive force occured between tread surface and the pavement surface, the hysteresis loss of tread compound, and the microtexture of tread surface. Especially, we will study the effects of the UFPR particles on the mechanism of wet skid resistance and dry skid resistance of tread compound using followed performance of the UFPR particles in detail, the chemical structure, the crosslink density, the dynamic viscoelasticity, polarity, size, thermal activation, UFPR loading and dispersion of UFPR particlesi in tread compound, etc. There are three research purposes in this proposal. The first research purpose is to develop the evaluating theory of the wet skid resistance of tread compound using the polar UFPNRB particles. The second one is try to build a relation between the dynamic viscoelasticity and the dry skid resistance of tread compound. The third one is to supply some research data for preparing the advanced tread compound with high wet skid resistance and dry skid resistance.

胎面胶在-20～20℃范围内的tanδ值是多年来评价其抗湿滑性能的重要理论依据，tanδ值大，抗湿滑性能高。超细全硫化粉末橡胶（UFPR）是一种玻璃化转变温度在-20～20℃范围的可达纳米级辐射硫化橡胶粒子。申请人发现，极性超细全硫化粉末丁腈橡胶（UFPNBR）能够提高胎面胶的抗湿滑性、非极性超细全硫化粉末丁苯橡胶（UFPSBR）显著提高胎面胶的抗干滑性。本课题优化设计UFPR粒子改性胎面胶的tanδ-T曲线，从胎面与路面之间的粘附力、胎面胶滞后损失力等方面，研究UFPR粒子的极性、动态粘弹性、交联结构、硬度、粒径、热活化和胎面微观构造等因素对胎面胶抗干滑、抗湿滑性能的影响机制。一方面，结合弹流润滑理论，丰富胎面胶的抗湿滑性理论，另一方面，应用动态粘弹性可控的硬质有机粒子，探索胎面胶的动态粘弹性与抗干滑性之间的关联性。为发展胎面胶的安全行驶性能评价理论和高性能胎面胶的制备提供新的研究思路。

应用橡胶乳液辐射硫化、喷雾干燥等技术制备了几种微纳米超细全硫化粉末橡胶粒子（UFPR，主要有UFPCNBR、UFPSBR-26、UFPSBR-50，UFPSBR-60、UFPSBR-70、UFPNBR），并研究了UFPR粒子的结构、交联程度、玻璃化转变温度（Tanδ峰值）、粒径等性能。一方面，应用UFPSBR-50，UFPSBR-60、UFPSBR-70、UFPNBR和UFPCNBR粒子制备了UFPR/乳聚丁苯（ESBR）/天然橡胶（NR）/炭黑胎面胶复合材料，从UFPR粒子的结构、动态热力学性能、交联密度、用量等方面研究了UFPR粒子对ESBR/NR/炭黑复合材料的抗滑性能的影响。另一方面，从UFPR粒子的结构、动态热力学性能、极性、用量等方面研究了UFPSBR-26、UFPSBR-50，UFPSBR-60和UFPNBR对溶聚丁苯（SSBR）/顺丁橡胶（BR）/白炭黑胎面胶复合材料的抗湿滑性能影响。.研究表明，UFPSBR粒子可明显提高ESBR/NR/炭黑胎面胶复合材料和SSBR/BR/白炭黑胎面胶复合材料的耐磨性能（提高率达66 %），同时降低UFPR/SSBR/BR/白炭黑胎面胶复合材料的压缩疲劳温升（降低率达25 %），提高了汽车高速安全行驶性。研究表明，UFPSBR-50能够提高UFPR/ESBR/NR/炭黑胎面胶复合材料的tanδ（0 oC）值；UFPSBR-26、UFPSBR-50、UFPNBR粒子都能够提高UFPR/SSBR/BR/白炭黑胎面胶复合材料的tanδ (0 oC）值，提高了胎面胶的抗湿滑性能。UFPSBR粒子均能改善UFPR/ESBR/NR/炭黑胎面胶复合材料的和UFPR/SSBR/BR/白炭黑胎面胶复合材料的水浸润性，UFPSBR粒子刺破SSBR/BR/白炭黑复合材料表面水膜的能力较强，明显提高了UFPR/SSBR/BR/白炭黑胶复合材料的抗湿滑性能。UFPSBR-60提高了UFPR/SSBR/BR/白炭黑复合材料的动摩擦系数，有助于抗干滑性能的改善。在采用损耗因子作为评价胎面胶抗湿滑性能的基础上，充分考虑影响水膜厚度及破坏的因素，提出了抗湿滑性能的简化经验函数表达式；从胎面胶的损耗因子、热活化能力、微观粗糙度、滞后损失方面，研究了UFPR粒子改性胎面胶的动态粘弹性与其抗干滑性能之间的关系，提出了抗干滑性能的简化经验函数表达式。