双氧水氧化废轮胎胶粉在改性沥青中的应用

采用双氧水对废轮胎胶粉进行表面氧化改性,将氧化改性胶粉用于制备胶粉改性沥青.通过XPS表征证明氧化改性胶粉表面的C—O和C=O的含量显著增加.通过多因素正交试验方法研究氧化剂用量、氧化温度及氧化时间对胶粉改性沥青的25,℃针入度、软化点和5,℃延度等主要性能指标的影响.运用极差分析法和方差分析法探讨了各影响因素对改性沥青性能的敏感性,发现氧化温度对改性沥青性能指标的影响最大,并提出了胶粉氧化改性的最佳反应条件为:氧化剂用量10,m L,氧化温度80,℃,氧化时间3,h.氧化胶粉改性沥青在不使用界面改性剂的条件下,能够使5,℃延度提高到11.6,cm,主要性能指标达到美国废轮胎胶粉改性沥青标准,说明废轮胎胶粉的表面氧化能够显著提高胶粉与沥青的界面结合强度.

Hydrogen Peroxide Oxidizing Modification of Crumb Tire Rubber and Its Application in Modified Bitumen

The crumb tire rubber was modified by hydrogen peroxide and used for the preparation of rubber modifiedbitumen. The XPS characterization showed that the contents of C-O and C=O on the rubber surface increased significantlyafter the oxidizing modification. The influences of oxidant dosage,oxidation temperature and oxidationtime on the properties of modified bitumen,such as penetration index at 25,℃,softening point and ductility at 5,℃,were studied through multi-factor orthogonal experiment. Range analysis and variance analysis were used to explorethe sensitivity of the influence factors on the properties of modified bitumen,and the results indicated that oxidationtemperature was the biggest influence factor. The optimum reaction conditions of rubber oxidizing modificationwere put forward（oxidant dosage 10,mL,oxidation temperature 80,℃ and oxidation time 3,h）. Furthermore,theprepared rubber modified bitumen exhibited excellent ductility （the ductility being 11.6 cm） at 5,℃ without usage ofinterface modifier,which indicated that the oxidizing modification of crumb tire rubber could obviously improve theinterface bonding capacity between rubber and bitumen.