Investigation on thermo‐rheological properties and stability of SBR modified asphalts containing palygorskite clay

One problem of polymer‐modified asphalts (PMAs) is the poor compatibility between polymer and asphalts. In this article, the effects of palygorskite clay (PC) and organomodified palygorskite clay (OPC) on the rheological and morphological properties of styrene butadiene rubber (SBR) modified asphalts are investigated. The dynamic mechanical analysis (DMA) of PC and SBR/PC (OPC) modified asphalts before and after ageing has been characterized by dynamic shear rheometer (DSR). The results indicate that the degree of SBR modification is a function of asphalt‐polymer compatibility. When the polymer concentration is higher, it produces a highly elastic network which increases the viscosity, complex modulus, and elastic response of the mixture, particularly at high service temperatures. However, ageing of the SBR and SBR‐PC mixtures result in a decrease in the elastic response of the modified asphalts. It also have been confirmed that the morphology observed by optical microscopy and scanning electron microscope (SEM) revealed the better compatibility between SBR/PC and asphalt. The storage stability of binder is improved significantly. Compared with PC, OPC shows better effect in improving viscoelastic properties and rutting resistance of the mixture, which contributes to the better improvement of interfacial adhesion based on larger size between layers in OPC‐modified asphalts. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009