【作者】 张宏雷；

【导师】 王仕峰；

【作者基本信息】 上海交通大学 ， 化学工程， 2011， 硕士

【摘要】 近年来,橡胶沥青技术快速发展,用于橡胶沥青制备的关键原料轮胎胶粉的来源也倍受关注,当前橡胶沥青用的胶粉是来自载重车的废轮胎,而轿车废轮胎多用于土法炼油,严重污染环境、浪费资源。为了促进废旧轿车轮胎资源的在沥青中的合理化应用,从轮胎橡胶与沥青相互作用、轿车轮胎胶粉脱硫再生工艺、脱硫胶粉改性沥青制备及性能等方面展开了研究。首先,通过溶胀实验分析了载重车胎橡胶与轿车轮胎橡胶的溶胀行为,考察了溶胀时间t、温度T、橡胶厚度d对溶胀质量增量的影响。通过菲克扩散公式验证了质量增量与2t^1/2/d的线性关系,根据拟合曲线得到橡胶溶胀扩散系数D,D值与溶胀温度成正比,并受轮胎橡胶类型影响。根据平衡溶胀比和质量损失率曲线发现载重车胎橡胶在溶胀过程中存在明显的交联网络结构降解,而轿车轮胎橡胶的网络结构变化不明显,经甲苯抽提实验发现轿车轮胎橡胶溶胀、抽提后质量较未溶胀、抽提的轿车轮胎橡胶,证明沥青组分与橡胶有反应结合。其次,制备了轮胎配方的混炼胶,通过平衡溶胀比、质量损失率曲线、TGA和DSC等分析了天然橡胶（NR）、丁苯橡胶（SBR）与沥青相互作用行为的异同。结果表明沥青对NR的网络结构破坏明显,对SBR网络结构影响较小,溶胀后NR和SBR玻璃化转变温度Tg均升高,沥青的结晶组分进入橡胶网络。橡胶与沥青的相互作用影响硫化橡胶的热氧降解过程。载重车胎橡胶与NR的溶胀规律相似,而轿车轮胎橡胶与SBR溶胀规律相似,轮胎橡胶使用过程中的老化并未从根本上影响其与沥青的相互作用。再次,探索了轿车轮胎胶粉改性沥青的工艺。SEM、TGA表明轿车轮胎以合成橡胶为主,且含有不能通过常规研磨工艺完全破碎的纤维。剪切实验表明胶粉粒径与剪切时间成反比。过滤实验发现载重车胎胶粉在剪切4h后微米级粒子明显增多,轿车轮胎胶粉微米级粒子随剪切时间缓慢增长,剪切过程有炭黑、无机填料脱落的现象,载重车胎胶粉受剪切作用影响更大。最后,采用螺杆挤出脱硫工艺制备了脱硫再生胶粉,考察了挤出温度、脱硫剂、石油树脂含量对脱硫再生橡胶溶胶-凝胶含量的影响。挤出温度越高、脱硫剂用量越大,溶胶含量越大。挤出温度增大,脱硫再生胶粉改性沥青针入度增大,延度、软化点、粘度均降低。随着脱硫胶粉含量的增大,复合改性沥青的针入度降低,软化点升高,延度、弹性恢复降低,RTFOT后延度提高,提高了耐老化性能。光学显微结构表明螺杆挤出脱硫能够有效减小胶粉的粒径,胶粉由毫米级转变为微米级均匀分散在改性沥青中,复合改性沥青中脱硫再生胶粉与SBS结合较好。更多还原

【Abstract】 Rubber asphalt technology developed rapidly in recent years, the high requirements of road performance need more high-quality crumb rubber. Curmb rubber used now in asphalt rubber mainly is truck tire rubber. Passenger car tire is consumed by unlawful oil refining, which has great threat to environment and oil market. In order to achieve the reasonable and effective application of waste passenger tire rubber resource, this paper conducted studies on waste rubber-asphalt interaction, vulcanized rubber -asphalt interaction, regeneration process of passenger car tire rubber and reclaiming crumb rubber modified asphalt.Tire rubber was immersed in asphalt for different time at different temperatures to study the interactions between rubber and asphalt. The mass and cross-linking network change were investigated using extraction experiments and equilibrium swelling method, as well as thermal analysis. This study shows that the mass increase （MI） of rubber is approximately linear with 2t^1/2/d （t as swelling time, d as rubber thickness）; and the diffusion coefficient D of asphalt is related to the swelling temperature and rubber type. The cross-linking network structure of truck tire rubber can be destroyed when the swelling temperature reaches 190 oC, and the rubber disintegrats after 24 h. However,the cross-linking network structure of passenger car rubber changes less during the whole interaction period. Thermal analysis results shows that the glass transition temperatures of tire rubbers increase after swelling, due to the absorption of the asphalt. The initial decomposition temperature of tire rubbers increase after swelling, with the disappearance of decomposition peak of oil in rubber. Thermal analysis indicates that the exchange of rubber and asphalt components appeare during interaction.Vulcanized rubber with tire rubber formulation were prepared, equilibrium swelling ratio,mass loss rate and thermal analysis were used to find the differences of interaction with asphalt between NR and SBR. The results showed that asphlt had great effect to NR networks but few effect to SBR networks. The glass transition temperature of both NR and SBR increased when immersed in asphalt, crystalline components of asphalt diffused into rubber networks. The swelling law of NR is similar to that of truck tire rubber and the swelling law of SBR is similar to that of passenger car tire rubber. Tire aging had no fundamentally impact on the rubber-asphalt interaction. The peak of thermal decomposition rate of NR shifted to high temperature region,while that of SBR strenghened. Thermal oxidative degragation of vulcanized rubber also affect by rubber-apshlt interaction. The tensile strength,elongation at break, hardness of all swelled rubber decreased, swelled NR reduced the fastest and SBR the slowest. Storage modulus E’of swelled vulcanized rubber decreased with swelling time, the damping peak of NR disappear gradually, but that of SBR strenghened and shifted to high temperature region.Process of crumb rubber modified asphalt was explored. SEM and TGA curves showed that the main component of truck tire rubber is NR, while that of passenger car tire rubber is synthetic rubber. What is more, crumb rubber, been ground from passenger tire rubber, consisted of fibers with irregular sizes. Shearing test indicated that the particle size was inversely proportional to shear time. Filtration experiment found that the number of micron-sized particles of truck tire rubber increased significantly after 4 hours shearing,but that of passenger car tire rubber increased slowly. the phenomena that carbon black and inorganic fillers separated out happened. The penetration, ductility of modified asphalt increased by shearing process,while the soft point of modified asphalt decreased. When reclaimed ground tire rubber was used, the penetration, ductility of modified asphalt increased largely, and the viscosity of modified asphalt reduced.Reclaimed ground tire rubber （RGTR） was prepared by twin-screw extruder, and RGTR was used as modifier of asphalt. sol.-gel fractions indicated that hot shearing and activator can largely enhance the devulcanization and degradation; Penetration of RGTR modified asphalt increased substantially, while the value of softening point degree, elastic restitution, viscosity decreased accordingly; With the increase of RGTR content ,the penetration, ductility, elastic restitution of compound modified asphalt reduced and softening point degree, ductility of RTFOT increased. Microstructure of RGTR modified asphalt showed that particle size decrease outstandingly and the dispersion of rubber particles was improved.更多还原