Effect of various organomodified montmorillonites on the properties of montmorillonite/bitumen nanocomposites

Three kinds of organomodified montmorillonites (OMMTs), OMMT1, OMMT2, and OMMT3, were prepared by using different organic modifiers. Nanocomposites of bitumen and three kinds of OMMTs were prepared by melt blending. X-ray diffraction (XRD) analysis was used to evaluate the degree of intercalation or exfoliation of OMMT and its dispersion in the bitumen. The effect of OMMTs on the physical and aging properties of the modified bitumen was studied. XRD results show that OMMT1-modified bitumen had an intercalated nanostructure, while OMMT2- and OMMT3-modified bitumens formed an exfoliated nanostructure. Compared with OMMT1-modified bitumen, the OMMT2- and OMMT3-modified bitumens showed a higher value of softening point and viscosity, and the better resistance to aging was due to the formation of exfoliated structure in the OMMT2- and OMMT3-modified bitumens. OMMT2 improved the aging resistance more remarkably than OMMT3, which can be attributed to the physical differences of the organic modifiers. DOI: 10.1061/(ASCE)MT.1943-5533.0000012 CE Database subject headings: Asphalts; Organic matter; Aging; Material properties; Nanotechnology. Author keywords: Bitumen; Montmorillonite; Organic modifiers; Aging resistance.