We characterised, from both a morphological and a rheological point of view, polymer modiWed asphalts prepared by the addition of styrene–(ethylene-co-butylene)–styrene block copolymer to a soft base asphalt. It was found that, even if the two components showed poor compatibility and interfacial adhesion, storage-stable mixtures could be obtained if the polymer content was maintained below about 4wt%, with respect to the total mass. In this case, the more polar part of asphalt stabilises the dispersed polymer-rich domains, which act similarly to a Wller and do not change signiWcantly the viscoelastic behaviour of the base asphalt. On the contrary, at higher polymer concentrations, a swelled polymer-rich phase creates a network that strongly inXuences the viscoelastic properties. In this case the material becomes unstable and tends to give macroscopic phase separation if stored at high temperature without stirring.
Effect of composition on the properties of SEBS modified asphalts
POLACCO, GIOVANNI;
2006-01-01
Abstract
We characterised, from both a morphological and a rheological point of view, polymer modiWed asphalts prepared by the addition of styrene–(ethylene-co-butylene)–styrene block copolymer to a soft base asphalt. It was found that, even if the two components showed poor compatibility and interfacial adhesion, storage-stable mixtures could be obtained if the polymer content was maintained below about 4wt%, with respect to the total mass. In this case, the more polar part of asphalt stabilises the dispersed polymer-rich domains, which act similarly to a Wller and do not change signiWcantly the viscoelastic behaviour of the base asphalt. On the contrary, at higher polymer concentrations, a swelled polymer-rich phase creates a network that strongly inXuences the viscoelastic properties. In this case the material becomes unstable and tends to give macroscopic phase separation if stored at high temperature without stirring.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
