اصلاح خواص قير با استفاده از آميخه PB/PS

In the last decades, extensive research works have been devoted to bitumen and asphalt modification by using polymeric thermoplastic-elastomers. In this research a physical thermoplastic elastomer was prepared by mixing polystyrene (PS) and polybutadiene (PB) for bitumen modification purposes. These blends were introduced into bitumen for making polymer-bitumen mixtures. Then, stabilization mechanism and mechanical properties of the mixture were studied by optical microscopy and conventional tests such as: Frass test, softening point, penetration, performance grade and penetration index. The PS/PB (75/25) blend forms larger PS droplets and shows minimum stability among the blends. The co-continuous composition of PS/PB blend (27/73) is stable and PS droplets are very well dispersed and its particle sizes are the lowest. In the next step, PS/PB/SBR compatibilized blend was mixed with bitumen and than further studies were carried out. The results show that mechanical properties and elastic recovery of these blends are highly improved as compared with the former non-compatibilized blend admixtures.