effect of sbs/hvs blend on modification of physical and chemical properties of bituminous emulsion insulators

bituminous emulsion insulators are types of bituminous emulsions groups composed of different grades of bitumen emulsified in water by bentonite and emulsifiers at 80-90oc. these emulsions are water resistant after drying andtheir physical and mechanical properties are superior in comparison to bitumen properties. iranian climate, because of variety and extreme variations in temperature imposes high performance insulators. modification of bitumen is considered as one of the most practical applications of polymers to impart more improved properties to bitumen. this investigation involved the study of polymers and resins such as sbs and heavy vacuum slops (hvs). for this purpose, the effect of each component of emulsions on the physical and chemical properties of insulators was examined and some insulators are made with more improved properties. moreover, the bitumen was modified by styrene-butadiene-styrene blocked copolymer (sbs) blends and hvs and their roles on the behavior of the emulsion were studied. the results show that: 1- the bentonite content of the emulsion should not be more than 11%; 2- addition of sbs/hvs blend increased physical and chemical properties (thermal stability, flexibility and adhesion); 3- increased water content of the production process improved the thermal stability and flexibility of the insulators, whereas it did not so the stability of emulsion. finally, it is found that the best formulation must contain: (1) bentonite with maximum content of 11%; (2) water content of 44% and (3) sbs/hvs blend of about 7%.