Effect mechanism of acidification and vulcanization on SBS-modified asphalt
Feng Zhang, Lei Li
Abstract
Abstract A styrene-butadiene-styrene (SBS) modified asphalt compound was prepared by the addition of polyphosphoric acid (PPA) and sulfur. The effect of PPA and sulfur on major physical properties, including toughness and tenacity, aging resistance, and storage stability was investigated. The structural characteristics of SBS-modified (SM) asphalt, SBS/PPA-modified (SPM) asphalt, and SBS/PPA/sulfur-modified (SPSM) asphalt were investigated using scanning electron microscopy (SEM), gel filtration chromatography (GPC), and thermal analysis. It has been found that acidification prompted the clustering of SBS particles and confined the swelling of SBS, making SPM asphalt more susceptible to aging. Vulcanization changed the morphological characteristics of SBS in asphalt, improved the compatibility between SBS and asphalt, and weakened the aging susceptibility. Therefore, it is reasonable to modify SM asphalt by using PPA and sulfur together.